Invasive SpeciesInvasive Species

September 5th, 2007

Announcements:Announcements: Check out Case Studies posted on website (if you forgot

which group you are in, scroll through to find your name, or ask me)

Come prepared for class discussion tomorrow Background Field Trip Questions: now posted Field Trip Waiver Forms: I need you to sign them Field final: will be passed out tomorrow

Summary of Monday:Summary of Monday:

• How do communities change?• Succession

• Primary vs. Secondary• Who wins at the beginning? Who winds at the end?

• Facilitation: biotic/abiotic interactions• Early colonizers vs. Pine vs. Oak• Grasses on sand dunes, eelgrass

• Acceleration• Climax communities?• Plant vs.Animal Succession?• Intermediate Disturbance Hypothesis

• Role of fire in Chaparral Biome

Why study invasive species?Why study invasive species?

• Invasive species are the second greatest threat to conservation of biodiversity

• economic consequences (good and bad)

• human health consequences

Invasive Species GlossaryInvasive Species Glossary• native: an organism that is living in its home environment

• Endemic: organism that is only found in/confined to a particular location • exotic• non-native originally from a different location• foreign/alien

• naturalized: a non-native that has become a part of its new environment

• invasive: a non-native that has spread to become a dominant member of its new environment

• weed: an invasive species of plant that causes environmental or economic problems

- Noxious weed: legally designated as a pest

How do non-native species arrive?

How do non-native species arrive?

• Accidentally• seeds• parasites• unintended cargo

• Deliberately• food• timber• pets• biocontrol

Data source: Eurostat. Source of figure: CNT, 2004

Data source: US Department of Transportation, 2004

Who are these invaders?Who are these invaders?

• Plants• Animals

• Microorganisms

What makes an invader successful?What makes an invader successful?• r-strategists

• grow quickly• produce many offspring• short generation time

• good dispersion • generalists: highly adaptable to new conditions

• broad geographic range in native environment• broad diet

• It has not coevolved with members of its new environment

What made the greencrab successful?

What makes a community vulnerable to invasion?What makes a community vulnerable to invasion?

• human disturbance• early succession• climate similar to native habitat

• absence of predators or pathogens •wrong ones for the invader•no predators or pathogens at all - islands

What do invasive plants do?What do invasive plants do?Change ecosystem structure

• fire suppression/enhancement• grassland shrubland• And vice-versa

• Change nutrient cycling• Spartina alterniflora

• Change physical structur of landscape• European beachgrass

• use up limiting resources, such as water, light• riparian zone desert• woodland kudzu-dominated land

Grassland to shrublandGrassland to shrubland

Changes fire regime!

Shrubland to GrasslandShrubland to Grassland

Changes fire regime!

Woodland to KudzulandWoodland to Kudzuland

Can you guess its strategy?

Riparian zone to desertRiparian zone to desert

Local Invaders: Castor Bean, Fennel Pampasgrass, Iceplant…Local Invaders: Castor Bean, Fennel Pampasgrass, Iceplant…

What do invasive animals do?What do invasive animals do?

Change foodweb structure

• Hyperpredation

• drive out native competitors and prey

A case study: zebra musselsA case study: zebra mussels• native to Russian lakes• introduced to North America in 1985 from bilge of

a ship• after <1 year, can produce 1,000,000 eggs• large colonies clog pipes• very efficient filterers

• clear water• eliminate native species

Zebra mussel range mapZebra mussel range map

Microorganisms: virus, fungi, bacteriaMicroorganisms: virus, fungi, bacteria

Invasive Plant and Animal Mutualism

Invasive Plant and Animal Mutualism

+

Can an invasive be unwanted at times, and desirable other times?

Can an invasive be unwanted at times, and desirable other times?

Management OptionsManagement Options

Do nothing Understand life strategy

Vulnerabilities, limiting factor Predict where it will invade, rate of spread,

during what time periods….Remote sensingMathematical models!

ERADICATE!

EradicationEradication

Physical control Chemical control Thermal control Biological control

PredatorVirusGrazing

www.dailynexus.com

Coalition Drops Black Rat Poison on Anacapa Island

by Rebecca Turek - Staff WriterThursday, December 6, 2001

Biological control: lessons from the OutbackBiological control: lessons from the Outback

Cane toads Rabbits

1950’s: myxoma virus1990’s: Calcivirus

Success stories:Schisto.

How can we avoid invasive species and preserve biodiversity?

How can we avoid invasive species and preserve biodiversity?

“Co-habitable” land useLand uses consistent with biota

– Give up the green lawn!– Organic/crop rotation based agriculture (but what is the cost?)

Habitat enhancementVariation of landscapeRestore disturbance regimes

Re-introduction Laws and Regulations

Pop Quiz!Pop Quiz!

Which plant/animal would you say is the MOST invasive???

Questions to Ponder:Questions to Ponder:

How long do you have to inhabit an area to be a native?

What point in time should we restore to? Is fighting invasives a losing battle? What are

the costs of doing nothing?

Where is biodiversity loss most prominent?Where is biodiversity loss most prominent?Conservation International: Biodiversity Hotspots

CI quantified by number of endemic plant species and threat

Assessing Biodiversity Assessing Biodiversity Indicator species: Species that are present only under

strict environmental conditions Can be used to detect healthy/unhealthy ecosystemsExample: steelhead, certain diatoms

Species diversity/richness: number of species in sample-diversity: number of species within a single habitat type-diversity: difference in species composition between habitats

Species evenness: equality of relative abundanceUnevenness might indicate unhealthy ecosystem

Biodiversity Index

CommunityRobin Mallard Crow Cardinal Geese

I 0.2 0.2 0.2 0.2 0.2

II 0.3 0.07 0.1 0.5 0.03

III 0.25 0.25 0.25 0.25

Relative Abundance

Shannon-Wiener Biodiversity IndexShannon-Wiener Biodiversity Index

Where:H = the Shannon-Wiener biodiversity index pi = proportion of each species in the sample (relative abundance)

loge = the natural log of pi

s = the number of species in the community (species richness)

∑=

−=s

iiei ppH

1

log

Community H indexRobin Mallard Crow Cardinal Geese

I 0.2 0.2 0.2 0.2 0.2 1.61

II 0.3 0.07 0.1 0.5 0.03 1.23

III 0.25 0.25 0.25 0.25 1.39

Relative Abundance

H(Community II) = -(.3*ln(.3)+.07*ln(.07)+.1*ln(.1)+.5*ln(.5)+.03*ln(.03))

How to Protect Biodiversity?How to Protect Biodiversity?

Protect SpeciesEndangered Species ActClassic Fisheries Managment

Protect HabitatReservesConservation EasementsMarine Reserves

Species ProtectionSpecies Protection

Minimum Viable Population (MVP) Inbreeding, genetic drift Genetic bottleneck Minimum Viable Area—habitat protection

Genetic bottleneck-Population loses much of its genetic diversity from a population decline

Genetic bottleneck-Population loses much of its genetic diversity from a population decline

Most geneticdiversity isretained

Which Species to Protect?Which Species to Protect?

Umbrella species

Flagship species

Keystone species

Habitat Protection: ReservesHabitat Protection: Reserves

One large or many small? Shape? Connectivity?

SLOSS Debate: Single Large vs. Several Small SLOSS Debate: Single Large vs. Several Small

Species-area curve

Management implications: Management implications:

•Small reserves: area = speciesSmall reserves: area = species

•As area increases, diminishing returnsAs area increases, diminishing returns

To consider:Genetic exchangeExtinction eventsEdge effectsFuture PressuresCost/Flexibility

Reserves…. Size matters!Reserves…. Size matters!

Shape Matters too! Cores and Buffers:

Shape Matters too! Cores and Buffers:

Connectivity: Nodes and Corridors

Connectivity: Nodes and Corridors

Is connectivity important in MPA’s?

Habitat Conservation Management Tools

Habitat Conservation Management Tools

Conceptual diagrams Collaboration (with stakeholders, community) Mathematical/computer models GIS (Geographic Information Systems) Remote sensing Environmental Impact Reports

The new trend……The new trend……

Ecosystem Based Management (EBM)"EBM looks at all the links among living and nonliving resources, rather than considering single issues

in isolation . . . Instead of developing a management plan for one issue . . ., EBM focuses on the multiple activities occurring within specific areas that are defined by ecosystem, rather than political,

boundaries." US Ocean Commission Report, 2004

http://ebm.nceas.ucsb.edu/faq/definition/