vol. 42, no. 2 • may 2014 fremontia · mary frances kelly-poh yerba buena (san francisco): ellen...

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JOURNAL OF THE CALIFORNIA NATIVE PLANT SOCIETY

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VOL. 42, NO. 2 • MAY 2014

FREMONTIA

CALIFORNIA’S DESERTS, PART 2:THREATS AND CONSERVATION STRATEGIES

F R E M O N T I A V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

Staff and board listings are as of May 2014.

The California Native Plant Society(CNPS) is a statewide nonprofit organi-zation dedicated to increasing theunderstanding and appreciation ofCalifornia’s native plants, and to pre-serving them and their natural habitatsfor future generations.

CNPS carries out its mission throughscience, conservation advocacy, educa-tion, and horticulture at the local, state,and federal levels. It monitors rare andendangered plants and habitats; acts tosave endangered areas through public-ity, persuasion, and on occasion, legalaction; provides expert testimony togovernment bodies; supports the estab-lishment of native plant preserves; spon-sors workdays to remove invasive plants;and offers a range of educational activi-ties including speaker programs, fieldtrips, native plant sales, horticulturalworkshops, and demonstration gardens.

Since its founding in 1965, the tradi-tional strength of CNPS has been itsdedicated volunteers. CNPS activitiesare organized at the local chapter levelwhere members’ varied interests influ-ence what is done. Volunteers from the34 CNPS chapters annually contributein excess of 97,000 hours (equivalentto 46.5 full-time employees).

CNPS membership is open to all.Members receive the journal Fremontiathree times a year, the quarterly state-wide CNPS Bulletin, and newslettersfrom their local CNPS chapter.

VOL. 42, NO. 2, MAY 2014

F R E M O N T I A

Copyright © 2014California Native Plant Society

Disclaimer:

The views expressed by authors publishedin this journal do not necessarily reflectestablished policy or procedure of CNPS,and their publication here should not beinterpreted as an organizational endorse-ment—in part or in whole—of their ideas,statements, or opinions.

CALIFORNIA NATIVEPLANT SOCIETY

Dedicated to the Preservation ofthe California Native Flora

Bob Hass, EditorKara Moore, Managing EditorLesley DeFalco, Greg Suba,

AdvisorsBeth Hansen-Winter, Designer

Brad Jenkins and Mary Ann Showers,Proofreaders

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STAFF – SACRAMENTOExecutive Director: Dan GluesenkampFinance and Administration

Manager: Cari PorterMembership and Development

Coordinator: Stacey FlowerdewConservation Program Director:

Greg SubaRare Plant Botanist: Aaron SimsVegetation Program Director:

Julie EvensVegetation Ecologists:

Jennifer Buck-Diaz, Kendra SikesEducation Program Director:

Josie CrawfordHorticulture Program Director:

Susan KrzywickiAdministrative Asst: Shanna GoebelEvents Coordinator: Becky Reilly

STAFF – AT LARGEFremontia and CNPS Bulletin Editor:

Bob HassLegislative Consultant:

Vern GoehringEast Bay Conservation Analyst:

Mack CastermanDevelopment Consultant:

Sandy McCoyWebsite Coordinator: Mark Naftzger

PROGRAM ADVISORSRare Plant Program Senior Advisor:

Jim AndréVegetation Program Senior Advisor:

Todd Keeler-WolfCNPS Press Director:

Nancy MorinPoster Program: Bertha McKinley,

Wilma Follett

CHAPTER COUNCILDavid Magney (Chair); Larry Levine(Vice Chair); Marty Foltyn (Secretary)

Alta Peak (Tulare): Joan StewartBristlecone (Inyo-Mono):

Steve McLaughlinChannel Islands: David MagneyDorothy King Young (Mendocino/

Sonoma Coast): Nancy MorinEast Bay: Bill HuntEl Dorado: Sue BrittingKern County: Dorie GiragosianLos Angeles/Santa Monica Mtns:

Betsey LandisMarin County: Carolyn LongstrethMilo Baker (Sonoma County):

Lisa GiambastianiMojave Desert: Tim ThomasMonterey Bay: Brian LeNeveMount Lassen: Catie BishopNapa Valley: Gerald TombocNorth Coast: Larry LevineNorth San Joaquin: Alan MillerOrange County: Nancy HeulerRedbud (Grass Valley/Auburn):

Joan JerneganRiverside/San Bernardino: Katie

BarrowsSacramento Valley: Glen HolsteinSan Diego: David VarnerSan Gabriel Mountains: Orchid BlackSan Luis Obispo: David ChippingSanhedrin (Ukiah): Geri Hulse-

StephensSanta Clara Valley: Judy FenertySanta Cruz County: Deanna GiulianoSequoia (Fresno): Jeanne LarsonShasta: Ken KilbornSierra Foothills (Tuolome/Calaveras/

Mariposa): Robert BrownSouth Coast (Palos Verdes):

David BermanTahoe: Brett HallWillis L. Jepson (Solano):

Mary Frances Kelly-PohYerba Buena (San Francisco):

Ellen Edelson

BOARD OF DIRECTORSLaura Camp (President); David Bigham(Vice President); Carolyn Longstreth(Secretary); Nancy Morin (Treasurer);At-Large: Kristie Haydu, Bill Hunt,Gordon Leppig, David Varner, MichaelVasey, Steve Windhager; ChapterCouncil Representatives: Orchid Black,Glen Holstein

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F R E M O N T I A 1V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

CONTENTS

THE COVER: The Ivanpah Valley in 2010 (top) and in 2013 (bottom) highlighting rapid and radical land conversion of intactdesert habitat to the largest solar thermal energy project in the world, which now covers 3,500 acres of leased public land.Ivanpah Valley is a biodiversity hot spot in the Central Mojave Desert and is home to several threatened and endangered plantand animal species. Such desert landscapes are easily damaged by the direct and indirect effects of human activities, and areunder mounting pressure from large-scale development. Photographs by Amber Swanson (top) and Kim Clark (bottom).

EDITORIAL by Greg Suba ........................................................................................ 2

THREATS TO CALIFORNIA’S DESERT ECOSYSTEMS by Michael F. Allen,Cameron W. Barrows, Michael D. Bell, G. Darrel Jenerette, Robert F. Johnson,and Edith B. Allen .......................................................................................................3California deserts are threatened by climate change, pollution, and energy develop-ment, causing reductions in biodiversity and an overlooked function of the desert,carbon sequestration.

CONSERVATION AND ENERGY DEVELOPMENT IN THE DESERTby Greg Suba ............................................................................................................. 9Landscape-scale conservation planning aims to keep pace with impacts from large-scale wind and solar energy facilities across California’s desert region.

VEGETATION MAPPING IS ESSENTIAL INCONSERVING RARE DESERT SPECIES AND PLANTCOMMUNITIES by Julie Evens and Todd Keeler-Wolf .... 11Newly produced, beautifully detailed maps of California’s

desert vegetation depict the location, rarity, and quality of vegetation and habitat.Regional planners can use this information in siting new renewable energy projects,and avoiding impacts to sensitive desert ecosystems.

MEASURING IMPACTS OF SOLAR DEVELOPMENTON DESERT PLANTS by Karen Tanner, Kara Moore, and Bruce Pavlik ............ 15As energy development ramps up in California’s desert regions, experimental re-search sheds light on impacts to desert plants and communities.

TOOLS FOR BALANCE: CONSERVATION ANDRENEWABLE ENERGY PLANNING IN CALIFORNIADESERTS by Rebecca Degagne .......................................... 17The Conservation Biology Institute is working with stakehold-

ers in the California deserts to create an easy-to-use online portal where users canshare geospatial information and collaborate to make scientifically sound decisions.

SOIL SEED BANKS: PRESERVING NATIVEBIODIVERSITY AND REPAIRING DAMAGED DESERTSHRUBLANDS by Lesley A. DeFalco and Todd C. Esque ......................................... 20Our unique desert shrublands are increasingly at risk of degradation. Does theanswer to combating exotic annuals and restoring native species lie beneath our feet?

NEW CNPS FELLOW: DOREEN SMITH by Amelia Ryan ................................ 24

BOOK REVIEW by David Magney ........................................................................ 25

WHAT SHAPED YOUR LOVE OF NATURE? by Suzanne Schettler and Katherine Greenberg .......... 28

2 F R E M O N T I A V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

EDITORIALby Greg Suba

Political, financial, and climateforces have created a situation thatpairs our incomplete understandingof desert ecology with a resolute insis-tence to develop desert lands. In thisissue we present examples of how sci-entists are working to address datagaps (Evens and Keeler-Wolf; DeFalcoand Esque), test planning assumptions(Tanner, Moore, and Pavlik), improvepredictability of species habitat, andreduce uncertainty by providing trans-parency for stakeholders engaged indesert development and conservationplanning (Degagne).

While many of the scientific ad-vances discussed in these two desertFremontia issues might well have hap-pened by their own merits, the expedi-ency and funding that produced themare in response to America’s ongoingeffort to move away from carbon-basedfuels by relying on energy generatedby sunlight and wind. This culturallytransformative endeavor has provencumbersome to say the least, and manyfundamental questions remain unre-solved and controversial. For instance,why do financial and political incen-tives for distributed generation (suchas rooftop solar) continue to lag farbehind those that benefit proponentsof utility-scale facilities?

Part of the answer lies in ourcountry’s deeply entrenched energygeneration model, where private elec-tric utility companies are granted aregulated monopoly over a service areain exchange for government (publicutility commission) control of theirpricing and profits. Distributed power,microgrids, and energy storage createdissonance within this model, andresolution will require more socio-political change than technologicalfixes.

Meanwhile, the push to developour wild deserts goes on and desertscience attempts to keep pace. As weassemble the last details of this issueof Fremontia, state and federal digni-taries gather at a bend in the highwayalong the California-Nevada border tocut ribbon on the world’s largest solarthermal energy facility. Just to the

north, field crews work to completevegetation mapping surveys for an-other 100,000 acres of previously un-mapped desert, while botanists (suchas many of the authors in these twoissues of Fremontia) continue search-ing for new and long-lost species, andcollect seeds to ensure the survival ofdesert species long into the future.

Perhaps humans in the 22nd cen-tury will see the wind and solar projectswe build in the desert today as theearly steps in a global transition to arenewable energy future, one ultimatelybased on a much different technologythan remote, city-sized desert powerplants. Indeed, we may be seing thebeginning of the next phase of renew-able energy unfolding today, as invest-ment financing for energy projects hasshifted toward much smaller-scalefacilities, and as public awareness ofand demand for the benefits of rooftopenergy continue to grow.

I hope history will tell of an equallytransformative philosophy that tookplace during our time, when disparategroups communicated through differ-ences and found ways to thoughtfullybalance our use of the land with ourwill to protect it. It will take more thanwe are doing now to demonstrate thatour society is capable of finding thatbalance. We will need to place greatervalue on protecting entire ecosystemsin the desert—those we understandwell, those we know little about, andstill others we have yet to discover.

I hope you enjoy reading and look-ing through these desert Fremontiaissues. If you find something particu-larly remarkable, I encourage you toshare it with family and friends, andbetter still copy and send it to thosewith a stake in making energy deci-sions affecting our use of desert lands.

California’s desert remains a bo-tanical frontier, where its mysteriesprovide both opportunities for botani-cal exploration and challenges to con-servation planning. We must not ex-pect those unfamiliar with its beautyto value the desert without knowingabout it first. Speak up for the desert.Pass it on.

he two most recent desert-focusedissues of Fremontia describe in-cremental advances in our un-

derstanding of the desert and ourability to plan for its long-term con-servation. At the same time, theseissues highlight the high stakes at thismoment of extraordinary decisionmaking in the California desert.

In the first Fremontia desert issue(January 2014), James André summa-rized the paradox facing desert plantconservation: across the desert there isstill much to discover, and very muchto lose. Conservation and develop-ment decisions today will influencethe functionality of desert ecologicalsystems for centuries to come. Yet ourcurrent lack of information aboutdesert species biology, distributions,and the changing climate creates trou-bling uncertainty when weighingwhere human activities will have leastimpact to Great Basin, Mojave, andSonoran ecosystems. Design of an ef-fective conservation reserve system ischallenging due to the current gaps inour knowledge of desert ecology.

In this second desert issue wepresent examples of natural and manu-factured disturbances occuring acrossCalifornia’s desert landscape. Extremetemperatures and low, unpredictableprecipitation are among the primaryelements of a natural disturbance re-gime to which desert life has adapted,evolved, and persisted over milennia.More recent man-made disturbancesadd further stress to desert ecosys-tems. Increased nitrogen depositionalters soil chemistry. Introduced inva-sive weeds outcompete native speciesand fuel uncharacteristic fires. Off-highway vehicle recreation, power-lines, and roads create linear vectorsfor encroachment by invasive speciesand fragment intact landscapes. Ex-tensive mining operations remove notonly some of the rarest desert plants,but take the mountainsides on whichthey grow along with them. Todaythese challenges are overshadowed byimpending, widespread impacts ofmassive desert solar and wind energyfacilities.

T


THREATS TO CALIFORNIA’S DESERT ECOSYSTEMSby Michael F. Allen, Cameron W. Barrows, Michael D. Bell,G. Darrel Jenerette, Robert F. Johnson, and Edith B. Allen

ot since the late 1800s,when European graz-ing animals were intro-duced, have California’s

deserts faced such ecosystem-altering threats. Chronic impactsincluding climate change, atmo-spheric pollution, and both urbanand industrial development are af-fecting desert wildlands in ways thatare initially subtle and difficult todetect, but have long-term devastat-ing effects on the functioning ofthese ecosystems. Understandinghow human impacts to our desertswill promote new monitoring andadaptive management approachesmay help policymakers address in-creasing threats. This is a timely pur-suit as the Desert Renewable EnergyConservation Plan (DRECP) is gen-erated, critiqued, and debated foradoption by California counties.

The desert is threatened by manywidespread and local disturbances

N caused by humans that influenceecological processes across the re-gion. These include both immediateimpacts from development andlonger-term impacts from climatechange. This article discusses im-pacts from climate warming drivenby elevated atmospheric carbondioxide (CO

2), nitrogen deposition

from atmospheric pollution, andchanges in carbon cycling and se-questration due to soil disturbanceand water depletion. Invasive spe-cies, wildfire, habitat fragmentation,and soil disturbance are additionalcompounding threats. Some impactsindirectly affect plant and animalspecies, while others directly alterthe physiology and reproductive ca-pacity of individual organisms. Be-yond the measureable effects of eachof these disturbances is the unpre-dictability that comes from the com-plex interactions among them. Ourdeserts are rapidly becoming a test

Joshua tree (Yucca brevifolia) woodland, lower Covington Flat, Joshua Tree National Park. The Joshua tree is an important indicatorspecies of species shifts under climate change. Photograph by Edith Allen.

case for studying these interactions,and present us with the challenge ofbetter managing our desert wild-lands.

CLIMATE CHANGE INTHE DESERT

It is clearly getting hotter. Whatdoes that mean for landscapes thatare already among the hottest inNorth America? Are plants and ani-mals that are adapted to desertsgenetically programmed to deal withclimate change, or are they alreadyat their physiological limits? Inmany cases temperature may notbe the limiting variable. Rather, un-predictable changes in the timingand abundance of precipitation drivespecies out of their current distri-butions. Arid lands will likely geteven drier with more severe andlonger droughts (Cayan et al. 2007,


IPCC 2007). Will species have timeto adapt or move to track suitableclimate and conditions on their own,or have humans created barriers thatblock such movement? Can andshould we assist those migrationswhen possible?

We know species distributionshave already changed (Kelly andGoulden 2008). Plants and animalsare moving upslope along the Uni-versity of California’s Deep CanyonDesert Research Station just southof Palm Desert. We do not knowhow far species will be able to mi-grate in response to climate change,nor can we predict for individualspecies and communities how theirability to migrate will be affectedby human barriers, by other habitatcharacteristics such as soil substrate,or by their interactions with otherspecies such as predators, pollina-tors, or symbionts (organisms thatdepend on one another for survival).And what happens when they reachmountain peaks? These are the ques-tions facing scientists and resourcemanagers dealing with climatechange. There are no easy answers,but coming up with objective pre-dictions is critical to reduce lossesin biodiversity that are predictedworldwide.

Often we hear that because

deserts are already hot, climatechange will not be an important is-sue, but that is simply not the case.In humid regions, water vapor is thedominant greenhouse gas, and re-duces the impact of increasing at-mospheric CO

2. But in deserts where

humidity is low, CO2 influences cli-

mate significantly. Climate modelssuggest that in our Southern Cali-fornia deserts, the average annualtemperatures will increase from 5.4o

to 9o F (3o to 5o C). What are theimpacts of this degree of change?

To illustrate this point, we com-pared two sites in the Californiadesert—Indio, east of Palm Springs,and Death Valley, approximately 200miles to the north with the hottestclimate in North America. DeathValley has an average annual tem-perature of 2o F higher than Indio,which is less than half of the in-crease projected by climatologists.Indio already has a warmer winterthan Death Valley. If we increasethe summer temperature of Indio tomatch the summer temperature ofDeath Valley, then the average an-nual temperature of Indio would stillincrease by only 3o F overall. In con-trast, to reach the projected annualaverage temperature change of cli-mate models for Indio, we must in-crease the average Indio tempera-

tures by an additional 5o F through-out the year! This example demon-strates the dramatic everyday in-creases that are being projected,which will be stressful for all organ-isms. Since heat is not evenly dis-tributed in time, projected tempera-ture increases will happen throughmore frequent and longer heatingevents, in addition to a likely in-crease in minimum temperatures.

Another way to assess the effectof temperature changes is to relatethem to the physiological tolerancesof plants and animals. For example,114o F is considered an extreme tem-perature for plant leaves that resultsin greater water use, reduced enzy-matic activity, and even mortality.With our projected change in Indio(equivalent to summers at the DeathValley average temperature and a 5o

F increase throughout the year), threemonths of the year are predicted tohave average highs at or exceeding114o F. Lizards, such as the desertiguana, have a maximum tempera-ture tolerance of about 112o F, belowthe projected increase to 114o F.While some animals will be able toshift their activity times or stay un-derground to avoid lethal tempera-tures, obviously plants cannot moveand are likely to be affected more bytemperature increases.

Air pollution in the western Coachella Valley, with a view to the Little San Bernardino Mountains that border Joshua Tree National Park.The gray haze consists in part of nitrogen oxides from the Los Angeles air basin. Nitrogen is deposited in the form of nitric acid andammonia, fertilizing the landscape. Invasive grasses are especially productive with high nitrogen deposition, more so than native species.Photograph by Edith Allen.


USE OF SPECIESDISTRIBUTION MODELING

One analytical tool that scientistshave developed to predict how spe-cies may respond to climate changeis called “species distribution model-ing.” A reasonable approximation ofa species’ current distribution canbe developed by creating a spatially-explicit model of soils, topography,and climate at each site where a spe-cies is known to occur, and thencomparing these values to the rest ofthe region. A model can then be ex-trapolated by shifting temperatureand precipitation values in directionsthat we expect as climate change in-creases. From these models, we canthen estimate where a species needsto move if it is going to stay within itscurrent preferences for climate, soils,topography, and ecosystem type.

We have constructed such mod-els for many desert species includ-ing the Joshua tree (Yucca brevifolia)within Joshua Tree National Park(Figure 1). Our model shows thatlocal adaptations to conditions atthe southern edge of this species’distribution in and near the parkcould impact how it responds toclimate change (Barrows andMurphy-Mariscal 2012). While 90%of the current distribution of Joshuatrees in the park would be lost, 10%or more of the species at the park’shigher elevations would still be ableto survive through the end of thecentury and beyond.

In order to test if our model wasa valid projection of how Joshuatrees will respond to a hotter, drierclimate, we examined the naturaldistribution of seedlings. We foundthat Joshua tree seedlings measuredin 2011 were distributed only withinthe modeled area for adult trees witha 1.8o F (= 1o C) increase in summertemperatures (Barrows and Murphy-Mariscal 2012). This indicates thatwhen Joshua trees die in these areasthey will not be replaced, since seed-lings cannot establish in areas wherethe temperature increases more than1.8o F.

THREATS FROM INVASIVESPECIES

Many species would struggle tocompete for resources in their cur-rent locations based on changingclimate conditions alone, but theirhabitat is also being changed byspreading invasive plant species. Incomparison to many other ecosys-tems, the extreme aridity of desertscan be a barrier to the establishmentof invasive plants. Unlike warm,mesic climates like Florida or Ha-waii where thousands of invasivespecies exist and are increasing ev-ery year, the number of invasive spe-cies that threaten California’s desertsdo not exceed a few dozen. How-ever, despite their relatively lownumbers, several of these invasivespecies are highly productive. They

outcompete and replace native spe-cies, thereby reducing native bio-diversity.

Many of our desert invaders alsocause changes in ecosystem pro-cesses, with impacts spanning wholecommunities. Examples include saltcedar (Tamarix ramosissima), a treethat depletes water from seeps andincreases soil salinity in desert wet-lands (Shafroth et al. 2008). Inva-sive annual forbs like Russian thistle(Salsola spp.) and Sahara mustard(Brassica tournefortii) stabilize ac-tive desert sand dunes, habitats thatare otherwise centers of speciationand endemism for plants, arthro-pods, and lizards. Endangered duneplants such as the Coachella Valleymilkvetch (Astragalus lentiginosusvar. coachellae) depend on sandmovement to scarify its seeds (Bar-rows et al. 2009). Milkvetch is indramatic decline in these invadedsand dunes. Mediterranean grassessuch as Bromus rubens, B. tectorum,and Schismus barbatus are largelyresponsible for causing shifts to in-creased fire frequencies across land-scapes. This has greatly reduced theabundance of local native speciesthat lack fire response adaptations(Steers and Allen 2011).

EFFECTS OF AIR POLLUTION

Air pollution from automobileemissions and agriculture are in-creasing levels of nitrogen oxides(NOx) and ammonium (NH

4) in

the California deserts. These are theforms of nitrogen that plants use,and they are deposited across thelandscape at high levels near urbanand agricultural areas where theyare emitted, to low levels downwind,forming gradients of high to lownitrogen deposition. For instance,nitrogen deposition is high in thewestern Coachella Valley, decliningto low levels toward the eastern sideof Joshua Tree National Park (Allenet al. 2009). Most of the depositionoccurs in dry form, and accumu-lates on plant and soil surfaces until

Joshua tree woodland burned in the May 1999 Covington Flat fire, and in April 2005dominated by red brome. Photograph by Edith Allen.


the next rainy season when it movesdeeper into the soil. Where nitrogendeposition is high, productivity ofinvasive grasses increases and di-versity of native wildflowers declines(Allen et al. 2009).

Concomitantly, the frequency offires in the deserts is increasing,since higher nitrogen availabilityleads to increased grass productiv-ity, which in turn results in higherfine fuel loads (Figure 2). Histori-cally, fires were extremely rare inCalifornia deserts (Brooks andMatchett 2006). Desert vegetation

recovers poorly from fires, and in-creased fire frequency can reduceplant diversity (Steers and Allen2011). Based on vegetation re-sponses in areas of varying levels ofnitrogen deposition and in fertil-ized test plots, we determined thatthe probability of fire increasesabove 3.2 kilograms of nitrogen perhectare/year (Rao et al. 2010). Thisvalue may be useful for setting airquality regulations to protect areaswith sensitive desert vegetation.

Atmospheric CO2 is also rapidly

increasing (IPCC 2007). In springof 2013, the concentration of CO

2 in

the atmosphere exceeded 400 partsper million, a 40% increase frompre-industrial revolution levels of280 ppm (~1750). Photosynthesisis the fixation of CO

2 into organic

carbon, the basis of most life onearth. How does increased CO

2 af-

fect desert plants? Desert shrubs andcacti may have increased growthrates because CO

2 becomes less lim-

iting to growth as its concentrationincreases in the atmosphere. How-ever, studies show that the plantsthat respond most to increased CO

2

are fast-growing invasive annuals,particularly brome grasses (Smith etal. 2014). Increased productivity ofannual brome grasses is anothercause of increased desert fires, thuselevated CO

2 and nitrogen deposi-

tion may interact to increase burnfrequency.

SOIL AND VEGETATIONDISTURBANCE

Plants are the only known or-ganisms that collect and store atmo-spheric carbon (a process called car-bon sequestration). As atmosphericCO

2 increases, plant fixation of the

increasing CO2 increases proportion-

ally. Indeed, recent estimates showthat if plants were not absorbingthe increased levels of CO

2, atmo-

spheric CO2 would be well above

450 ppm and temperatures as muchas 2º–5o F higher than currently ex-ists (IPCC 2007). Rain forests areoften where scientists find clear evi-dence of carbon sequestration be-cause they have high levels of easilyobserved production (wood) andhigh leaf area. However, a little

known fact is that duringwet periods, desert plantscan fix as much CO

2 per leaf

area as tropical rain forests!Desert plants also pro-

vide an added CO2 fixation

benefit. They grow rootsdeep into the soil to accesswater, depositing carbonin places where it can noteasily make its way back intothe atmosphere. This pro-cess slows the release ofcarbon, thereby reducingatmospheric CO

2. Alterna-

tively, tropical rain forestsfix a lot of carbon, butthe CO

2 is respired rapidly

back out. Deserts currentlysequester a large proportionof global carbon, but can-not continue to do so if thevegetation is disturbed bydevelopment.

Another fascinating

The fringe-toed lizard responds to hottemperatures by burrowing under thesand. Plants, of course, do not have thatflexibility. Photograph by CameronBarrows.

Brittlebush (Encelia farinosa) in foreground (near Mount San Jacinto) has responded to climatewarming by moving upslope 100 meters since 1977. Photograph by Edith Allen.


means of carbon sequestration indeserts is how deep respiration bydeep-rooted plants promotes the for-mation of desert caliche, a soil pro-file in which a substantial amountof carbon is bound. The amount ofcarbon bound in caliche worldwideis equivalent to the amount in theatmosphere, so it is a substantialsink for CO

2.

Caliche is comprised of calciumcarbonate (CaCO

3) dissolved in soil

water and is deposited deep in thesoil profile. This causes CO

2 to be

locked in calcium carbonate globallyin the form of caliches and desertsediments. While CaCO

3 deposition

is generally considered only a geo-logic process, our results show thatit is also biological and dynamic(Allen et al., in preparation). CaCO

3

crystals repeatedly form on the sur-

face of microorganisms inthe rooting zone (see photosat left). We measured sur-prisingly high levels of CO

2

respired by deep roots andmicrobes, up to 10,000 ppm CO

2,

following precipitation. This is muchhigher than atmospheric CO

2 of 400

ppm, and has not previously beenrecognized as the reason why somuch CO

2 can be sequestered in

desert soils. When surface soil layersare disturbed and vegetation, par-ticularly deep-rooted trees andshrubs, are destroyed and removeddue to large off-road vehicle devel-opment or utility scale renewableenergy construction, the carbonlosses may be measureable at a glo-bal scale.

Water extraction for urban andenergy development will have nega-tive impacts on deep and shallow-rooted plants of washes and wet-lands by lowering water tables. Deep-rooted plants, particularly legumetrees in desert washes, use ground-water that has recharged over de-cades or centuries. Other plants inwashes and sloughs, such as the en-dangered Amargosa niterwort (Ni-trophila mohavensis) or the federallylisted Ash Meadows gumplant (Grin-delia fraxino-pratensis), require pe-riodic surface waters to survive(Hasselquist and Allen 2009). Over-use of ground and surface water,whether locally for agriculture, golfcourses, suburban development, orutility scale steam-based, wind, orsolar energy development, will in-evitably impact plant and animalcommunities.

INTERACTIONS BETWEENIMPACTS

Probably the most critical re-search area in ecology today is thecomplexity resulting from the inter-actions of multiple factors on an eco-system. Our deserts represent a criti-cal test case for both the theory andapplication of how different threats

converge to further impact desertspecies and ecosystems.

Many plant and animal species,such as the Joshua tree, have per-sisted through climate change formillennia by migrating in responseto environmental change. But frag-mentation of California’s deserts byurban expansion and energy devel-opment reduces the migration po-tential of all species by altering spe-cies movement, dispersal, gene flow,and interactions. Simultaneously ni-trogen and CO

2 levels are rapidly

increasing, which creates a novel en-vironment in which weedy speciesreadily proliferate.

As the productivity, fire, climate,and competitive environments with-in desert plant communities changesimultaneously, it will become in-creasingly difficult to manage andprotect this sensitive habitat. Con-ceptual approaches, such as single-species conservation or a singlefactor focus upon invasives or fireor climate change, are clearly inad-equate to protect California’s deserts.Monitoring, measuring, and under-standing the simultaneous host ofimpacts is critical to managing andprotecting desert resources.

REFERENCES

Allen, E.B., L.E. Rao, R.J. Steers, A.Bytnerowitcz, and M.E. Fenn. 2009.Impacts of atmospheric nitrogendeposition on vegetation and soils inJoshua Tree National Park. Pages 78-100 in R.H. Webb, L.F. Fenstermaker,J.S. Heaton, D.L. Hughson, E.V.McDonald, and D.M. Miller, editors.The Mojave Desert: Ecosystem Pro-cesses and Sustainability. Universityof Nevada Press, Las Vegas.

Barrows, C.W., and M.L. Murphy-Mariscal. 2012. Modeling impacts ofclimate change on Joshua trees attheir southern boundary: how scaleimpacts predictions. Biological Con-servation. 152:29–36

Barrows, C.W., E.B. Allen, M.L. Brooks,and M.F. Allen. 2009. Effects of aninvasive plant on a desert sand dunelandscape. Biological Invasions11:673-686.

CaCO3 crystals associated with the roots

of desert plants. Shown are (above) a micro-scope taking high-resolution images of soil,root, and microbial dynamics at DeepCanyon Natural Reserve System, and animage magnified 100 times its original sizeshowing CaCO

3 crystals forming along a

single hypha radiating from a fine root.Deposition of CaCO

3 on the surface of soil

microorganisms is one important mech-anism by which CO

2 is sequestered in the

soil. Photographs by Mike Allen.


Climate changescenarios for theCalifornia region.Climate Change.DOI 10. 1007/s 1 0 5 8 4 - 0 0 7 -9377-6.

Hasselquist, N. andM.F. Allen. 2009.Increasing de-mands on limitedwater resources:consequences fortwo endangeredspecies in Amar-gosa Valley, USA.American Jour-nal of Botany 96:1-7.

IPCC. 2007. ClimateChange 2007: ThePhysical Basis.Contributions ofWorking Group Ito the fourth as-sessment report ofthe Intergovern-mental Panel on

Climate Change[(Solomon, S., D.Qin, M. Manning, Z. Chen, M. Mar-quis, K.B. Averyt, M. Tignor, andH.L. Miller (eds)]. Cambridge Uni-versity Press, Cambridge, UnitedKingdom and New York, NY, USDA.996 pp.

Kelly A.E., M.L. Goulden. 2008. Rapidshifts in plant distribution with re-cent climate change. Proceedings ofthe National Academy of Sciencesof the United States of America105:11823-11826.

Rao, L.E., E.B. Allen, and T. Meixner.2010. Risk-based determination ofcritical nitrogen deposition loads forfire spread in southern Californiadeserts. Ecological Applications20:1320-1335.

Shafroth, P.B., V.B. Beauchamp, M.K.Briggs, K. Lair, M.L. Scott, and A.A.Sher. 2008. Planning Riparian Res-toration in the Context of TamarixControl in Western North America.Restoration Ecology 16:97-112.

Smith, S.D., T.N. Charlet, S.F. Zitzer,S.R. Abella, C.H. Vanier, and T.E.Huxman. 2014. Long-term responseof a Mojave Desert winter annualplant community to a whole-ecosys-tem atmospheric CO

2 manipulation

(FACE). Global Change Biology20:879-892.

Steers, R.J. and E.B. Allen. 2011. Fireeffects on perennial vegetation in thewestern Colorado Desert, USA. FireEcology 7:59-74.

All authors are affiliated with the Centerfor Conservation Biology, University ofCalifornia, 1435 Boyce Hall, Riverside,CA 92521; [email protected]

FIGURE 1. CLIMATE-SHIFTED DISTRIBUTION MODELS FORJOSHUA TREE WITHIN AND SURROUNDING JOSHUA TREENATIONAL PARK.

FIGURE 2. NITROGEN GRADIENTS AND FIREOCCURRENCES WITHIN THE CALIFORNIA DESERT.

The western park boundary is indicated by the black dashed border.These models suggest that Joshua trees (Yucca brevifolia) will moveup in elevation in the Little San Bernardino and San BernardinoMountains as a result of climate change, with a reduced presence inJoshua Tree National Park.

Source: Barrows and Murphy-Mariscal, 2012.

Most desert fires can be found in regions of higher nitrogendeposition. Invasive grass grows profusely in such areas, and islargely responsible for carrying fire into shrubs and trees.

Source: Nitrogen deposition data are from Fenn et al. 2010, and fire datafrom the Department of Interior, 2009.

Brooks, M.L., and J.R. Matchett. 2006.Spatial and temporal patterns ofwildfires in the Mojave Desert, 1980-2004. Journal of Arid Environments67: 148-164.

Cayan, D.R., E.P. Maurer, M.D.Dettinger, M. Tyree, K. Hayhoe. 2007.

FIGURE 3. MODEL OF PROJECTED MOVEMENT OFJOSHUA TREES SHOWING COMPLEX NATURE OFMULTIPLE STRESSORS IN A DESERT LANDSCAPE.The projected model of Joshua Tree movement across the westernregion of Joshua Tree National Park, outlined by the dashed line.The current distribution model is in dark blue. The model witha +1o C temperature shift is in light blue, showing an upslopeand a westerly shift. But this is into the area of increasing nitrogendeposition, shown in the color banding of low (green) to redzones. The critical load for desert ecosystems is three kilogramsper hectare per year. The added nitrogen stimulates the growthof invasive grasses that, in turn, promote fire during the dryseason.

Source: Cameron Barrows, unpublished.


CONSERVATION ANDENERGY DEVELOPMENT IN THE DESERT

by Greg Suba

lobal climate change, theneed to reduce human-made greenhouse gasemissions, and myriad

political and economic forces aredriving a global effort to transformhow society generates, distributes,and uses energy. In the US, con-struction of utility-scale renewableenergy projects across the West hasbeen the centerpiece of these efforts.Today a major conservation chal-lenge, especially for native plants, isto identify appropriate locations tobuild utility-scale solar and wind en-ergy facilities, while mitigating theimpacts associated with their con-struction. In California this chal-lenge is greatest in Mojave andSonoran desert regions where na-tive habitats remain undisturbed andthe flora is largely under-surveyed,relative to other less remote andmore inhabitable parts of the state.

By early 2014, federal, state, andcounty agencies had received over150 applications for energy genera-tion and transmission projects inthe California desert. The environ-mental review and approval process

for such applications varies depend-ing on the location, size, and type ofenergy project. Each new construc-tion site can disrupt the integrity ofexisting habitat and create a vectorfor further degradation over time.

Inadequacies in the current en-ergy project review process threatenconversion of intact desert into frag-mented landscapes while insuffi-ciently considering cumulative ef-fects to the desert ecoregion as awhole. The north end of IvanpahValley has become an unfortunateexample of how an intact, highlybiodiverse area of critical deserthabitat, which has persisted overmillennia, can be undone over thecourse of a few months. SilurianValley, Rice Valley, the McCoyWash, Chuckwalla Valley, IndianPass, and other areas of California’sMojave and Sonoran deserts facesimilar threats.

Two desert energy-related re-gional conservation plans, the USBureau of Land Management’s(BLM’s) Western Solar Program, andthe multi-agency-led Desert Renew-able Energy Conservation Plan

(DRECP), aim to lessen the environ-mental costs associated with the cur-rent project-by-project approach. Ingeneral the plans would reduce regu-latory and financial uncertainty forenergy developers, direct energyprojects and their impacts to pre-determined areas, and use mitiga-tion funds to build a comprehensivenetwork of conservation lands thatcan be adequately monitored andadaptively managed. If well executed,these plans could offer a better fu-ture to desert wildlife than the statusquo by proactively guiding projectsto desert areas where they wouldcause less ecological disruption.

BLM’s Western Solar Programprovides expedited federal environ-mental review for projects built onpublic lands in specified SolarEnergy Zones (SEZs). Approved in2012, the Program has establishedthree California SEZs totaling ap-proximately 200,000 acres locatedin areas east of El Centro, west ofthe Chocolate Mountains, and acrossthe Chuckwalla Valley. The loca-tion and extent of California’s SEZsreflect the politics more than the

G

The view across Broadwell Dry Lake, California. This is one of many vast, intact desert landscapes where solar and wind companies haveproposed building projects, and where vistas and habitat would be forever altered by industrialization. Photograph by James M. André.

1 0 F R E M O N T I A V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

science associated withthe planning process.BLM is currently devel-oping pilot mitigation,long-term monitoring,and adaptive manage-ment plans for SEZs inCalifornia and Nevada.

The DRECP willdevelop a comprehen-sive conservation strat-egy across 22 millionacres of Californiadesert habitat, whileexpediting the permit-ting of desert renew-able energy projects.The DRECP must meetthe conservation stan-dards required byCalifornia’s NaturalCommunities Conser-vation Plan (NCCP)Act, and will need thesupport of stakeholder groups andlocal governments to be successful.The draft plan is scheduled for pub-lic review by summer 2014. As thisprocess will continue into late 2014and perhaps beyond, its outcomeremains uncertain.

To date, construction of severallarge-scale wind and solar energyprojects have permanently impactedhabitat of rare and ancient nativeplant species, and have fragmentedsensitive plant communities inChuckwalla, Ivanpah, and westernAntelope Valleys. During this time,there have been some beneficialplant conservation outcomes as aconsequence of desert energy projectplanning and certification processes.For example, one huge benefit ofthe DRECP process thus far is a re-cently completed vegetation map,whose detailed data greatly improvesour ability to identify and avoid rarevegetation types, and differentiatebetween more and less degraded lo-cations (see Evens and Keeler-Wolfin this issue).

Additional conservation ad-vancements from the energy devel-opment process include

• a requirement that both spring andfall rare plant surveys are con-ducted in areas that experiencerains in late summer, as well as inwinter;

• mitigation measures for CaliforniaRare Plant Rank (CRPR) 4 plantsif they are found to be locally im-portant, i.e., those exhibiting un-usual morphologies or occurringin atypical habitats for the species;

• a more sophisticated and trans-parent process for developing spe-cies habitat models for desert rareplants than originally employed(see Degagne in this issue);

• new protocols for more accurate-ly delineating ephemeral desertstreams (desert washes) and theirassociated vegetation (see Chainey-Davis in previous issue);

• specific conservation targets andconservation management actionsthat have been developed for rareand at-risk plant communities in-cluding microphyll woodland,Joshua tree, desert dune, and al-kali soil plant alliances;

• research to test methods of pre-dicting rare plant habitat (seeMcIntyre in previous issue); and

• research to documenthow plants respondto life under solarpanels (see Tanner etal. in this issue).

These are bypro-ducts of stakeholderand scientific inputby groups, includingCNPS, related to theplanning and buildingof desert renewableenergy projects. Allrepresent useful plantconservation tools thatcould be applied else-where in California.

As noted, establish-ing a botanical base-line to facilitate desertconservation planningis an ongoing effort.To help achieve this,

CNPS has recently received grantfunding from the Giles W. and EliseG. Mead Foundation to compile on-the-ground knowledge from profes-sional and amateur botanists withdesert expertise, and include thisinformation into comments advo-cating for the conservation of desertbotanical priority protection areas.

Together, accurate up-to-datefield data, the new vegetation map,and progressive plant conservationrequirements will help advanceCNPS’s efforts to ensure that theneeds of California’s native floraare appropriately addressed duringdesert energy planning. At the sametime, CNPS will continue to advo-cate a greater emphasis on alterna-tive approaches to energy genera-tion, such as “distributed energy”—small power generating sourceslocated near where the energy willbe consumed, such as rooftop solarpanels—that do not carry the im-pacts associated with utility-scalefootprints.

Greg Suba, CNPS, 2707 K Street, Suite 1,Sacramento, CA 95816, [email protected]

Fatalities to avian species, especially Golden Eagle and California Condor,are among the greatest negative impacts of desert wind turbines. Thoughwind projects require fewer acres cleared during construction, their lineardisturbances provide inroads for invasive weeds and can significantlyfragment terrestrial habitat like this Joshua tree woodland in northwestAntelope Valley. Pausing the blades for approaching birds, and micro-sitingturbines to avoid sensitive terrestrial species can lessen wind project impacts.Photograph by Michael Fortuna.

F R E M O N T I A 1 1V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

VEGETATION MAPPING IS ESSENTIAL IN CONSERVINGRARE DESERT SPECIES AND PLANT COMMUNITIES

by Julie Evens and Todd Keeler-Wolf

etailed mapping of vegeta-tion is one way to assessthe biological values ofan area. A vegetation map

depicts the natural patterns of plantlife including forests, woodlands,scrub, grasslands, and sparsely veg-etated cliffs, dunes, and flats. Today’svegetation maps are created using acombination of botanical field sur-veys, high-resolution aerial imagery,and geographic information systemtechnology. Based on analysis of fieldsurvey data, vegetation types are de-fined using a nationally prescribedset of rules. For example, if an areahas at least 2% cover of Joshua trees,it would be classified as a type ofJoshua Tree Wooded Shrubland.These rules are then used to inter-pret aerial imagery and map vegeta-tion over larger areas, and again usedto determine the accuracy and valueof the end product.

A CONSERVATION PLANFOR CALIFORNIA’S WARMDESERTS

The Desert Renewable EnergyConservation Plan (DRECP) is thelargest and most complex of anyNatural Community ConservationPlan (NCCP) ever undertaken inCalifornia. Identification and map-ping of distinct natural vegetationtypes, or “Natural Communities,”are foundations of regional planningbecause these communities sustainspecies and habitats of conservationconcern. Examples in California’sdeserts include the federally endan-gered Lane Mountain milk-vetch(Astragalus jaegerianus) occurring inMojave mixed desert scrub withrocky soils in the western MojaveDesert, and rare habitats such as fan

palm oases at spring sites, and bluepalo verde–ironwood woodlandsalong washes of the Colorado Desert.

Natural communities define spe-cies’ habitats, provide tools for as-sessing landscape quality within theplan area, and serve as units of con-servation based on their distinctiveassemblages of species. By preserv-ing intact communities we ensurehabitat is preserved for individualspecies and promote the persistenceof functioning desert ecosystems.

SELECTING ACLASSIFICATION SYSTEM

Conservation planners in thisvast and diverse area can’t employa simple “one-size-fits-all” approachbecause decisions are based on mul-tiple variables including species,communities, ecosystems, and natu-ral processes. Within the vastDRECP area (Figure 1) two mainissues arose in developing a classifi-

cation system for mapping naturalcommunities. The first challenge washow to adopt a single standard fordescribing vegetation in distinctcategories. Second, and more diffi-cult, was how to craft a plan-widegeographic approach to classify allnatural communities embodied inthe NCCP. For a map to be usefulfor conservation, great considerationmust be given to accurately repre-sent the many patterns of vegeta-tion, some of which are visuallysubtle or small in size. This consid-eration is particularly important fora map of desert vegetation, which,by definition depicts a landscapewith sparse plant cover.

The key to developing an NCCPis to have sound definitions for natu-ral communities and to appropri-ately depict the ecological relation-ships that capture the conservationrequirements of the plan at the spe-cies, community, and ecosystemscales. The US National VegetationClassification (NVC) system was

The Joshua Tree (Yucca brevifolia) Wooded Shrubland Alliance in the Mojave NationalPreserve is a diagnostic natural community of mid-elevations in the Mojave Desert.Photograph by Julie Evens.

D


chosen as the best standard for de-fining vegetation types because ofits quantitative, defensible, and hi-erarchical design, and its adherenceto rigorous mapping standards. TheNVC was updated in 2008 by re-searchers from federal and stateagencies, conservation organiza-tions, and universities to standard-ize vegetation mapping across theUS. It recognizes natural vegetation,as well as semi-natural (introducedself-perpetuating), cultural (agricul-tural and horticultural), and sparselyvegetated (e.g., dunes, playas, bad-lands, and rock outcrop) naturalcommunities. For more information,go to http://usnvc.org/overview/.

By using this standard, the Cali-

fornia Native Plant Society, Califor-nia Department of Fish and Wild-life, and other agencies and organi-zations have mapped and classifiedvegetation in detail across more thanone-third of the state during the past15 years. These efforts have collec-tively identified many natural veg-etation communities, some rare,some common, providing an un-precedented understanding of Cali-fornia’s vegetation.

WHAT WAS MAPPED

These vegetation mapping meth-ods were applied to the DRECP re-gion largely because the plan’s 2010Independent Science Advisory (ISA)

report identified better vegetationdata as a fundamental data gapto be addressed. The resultant newDRECP Vegetation Map uses fine-scale classification and mapping, andcovers approximately six millionacres or 30% of the planning area.This revised fine-scale map focusedon areas where no detailed vegeta-tion maps had been available, in-cluding the western Mojave, toevaluate impacts of renewable en-ergy projects and to help decidewhere future renewable energy sitesmight be placed.

Unfortunately, constraints oftime and funding restricted detailedmapping across the entire DRECParea. Therefore, in addition to the

California Fan Palm (Washingtonia filifera) Oasis in the Orocopia Mountains Wilderness. This iconic desert riparian community isisolated in fewer than 100 locations in the Sonoran Desert and adjacent southern Mojave Desert. Photograph by Bob Wick.


fine-scale DRECP Vegetation Mapfor focal areas, a coarser-scale map,the DRECP Land Cover Map, wasproduced for the entire plan area.To generate this map, a related “eco-logical systems” classification andcoarser, mid-scale maps from ear-lier vegetation mapping efforts (suchas the 2008 California GAP analysisand Landfire maps) filled in the gapswhere recent, finer-scale mappingwas incomplete. Both old and newmaps were joined using the broaderunits of the NVC to produce a seam-less land cover map for the entire22.5 million-acre DRECP area.

The final DRECP Land CoverMap integrates the DRECP Vegeta-tion Map with the best available map-ping data for the entire planningarea, including data from California

GAP 2008, California Departmentof Fish and Wildlife for Anza-Borrego (Keeler-Wolf et al. 1998),the Mojave Desert Ecosystem Pro-gram (Thomas et al. 2004), and up-dates for agricultural and urban ar-eas from the California Departmentof Conservation Farmland Mappingand Monitoring Program. (See Fig-ure 1 for details.)

ACCURACY OF THE MAPS

The classifications used in thecoarser-scale DRECP Land CoverMap were also used during DRECPenvironmental review and conser-vation planning. They differ, as de-scribed, from those used in the finerscale DRECP Vegetation Map andcan be viewed on the CDFW BIOS

TOP: A mixture of ironwood (Olneya tesota), blue paloverde (Parkinsonia florida), smoketree(Psorothamnus spinosus), sweetbush (Bebbia juncea), wolfberry (Lycium spp.) and othershrubs make up the microphyll woodland (Parkinsonia florida–Olneya tesota Alliance)washes in the southeastern DRECP. This vegetation is considered important wildlifehabitat for the rare burro deer and other wildlife species. Photograph by Julie Evens. •BOTTOM: One of the largest and least disturbed stands of the Big Galleta Grass (Pleuraphisrigida) Alliance occurs adjacent to Rice Valley Dunes (Riverside County), part of the newmapping area in the Colorado Desert to be completed in April 2014. Photograph byEdward Reyes.


website (www.bios.dfg.ca.gov; seeFigure 2 for an example). Whilebased on quantitative rules, the draw-back of coarser maps is that they aremore general and not particularly

accurate, although they may be allthat are available due to the expenseof processing imagery or the lack ofavailability of high-resolution aerialimagery. In particular, the Califor-nia GAP map’s minimum pixel sizeis 30-meters, and the map accuracyis largely untested; this inaccuracyis passed on to the DRECP LandCover Map. Thus, in the westernMojave, large areas appear to haverelatively little biological value be-cause the existing GAP/Landfiremaps only denote simple and abun-dant vegetation types.

In contrast, using the new map-ping criteria, most of the majorareas being designated for solardevelopments are considered veg-etated and to some degree “natu-ral.” Their individual componentsof vegetation can now be comparedbased on their size, rarity, and otherecologically valuable qualities. Oncoarse scale maps, finer-scale datacan still be accessed where it is avail-able. For example, when DRECPconservation targets address speci-fic sensitive natural communities,or when specific mapping attributesof certain natural communities arerequired to help define habitat qual-ity for a covered species, the finer,alliance level classification scalesare used. An example is the Big Gal-leta Grass Alliance (Figure 3 andaccompanying photo on page 13), arare vegetation type that occurs onmargins of undisturbed sand dunes.If mapped more generally as dunevegetation, its uniqueness wouldbe lost.

FUTURE PLANS

To date, a large majority of theDRECP area has been mapped tosome level of detail in the past 15years using the NVC, and effortsare underway to get the remainingareas mapped. At least 100,000 moreacres of the Colorado Desert will bemapped in the next few months,with more funding from state andfederal agencies slated to cover sev-

eral hundred thousand acres of pro-posed renewable energy develop-ment areas over the next year. Fed-eral funds are also being appropri-ated for detailed mapping of DeathValley National Park and MojaveNational Preserve. Outside of theDRECP, plans to map the CoachellaValley are being made, thus fillingin much of the mapping gap be-tween Joshua Tree National Park andAnza-Borrego Desert State Park.

Detailed vegetation mapping ofover six million acres was completedwithin a period of less than 18months, which is quite an accom-plishment. The information con-tained in these maps has been im-mediately adopted by the agenciesinvolved in the DRECP and is beingused in the Draft DRECP. In thefuture we hope agencies and stake-holders will now better understandthe value of such mapping andstrongly support its completion inadvance of any decisions beingmade.

Julie M. Evens, California Native PlantSociety, 2707 K Street, Suite 1, Sacra-mento, CA 95816, [email protected]; ToddKeeler-Wolf, Biogeographic Data Branch,California Department of Fish and Wild-life, 1807 13th Street, Sacramento, CA95811, [email protected]

Areas identified as mapped by AIS andCDFW in 2013 are considered “fine scale”as described in this article, which is whyJoshua Tree National Park and Anza-Borrego State Park maps are comparable.Other maps of desert areas are less finelydefined. The only single map to cover allof the DRECP is the GAP 2008 map, whichis coarser and less useful for local planningneeds.

Source: California Department of Fish andWildlife (CDFW), 2013.

FIGURE 2. CLOSE-UP COMPARISONOF THE DIFFERENT VEGETATIONMAP PRODUCTS IN THE DRECP.

FIGURE 3. STANDS OF BIGGALLETTA GRASS.

FIGURE 1. COMPILATION OFMAPPING EFFORTS FOR THE DRECP.

Close-up view of the coarse-scale GAP 2008map (blocky checkered shadings) com-pared to the detailed, fine-scale DRECPVegetation 2013 map (solid narrow pinklines define separate polygons of differentvegetation alliances identified by pinklabels based on the diagnostic plantspecies). Fine-scale maps provide moredetailed information than coarse-scalemaps on the values of desert habitat.

Source: CDFW, 2013.

The distribution of the Big Galleta Grass(Pleuraphis rigida) Alliance, a rare naturalcommunity in the DRECP, based on allmapped occurrences and sampled stands.

Source: CDFW, 2013.


MEASURING IMPACTS OF SOLAR DEVELOPMENTON DESERT PLANTS

by Karen Tanner, Kara Moore, and Bruce Pavlik

he state of California hasset a goal for electric com-panies to generate 33% oftheir power from renewable

sources by 2020. This requirementhas spurred large-scale solar devel-opment in California’s desert regions,home to unique natural communi-ties and many rare plant species. Weneed to understand how changesimposed by solar installations may

directly or indirectly affect desertplant communities, particularly thosesupporting numerous rare species thatrequire state or federal protection.

Desert plants are adapted to in-tense solar radiation, high tempera-tures, and low rainfall. Plants shadedby solar arrays experience less sun-light, lower temperatures, and lessrainfall than those growing near theedge of arrays, where extra water is

delivered via storm runoff and wash-ing of solar panels. With fundingfrom the Barrett Foundation, theCalifornia Energy Commission, andCNPS, we designed and installed anongoing study using experimentalpanels to mimic conditions createdby photovoltaic solar arrays.

Its purpose was to measure theeffects of shading and water runofffrom these panels on annual plants

Experimental panels at a study site near Daggett, California. Panels shade Wallace’s woolly daisy and alter the amount of sunlight andrainfall delivered to plants. Control plots at the site (not shown) expose plants to natural sunlight and rainfall patterns. All photographsby Karen E. Tanner.

T


LEFT: Wallace’s woolly daisy (Eriophyllum wallacei) in flower, exhibiting both ray and discflowers. When rain is plentiful these daisies unfurl a bright yellow carpet across thelandscape. • RIGHT: Two Barstow woolly sunflowers (Eriophyllum mohavense) nestle together.In a good rainfall year, individual plants may reach 2 cm in diameter and have dozens ofdisc florets. In drier years plants have few florets and diameter may only reach half acentimeter.

in the Mojave Desert. Our monitor-ing focused on two tiny, closely re-lated species: the common Wallace’swoolly daisy (Eriophyllum wallacei)and Barstow woolly sunflower (Erio-phyllum mohavense), a CRPR 1B.2species (rare, threatened, or endan-gered in California and elsewhere).Our goal was to compare the per-formance of individuals of each ofthese two species and their annualplant communities under the ex-perimental panels, where they wereshaded and received limited rain-fall, and in control plots where theyreceived natural light and rain. Wemeasured performance by tallyingthe number of individuals of eachspecies, their size, and their seedproduction.

Collecting data in the MojaveDesert can be physically demanding,and finding young plants of theEriophyllum species is made all themore difficult when adult plants areonly the size of a thumbnail. How-ever, in our study the greatest chal-lenge is that these two annual spe-cies are not present in every year.Rainfall in the Mojave is highly vari-able, and annual plants only emergefrom the soil seed bank in some yearsunder a narrow range of appropriatemoisture and temperature conditions.

We began our study in 2011, ayear when a thick carpet of desertannuals covered many areas due toheavy winter rains. In that year, weobserved average densities of 850Barstow woolly sunflowers and 454Wallace’s woolly daisies per squaremeter. In contrast, not a singleBarstow woolly sunflower emergedfrom the seed bank in the extremelydry conditions that followed in 2012.Wallace’s woolly daisy did emerge,but average density was less thanone plant per square meter. Suffi-cient rain fell in 2013 to trigger emer-gence of both species, but in farlower numbers than observed thefirst season. These fluctuations ob-viously affect sample size and statis-tical power in our experiment, soanalyses of data must take that intoaccount.

Despite this enormous variabil-ity in annual plant density, we’vefound clear effects of experimentalshading on Wallace’s woolly daisyand its community. Under panels,photosynthetically active radiationis reduced by about 85%, and after-noon soil temperatures are on aver-age 11º C cooler. These conditionsrepresent a strong departure fromthe natural regime which is reflectedin species and community response.

In each year thus far, density ofWallace’s woolly daisy was lower inshaded plots, suggesting that shadesuppressed emergence from the seedbank. In 2013, significantly moreplants died before flowering undershade panels, which means that av-erage seed production per plot wasreduced in shaded plots. We alsofound that species richness (thenumber of different species present)and community abundance (thenumber of individual plants present)was reduced by panel shade. Weawait more favorable climatic con-ditions to ascertain the effects ofpanels on Barstow woolly sunflowerand its community. The importantthing is to keep the experiment go-ing for many years in order to cap-ture the full range of biological re-sponses to our intervention.

We will be collecting additionaldata in 2014 to extend our findings,and are excited to see what the nextfield season will bring. By taking arare experimental approach to ex-ploring the effects of solar panels,this work will provide insight thatcan be used by public land agenciesas they consider impacts of solardevelopment on rare desert plantsand their communities.

Karen E. Tanner, 40 Cleaves Avenue, SanJose, CA 95126, [email protected]; Kara A. Moore, Center for Popula-tion Biology, Department of Evolution andEcology, University of California, Davis,One Shields Avenue, Davis, CA, 95616,[email protected]; Bruce M. Pavlik,Restoration Ecology, Royal Botanic Gar-dens, Kew, Richmond, Surrey, TW9 3DS,United Kingdom, [email protected]


TOOLS FOR BALANCE:CONSERVATION AND RENEWABLE ENERGY PLANNING

IN CALIFORNIA DESERTSby Rebecca Degagne

alifornia’s deserts sustainunique ecosystems thathave been shaped byfierce physical constraints

of climate, soils, and topography.These vast expanses of land, muchof which is managed by public agen-cies, support numerous rare and en-demic species. Ironically, these verylandscapes forged from extremes aresome of the most sensitive to hu-man impacts (Pavlik 2008). Conse-quently, the growing interest in de-veloping these lands for renewableenergy (primarily solar and wind)presents exceptional conservationchallenges.

THE DESERT RENEWABLEENERGY CONSERVATIONPLAN

The Desert Renewable EnergyConservation Plan (DRECP) wascreated to balance renewable energydevelopment with conservation overthe coming decades using a science-based management strategy. Thisplanning effort, which covers 22.5million acres of Southern Califor-nia, arose from an unprecedentedcollaboration between federal andstate agencies. The plan’s goal is topreserve, restore, and enhance na-tive vegetation while providing re-newable energy developers withstreamlined permitting under theFederal and California EndangeredSpecies Acts.

There are approximately 50 spe-cies (19 plants and 33 animals) and30 native plant communities pro-posed for coverage under the plan’sregulatory considerations, includingspecial protections, monitoring and

management guidelines, and/or“take” permits (http://www.drecp.org). Understanding where theseflora and fauna occur across theDRECP landscape is crucial to de-termining the best locations for newprotected areas and energy infra-structure. However, this informationis not readily available, even intoday’s data-driven world.

FILLING GAPS IN OURKNOWLEDGE

To help fill gaps in the data recordfor the California deserts, scientists

from UC Berkeley, UC Davis, UCSanta Barbara, US Geological Sur-vey, Dudek (an environmental con-sulting firm), and the ConservationBiology Institute used digital model-ing techniques to predict whereplants and animals likely occuracross the DRECP area. During thisprocess, species location informationwas combined with mapped envi-ronmental conditions (temperature,precipitation, topography, vegeta-tion) to create species distributionmaps for many rare plant and ani-mal species being considered in theregional planning effort. Such mapsapproximate where the environment

C

The Desert Renewable Energy Conservation Plan area spans seven California counties andcovers an area approximately the size of the state of Indiana (35,300 square miles). Photo-graph by Bob Turitz.


is suitable to sustain a species, thusgiving insight into its geographic dis-tribution (Guisan and Thuiller, 2000;Wintle 2013).

While such maps are not a sub-stitute for extensive survey data, theycan provide a useful planning foun-dation. Biologists and managers can

use them to estimate where rare and/or sensitive species might occur andcan refine these predictions basedon future field surveys. Furthermore,overlaying multiple species’ distri-bution maps can reveal places with

high biodiversity and help guide de-cisions about which areas should bedesignated as high priority for con-servation.

AN INFORMATIONGATEWAY

Given the size of the DRECParea and the plan’s scope and com-plexity, full engagement of partici-pants and timely communication ofgoals, objectives, and progress isessential for this endeavor to suc-ceed. Plan information must also bemanaged in a manner that promotesaccessibility, transparency, and func-tionality over time. To that end, theConservation Biology Institute isworking with agencies and otherstakeholders to create the DRECPGateway, a Web-based interface

Alkali mariposa lily (Calochortus striatus)is one of approximately 50 species (19plants and 33 animals) proposed forcoverage under the DRECP’s regulatoryconsiderations, including special pro-tections, monitoring and managementguidelines, and/or “take” permits. Photo-graph by James M. André.

Scientists use digital modeling techniquesto predict where animals and plants, suchas Bakersfield cactus (Opuntia basilaris),likely occur across the landscape. Thisinformation can then be used to guide thecreation of new conservation areas.Photograph by Steve Prorak.

The DRECP digital gateway was created to provide information and geospatial data to allproject stakeholders, including the public. Please come explore the site and see how youmight participate at http://drecp.databasin.org.


where participants can access inter-active planning tools and share im-portant geospatial information. Thisonline portal was developed usingData Basin (drecp.databasin. org), ascience-based mapping and analysisinterface that supports learning,research, and sustainable environ-mental stewardship. Data Basin iscurrently used by thousands ofpeople, including interested citizens,students, educators, natural re-source practitioners, and scientists.In this virtual space, participantscollaborate on conservation pro-jects, create custom maps to displayfeatures of interest, and explore geo-graphic information. Such increasedaccess to information is likely to

increase the openness of decision-making and make greater use ofpublic input to strengthen conser-vation plans.

DIGITAL DATA FORDECISION-MAKING

The DRECP Gateway websitehouses a wide range of data, includ-ing products that compile multiplelayers of complex information intoeasily digestible formats to facilitateobjective decision-making. Amongthe unique datasets created by theConservation Biology Institute areinteractive layers that allow stake-holders to examine factors affect-

A decision-support map showing the degree of human impacts (from agriculture, grazing,development, invasive species, and non-natural fire regimes) across the DRECP landscape.Areas that are more “intact” (less impacted by humans) generally contain higher biodiversityand therefore warrant greater protection from development.

ing landscape condition and valueacross the DRECP area. One suchlayer represents human changesto the natural landscape, such asagriculture, grazing, urban devel-opment, invasive species, and non-natural fire regimes. Judicious useof this information during infra-structure planning can focus devel-opment toward disturbed areas, andpreserve intact areas with higherconservation value.

The DRECP Gateway’s numer-ous offerings are designed to givestakeholders the means to empiri-cally weigh evidence before choos-ing a path for renewable energy de-velopment. Ideally, this approachengages all people vested in theland, thus ensuring that the con-servation of California’s deserts isthoughtfully coupled with devel-opment of a clean energy future. Asrenewable energy implementationpushes further into our local areasand onto our public lands, plan-ning efforts like the DRECP offeropportunities to plan for the long-term protection of unique speciesand habitats while allowing energydevelopment, and extend to citi-zens the chance to participate inthe planning process.

REFERENCES

Guisan, A., and N.E. Zimmerman.2000. Predictive habitat distributionmodels in ecology. Ecological model-ling 135:147–186.

Pavlik, B. 2008. The California Deserts:An Ecological Re2discovery. UC Press,Berkeley, CA.

The Desert Renewable Energy Conser-vation Plan (DRECP). http://www.drecp.org.

The DRECP Gateway. http://drecp.databasin.org/.

Wintle, B. 2013. Developing and inter-preting species distribution models:A checklist of the basics. DecisionPoint 67: 12–13.

Rebecca Degagne, 136 SW WashingtonAvenue, Suite 202, Corvallis, OR 97333,[email protected]


SOIL SEED BANKS: PRESERVING NATIVE BIODIVERSITYAND REPAIRING DAMAGED DESERT SHRUBLANDS

by Lesley A. DeFalco and Todd C. Esque

ascular plants in California’sMojave and Sonoran desertsproduce seeds that with-stand inhospitable condi-

tions in the soil for months or years.Viable seeds that accumulate in thetop inch of soil comprise the “seedbank.” Often underappreciated, seedbanks represent future plant popu-lations and comprise the species thatmay persist in a changing climate.

In 1949 botanist and ecologistFritz Went (1949) gathered surface

soils at then-namedJoshua Tree NationalMonument that revealeddistinct annual florashidden below ground.He discovered a florathat germinates in sum-mer when soil tempera-tures are warm and a dif-ferent flora in winterwhen soil temperatures

are cold. In the Coachella Valley,Lloyd Tevis (1958) snatched seedsfrom harvester ants as they foragednear their nests and observed howgranivores could change the speciescomposition of desert vegetation.Since these early efforts, awarenesshas grown about the importance ofseed banks as well as their role inrevegetating disturbances through-out the deserts.

THE EXPOSED SEEDAND STRATEGIES FORPERSISTENCE

Ripened seeds are vulnerablefrom the time they fall to the groundand settle into the seed bank untilthe right weather conditions triggergermination. Precipitation is unpre-dictable in California’s deserts, andseasonal rains that promote germi-

nation are often fol-lowed by dry periodsthat stress or kill de-veloping seedlingsbefore they reproduceand replenish theseed bank. Many spe-cies cope with thepossibility of massseedling mortality bymaintaining a portionof their seed bank ina dormant state forsuccessive years, astrategy known as“bet hedging.”

Seeds need spe-cific environmentalconditions to over-come dormancy. Forexample, heavy rainswash away chemicalinhibitors in the seedcoat, and hot or cold

soil temperatures initiate physiologi-cal changes for germination (Baskinand Baskin 1998). Various strate-gies of seed dormancy promotespecies coexistence and high bio-diversity in desert shrublands. Thisbiodiversity is important at a timewhen extreme and fluctuating cli-mate patterns present strong selec-tive pressures for adaptation.

Birds, small mammals, and antsdistribute seeds to locations that arefavorable for seedling establishment(Tevis 1958, Nelson and Chew1977), but they also consume copi-ous amounts of seeds. Perennialsknown as “masting” species produceextraordinarily large seed crops insome years. These large crops dur-ing “mast years” overwhelm seedharvesters by producing more seedsthan can be consumed or stored.For example, Joshua tree (Yuccabrevifolia) produces large seed cropsonly once or twice a decade. Be-cause seeds rapidly lose viability inthe soil, the opportunity for seedgermination and seedling establish-ment is urgently timed to coincidewith summer rains that closely fol-low seed dispersal (Reynolds et al.2012).

THREATS TO NATIVE SEEDBANKS

Seed banks are vulnerable tohuman-caused disturbances thatimpact desert soils. Concentratedvehicle use has cascading impactson seed banks: vehicles crush andkill seed-bearing shrubs, and theycompact soils or destabilize soil ag-gregates so that soil, litter, and seedsare exposed to wind and water ero-sion. In a study at Fort Irwin,California’s National Training Cen-

V

ABOVE: Understanding seed banks commonly starts in thegreenhouse by subjecting field-collected soils to alternatingwetting-drying cycles until all seeds germinate and seed-lings are identified and counted. This process takes up tonine months. TOP: Native seeds of perennial shrubs such aswhite bursage (Ambrosia dumosa) are rare in the seed bankcompared to annual species. All photographs by Lesley A.DeFalco unless otherwise noted.


ter near Barstow, militarytraining reduced the numberof species in the seed bank byhalf and the number of seedsto one-sixth those of undis-turbed areas (DeFalco et al.2009). Excavation of trenchesfor tank exercises diminishedthe abundance of perennialseeds, burying them too deepfor seedlings to emerge whenthe trenches were refilled. Thesedisturbances resemble those com-mon throughout the desert associ-ated with recreation, constructionof aqueducts, power lines, and pipe-lines. Comparable impacts to seedbanks are expected as urban areasexpand and alternative energy pro-jects increase.

Fire and invasive species alsothreaten desert seed banks. The in-creasing incidence and size of wild-fires in recent decades is paralleledby the invasion and dominance ofexotic annual grasses at middle(cheatgrass, Bromus tectorum) andlow elevations (red brome, B. madri-tensis ssp. rubens; Mediterraneangrass, Schismus spp.). In contrast toCalifornia coastal scrub, manyMojave and Sonoran shrublandspecies do not readily resprout afterinjury by fire. Whereas new seed-lings typically arise from the seedbank following natural distur-bances, a recent study found thatfire killed 55%–80% of seeds in aMojave Desert seed bank of north-ern Arizona (Esque et al. 2010). Twoexotic species, one with small seedsthat filtered into soil cracks (Medi-terranean grass) and another with aself-drilling appendage (stork’s bill,Erodium cicutarium) helped themescape lethal temperatures.

Comparing seed banks in recov-ering burned and unburned shrub-lands, we found seed densities ofthe dominant native annual grass(six-weeks fescue, Festuca octoflora)declined by more than 70% andnative forbs by more than 50% dueto wildfire. In contrast, exotic an-nual grass and forb seed densities

were two- and six-times higher, re-spectively, than their native coun-terparts. Furthermore, burned siteshad one-third the number of nativespecies than adjacent unburned ar-eas, signaling a significant loss ofplant diversity.

Air pollution associated with ur-ban development, particularly fromthe Los Angeles basin, is making itsway into desert wildlands. Nitrogenemissions are blown inland and en-rich the ordinarily infertile desertsoils. Exotic annual grasses are well-

suited to nitrogen pulses forgrowth and reproductioncompared with native species.A study at Joshua Tree Na-tional Park showed that siteswith the lowest nitrogendeposition had the highestseed bank species richness(Schneider and Allen 2012).Continued nitrogen exposureis expected to reinforce ex-

otic dominance in the seed bank,thereby reducing native speciesdiversity.

A PRESCRIPTION FORREPAIR

Rehabilitating degraded shrub-lands depends in part on minimiz-ing further disturbances, develop-ing methods for suppressing aggres-sive exotics, and replenishing nativeseed banks. We have found acrossmultiple sites that pre-emergent her-bicides (applied before the arrival offall and winter rains) are effective atnot only suppressing exotic annualsby 50–95% up to three years afterapplication, but also at reducing theirseed bank in as many years. Fur-thermore, native annual species—six weeks-fescue in particular—in-creased in shoot mass and seed bankdensity following herbicide treat-ments. Seed dormancy may play arole in protecting native seed popu-lations from herbicide impacts,whereas exotic species such as redbrome that lack dormancy can begradually reduced in infested areas.

In a related study, herbicideapplication in combination withnative seeding increased the densityof early-colonizing species six-fold,including desert marigold (Baileyamultiradiata) and desert globe-mallow (Sphaeralcea ambigua).Larger areas of treatment may ex-clude exotic annuals for longer peri-ods of time and restore native spe-cies’ ability to accumulate in the seedbank. Limited herbicide use is in-tended to accelerate native speciesestablishment so that the plant

Small mammals such as kangaroo rats(Dipodomys sp.) and harvester ants (Pogo-nomyrmex rugosus) collect seeds of mostshrub species. Rodents gather seeds andstore them in shallow caches, and seedlingsemerge when seeds are forgotten. Alsopictured is a Joshua tree seedling (Yuccabrevifolia). Harvester ant and Joshua treeseedling photographs by Todd C. Esque.


community can resist reinvasionand rebound from future distur-bances. However, the impacts ofherbicides to soil microbes and tothe animal populations in largertreatment areas are unknown.

Based on supplemental seedstudies, ants and rodents can collectmore than 80% of the seeds broad-cast during revegetation (DeFalcoet al. 2012). We are exploring meth-ods to encapsulate seeds and shieldthem from granivores until suitableconditions promote establishment.One method has been to use “seedballs,” a mixture of seeds, clay, andorganics. When dried, the marble-sized pellets are durable when scat-tered across large disturbances.

However, initial evaluation of seedballs using native desert speciesproved less successful than expected,so we are adjusting the recipe toimprove seedling emergence andassessing plant establishment at avariety of sites.

Despite our progress using res-toration methods on small experi-mental plots, seed availability forrestoration projects is limited be-cause desert species do not reliablyproduce enough seed from one yearto the next. Seeds purchased fromcommercial collectors are expensiveand not always representative oflocal ecotypes, or may even havebeen collected outside the desertecoregion. Since 2010, federal andstate agencies, universities, arboreta,and botanic gardens have cooper-ated to acquire local populations ofnative species (see the Seeds of Suc-cess Program, nps.gov/plants/sos).

Spring 2013 was a unique mastyear for a variety of species includ-ing Joshua tree, Nevada joint-fir(Ephedra nevadensis), and black-brush (Coleogyne ramosissima). Infact, blackbrush reproduced acrossits entire range in the Mojave Desertand the Colorado Plateau. Thesemast events are opportunities tocollect the seeds of multiple popu-lations across species’ ranges foruse in restoration, and when prop-erly stored, the seedsremain viable for up to20 years (Kay et al.1988). However, collect-ing seeds cannot, alone,keep pace with thegrowing need caused byincreasing disturbances.Seed production of na-tive species by farmersdistributed across thedesert ecoregion mayeventually provide a re-liable and abundantsource for wildlandseedings and at reason-able prices.

Even when seed pro-duction is sufficient,

preserving and restoring vulnerabletopsoil layers is essential for reveg-etating degraded desert lands. Sur-face soil not only holds the seedbank but also holds organic litterand microbes important for plantmineral nutrition. Topsoil collectionand replacement (using heavy equip-ment) has potential application forsevere disturbances (for example,bladed sites for solar arrays, windfarms, and geothermal facilities).Large-scale seed bank conservationis difficult, however, because con-ventional equipment collects soilbelow a 1–2 inch depth, often mix-ing deeper seedless soil fractionswith seed-rich topsoil. This mixingdilutes seed numbers in the storedsoil and upon redistribution, buriesseeds too deeply for seedling emer-gence (Scoles-Sciulla and DeFalco2009).

Traditional approaches to reha-bilitate degraded shrublands, in ad-dition to seed bank conservation,aim to replace ecosystem compo-nents destroyed by disturbances andinclude transplanting seedlings, pro-viding structure through verticalmulch, and improving soils beforereseeding, to name a few. Althoughrestoration ecologists are workingon solutions to reverse the degrada-tion of disturbed shrublands, mini-mizing disturbances and promot-

Experimental application of herbicide in late fall (bluedye) has been effective at diminishing exotic annuals inthe seed bank of repeatedly-burned areas.

Landscape-scale disturbances such as con-centrated vehicle areas (above) and areasburned by desert wildfires (below) killseed-bearing shrubs and disrupt vulnerablesurface soils where seeds reside, makingvegetation recovery difficult.


ing shrubland function is the firstpriority.

Importantly, our progress in de-veloping rehabilitation solutionsdoes not justify the continuing deg-radation of California’s desert lands,because plant community composi-tion does not readily recover formany decades to centuries. Limitinghuman activities to areas already dis-turbed and protecting areas withminimal disturbance is the best strat-egy for preserving our unique desertshrublands and the plants and ani-mals that depend upon them.

REFERENCES

Baskin, C., and J. Baskin. 1998. Seeds.Ecology, Biogeography, and Evolutionof Dormancy and Germination. Aca-demic Press, San Diego.

DeFalco, L.A., et al. 2012. Supplement-ing seed banks to rehabilitate dis-turbed Mojave Desert shrublands:Where do all the seeds go? Restora-tion Ecology 20:85–94.

DeFalco, L.A., et al. 2009. Seed banksin a degraded desert shrubland: In-fluence of soil surface condition andharvester ant activity on seed abun-

dance. Journal of Arid Environments73:885–893.

Esque, T.C., et al. 2010. Short-termeffects of experimental fires on aMojave Desert seed bank. Journal ofArid Environments 74:1302–1308.

Kay, B.L., et al. 1988. Long-term stor-age of desert shrub seed. MojaveRevegetation Notes (University ofCalifornia, Davis, Agronomy andRange Science) 23:1-22.

Nelson, J.F., and R.M. Chew. 1977. Fac-tors affecting seed reserves in the soilof a Mojave Desert ecosystem, RockValley, Nye County, Nevada. Ameri-

can Midland Naturalist 97:300–302.Reynolds, M.B.J., et al. 2012. Short seed

longevity, variable germination con-ditions, and infrequent establish-ment events provide a narrow win-dow for Yucca brevifolia (Agavaceae)recruitment. American Journal ofBotany 99:1647–1654.

Scoles-Sciulla, S.J., and L.A. DeFalco.2009. Seed reserves diluted duringsurface soil reclamation in easternMojave Desert. Arid Land Researchand Management 23:1–13.

Schneider, H.E., and E.B. Allen. 2012.Effects of elevated nitrogen and ex-otic plant invasion on soil seed bankcomposition in Joshua Tree NationalPark. Plant Ecology 213:1277–1287.

Tevis, L. 1958. Interrelations betweenthe harvester ant Veromessor pergand-ei (Mayr) and some desert ephemer-als. Ecology 39:695–704.

Went, F.W. 1949. Ecology of desertplants. II. The effect of rain and tem-perature on germination and growth.Ecology 30:1–13.

Lesley A. DeFalco and Todd C. Esque,US Geological Survey, Western Ecologi-cal Research Center, 160 North StephanieStreet, Henderson, NV 89074, [email protected], [email protected]

Laboratory trials with “seed wafers,” animprovement over seed balls, have shownthat encapsulating seeds in a soil matriximproves water status and increases seed-ling emergence over unprotected seeds.Field trials are ongoing to determine ifwafers reduce the need for high seedingdensities, thereby reducing costs.

Reseeding with natives in combination with herbicide applications promotes native establishment, as pictured here for desert marigold(Baileya multiradiata) on small experimental plots in the eastern Mojave Desert.


NEW CNPS FELLOW: DOREEN SMITHby Amelia Ryan

fter more than 30 years as amember of CNPS andmore than 20 years of ser-vice on the Marin Chap-

ter Board, Doreen Smith joined theaugust ranks of CNPS Fellows in June2013. Today Doreen is generally re-garded as the chapter member withthe deepest and most comprehensiveknowledge of the flora of Marin.

Her introduction to the Societycame through interactions with an-other CNPS Fellow and pioneeringmember of the Marin Chapter,Wilma Follette. For many yearsWilma had taught a course on plantcommunities at the College of Marin,but when a young transplant fromBritain joined her course sometimein the late 1970s, the newcomer im-mediately stood out.

“She was by far the most knowl-edgeable person in the class,” saysWilma of Doreen. Through Wilma’sencouragement, Doreen soon joinedthe California Native Plant Societyand began accompanying Wilma onher weekly wildflower walks. Thusbegan a long and fruitful relation-

ship with the Marin Chapter andCNPS.

Doreen’s interest in the plantkingdom predates her arrival in theUS in 1967. The daughter of a gar-dener and a housemaid, Doreen LinaWood was born outside Luton, En-gland in a country in the midst of awar, and spent her childhood in theaustere years that followed. Never-theless, growing up as she did, partof the “downstairs” of a large coun-

try estate did afford some ad-vantages. The formal gardensher father oversaw and thepastures and remnants of wildwoods were wonderful placesto learn plants and explorewildflowers when the estate’sowners were not in residenceand the head gardener’sdaughter could wanderabout.

A good student, Doreenwon a scholarship to BristolUniversity where she ac-quired a bachelor of sciencein botany and importantlymet Vernon Smith, then ayoung physics student fromthe North of England, nowher husband of more than 50years. She also achieved a cer-

tificate in secondary science educa-tion, but ended up working on theflora of Tropical East Africa at theherbarium of the Royal Botanic Gar-dens, Kew, noting that “this was amuch quieter job than managing aclassroom of adolescent girls.” She’deven begun work on a master’sdegree when Vernon was offered aposition at UC San Francisco, andthe couple set sail for the Bay Area.

Although Doreen began heractivities with the Society when shewas a young mother in the seventiesand continued them when she wentback to work as a science teacher inthe Marin Public Schools, they werenecessarily more limited until herretirement in 1991. At that time shethen became the education chair forthe Marin Chapter, a post she servedin for five years. From 1995 to2013—a period of 18 years—sheserved as the chapter’s rare plantchair. She also served briefly as co-vice president in 2009–2010. In to-tal, she served on the chapter’s boardfor nearly 25 years.

Doreen’s passion for, and knowl-edge of, the flora of California arelegendary. Her knowledge of theMarin flora, and in particular its rareplant species, is encyclopedic. Sheknows the locations, lineages, ecol-ogy, and nomenclature of all therecognized and unrecognized varia-tions of the plants that grow there.She has been responsible for findinguncountable new populations of rarespecies, for rediscovering severalspecies thought extirpated, for ex-panding the list of known Marinnatives, and for being the first tospot and sound the alert on many anew invader. In fact, by all accountsshe drove the authors of the SecondEdition of the Marin Flora quitecrazy because, as co-author WilmaFollette recalls, “she kept adding newspecies and occurrences.”

Doreen Smith botanizing at Bodega Bay in 1970.All photographs by Vernon Smith.

A


The Marin Chapter is not theonly group that has relied on herdetailed and precise knowledge ofthe county’s flora. Many public agen-cies call on her to identify trickynew species, locate cryptic rarities,and double check lists for accuracyand completeness. In addition, sheis often found at public meetingsproviding testimony on behalf ofrare plants.

No matter how versed you are inthe California flora, you are sure tolearn something new if you accom-pany Doreen on an excursion. Saysfellow board member CarolynLongstreth, “I went on a field tripwith Doreen along a trail I oftenhike. I thought I knew all the plantsthat grew along that trail, but shemust have pointed out a dozen plantsI hadn’t ever even noticed before.”In fact, a great way to test your plant

BOOK REVIEW

Seed of the Future: Yosemite and theEvolution of the National Park Idea byDayton Duncan. 2013. Yosemite Con-servancy, San Francisco, CA. 224 pp.,$27.00 softcover. ISBN# 978-1-93023-842-8.

To start, this is my kind of book! Itis packed full of interesting facts andhistory about Yosemite and how it be-came a park. Included are over 100archival images and beautiful land-scape photographs of Yosemite and

those visionary people who were in-strumental in protecting this sublimepart of California for future genera-tions, including Galen Clark, JohnMuir, Frederick Law Olmsted,Theodore Roosevelt, and others. The

TOP: Doreen and fellow Marin CNPS member Vivian Mazur on a rare plantmonitoring excursion led by Doreen in March 2013 at Kehoe Beach. Vivianis the Marin Chapter historian. • BOTTOM: Doreen leading another rareplant outing at Abbott’s Lagoon, Point Reyes National Seashore, in April2013.

knowledge is to takealong on a hike one ofthe dozens of Marinplant lists that Doreenmaintains, adds to,and continually up-dates. It can be a hum-bling experience!

CNPS, land man-agers, and the publichave all benefittedfrom Doreen’s formi-dable knowledge andwillingness to shareit. But even more, inDoreen Smith, the rareand special plants ofCalifornia have an un-wavering champion.

Amelia Ryan, P.O. Box162, Inverness, CA 94937,[email protected]

TELOS RAREBULBS

Telos Rare BulbsP.O. Box 1067, Ferndale, CA 95536

www.telosrarebulbs.com

The most complete offering of bulbs native to the

western USA available anywhere, our stock is

propagated at the nursery, with seed and plants

from legitimate sources only.


book also familiarizes us with thosepeople who wanted to exploit Yosemitefor their own financial gain withoutconsidering the environmental im-portance of such outstanding naturalplaces. Dayton also explains how theidea of preserving natural areas likeYosemite turned into our current Na-tional Parks program, which inspiredsimilar programs throughout theworld.

The book includes copies of im-portant documents that are integralto the protection and formation ofYosemite National Park. Its publica-

tion is in honor of the 150th anniver-sary of the founding of the YosemiteGrant, a bill signed by PresidentAbraham Lincoln.

In his compelling narrative, Day-ton describes the struggles that vi-sionaries like Muir and Olmstead hadwith the powers that be on how tosave and protect Yosemite. John Muirstruggled to his dying day to protectthe Hetch Hetchy Valley from havinga dam installed, and Frederick LawOlmsted knew way before his timehow best to develop Yosemite whileprotecting it for future generations.Dayton reminds us that Muir knewthe only way to get people to protectthis beautiful area, especially those ina position of power, was to have themexperience the place for themselves.Olmsted had written a very detailedmanagement plan for Yosemite, which

was squashed and buried for politi-cal reasons. It took Congress and theNational Park Service many decadesto actually figure out that his plan wasspot-on. The report wasn’t rediscov-ered until 1952 when a descendentfound it in Olmsted’s papers.

My only complaint about the bookis that it is relatively heavy because itis printed on high-quality paper, mak-ing it hard to hold in your hands.However, this could be seen as anopportunity for armchair enthusiaststo get some exercise (if only for theirarms and wrists).

Seed of the Future could easily serveas an authoritative historical referenceon our National Parks due to its thor-oughness in covering the history ofthe formation of this jewel of a na-tional park, and in tracing how theidea of setting aside natural areas forpreservation and enjoyment grew intoour national park system. It belongsin every library, and is also attractiveenough to display on a coffee table.

Dayton’s book has inspired me toget back to Yosemite, which I have notvisited now for several years, and itwill likely inspire many other peopleto visit and fall in love with Yosemiteand our other national parks. It is cer-tainly a great book to read, as I did, infront of a fire on a cold winter evening,although it will hold your interest justas much on a balmy summer day.

—David L. Magney


WHAT SHAPED YOUR LOVE OF NATURE?

nurture, I apparently had both becauseI was lucky that my parents supportedmy budding interest. Today I am alicensed landscape contractor special-izing in native plant restoration.

✦ ✦ ✦

[Editor’s Note: Fremontia readers wereinvited to send in their stories of whatshaped their love of nature. These arethe first two responses we’ve received. Ifyou are motivated to send us yours, itcan be about 250 words, and shouldbe emailed to [email protected]. Be sureto include a high-quality headshot, or aphotograph of yourself in a natural placeyou love, and the name of the photogra-pher who took it.]

SUZANNE SCHETTLERSanta Cruz County Chapter

grew up in a middle-class suburb. Onweekends the family took care of the

yard. The neighbors across the streetalways had a perfectly manicured yard,and we tried to keep up with theMullinses.

I must have taken to gardeningmore than my two sisters, because Iadopted a little planting bed by thefront door of our house. I grew portu-laca and zinnias and other mundanethings appropriate for a child gardener.

Later, when I was eight, I asked fora garden of my own. There was a stripof land, maybe 18–20 feet wide, on theeast side of the house (ideal!) under mybedroom window that my parents let

me have. I had to climbover a fence to get to it,and I grew vegetablesand flowers all mixedtogether long beforethat was fashionable.The fence would be achallenge now.

In fall when weraked leaves in theback yard, my sistersand I would play inthe leaf piles. A neigh-borhood friend hadparents who let us

build a tree house and dig a fort at theback of their yard. We were at home innature, and it’s sad that children arenow so isolated from their naturalhome.

On the question of which is moreformative in a person’s life, nature or

Suzanne Schettler’s varied careerhas included, among other things,working as a native plant nursery man-ager and on a UC natural historyreserve. She also served as state CNPSpresident from 1989 through 1991.

KATHERINE GREENBERGEast Bay Chapter

not to touch it just as I was about topick some of the most beautiful, glossyred leaves that I had ever seen. In mygarden in the East Bay hills I have triedto recreate the landscapes of my child-hood with plants from California’sgrasslands, chaparral, oak woodlands,riparian woodlands, and redwoodforests.

✦ ✦ ✦

Katherine Greenberg is a gardendesigner and co-author of GrowingCalifornia Native Plants (2nd edition,UC Press, 2012). She was the found-ing president of the Friends of theRegional Parks Botanic Garden inBerkeley, California.

y impressions of the naturalworld were formed by child-

hood walks in the wildflower fields ofthe Jolon Valley, hikes in the ruggedcanyons of Big Sur and mountainmeadows in the High Sierra, and sum-mers at Camp Cawatre in Arroyo Seco.I grew up hearing stories about thehomestead where my great grandpar-ents lived near Mission San Antonio,my grandfather’s adventures with hischildhood friend John Steinbeck, andmy father’s native plant scrapbooksthat he filled with pressed leaves andflowers.

I also remember my first encoun-ter with poison oak, when I was warned

SAXON HOLT

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CNPS member gifts allow us to promote and protect California’s native plants and their habitats. Giftsare tax-deductible minus the $12 of the total gift which goes toward publication of Fremontia.

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SUBMISSIONINSTRUCTIONS

CNPS members and others areinvited to submit articles for pub-lication in Fremontia. If inter-ested, please first send a shortsummary or outline of whatyou’d like to cover in your ar-ticle to Fremontia editor, BobHass, at [email protected]. Instruc-tions for contributors can befound on the CNPS website,www.cnps.org, under Publica-tions/Fremontia.

Fremontia Editorial AdvisoryBoardSusan D’Alcamo, Jim Andre, EllenDean, Phyllis M. Faber, HollyForbes, Dan Gluesenkamp, BrettHall, David Keil, Kara Moore,Pam Muick, Bart O’Brien, RogerRaiche, Teresa Sholars, DickTurner, Mike Vasey

Julie Evens is director of the CNPS Vegetation Program and oversees surveying,classification, and mapping of vegetation in California.

G. Darrel Jenerette is an associate professor in the Department of Botany andPlant Sciences, UC Riverside, and conducts research in landscape ecology.

Robert F. Johnson is a GIS specialist with the Center for Conservation Biology,UC Riverside.

Todd Keeler-Wolf leads the Vegetation Classification and Mapping Program forthe California Department of Fish and Wildlife, and is the senior advisor to theCNPS Vegetation Program.

David Magney is a botanist and environmental consultant with over 30 years ofexperience, and since the mid-1980s has served CNPS in leadership roles at thestate and chapter levels.

Bruce M. Pavlik founded BMP Ecosciences, an Oakland-based environmentalconsulting firm, and is the head of restoration ecology at the Royal BotanicGardens, Kew, England.

Amelia Ryan is an ecologist and a member of the CNPS Marin Chapter Boardsince 2010.

Greg Suba is the CNPS Conservation Program Director.

Karen Tanner is a biological researcher at BMP Ecosciences, and is currentlyassessing solar development impacts on rare plants in the Mojave Desert.

(continued from back cover)

F R E M O N T I A V O L . 4 2 , N O . 2 , M A Y 2 0 1 4

CONTRIBUTORS

California Native Plant Society2707 K Street, Suite 1Sacramento, CA 95816-5130

Nonprofit Org.

U.S. PostagePAID

A.M.S.

FROM THE EDITOR

(continued on inside back cover)

n the last issue I extolled the hard work of researchers whospend countless hours “in the field”—an expression widelyused by those who trek out into nature to conduct sur-

veys, gather data, or restore habitat. Maybe because I spendso much time working with words and enjoy all theirnuances, I’ve always found that expression mildly enter-taining, because being told someone will be “in the field”conveys an implicit message that they may be unavailablefor a while. And the “field” being referred to is not the onedescribed in the dictionary, but instead a wild or undevel-oped area that we hope still contains an intact ecosystemwith a diversity of plant and animal life.

This second Fremontia issue on California’s deserts con-tains additional valuable information on these “fields” ofbiological observation, with an emphasis on current threatsand promising conservation strategies.

As these two issues have materialized, I’ve come toappreciate more than ever the central, essential role thatphotographs play in telling the story of our deserts. When anatural area is under threat, the old saying that “a picture isworth a thousand words” rings true. Photojournalists haveknown this for decades, but so have naturalist photogra-phers, which is why the photographs of Ansel Adams andothers move us. They convey so much information withoutthe use of a single word.

Before and after photographs taken in the same spotover time are the most effective way for people to reallygrasp the scale of the changes taking place in our desertsand other natural areas. It was a challenge for us to find theperfect photos for these two desert issues of Fremontia.Naturalist photographers reading this note, pay heed to thisgreat challenge!

—Bob Hass

I

Printed on sustainably harvested paper containing 50% recycled and10% post-consumer content, processed chlorine-free.

Edith B. Allen is a professor of plant ecology and coopera-tive extension specialist in the Department of Botany andPlant Sciences, UC Riverside, and focuses on restorationecology.

Michael F. Allen is a professor of biology and plant pathol-ogy and director of the Center for Conservation Biology, UCRiverside, with research interests in ecosystem ecology andmicrobial ecology.

Cameron W. Barrows is an associate researcher with theCenter for Conservation Biology, with a research focus ondynamics of sensitive species, invasive species, and climatechange impacts.

Michael D. Bell was a postdoctoral fellow at UC Riversidewhere he did research on modeling for habitat conservationplans, and is currently a postdoc at the Center for Environ-mental Biology, UC Irvine.

Lesley DeFalco is a research plant ecologist with US Geo-logical Survey. She studies endangered plants, impacts ofinvasive annual species, and restoration of desert habitats.

Rebecca Degagne is a biologist and GIS analyst for theConservation Biology Institute, a nonprofit providing scien-tific expertise to support conservation and recovery ofbiodiversity locally, regionally, and globally.

Todd Esque is a research ecologist with USGS. His recentwork focuses on habitat modeling, climate change, landscapegenetics, and conservation in desert lands.

vol. 42, no. 2 • may 2014 fremontia · mary frances kelly-poh yerba buena (san francisco): ellen...

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