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Göteborg UniversityFaculty of Science

2008

Oak-rich Temperate ForestsConservation Ecology of

Cryptogams and Vascular Plantsat Local and Landscape Level

Heidi Paltto

Dissertation

Akademisk avhandling för filosofie doktorsexamen i Växtekologi som enligt Natur-vetenskapliga fakultetets beslut kommer att offentligen försvaras fredagen den 29februari 2008, kl. 10.00 i Föreläsningssalen, Institutionen för Växt- och Miljö-vetenskaper, Carl Skottsbergs Gata 22 B, Göteborg. Examinator: Ulf Molau. Fakul-tetsopponent: Magne Sætersdal, Norsk Institutt for Skog og Landskap, Fana, Norge.

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Paltto. H. 2008. Oak-rich Temperate Forests: Conservation Ecology of Cryptogams and VascularPlants at Local and Landscape Level. Doctoral thesis. Department of Plant- and EnvironmentalSciences, Göteborg University, Göteborg, Sweden.

Heidi PalttoDepartment of Plant- and Environmental SciencesGöteborg UniversityBox 461SE-403 50 GöteborgSwedene-mail: heidi.paltto@dpes.gu.sehttp://www.dpes.gu.se/personal/doktorander/heidi_paltto/

Cover photographs: The lichen Lobaria pulmonaria (upper left), the fungi Plicaturopsis crispa(upper right) and the vascular plant Lathyrus niger (lower left) are taken by Leif Stridvall andthe bryophyte Porella platyphylla is photographed by Tomas Hallingbäck.

ISBN: 978-91-85529-18-6Copyright © Heidi Paltto 2008Printed by Chalmers Reproservice 2008

Published papers in the thesis are reprinted by the kind permission of Elsevier:

Götmark, F., Paltto, H., Nordén, B. & Götmark, E. 2005. Evaluation of partial cutting in broadleavedtemperate forest under strong experimental control: Short-term effects on herbaceous plants. ForestEcology and Management 214: 124-141.

Paltto, H., Nordén, B., Götmark, F. & Franc, N. 2006. At which spatial and temporal scales doeslandscape context affect local density of Red Data Book and Indicator species? BiologicalConservation 133: 442-454.

Nordén, B., Paltto, H., Götmark, F. & Wallin, K. 2007. Indicators of biodiversity, what do they indicate?– Lessons for conservation of cryptogams in oak-rich forest. Biological Conservation 135: 369-379.

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Table of Contents

List of papers.................................................................................................................... 5

Abstract............................................................................................................................ 6

Sammanfattning............................................................................................................... 8

1. Introduction................................................................................................................. 10

2. Methods...................................................................................................................... 12

3. Species groups and their responses to habitat changesat different spatio-temporal scales............................................................................... 14

4. Effects of partial cutting/biofuel harvest for differentspecies groups............................................................................................................ 18

5. Relationships among organism groups........................................................................ 20

6. On finding good indicators of Red Data Book species.................................................. 21

7. Towards an approach for efficient conservation ofdifferent species groups in oak-rich forest stands......................................................... 23

8. References.................................................................................................................. 25

9. Tack/Thanks................................................................................................................ 29

An oak in a dense oak-rich forest at Aspenäs, one of the study sites, at the start of the partialcutting in the autumn of 2002. Note the forester to the left. (Photographer: Frank Götmark)

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The life as a PhD-student...

Andreas Karlssonmeasuring tree girths

Ingela Sandbergsurveying vascular

plants

Johan Dahlbergsurveying bryophytes

Kia Jungbarkmeasuring tree girths

Heidi drawing the measuring-tape, assistingwith surveys, and coordinating the field work

The Oak Forest Research Group 2001-2007:Frank Götmark, Björn Nordén, Ted vonProschwitz, Heidi Paltto, Niklas Franc,

Bjørn Økland

The grid for vascular plant surveys.

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List of papers

This thesis is based on the following papers which will be referred to in thetext by their Roman numerals:

I Paltto, H. & Nordén, B. Which spatio-temporal scales are most important to predict occurrenceof species at a local scale (Manuscript)

II Paltto, H., Nordén, B., Götmark, F. & Franc, N. 2006. At which spatial and temporal scalesdoes landscape context affect local density of Red Data Book and Indicator species? BiologicalConservation 133: 442-454.

III Götmark, F., Paltto, H., Nordén, B. & Götmark, E. 2005. Evaluation of partial cutting inbroadleaved temperate forest under strong experimental control: Short-term effects on herbaceousplants. Forest Ecology and Management 214: 124-141.

IV Paltto, H., Nordén, B. & Götmark, F. Partial cutting as a conservation alternative for oakQuercus spp. forest – response of bryophytes and lichens on dead wood. (Manuscript)

V Nordén, B., Götmark, F., Ryberg, M., Paltto, H., Allmér, J. Partial cutting reduces speciesrichness of fungi on woody debris in oak-rich forests. (Manuscript under revision, preliminaryaccepted by Canadian Journal of Forest Research)

VI Nordén, B., Paltto, H., Götmark, F. & Wallin, K. Indicators of biodiversity, what do theyindicate? – Lessons for conservation of cryptogams in oak-rich forest. Biological Conservation135:369-379.

My contributions to the six papers:

(I) I came up with the research idea, carried out the modelling work and analyses, and I wrotemost of the manuscript with assistance by BN. I got help with the construction of the GIFM-model and with writing of the technical parts about the model.

(II) I conducted part of the field work (vascular plants, forest floor bryophytes/lichens), all theanalyses, and I wrote the manuscript with assistance by BN and FG. Environmental data wasgathered jointly by the research group.

(III) I conducted part of the fieldwork together with FG, EG and others, I conducted the ordinationanalyses, and gave comments on the manuscript.

(IV) I conducted part of the field work, all the analyses and wrote the manuscript, with assistanceby FG and BN.

(V) I carried out the ordination analyses, and gave comments on the manuscript.

(VI) I conducted part of the field work (forest floor bryophytes/lichens), part of the data analyses,and gave comments on the manuscript.

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Oak-rich forests – a species rich butthreatened habitat

Oak-rich temperate forest is a species-rich foresttype, which mainly occurs as more or less iso-lated remnants. The area of oak forest hasdecreased dramatically during recent centuriesdue to overexploitation and changed land use.In addition, during the last century the few re-maining oak forests have become denser anddarker due to ceased hay-cutting and grazingby domestic animals. Fragmentation and suc-cession are probably the main threats facingbiodiversity in this forest type. In this thesis, I study oak-rich forests andexamine how different species (organism)groups respond to habitat fragmentation, andto partial cutting with the combined goals ofincreased biodiversity and biofuel extraction. Ialso examine how well different species groupsindicate one another with respect to their speciesrichness, and how these correlations may berelated to the dispersal ability and habitatrequirements of the species groups. For thesepurposes, I study four organism groups – vascu-lar plants, bryophytes, lichens and wood-inha-biting fungi – in 25 old oak-rich forest standsin southern Sweden. In addition, I carry out atheoretical landscape ecological study to comp-lement the empirical studies.

Lichens and bryophytes need largelandscapes, while vascular plantsand wood-inhabiting fungiresponded to small landscapes

Species may be affected negatively by lossesof their natural habitat, both directly by the lossof habitat patches, and indirectly in the re-maining habitat patches due to limited dispersalresulting in insufficient recolonisation of emptypatches. However, few studies have shed lighton at which spatial and temporal scales the habi-tat amount is of practical importance for speciesand their conservation. Using a metapopulationmodel, I showed that species superior atdispersal generally were affected by the amountof habitat in larger landscapes compared to

Abstractspecies inferior at dispersal for which habitatin smaller landscapes had a stronger impact.This means that the minimum landscape sizemeaningful for conservation of a species is lar-ger for species with long average dispersaldistance compared to species with short-distance dispersal. The empirical study showedthat the density of lichens and bryophytes (ofconservation concern) increases in a local foreststand with increasing amount of currentdeciduous forest 1–5 km from the study stands.In contrast, the current number of vascularplants and wood-inhabiting fungi (of conser-vation concern) increased with increasingamount of deciduous forest at a smaller spatialscale (0–1 km). These results may indicate thatlichens and bryophytes are superior at dispersalcompared to vascular plants and wood-inha-biting fungi. In addition, the two latter organismgroups were affected more by the habitatamount 120 years ago than by the currentamount of habitat. In other words, vascularplants and wood-inhabiting fungi showed adelayed response to changing landscapes, whichis consistent with an extinction debt since theamount of habitat has decreased recently in thelandscape.

After partial cutting the vascularplants and lichens on dead woodincreased, while the wood-inhabitingfungi decreased

Many species in oak-rich forests are adapted tosemi-open conditions, but the oak-rich forestshave become darker. Large-scale restoration tograzed pastures would be desirable but may betoo costly for large-scale implementationoutside existing nature reserves. Thereforemanagement with combined goals of biodi-versity conservation and forest managementcould be a good complement to core forestconservation. A partial cutting experiment wasstarted to evaluate the effect of sunnier condi-tions for species expected to gain from suchcutting, as well as for other species groups. Oldoaks were retained and some of the thinner treeswere cut for biofuel. At each of the study sites,one experimental and one control plot, each 1ha, were surveyed before and after the cutting.The short-term response to partial cutting varied

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among organism groups: the species density ofvascular plants and lichens on dead wood in-creased; bryophytes on dead wood were notsignificantly affected; and wood-inhabiting fun-gi decreased. If also the responses of speciesgroups studied within the same project but notincluded in this thesis (forest floor bryophytes;beetles; fungus gnats) are taken into account,the majority of the organism groups werepositively affected or not affected at all, whileonly one organism group (wood-inhabitingfungi) was negatively affected.

Species with similar ecologycovaried weakly

Species groups with similar ecology may covaryin richness across landscapes. However, thespecies densities of four organism groups (onlyspecies of conservation concern considered)were weakly correlated or not correlated at all(n = 25 study sites; 2 ha study plots). Weak pair-wise correlations (bryophytes with lichens; andvascular plants with wood-inhabiting fungi)were related to similar substrate requirementsand dispersal ecology, while no correlationswere found between species with large diffe-rences in their ecology. Possible explanationsto the lack of strong correlations among spe-cies groups may be that the species groups areheterogenous and rarely have same substraterequirements and dispersal ecology.

Indicator species were weakpredictors of Red Data Bookspecies in oak-rich forests ofhigh conservation values

In Sweden and other Nordic countries, Indicator(or ‘signal’) species have been used to find for-est stands with Red Data Book (threatened)species. Such data could potentially also be usedfor prioritising forests for conservation purpo-ses, e.g. establishment of nature reserves. Ievaluated the relationships for three cryptogamgroups (lichens, bryophytes and wood-inha-biting fungi) and found that the total number ofIndicator species was not correlated with thetotal number of Red Data Book species in oak-rich forests. When only deciduous forest lichenswere considered, the Indicator species and Red

Data Book species were weakly correlated.Thus Indicator species, when treated collecti-vely as a group, are not very useful in prioriti-sing oak-rich forests for conservation. Indeed,they may still work for prioritising forest of highconservation value from production forestswithout conservation values.

Landscape scale conservation ofoak-rich forests

In conclusion, the Indicator species may not beuseful to find the most valuable oak-rich forestsfor conservation among oak-rich forests of highconservation value, with the exception of lichenindicators species. The amount of habitat atlandscape scale may be a better indicator of RedData Book species than are Indicator speciesused at local level. I suggest that conservationin oak-rich forests should preferably be focusedon landscapes rich in deciduous forests insteadof selecting individual forest patches rich inIndicator species. An appropriate minimum sizeof a landscape suitable for conservation maybe 300 km2 if the target group is lichens, 80km2 for bryophytes and 3 km2 for vascular plantsand wood-inhabiting fungi. In these landscapesthe aim should be to maximize the amount ofoak-rich deciduous forest. My suggestion is thatgrazing in oak woodland pastures and resto-ration of dense oak-rich forests to oak woodlandpastures should be concentrated to these coreconservation areas, while partial harvesting inoak-rich forests may be a good complement tothis type of conservation, and should be appliedelsewhere in the landscape. My suggestion isto carry out partial harvesting (or pure conser-vation actions) in 80–90 % of all oak-rich forestin southern Sweden, and leave 10–20 % of theforests for natural succession. However, it isimportant that the partial cuttings are donecarefully, and the cuttings are evaluated in long-term perspective. The recommendation to cutsuch a high proportion of the oak-rich forests isbased on the assumption that many of the wood-inhabiting fungi, that decreased due to cutting,also can be found in naturally closed deciduousforests without oak, while species confined toopen oak-rich forests (many lichens and beetles)to large extent lack suitable habitat in currentforests.

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Artrikedomen i ekskogar är hotad

Ädellövskogar, och i synnerhet lövskogar medek, är oerhört artrika miljöer, men arealen avdessa har minskat till en bråkdel av vad somfanns för 300 år sedan. Traditionellt har denhär typen av skogar betats av nötkreatur, fåreller hästar, och ännu längre tillbaka i tiden harmånga av markerna skötts som slåttermarker.Under det senaste århundradet har flertalet löv-skogar vuxit igen. Igenväxningen och den kraf-tiga arealminskningen av ekrik skog är troli-gen två viktiga orsaker till den utarmning avarter som observerats i ekskogar och annan ädel-lövskog.

Mitt doktorandarbete baseras på studier avbiologisk mångfald av kärlväxter, lavar, mossoroch vedsvampar i 25 ekrika lövskogar i Göta-land. Jag har studerat hur den biologiska mång-falden påverkas av det omgivande landskapetoch utvärderat effekterna på biologisk mång-fald av naturvårdsgallring. Gallringen syftar tillatt öppna upp skogen till gagn för de mångaarter som minskat pga igenväxning samtidigtsom skogen kan nyttjas till biobränsle-produktion. Jag har också undersökt hur olikaorganismgrupper samvarierar i landskapet ochhur detta kan relateras till likheter och olikhe-ter i artgruppernas ekologi. Utöver dessa stu-dier har jag gjort datasimuleringar i enlandskapsmodell för att studera landskapetsbetydelse för arter med olika egenskaper.

Olika organismgrupper är beroendeav olika stora landskap

Enligt landskapsekologiska teorier minskar enart om arealen eller kvaliteten på dess habitat(livsmiljö) minskar. Överlevnaden av en art ärstörre i större landskap (givet samma täthet avhabitat), men det finns få studier som under-sökt vilken storlek på landskap som är mest be-tydelsefull för en viss art eller artgrupp, ochhur denna storlek på landskap skiljer sig mel-lan olika arter eller artgrupper. I en teoretiskstudie visade jag att arter med god spridnings-förmåga är beroende av större landskap (givetsamma täthet av habitat) jämfört med arter med

sämre spridningsförmåga. Detta resultat an-vände jag vid tolkning av en studie där jag re-laterade artrikedomen av naturvårdsintressantaarter av kärlväxter, lavar, mossor och ved-svampar i de ekrika skogarna med mängden löv-skog i det omgivande landskapet. Lavar ochmossor, vars artrikedom ökade med ökandemängd lövskog i stora landskap (cirkelradie 5-10 km), borde därmed vara mer lättspridda änkärlväxter och vedsvampar, vars artrikedomökade med mängden lövskog i små landskap(cirkelradie 1 km). Utöver detta fann jag attartrikedomen av kärlväxter och ved-svamparvar bättre relaterad till mängden lövskog för120 år sedan jämfört med dagens landskap, vil-ket tyder på att arterna reagerar långsamt påförändringar som sker på landskapsnivå. Efter-som mängden lövskogar har minskat i landska-pet under de senaste 120 åren innebär detta attarter ännu inte anpassat sig till den mindremängden habitat som finns nu, och att det finnsrisk att vissa arter inte kommer att kunna an-passa sig utan dör ut.

Antalet kärlväxter och vedlevandelavar ökar efter naturvårdsgallringmedan antalet vedsvampar minskar

Många arter som är knutna till öppna och halv-öppna ekskogar och ekhagar, men under det se-naste århundradet har de flesta ekrika hagar ochskogar vuxit igen och blivit för mörka för dessaarter. För att bevara många utrotningshotadearter, vore det önskvärt att dessa skogar öppna-des upp igen och betades med t ex nötkreatur.Detta skulle bli dyrt, och frågan är om inte detfinns andra möjligheter att komplettera den re-lativt dyra skötseln som idag görs inom mycketbegränsade arealer, inte minst i naturreservat.Därför startades det ett projekt med fokus pånaturvårdsgallringar i ekskogar, och deras ef-fekt på biologisk mångfald. Gallringarna görs isyfte att utvinna biobränsle, vilket ger en in-komst för markägaren, samtidigt som art-grupper, som missgynnas av igenväxning fåren möjlighet att bevaras och/eller nyetableras.Vid naturvårdsgallringarna sparades de gamlaekarna, medan yngre träd togs ut för biobränsle.I varje ekskog inventerades två 100 x 100 mstora ytor, en gallringsyta och en referensyta,före och efter gallringen. Antalet kärlväxter och

Sammanfattning

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vedlevande lavar ökade efter gallringen, anta-let vedlevande mossor förändrades inte, och an-talet vedlevande svampar minskade. Samman-taget ökade artmångfalden tack vare gallringen,särskilt om man räknar med andra artgruppersom inte studerades i denna avhandling (mark-mossor, skalbaggar och svampmygg).

Arter med liknande ekologi visarsamma mönster i artrikedom

Artrikedom av olika artgrupper kan samvarieraöver ett landskap. Om två artgrupper är bådatvå artrika på ett ställe och artfattiga på ett an-nat ställe, och i övrigt varierar på liknande sätt,kallar man detta för samvariation. Artrikedomenav naturvårdsintressanta arter bland de fyra stu-derade organismgrupperna samvarierade svagteller inte alls bland de 25 ekrika skogarna. Svagsamvariation (mellan lavar och mossor; mel-lan kärlväxter och vedlevande svampar) varrelated till likartade krav på livsmiljöer och lik-artad spridningsekologi, medan artrikedomenav artgrupper som hade mycket olika ekologiinte samvarierade alls. Stark samvariation mel-lan artgrupper verkar vara en sällsynt förete-else och en orsak kan vara att artgrupper sällanhar lika krav på sina livsmiljöer och skiljer sigofta med avseende på spridningsförmåga.

Antalet signal- och rödlistade artersamvarierar inte i ekskogar medhöga naturvärden

I Sverige och andra nordiska länder användssignalarter – tillsammans med ett antal skog-liga strukturer såsom död ved och gamla träd –för att hitta rödlistade (hotade) arter. Om detfinns ett starkt samband mellan antalet röd-listade och signalarter, skulle signalarter ävenkunna användas för att välja ut de mest värde-fulla skogarna (med flest rödlistade arter), in-för exempelvis naturreservatsbildning, blandskogar med höga naturvärden. Vid utvärderingav signal- och rödlistade arter av tre organism-grupper av kryptogamer fanns inget sambandnär artgrupperna (lavar, mossor, vedsvampar)testades ihop. Däremot samvarierade antaletsignal- och rödlistade arter när lövskogs-beroende lavar testades separat, men samban-det var svagt. Därför drar jag slutsatsen att

signalarter, om flera organismgrupper användsihop, inte kan användas för att välja ut de mestvärdefulla ekskogarna till naturvårdsändamål.Möjligen skulle antalet signalarter av lavarknutna till lövskogar kunna användas för ända-målet, men sambandet var som nämndes –svagt.

Skoglig naturvård på landskapsnivå

Eftersom signalarter förmodligen inte är till-räckligt effektiva mätare på antalet rödlistadearter i ekskogar (förutom möjligtvis lavar), ärfrågan om inte det finns bättre sätt att finnaområden med rödlistade arter. Eftersom anta-let rödlistade arter är beroende av mängden löv-skogar i landskapet, föreslår jag att artbevarandesnarare bör utgå från landskap som enhet i prak-tisk naturvård, istället för enskilda skogsbeståndpå basis av antalet signalarter. Utifrån mina re-sultat föreslår jag att en potentiellt meningsfullskala för detta ändamål kan vara 300 km2 förlavar, 80 km2 för mossor och 3 km2 för kärl-växter och vedlevande svampar. I dessa land-skap bör man maximera mängden ekrika löv-skogar. Jag föreslår också att restaurering avigenvuxna ekbestånd till ekhagar eller betadeekskogar görs företrädesvis i dessa landskap,och att dessa åtgärder kompletteras mednaturvårdsgallringar där restaurering inte ärmöjlig och framförallt i övriga delar av Sverige.Jag föreslår att 80-90 % av de ekrika skogs-typerna naturvårdsgallras eller sköts somekhagar/betade ekskogar och 10-20 % lämnasför fri utveckling. Den höga andelen gallringarmotiveras av att det finns ett flertal arter – fram-förallt skalbaggar och lavar – som är beroendeav ljusöppna skogar och som idag inte har an-dra alternativa livsmiljöer än trädklädda hagar,medan t ex vedsvamparna även kan finna lämp-liga växtmiljöer i lövskogstyper utan ek. Det ärmycket viktigt att ingreppen görs med fokus påatt maximera naturvärdena och på att bevaradenna skogstyp för framtiden. Uttagen får intebli ett självändamål. Det är också nödvändigtatt andra typer av nyckelbiotoper utan ek, läm-nas för fri utveckling och att följderna avnaturvårdsgallringar i de ekdominerade nyckel-biotoperna följs upp på längre sikt och pålandskapsnivå.

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1. IntroductionOak-rich temperate forest is a disproportio-nately species-rich forest type that in Europemainly occurs as more or less isolated remnants.For example, in many areas in south-easternSweden up to 95 % of the old oaks were cutduring the 18th and 19th century (Eliasson 2002).In addition, the forest structure of oak-richforests has changed because of a lack of naturaldisturbance regimes such as flooding, fire andgrazing by large mammals (Rose 1992). Ingeneral, the forests are now denser and darkerthan a century ago (Nilsson et al. 2005). Thechange in forest structure is considered as acause of widespread species decline in oakforests (Rose 1992).

Belyea & Lancaster (1999) consider threemajor factors that define local communityassembly: dispersal constraints, environmentalconstraints and internal dynamics. Species di-spersal is constrained by the amount of suitablehabitat available in the landscape (Fahrig 2003;Hanski & Gaggiotti 2004). Thus the loss of ha-bitat is a serious threat to species living in parti-cular habitat types (Fahrig 2003; Meffe & Carr-oll 2005), but species may respond to habitatloss at different spatio-temporal scales depen-ding on their life history traits, especially disp-ersal characteristics. To better understand theeffects of habitat loss for biodiversity in generaland if necessary, to halt its effects, it is importantto understand which landscape scales are of im-portance for different species.

Local environmental factors is one of theconstraints for a community of species (Belyea& Lancaster 1999). Some environmental factorsare not easily influenced by man, for exampletemperature and soil-pH, while other factors,e.g. forest structure may change substantiallythrough time because of human impact. Eventhough the oak forest and the associated di-sturbance regimes are natural from a long-termperspective (Lindbladh et al. 2000), the presentstructure of old oak-rich forests is strongly in-fluenced by historical factors such as wood de-mands for ship-building and grazing regimes.A large proportion of the species found in theSwedish oak forests depend on relatively openor semi-open conditions that were common ingrazed or wind- and fire-disturbed forests. After

the abandonment of grazing in forests for 50–100 years ago the forests became denser, andmany species have decreased and are today atrisk of extinction. Increasing the light pene-tration to the old oaks, e.g. by cutting trees inbetween the oaks, could potentially reverse thecurrent negative trend for biodiversity. Openingof the forest may also be critical for oak re-generation, as there is now widespread lack ofoak seedlings in dense forest (Götmark 2007).With increasing national and international in-terest in biofuel extraction, i.e. harvesting treesof thinner dimensions as an energy resource,conservation efforts could potentially be com-bined with sustainable forestry practices. Thispossibility has not previously been exploredexperimentally.

Nature conservation and forestry authoritiesat international, national and regional levelsseek and attempt to produce long-term con-servation strategies. It is important that usefulscientific knowledge is translated into practicein a way that conservation efforts may be carriedout in the best and most efficient way. For ex-ample, accurately locating areas of highestconservation value is of great importance. Thismay be done by comparing surveys of total spe-cies richness or surveys of threatened species(Red Data Book species) for various areas, butsuch surveys are time consuming and thereforeexpensive. Species indicators of high con-servation value are in use, but have rarely beenscientifically evaluated.

My thesis focuses on species conservationat regional level. I study the richness of fourorganism groups, vascular plants, lichens, bryo-phytes and wood-inhabiting fungi, in 25 oak-rich forest stands located in southern Sweden.In addition to local species richness, I use therichness of Red Data Book species as animportant measure of conservation value of aforest stand, since these are key species for ma-intaining the regional species richness. The usedRed Data Book species are nationally listed asthreatened (Gärdenfors 2005) according tocriteria developed by the World ConservationUnion (IUCN). I also measure the richness ofIndicator species as a proxy for high con-servation value. The Indicator species (or ‘signalspecies’ in Swedish) that I study are used in theSwedish Woodland Key Habitat inventory,

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which aims at locating forest stands with highconservation value. By definition, a WoodlandKey Habitat is a forest where Red Data Bookspecies occur or probably occur (Nitare & No-

rén 1992). The list of Indicator species wasestablished by the Swedish National Board ofForestry (Norén et al. 1995) to be used togetherwith aspects of forest structure as indicators of

Explanations of ecological termsBiodiversity = a general term including diver-

sity of species, genes, habitats, landscapesetc.

Forest type = a forest with defined characte-ristics such as a typical tree species com-position

Deciduous forest = Forest mainly consistingof trees that drop their leaves in the autumn

Habitat = an area that supports the needs ofan organism, i.e. a suitable environmentfor that species

Habitat patch = a patch of habitat, for examplea forest stand for forest-living species

Habitat loss = the decrease of habitat regard-less how the configuration of habitat is aff-ected

Habitat fragmentation = the configuration ofhabitat is changed towards a larger numberof small habitat patches, the amount of ha-bitat is not affected; the term is also comm-only used broadly for simultaneous habitatloss and fragmentation

Species richness = species number or spe-cies density collectively

Species density = species number/area unitSpecies occupancy = species presence (in

contrast to species absence)Species abundance = amount/frequency of a

speciesIndicator species = species that indicate pre-

sence of other species/species groups orenvironmental conditions

Signal species = indicator species as used inthe Key Habitat Inventory, these speciesare expected to indicate presence of RedData Book species

Red Data Book species = species at risk ofextinction to various degree according tocriteria developed by the World Con-servation Union (IUCN)

Population = a group of organisms of thesame species living together within a com-mon area at the same time

Population dynamics = change in size of apopulation due to reproduction, dispersaland extinction

Viable population = a population that persistsin the long run

Metapopulation = a number of populationsinteracting with one another through dis-persal between distinct patches of habitat

Life history trait = characteristics of a spe-cies, e.g. age, amount of dispersal units,extinction rate etc., influencing the spe-cies population dynamics

Spatial scale = a scale with area as unit, e.g.a small spatial scale consists of a smallarea

Temporal scale = time scaleSpatio-temporal scale = combination of area

and time scaleWoodland Key Habitat (WKH) = a forest area

of high conservation value, i.e. Red DataBook species occur or are expected tooccur,

Extinction debt = a species have an extinctiondebt when it still persists in a recently frag-mented landscape that no longer supportsits long-term existence

Epiphytic = ‘living on plants’, in this thesis‘living on bark’

Epixylic = living on dead woodSaproxylic = wood-decaying

Some Swedish-Englishtranslations:Lichens = lavarBryophytes = mossorWood-inhabiting fungi = VedsvamparAscomycetes = sporsäcksvampar, t e x. skål-

och kärnsvamparVascular plants = KärlväxterHerbaceous vascular plants = örtartade kärl-

växterRuderal species = ruderatväxter, dvs växter

som trivs i störda miljöerFungus gnats = svampmygg

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valuable forests.In this thesis I address four main questions

that aim at 1) describing ecological patterns ofbiodiversity and 2) understanding the processesunderlying these ecological patterns:

– How are different species groups affectedby habitat loss? Which species show time delaysin their response to changes in the landscape,and may thus suffer from an extinction debt?What are the most important landscape scalesfor species differing in their life history traitssuch as dispersal distance and local extinction?

– How do different species groups respondto partial cutting with combined goals of con-servation and sustainable forestry (biofuel ex-traction)?

– How well is the species richness of diffe-rent species groups correlated to one another atthe forest stand level? How are the correlationsand absences of correlations related to the spe-cies life history traits, and environmental con-straints at local and landscape scales?

– How well is the species density of Indicatorspecies correlated to the species density of RedData Book species? Are Indicator species usefulin prioritising oak-rich forests for conservation?

In addition, I consider how the results of thisthesis can be used as a basis for recommen-dations and advice in practical nature conser-vation:

– Given limited resources for conservation,how do we best organize the conservation ofoak-rich forests in Southern Sweden?

My doctoral thesis is a part of the researchconducted within the Oak Forest ResearchGroup at the Göteborg University, which is stud-ying conservation biology in relation to foreststand management (partial cutting or absenceof it) and landscape ecology for seven differentorganism groups (vascular plants, bryophytes,lichens, fungi, beetles, fungus gnats (Diptera,mycetophilids), and terrestrial molluscs). From2000–2007, the group mainly consisted of FrankGötmark, Björn Nordén, Heidi Paltto, NiklasFranc, Bjørn Økland and Ted von Proschwitz.In addition, many undergraduate students andassistants have contributed with valuable workand help.

2. MethodsI briefly summarize the methods, for details seethe Methods sections of individual papers.

2.1. A theoretical study of landscapeeffects (paper I)

By using a ‘focal species landscape study’ app-roach I systematically explored what effecthabitat amount in a landscape had on 18 hypo-thetical species with different dispersal and ext-inction characteristics. The average dispersaldistance, but not the amount of dispersal unitsper time (colonization rate), was varied amongthe species. Thus, I consequently refer to ave-rage dispersal distance below when I use exp-ressions such as ‘inferior’ and ‘superior’ at disp-ersal, or ‘mobile’ and ‘less mobile’ species.

A spatially explicit grid-based metapop-ulation model that simulates habitat loss wasconstructed, and was run 200 times for eachspecies, one at a time. Initially the whole grid(500 × 500 cells) represented suitable habitatfor the focal species, but during the simulationabout 1 % habitat was lost per time step (year).The habitat loss was stochastic and varied great-ly among time steps and among runs. New habi-tat patches were never created during the simu-lation. In the beginning of a run the model spe-cies occupied all the grid cells, and thereafterthe population dynamics was adjusted for diff-erent species by changing mean values for ave-rage dispersal distance and extinction risk.There-upon I related ‘current’ species occu-pancy in a focal habitat patch in the fragmentedland-scape (5 % habitat remaining) to the a-mount of habitat in the surrounding landscapeat varying points back in time and at varyingspatial scales.

2.2. Empirical studies (papers II–VI)

The empirical studies (papers II–VI) were basedon field surveys in 25 oak-rich temperate forestsin Southern Sweden (Fig.1) or a subset thereof.The forests were situated >15 km apart fromone another. The study sites were former oakwoodland pastures or oak meadows abandoned

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1. Skölvene 14. Aspenäs2. Karla 15. Norra Vi3. Östadkulle 16. Fröåsa4. Sandviksås 17. Ulvsdal5. Rya åsar 18. Hallingeberg6. Strakaskogen 19. Ytterhult7. Bondberget 20. Fårbo8. Långhult 21. Emsfors9. Bokhultet 22. Getebro10. Kråksjö by 23. Lindö11. Stafsäter 24. Lilla Vickleby12 Åtvidaberg 25. Albrunna lund13 Fagerhult

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1. Skölvene 14. Aspenäs2. Karla 15. Norra Vi3. Östadkulle 16. Fröåsa4. Sandviksås 17. Ulvsdal5. Rya åsar 18. Hallingeberg6. Strakaskogen 19. Ytterhult7. Bondberget 20. Fårbo8. Långhult 21. Emsfors9. Bokhultet 22. Getebro10. Kråksjö by 23. Lindö11. Stafsäter 24. Lilla Vickleby12 Åtvidaberg 25. Albrunna lund13 Fagerhult

Fig. 1. Map of southern Sweden and the 25 study sites with oak-rich temperate forest. Reproduced fromFranc (2007) with kind permission from the author.

50–75 years ago, and were characterized byremnant large oaks (the oldest at each site 80–250 years old) and other broadleaved/coniferoustrees of smaller dimensions. They all had highconservation value for nature conservation andhave been designated as nature reserves (n = 7)or Woodland Key Habitats (WKHs, n = 18). In

each stand, two plots (each 1 hectare) were de-limited. One of the plots was partially cut inthe winter 2002/2003, while the other was trea-ted as a non-intervention control plot.

For the landscape study (paper II) and theindicator study (paper VI), species data frombefore partial cutting was used from six diffe-

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rent inventories: (1) epiphytic Red Data Bookand Indicator species (bryophytes and lichens),(2) forest floor bryophytes and lichens; (3) epi-xylic bryophytes and lichens and (4) epiphyticbryophytes and lichens on the largest oak trees;(5) wood-inhabiting fungi and (6) forest floorherbaceous vascular plants. In the landscapestudy the local species density of Red Data Bookand Indicator species of vascular plants, lichens,bryophytes and wood-inhabiting fungi were cor-related to one another, and related to landscapeand local data using regression analyses (n =22 study sites). Only species typical of deci-duous forests were included in the analyses (i.e.species mainly occurring in coniferous forestswere excluded). The Indicator species of vasc-ular plants were mainly long-lived forest spe-cies with clonal growth and relatively largeseeds. In the Indicator species study the dens-ity of Red Data Book species, Indicator spe-cies and total species richness of lichens, bryo-phytes and wood-inhabiting fungi were relatedto one another using correlation analyses (n =25 study sites).

For the evaluation of partial cutting (papersIII, IV and V), species data from before andafter cutting were used. Paper III evaluated theeffect of partial cutting for vascular plants (n =6 study sites), paper IV evaluated the effect forepixylic bryophytes and lichens (n = 15 studysites), and paper V evaluated the effect forwood-inhabiting fungi (n = 21). Throughout thethesis the term”species of conservation con-cern” refers to Indicator & Red Data Book spe-cies, as treated collectively.

3. Species groups andtheir responses to habitatchanges at different spatio-temporal scales(Papers I and II)Widespread habitat loss is a landscape scaleprocess that has negative consequences for spe-cies living in the habitat type in question (Fahrig2003). The species become extinct from the losthabitat fragments, and may also decrease in theremaining habitat if the habitat quality decreases

or the species is dispersal limited (Saunders etal. 1991; Eriksson & Ehrlén 2001; Hanski &Gaggiotti 2004; With 2004). Around the oak-rich forests studied in this thesis the averageloss of deciduous forest area was 26 % duringthe last 120 years (within circles of 5 km radius;paper II). Around 16 of the study sites the areaof deciduous forest decreased, while it increasedaround six sites.

An important question is how habitat changesat landscape level affect different species andspecies groups, and what mechanisms cause thedifferences among these species. Species differin their life history traits, which probably isimportant for their capability of resisting theeffects of habitat loss (Ewers & Didham 2006).Especially their dispersal ability is importantsince the population dynamics at landscapelevel is restricted by dispersal and by esta-blishment at new sites. I tested empirically thelandscape effects for four different organismgroups (paper II) using a study design called‘focal patch landscape study’ (Brennan et al.2002; Fig. 1, paper II). This method is used tostudy the relationships between species occu-pancy/abundance or species richness and habitatamount in a landscape. In such analyses currentspecies occupancy/abundance or species rich-ness in a focal habitat patch is related to the a-mount of habitat in the surrounding landscapeat various spatial scales (eg. in circles of diffe-rent radii around the focal patch) or at varioustemporal scales (current and historic amountsof habitat). However, the lack of historic dataof sufficiently good quality is an obstacle forthe analyses and for drawing general con-clusions from such studies. This is the caseespecially for studies exploring the length oftime delays in species responses to landscapechanges, which would need long time series ofhistorical habitat data. In addition, the inter-actions of spatial and temporal scales in speciesresponses are largely unexplored in a theoreticalperspective. Therefore, I complemented the em-pirical study (paper II) with a modeling app-roach exploring the effects of species’ dispersaland extinction characteristics on their responsesto landscape (paper I).

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Fig. 2. Oak-rich forest beforeand after partial cutting at thestudy site Norra Vi. Thephotographs are taken at thesame point at the samedirection.Photographer: Frank Götmark.

Before partial cutting 2002

After partial cutting 2003

After partial cutting 2006

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3.1. Lichens and bryophytes weredependent on habitat in largelandscapes, while vascular plantsand wood-inhabiting fungiresponded to small landscapes

Dispersal influences the species’ capability towithstand habitat loss (Clobert et al. 2004). Inthe metapopulation model used in paper I, anincrease in the average dispersal distance of aspecies enhanced its survival probability inlandscapes undergoing fragmentation. When 5% habitat remained in the landscape, the occu-pancy of species superior at dispersal in thefocal habitat patch were better explained by theamount of habitat at large landscape scales com-pared to species with shorter average dispersaldistance (Fig. 2, paper I). The results from theempirical landscape study dealing with speciesof conservation concern (paper II) can be inter-preted in the light of these results: Bryophytesand lichens, which responded to the amount ofhabitat at large spatial scales (1–5 km or 1–10km), are probably better at dispersal than vasc-ular plants and wood-inhabiting fungi, whichresponded to the landscape at 0–1 km scale.Also other empirical studies suggest that diff-erent species or species groups respond to diff-erent spatial scales, e.g. birds and terrestrialmollusks may be most dependent on the amountof habitat at large scales (5–10 km; Bailey etal. 2002; Götmark et al. 2008, in press), beetles,and Diptera on an intermediate scale (1–5 km;Chust et al. 2004; Holland et al. 2004), and vasc-ular plants, beetles, mycetophilids (Diptera:Sciaroidea) and Homoptera on a small scale (0–1 km; Bailey et al. 2002; Chust et al. 2004; Holl-and et al. 2004; Økland et al. 2005; Franc et al.2007).

The response of vascular plants to small spa-tial scales was expected since the species in thisgroup mainly consist of typical ‘forest’ or ‘anc-ient forest’ species with long life span, clonalgrowth and relatively large seeds (Honnay etal. 1998; Hermy et al. 1999; Kolb & Diekmann2005). Similarly, it may be reasonable that lich-ens and bryophytes, of which many dispersewith small airborne and plentiful spores, arebetter at dispersal. Also the Indicator and RedData Book lichen Lobaria pulmonaria, foundat our study sites, seems to be relatively good

at dispersal (Werth et al. 2006; Werth et al.2007). However, few comparative studies of di-spersal distances for different species groupshave been carried out.

The response at a small spatial scale forwood-inhabiting fungi was the least expected,since fungi often are considered as relativelygood at dispersal (Nordén & Appelqvist 2001).On the other hand, Sverdrup-Thygeson andLindenmayer (2003) found that the occupancyof one wood-inhabiting fungi (listed as a RedData Book species) was explained by the a-mount of habitat in the surrounding landscapeat an even smaller landscape scale than in mystudy. In addition, this species showed delayedresponse to the amount of habitat in the land-scape, which indicates that the species has rela-tively short-distance dispersal. The possible di-fference in dispersal between lichens and bryo-phytes, on one hand, and wood-inhabiting fungi,on the other hand, might be explained by diff-erences in their dispersal ecology. In additionto spores, many lichens and bryophytes disperseby asexual propagules much larger than spores,which may be more easily dispersed by animalscompared to spores. Fungi do not have this typeof dispersal. However, whether these diff-erences can explain the differences in my studyor not, remain untested. In addition, somegroups of epiphytic lichens may also be inferiorat dispersal, since they are better explained bythe habitat amount at small landscapes and alsoshow delayed responses to habitat changes (Ellis& Coppins 2007).

3.2. Vascular plants and wood-inhabiting fungi showed a time delayin their responses to landscapechanges

Species responses to habitat changes often occurafter a time delay, especially if the species arelong-lived or they are near their extinction thres-holds (Ovaskainen & Hanski 2002). A long-lived species can persist a long time in a localhabitat patch with little interaction with otherindividuals of the same species in other patches.In contrast, the time delay in a species responseto increasing amount of habitat in the landscapemay be mainly caused by limitation in the spe-cies dispersal. But for most species, both

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dispersal and extinction characteristics may beimportant for the length of the time delay intheir response to changes in landscape.

A time delay in a species’ response followinghabitat loss may also be linked with a delay inextinction, if the amount of habitat in the currentlandscape does no longer support the occurrenceof the species, and this is called extinction debt(Tilman et al. 1994). Shortly after habitat loss,delay in local extinctions should result in over-saturation of species in habitat patches. Afteran increase of the habitat in the landscape, slowdispersal should result in under-saturation, untila new equilibrium is reached. It is possible toexplore the presence of time delays by analysingspecies’ responses or relation to current versushistoric amount of habitat. A stronger species’response to historic compared to current amountof habitat (at a certain spatial scale) is an indi-cation of their slow response to temporal chang-es and this is often interpreted as a delayed resp-onse, or possibly an extinction debt if the land-scape has experienced habitat loss.

In the metapopulation modelling study, onlyone species showed a clear effect of habitat a-mount in the landscape in combination with aclear time delay to changing amount of habitat(Fig. 2g, paper I). This species had an inter-mediate dispersal capacity and I suggest thatthe reason for the time delay may be a near-extinction-threshold effect, since the species de-clined substantially during the simulation of ha-bitat loss. For species inferior at dispersal (Fig.2a, b, c, paper I) the overall landscape effectswere weak, but the length of the time delaysincreased clearly with decreasing local ext-inction risk, as predicted by theory (Ovaskainen& Hanski 2002). In contrast to the speciesshowing clear time delays, the time delays,especially at the largest landscape scale, werehardly detectable due to low R2-values, andwould probably be interpreted as lack of land-scape effects in empirical studies. This type ofweak landscape responses may be typical ofspecies showing ‘remnant population dynamics’(Eriksson 1996), e.g. by long-lived, often clonalplants with large seeds. These hardly detectabletime delays in species responses may possiblyexplain the lack of landscape effects in someempirical studies of vascular plants (Cousinset al. 2007; Öster et al. 2007). In conclusion,

species with low extinction rates, e.g. due totheir long life lengths, may suffer from an ext-inction debt that is difficult to detect in em-pirical studies such as ‘focal patch landscapestudies’.

In the empirical study (paper II) the vascularplants and wood-inhabiting fungi showed timedelays in their responses to habitat change inthe landscape, and thus these may be linked witha risk of an extinction debt. The reason may bea low extinction risk or a near-threshold effectfor the species within the organism group . Thevascular plants in this study are long-lived, thusthe first explanation may be appropriate. Theexplanatory power of the regression model wasmuch higher for the wood-inhabiting fungi (R2

= 0.78 compared to R2 = 0.40 for vascularplants; paper II) and their response alsootherwise resembled the response of species (g)in paper I (Fig. 2), which could indicate thatthe fungi rather are near their extinction thres-hold than long-lived and inferior at dispersal.It is also possible that the delayed response forwood-inhabiting fungi in the current study isan effect of a delay in substrate (dead wood)production compared to the dynamics of livingtrees, see paper II for further discussion of thispossibility.

Also other studies found that species orspecies groups are better predicted by historicalthan current amount or connectivity of habitatin the landscape: the species richness of vascularplants in semi-natural grasslands (Lindborg &Eriksson 2004; Helm et al. 2006), one polyporefungi (Sverdrup-Thygeson & Lindenmayer2003), epiphytic lichens in aspen forests (Ellis& Coppins 2007), and rainforest fauna (Grahamet al. 2006). However, these studies do not exp-licitly discuss differences in responses of diff-erent groups of species, with respect to differentspatio-temporal scales of landscape included inthe studies.

3.3. Red Data Book species wereaffected by the landscape, whileIndicator species were not

Two species groups often used in Swedish for-est conservation are Red Data Book species (i.e.threatened species) and Indicator species ofwich the latter are supposed to indicate presence

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of Red Data Book species. The densities of RedData Book and Indicator species were low, andtherefore I pooled data for four organism groups(vascular plants, lichens, bryophytes and wood-inhabiting fungi) to be able to test their depend-ence on the amount of habitat at landscape level.The density of Red Data Book species per studysite (n = 22 study sites) was affected by the a-mount of deciduous forest in the landscape atthe 1–5 km scale, while the Indicator specieswere not affected by the landscape factors atall. One reason for the lack of landscape effectfor Indicator species may be the difference inthe ecological amplitude between these twogroups: The Red Data Book species arenarrower in their substrate requirements whilethe Indicator species include a broader rangeof species with contrasting ecology (paper II).See further discussion on how species ecologyand dependence of landscape may be related insection 5.

The scale of importance for Red Data Bookspecies was 1–5 km, i.e. a scale intermediateof the scale important for lichens (1–10 km)and wood-inhabing fungi (0–1 km), whichsounds reasonable since both groups are in-cluded in the Red Data Book species in aboutequal frequencies. (Only one Red Data Bookspecies of vascular plants and bryophytes eachwas found).

3.4. Landscapes and ecologicalcontinuity

Long ecological continuity of forests has beensuggested to be an important factor for bio-diversity, and indicator species for long eco-logical continuity has been used by conser-vationists to find valuable forests for conser-vation. However, the term ‘ecological conti-nuity’ remains poorly defined, and includes oft-en aspects of both forest age and true ‘conti-nuity’. Ecological continuity is often referredto as local continuity at stand level, and can bedefined as the length of time a forest have hada typical old-growth forest structure (Nordén& Appelqvist 2001). Landscape level continuityhas also been discussed (Nordén & Appelqvist2001) and in this case, the continuity of habitatat landscape level is addressed regardless of thelocal continuity of individual forest stands. In

a dynamic land-scape with forest fires or otherdisturbance regimes, landscape continuity maybe more decisive for species long-term per-sistence than local continuity.

The historical landscape was important toexplain the richness of vascular plants andwood-inhabiting fungi of conservation concern,which can be interpreted as these organismgroups depend on ecological continuity at somelandscape level. In contrast, local ecologicalcontinuity seems not to be important for rich-ness of the studied groups (Röstell 2006). Incontrast, landscape continuity did not determinespecies richness of lichens and bryophytes ofconservation consern at the spatial scales mea-sured in paper II. Although it is probable thatthe continuity at larger spatial scales could beimportant for these species groups.

4. Effects of partial cutting/biofuel harvest for differentspecies groups(Papers III, IV and V)Oak forest is a disproportionately species richforest type in southern Sweden as compared toother forest types (Ranius et al. 2001). Reasonsfor this may be the large size and the high ageof oaks compared to other trees, hence theyprovide a wide range of microhabitats such asbark structures, large hollows and special qua-lities of dead wood (Rose 1974; Pihlgren 2000).Many insects, lichens, fungi and birds are de-pendent on these structures for their survival(Thor 1998; Ranius et al. 2001). But the bio-diversity of oak forests is seriously threateneddue to habitat loss and decreased structural di-versity in the remaining forest remnants.

Oak was one of the most common trees insouthern Sweden and elsewhere in Europe du-ring the postglacial time (Lindbladh et al. 2000).The openness of the primeval temperate forestsis debated, with arguments for closed forests(Ellenberg 1988; Peterken 1996; Mitchell2005), and for more open forest structure (An-dersson & Appelqvist 1990; Nilsson 1997; Vera2002). Regardless of the primeval conditions,humans were the cause of oak forest opennessin southern Sweden and in Europe in historical

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time, i.e. during the last about 5000–10 000years, which should have had a positive effecton species dependent on oaks standing in lightor semi-light conditions. Due to ceased grazingand secondary succession during the last 50–100 years, the oak forests have become signi-ficantly denser, which seems to be a seriousthreat for the biodiversity of oak forests (Nilssonet al., 2005).

Traditionally, conservation of biodiversityhas been a matter for the state in Sweden, andit has been a political question how expensivenature conservation is allowed to be and whoshould pay for short-term costs. Better know-ledge about species ecology is important, but itis also important to evaluate new conservationconcepts including significant benefits for hu-man being. If biodiversity in oak forests benefitsfrom increased canopy openness, some cuttingin the forests could be desirable. Further, thiscould potentially be combined with extractionof woody material for biofuel production. Anincome from some cutting should be a bettermotivation for forest owners to conduct con-servation action compared to traditional ‘hands-off’ state conservation. This motivation haspotential to result in cuttings in regionally muchlarger scales than pure conservation actionsfinanced by the limited budgets of conservationauthorities.

The interest in biofuel extraction has in-creased during the last 10–15 years. Today about20 % of the energy consumption in Sweden con-sists of biofuels, of which 85 % comes fromthe forest. The amount of biofuel is predictedto increase with about 80 % until year 2020(Skogs-Eko 1997). However, except for the ex-traction of tree tops and branches of coniferoustrees, little research has been conducted on theeffects of forest fuel harvest on biodiversity. Ifconducted with care and evaluated in the long-term, biofuel extraction in dense oak forestsmay result in benefits for both conservation andforest production (Skogsstyrelsen 2001).

Although species richness of epiphyticlichens and wood-depending beetles may beexpected to respond positively to partial cutting,it is important to evaluate the effects on a broadrange of organism groups. It is possible thatsome groups would be disfavoured by openingof canopies even if it is done carefully. I quan-

tified short-term effects of partial cutting on vas-cular plants (paper III), lichens and bryophytesliving on dead wood (paper IV) and wood-in-habiting fungi (paper IV).

4.1. Vascular plants and wood-inhabiting lichens increased afterpartial cutting, while the wood-inhabiting fungi decreased

The species richness of vascular plants (paperIII, Table 2) and lichens on stumps (paper IV,Fig. 2b) increased due to the partial cutting.Lichens and bryophytes on logs, bryophytes onstumps, and wood-inhabiting ascomycetes werenot significantly affected (paper IV, Fig. 2a and2b; paper V; bryophytes on stumps showed anear significant decrease, p = 0.058). Thespecies richness of wood-inhabiting basidio-mycetes decreased due to cutting (paper V), tho-ugh the decrease was smaller than between-yearvariation in the reference plot.

Several ruderal species among the vascularplants increased in abundance, but the most ofthe changes occurred in grassland and forestspecies. The epixylic species composition shift-ed towards a flora typical for dryer dead wood.For vascular plants and lichens on stumps, thetwo groups that clearly increased due to cutting,the increase was caused by increased coloni-sation, while the extinction rates were not aff-ected. For the wood-inhabiting fungi, the de-crease was significant for species living on finewoody debris, while species richness on coarsewoody debris was unaffected. The number ofRed Data Book species was too low to be testedone organism group at a time.

Also the animal groups studied at the sameoak-rich study sites varied in their responses topartial cutting. Wood-inhabiting and herbi-vorous beetles were favoured in species richness(Franc 2007; Franc & Götmark 2008); the spe-cies richness of Red Data Book species of wood-inhabiting beetles was unaffected, but regress-ion analyses suggest that opening of forest cano-pies by more than in the current cutting woulddisfavour this group of species. Species richnessof fungus gnats was not affected (Økland et al.2008, in press).

In conclusion, the richness of three organismgroups (vascular plants, lichens and wood-in-

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habiting/herbivorous beetles) clearly increaseddue to the partial cutting as expected. One groupdeclined (wood-inhabiting basidiomycetes) andthree groups were not significantly affected(wood-inhabiting bryophytes, wood-inhabitingascomycetes and fungus gnats). The main trendis thus an increase in species richness after part-ial cutting.

5. Relationships amongorganism groups(Papers II and VI)An Indicator species is a species indicating pre-sence of another species, a set of species, a spe-cies community, or environmental condition(Ferris & Humphrey 1999). Indicators of bio-diversity may be useful in conservation, if thetarget group of species or species richness isdifficult or time-consuming to investigate incomparison with the Indicator species or Indi-cator species group. For example, well-knownspecies groups may act as indicators of lesswell-known species groups, or conspicuousspecies may act as indicators of small or crypticspecies. In this thesis I have evaluated therelationships among the species groups studiedand their usefulness as indicators for selectionof conservation areas.

5.1. Correlations among speciesgroups are weak or absent

The species richness of three organism groupsin oak-rich forests was tested pair-wise withcorrelation analyses, using sites as statisticalsample units (paper VI). The number of bryo-phytes increased with increasing number ofwood-inhabiting fungi (non-parametric boot-strapping r = 0.37; p = 0.021; n = 25), whilespecies richness of lichens was not related tothe richness of the other two groups.

Correlation analyses among four organismgroups with respect to the number of species ofconservation concern (deciduous forest Indi-cator and Red Data Book species pooled; onlyspecies confined to deciduous forests included)revealed no significant correlations (paper II).Two of the correlations were near significant

(bryophytes–lichens: Spearman r = 0.41; p =0.060; n = 22; and vascular plants–wood-inhabiting fungi: Spearman r = 0.37; n = 22; p= 0.094).

Overall, the correlations between differenttypes of richness-measures were weakly posi-tive or absent (see above, and papers II and VI).This corresponds well to the general trend incorrelation tests between different speciesgroups (reviewed by Wolters et al. 2006). Thecorrelation coefficients in the reviewed studiesare on average 0.374 (both significant and non-significant correlations included), which corre-sponds to a degree of explanation as low as 14% (Wolters et al. 2006). The correlation co-efficients for the significant correlations foundin this thesis were of about the same magnitude(0.37–0.42). Only 1/3 of all correlations in thereview (n = 152) were significant, which corre-sponds well with the results in this thesis. Thequestion is why the correlations among differentspecies groups often are weak, and con-sequently, if Indicator species are useful in con-servation work.

The richness of different organism groupsmay be correlated for several reasons: (1) ran-dom coincidence, (2) interactions between spe-cies in the various organism groups, (3) similarresponse to common factors such as soil-pH,substrate type or precipitation, and (4) responseto different environmental factors that covaryspatially (Gaston 1996). Here I will discuss thethird explanation with respect to Indicator andRed Data Book species of vascular plants,lichens, bryophytes and wood-inhabiting fungi.

5.2. Species groups with similarecology were weakly correlated toone another…

Bryophytes and lichens (Indicator species andRed Data Book species pooled; paper II) hadsimilar habitat requirements (favoured by highprecipitation) and they were related to thehabitat amount in the landscape at about thesame spatial scale (1–5 for bryophytes and 1–10 km for lichens). The species density of li-chens was predicted by the amount of WoodlandKey Habitats while the bryophytes were pre-dicted by the amount of deciduous forests ingeneral. I suggest that the similarity in the spe-

21

cies requirements explains the weak, nearly sig-nificant correlation between bryophytes and li-chens. Similarly, both vascular plants and wood-inhabiting fungi were mainly favoured by thesame environmental factors, high soil-pH andthe amount of habitat at the same spatial scale(0–1 km), thus a weak, nearly significant, cor-relation was found between these two groups.

…and species with different ecologywere not correlated at all

In contrast to the correlations presented above,no other pair-wise correlations were foundamong these four organism groups. This maybe explained by larger differences in ecologybetween the other possible comparisons of spe-cies, e.g. lichens–vascular plants.

In conclusion, an explanation to the lack ofstrong correlations among species groups maybe the fact that two species never have exactlythe same substrate requirements or dispersalecology, thus a large but not easily explainedvariation is always included in the measures ofspecies richness. In addition, stochasticity inexternal factors such as weather conditionsaffecting dispersal and extinction processes pro-bably cause additional variation in speciesdensities. The question is if the weak cor-relations among organism groups can be usefulfor practical conservation. Different organismgroups may need different conservation actions,and may only marginally be pooled to gain effi-ciency in conservation.

6. On finding goodindicators of Red Data Bookspecies (Paper VI)

6.1. What kind of species should bein focus in conservation?

An area of high conservation value, a hot spotfor conservation, is often defined as an area withhigh local species richness or presence of rareor threatened species. High local species rich-ness may arise due to several factors. One suchfactor is the naturalness of an area: a high di-versity of natural micro-habitats favours a wide

array of species. For example, an old-growthforest may be species rich because it contains ahigh number of different tree species, and deadwood of different qualities including largestumps and logs. High species richness may alsoarise due to other factors, such as high diversityof habitats surrounding a habitat patch. For ex-ample, a forest stand surrounded by several ha-bitat types may be more species rich than a fo-rest surrounded solely by one type of forest,even though the forest stands are very similar.Thus, the species in the species richer habitatmay be easily dispersed ones from many typesof habitats, especially ruderal species commonin the region.

To conserve species diversity at a regional(for example national) level, it may be ineffi-cient to conserve common species with viablepopulations. Therefore nature conservation inthe Nordic countries often focuses on regionallyrare species, especially Red Data Book species,i.e. species considered threatened (Gärdenfors2005). One rational for this conservation stra-tegy is: If we can protect many of these species,much of the regional species pool may also beconserved.

Ideally, we would conserve all areas suitablefor Red Data Book species, and areas that al-ready host Red Data Book species. However,many Red Data Book species are small, cryptic,rare and not well known by people other thantaxonomic experts. Therefore it would be easierif indicators of Red Data Book species couldbe used instead to prioritise areas for conserv-ation. A good indicator species for old-growthforests should be easy to find, easy to identify,have an even distribution across the region, andbe restricted to semi-natural or old-growth forestof conservation values (Ferris & Humphrey1999; Nitare 2000).

In the Woodland Key Habitat Inventories inNordic countries, a pre-selected group of Indi-cator species (Signal species) have been used,in combination with indicators of forest struc-ture, to find potential forests with presence ofRed Data Book species. Forests delineated inthe inventory are called Key Habitats. The se-lection of Indicator species was based on expertjudgments, without thorough scientific eva-luation. This course of action enabled the inven-tory to start very quickly, but still very few eva-

22

luations have been done on the efficiency ofthe inventory.

In addition to using Indicator species for de-lineating Key Habitats from surrounding pro-duction forests, the Indicator species themselvescould potentially be used to prioritize areas forconservation among forests of high conservationvalues. In this study, I have evaluated the Indi-cator species’ capability of indicating Red DataBook species among Key Habitats and otherforests of high conservation values, i.e. naturereserves.

6.2. Indicator species are notcorrelated with Red Data Bookspecies

Correlation analyses were carried out betweenthe number of Indicator species and Red DataBook species (bryophytes, lichens and wood-inhabiting fungi pooled; paper VI). Regardlessof whether all species or only species confinedto temperate deciduous forests were included,the number of Red Data Book species recordedwas essentially independent of the number ofIndicator species (Fig. 3a and 3b, n = 25 oak-rich forests). These results are consistent with

previous conclusions that among sites, speciesrichness for species groups with different eco-logy may not be correlated to one another. TheIndicator species had generally a broader eco-logical niche compared to Red Data Book spe-cies (paper II, Fig. 2a.), which may weaken theapplicability of them as indicators, at least ifall Indicator species, regardless of organismgroup, are pooled.

6.3. Indicator species of deciduousforest lichens are weakly correlatedwith Red Data Book species

As the next step, the organism groups weretested separately. When both species typical ofconiferous and deciduous forests were included,the number of Indicator species of lichens wasnot significantly correlated to the Red DataBook species (Fig 3c: Non-parametric boot-strapping: r = 0.37; n = 25; p = 0.067), but whenspecies confined to temperate deciduous forestswere considered separately, the number of RedData Book species more clearly increased within-creasing number of Indicator species (Fig.3d: Non-parametric bootstrapping: r = 0.42; p= 0.039). For wood-inhabiting fungi, no such

Fig 3. The relationship between the density of Red Data Book species and Indicator species (n = 25 oak-rich forests): a) all bryophytes, lichens and wood-inhabiting fungi, b) bryophytes, lichens and wood-inhabiting species characteristic for deciduous forest, c) all lichens, and d) lichens characteristic fordeciduous forest.

0

1

2

3

0 2 4 6 8

Indicator species (signalarter)

Red

Dat

a B

ook

spec

ies

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2

3

0 2 4 6 8

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Red

Dat

a B

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spec

ies

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0 5 10 15

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p = 0.067 p = 0.039

a)

c)

b)

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correlation was found. The bryophytes and vas-cular plant species were too few for meaningfultests.

6.4. The Indicator species are notvery useful in prioritising oak-richforests of conservation values

Deciduous forest lichens seem to be the onlyspecies group among the studied ones that maybe useful as Indicators for Red Data Bookspecies, although also this correlation was rela-tively weak (paper VI). The correlation is rea-sonable since naturally dry semi-open oakforests host a disproportionately large numberof both Indicator and Red Data Book lichens,and many of these lichens depend on old, largeoaks and dead wood thereof. A high density ofKey Habitats with old oaks or other deciduoustrees of high conservation quality at the land-scape level seems necessary for locally high di-versity of Indicator and Red Data Book speciesof lichens (paper II). Thus the number of thesetwo species groups could be expected to covary.In contrast, the number of indicator species andRed Data Book species of wood-inhabitingfungi were not correlated, and I suggest onemain reason for this: The Indicator species areconfined to fine woody debris (often of hazel)while the Red Data Book species grow on bothfine and coarse woody debris, i.e. the two groupsdiffer in their ecological requirements more thando the Red Data Book and Indicator species oflichens. In addition, the fungal species may beinferior at dispersal compared to lichens (paperII, see also section 3 in this thesis), and thus thedelay in their responses to habitat changes atlandscape level may weaken their relationshipto their substrate at landscape level. A third exp-lanation could be that the rare wood-inhabitingfungi are disfavoured by light and dry conditions(paper V) and may therefore have arrived latelyto the forests due to secondary succession. Theadjustment of species distribution may vary a-mong species within the group of wood-in-habiting fungi, and if the Red Data Book speciesdiffer from the Indicator species in this respect,the correlation between these two groups maybe weak. In other words, compared to wood-inhabiting fungi, the Indicator and Red DataBook species of lichens may have more similar

habitat requirements, and similar immediate re-sponse to changing substrate amounts in thecurrent landscape, explaining the stronger cor-relation between them.

The number of Red Data Book species ofvascular plants and bryophytes was very low inthe inventories carried out at the 25 study sites(only one species of each group was found).The reason for this may be the preference ofRed Data Book bryophytes to moist forests,hence oak forests may be suboptimal for these.Generally, few forest-dependent vascular plantsin Sweden are currently red-listed. Notwith-standing, many of the long-lived forest vascularplants inferior at dispersal may be doomed toextinction because of long time delays in theirresponses to large-scale habitat loss at landscapelevel. These species may not been included inthe Red Data Books, since they have not yetdecreased to alarming low levels.

In conclusion, the indicator species were notvery efficient at identification of oak-rich forestsrich in Red Data Book species. A possible ex-ception may be the group of deciduous forestlichens, although only weak correlations werediscovered. The indicator species concept forselecting very rich forests among a set of rela-tively rich sites seems too vague. But, it is stillpossible that individual species may be usefulas good indicators of Red Data Book species a-mong forests of high conservation value, e.g.the lichen species Lobaria pulmonaria (Nilssonet al. 1995).

7. Towards an approach forefficient conservation ofdifferent species groups inoak-rich forest stands(Papers I–VI)Belyea & Lancaster (1999) listed three majorfactors defining local community assembly:dispersal constraints, environmental constraintsand internal dynamics. The dispersal constraintsof species is linked to the species dependenceon habitat at landscape level, and the environ-mental constraints for cryptogam species andvascular plants consists mainly of precipitation,

24

forest structure, i.e. presence of large trees anddead wood of different qualities, presence ofboulders, and for vascular plants edaphic factorssuch as soil-pH.

One conclusion from this thesis, relevant forconservation, is that vascular plant and crypto-gam species may depend on much larger land-scapes than have been supposed by researchersor conservationists. In addition, the four studiedorganism groups have different ecological re-quirements at local and landscape level. Hence,one conservation strategy may not satisfy therequirements of all species groups.

The concept of Indicator species for indi-cating presence of Red Data Book species hasbeen extensively used in the Swedish Key Ha-bitat Inventory, together with information aboutstructural qualities of the forests. The aim hasbeen to separate sites of special conservationvalue from those without such value. As shownin the previous section and in paper VI, the in-dicator species are not very precise and usefulin separating oak-rich forests of highest con-servation value from those of lower or inter-mediate conservation value. Nevertheless, theKey Habitat Inventory identified a large numberof potential sites for species dependent uponold trees and dead wood. In addition, many old-growth forests on calcareous ground have beenidentified, which may be important for Red DataBook species of fungi.

7.2. Finding high priority landscapesfor conservation

Landscapes rich in deciduous forests are pre-dicted to be rich in Red Data Book species, andlandscapes rich in WKH:s, i.e. old-growth de-ciduous forests, are predicted to be rich in RedData Book and Indicator species of lichens(paper II). Based on my results, I suggest thatan efficient strategy would be to use the KeyHabitat Inventory, satellite data, IR-photographsand other map data for identification of land-scapes rich in deciduous forests for landscapelevel conservation. Currently, the selections ofconservation areas are often done at stand level,based on information about individual Key Ha-bitats or other surveys.

7.3. The minimum area of a highpriority landscape

The focus of conservation is currently shiftingfrom local stands as main units of conservationto a broader landscape perspective (Groom etal. 2005; SEPA & NBF 2005). Multiscaled bio-diversity planning, matrix management (Lin-denmayer & Franklin 2002; Lindenmayer et al.2006) and conservation priorities for landscapeswith large proportion of semi-natural habitats(Andersson 2002; SEPA & NBF 2005) are in-creasingly emphasized, but in most cases re-commendations about minimum landscapesizes are vague or lacking. My thesis has con-tributed to this work by pointing out some po-tentially important scales for long-term con-servation planning that preferably should spanover several centuries, since oaks may be verylong-lived. For lichens (Indicator species andRed Data Book species pooled) landscapes ofa minimum size of 300 km2 (corresponding tocircle radius 10 km) may be an appropriaterecommendation, for bryophytes the minimumlandscapes could be 80 km2 (corresponding tocircle radius 5 km) and for vascular plants andwood-inhabiting fungi 3 km2 (corresponding tocircle radius 1 km). In addition, the largest land-scape scale may be appropriate for terrestrialmolluscs (Götmark et al. 2008, in press), andthe smallest landscape scale may be appropriatefor animal groups such as wood-inhabitingbeetles (Franc et al. 2007) and fungus gnats (Øk-land et al. 2005). For beetles, the area of oak-rich Woodland Key Habitat was important,while Woodland Key Habitats with mixed (deci-duous-coniferous) forest was important forfungus gnats.

7.4. Partial cutting in oak-richforests as a tool for restoring foreststructural qualities

Some valuable species, e.g. wood-inhabitingbeetles and lichens, are restricted to semi-openor open oak forests. One probable reason fortheir recent decrease in Sweden is changedforest structure following ceased forest grazingby domestic animals. The partial cuttingexperiment showed positive short-term effectson species richness of four species groups

25

(lichens on stumps, forest floor bryophytes,vascular plants and wood-inhabiting/herbi-vorous beetles). Three species groups were notsignificantly affected (wood-inhabiting bryo-phytes, wood-inhabiting ascomycetes and fun-gus gnats) and one species group (wood-in-habiting basidiomycetes) was negatively aff-ected (though not much).

Although partial cutting increased speciesrichness of many species groups, this manage-ment option will not be suitable for all Red DataBook species. Especially some light demandingspecies may still need a degree of openness notavailable in partially cut oak-rich forests. It maybe a good suggestion to concentrate grazing inoak woodland pastures and restoration of denseoak-rich forests to oak woodland pastures, tothe high priority landscapes suggested in theprevious subsection (7.3.), while partial harv-esting in oak-rich forests may be a good com-plement to this type of conservation, and couldbe applied elsewhere in the landscape.

My suggestion is to carry out partial harv-esting (or pure conservation actions) in 80–90% of the oak-rich forest area in southern Swe-den, and leave 10–20 % of the forests for naturalsuccession. The reason for the recommendationof a relatively high proportion of partial cuttingis based on the assumption that many of thewood-decaying fungi found in our study areasalso can be found in naturally closed deciduousforests without oak, while species confined toopen oak-rich forests to large extent lack suit-able habitat in other types of forests.

The suggestions above are tentative, sincethe effect of the surrounding landscape on spe-cies composition in restored local stands re-mains unclear, as well as the impact of the localrestored stands to species composition in similarhabitats in the surrounding landscape. Dispersalof species is potentially a slow process, and itmay take long time for species gaining by partialcutting to actually establish in the cut forests.In landscapes changing rapidly the drawbacksof extinctions must not be outweighed by re-colonisations of threatened species. The eva-luation performed in this thesis is based onshort-term observations that cannot fully coverthe total potential immigration of new species.It is of utmost importance that the effect ofpartial cutting for species richness is continued

in a long-term perspective, and that the effectof the surrounding landscape is included in theevaluations.

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9. Tack/Thanks...

– Min handledare Björn Nordén, för all den kun-skap om lavar, svampar, mossor, kärlväxter ochfåglar som han delat med sig av under mingrundutbildning, på gemensamma exkursioner,och under mitt examensarbete (som handladeom kärnsvampar) där han också var min hand-ledare, och under doktorandarbetet. Han harstöttat mig i mitt doktorandarbete med kunskap,och många intressanta naturvetenskapliga ochfilosofiska diskussioner. Jag har också uppskat-tat att han vid strategiska tillfällen alltid påminntmig om att man måste bli färdig också, och intebara leta efter mer kunskap och ännu bättre sättatt hantera redan bearbetade data.

– Min handledare Frank Götmark, som har kom-pletterat Björn på ett fantastiskt sätt. Jag haruppskattat hans stora entusiasm för vårt gemen-samma ”Ekprojekt”, där han varit drivande. Jaghar uppskattat den gemenskap Frank, Björn,Niklas Franc och jag haft (och ibland även Tedvon Proschwitz och Bjørn Økland), med gemen-samma luncher, möten, fältarbeten, manus-läsning och andra kontakter. Det har varit spän-nande att jobba ihop med Frank för hans forsk-ningsplanering är oftast preliminär och öppenför förändringar, och där jag efter kloka förslagfrån honom och Björn ibland fått tänka om, vil-ket inte alltid varit helt enkelt.

– Min handledare Ulf Molau för allmänna dis-kussioner och för granskning av manuskript.

– Niklas Franc som doktorerat nyligen inomvårt Ekprojekt, och alla examensarbetare inomsamma projekt (Mattias Lindholm, Bettina

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Olausson, Martin Ryberg (som numera är dok-torand), Johan Dahlberg, Camilla Niklasson,Ingela Sandberg, Åsa Pålsson, Åsa Berglund,Anna Bergqvist, Daniel Johansson, Åsa Rös-tell, Therese Ludvigsson, Ingrid Thomasson,Anna Nordberg) och assistenter (Andreas Karls-son, Kia Jungbark, Ellen Rube, Anders Malm-sten, Elin Götmark, Therese Helgesson) somhjälpt till vid inventeringar och bearbetning avdata under min doktorandtid, och/eller bidragittill att höja stämningen på våra gemensammainventeringsrundor med många gemensammamiddagar och vandrarhemsnätter.

– Paul Lazar, min ”mentor” som delat med sigav sitt vetenskapsfilosofiska perspektiv påforskning och diskuterat forskning på ett vidareplan på ett sätt som hjälpt mig att struktureraoch fokusera mitt skrivande, inte minst i slut-fasen av avhandlingsskrivandet.

– Föreningen Fältbiologerna och alla de aktivafältbiologer, som inspirerat och delat med mighärliga naturupplevelser, kunskaper om växteroch djur och som smittat av sig sitt engagemangför att bevara de hotade arter som numera harsvårt att överleva i de små fragment av natursom finns kvar. I denna förening grodde detintresse som så småningom ledde mig till dettadoktorandarbete. Mitt intresse har även stöttsav ett flertal andra föreningar, bl a MossornasVänner, och Svensk Lichenologisk Förening,efter att jag lämnat min aktiva roll i Fältbiologe-rna.

– Stiftelsen Pro Natura med Leif Andersson,Thomas Appelqvist, Tomas Fasth, Mattias Lind-holm, Ola Bengtsson, Mikael Finsberg, ArturLarsson, Richard Gimdal, Camilla Finsberg,Vikki Forbes, Bettina Olausson och MartinRyberg, som jag fått äran att arbeta ihop medinnan jag började doktorera (och lite parallelltmed doktorandstudierna också), och där jag för-värvat en stor del av min kunskap om natur-inventeringar, praktisk naturvård, arter, signal-arter, rödlistade arter, GIS, databaser etc. somjag haft stor nytta av som doktorand, inte minsti undervisningen.

– Statistikern Kerstin Wiklander som tålmodigtdiskuterat statistiska spörsmål med mig.

– Tomas Hallingbäck som ställde upp med sinfältkunskap om mossor (speciellt fältbestäm-

ning av gräsmossor) genom att under två dagaråka runt med mig och examensarbetaren JohanDahlberg till våra inventeringsytor. Ett stort tackför framsidesbilden av mossan Trädporella somTomas tagit.

– Leif Stridvall, som delat med sig av sina fo-tografier på kärlväxter, svampar och lavar tillmina powerpoint-presentationer, postrar och nutill framsidesbilder på avhandlingen. Tack ocksåAnita Stridvall för dina exkursionstips till Hun-neberg.

– Bo Nielsen, som utvecklat Ekprojektets da-tabas där vi samlat fältdata för hela projektet.

– Tina Granqvist-Pahlén som hjälpt mig medsatellitdata, och nyckfulla GIS-program.

– Atte Moilanen, who supported my researchidea in paper I by providing a metapopulationmodel for the study.

– Tord Snäll, Otso Ovaskainen, Atte Moilanen,Kjell Wallin and David Ratkowsky for discus-sing study designs and statistical issues.

– Jörgen Rudolphi, Thomas Ranius and RobertBjörk, for reading early drafts of manuscripts.

– Kim With and all kind researchers and PhD-students at Kansas State University, who guidedme during my one-week long visit. It was won-derful to follow you for bird watching and field-work at the tall-grass prairies with its lovelyvascular plant flora, bisons, birds, lizards andthe oaks (and other trees) along the small riv-ers.

– Lena Gustafsson för den 3 år långa Forskar-skolan om skog och biologisk mångfald, somhon anordnade under min doktorandtid och därjag under doktorandkurser och övriga träffar fåttmånga givande kontakter med företrädare fördet svenska skogsbruket, journalister, svenskaoch internationella forskare och inte minst an-dra doktorander som sysslar med forskning re-laterad till naturvård i skogen.

– Kollegorna på min institution, som jag delatluncher och fikaraster med, men också festattillsammans med, och alla forskare, doktoranderoch studenter som jag mött på de otaliga dok-torandkurser och andra aktiviteter jag fått del-taga inom och utanför Sverige.

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– Doktoranderna i Fakultetets Doktorandråd, le-damöterna i Forskarutbildningsberedningen ochFakultetetsnämnden där vi diskuterat många in-tressanta viktiga saker.

– Markägare som ställt upp med sin mark fördetta projekt: Anette Karlsson, Göte Isakssonmed familj, Bo Karlsson, Anders Heidesjö, DanEkblad, Robert Ekman, Nils-Olof och BengtLennartsson; Skara och Linköping stift; Svea-skog, Boxholms skogar, Holmen skog; Borås,Jönköpings, Oskarshamns, Växjö kommun;Länsstyrelserna i Östergötlands och Kalmar län.

– Länsstyrelserna i Västra Götalands, Öster-götlands, Kalmar, Jönköpings och Kronobergslän samt Skogsstyrelsen för kartmaterial, flyg-bilder, information om naturreservat ochnyckelbiotoper och annat som behövts till mittdoktorandarbete.

– Min f d sambo Mats Rosengren, som delatmitt stora naturintresse ända sedan tiden somvi båda två var aktiva fältbiologer. Min kun-skap om kärlväxter har jag förvärvat genom ochtillsammans med honom på de otaliga natur-äventyr vi gjort genom åren. Jag har också upp-skattat våra spännande diskussioner vi haft omfåglar, växter, praktisk naturvård och kulturhis-

toria. Han har delat en stor del av mitt, och vårabarns gemensamma vardag under mindoktorandtid. Jag har uppskattat det 100 % stödför mitt doktorerande, inte minst genom att tahand om barnen när jag haft perioder av fält-jobb, doktorandkurser, utlandsresor och hjälpenmed layouten av avhandlingen.

– Mina barn Rasmus och Ola, de är de under-baraste killar som finns i hela världen och värl-dens bästa avkoppling från skrivarbetet.

– Min nuvarande kärlek Richard Larsen för atthan finns och för hans intresse för djur och na-tur som återinspirerat mig för naturutflykter ochlockat mig tillbaka från skrivbordsbiologin somupptagit en allt större andel av mitt naturintressenuförtiden. Richard har betytt ofattbart mycketför mig det sista halvåret jag skrivit på min av-handling.

– Slutligen vill jag tacka alla stiftelser och fon-der som stött mig ekonomiskt under doktorand-tiden: M. C. Cronstedt, L. Hierta, H. Ax:sonJohnson, E. and E. Larsson and T. Rignell(Tranemålafonden), C. Stenholm, Adlerbertska,W. and M. Lundgren, K. and A. Binning, P. andM. Berghaus, O. och L. Lamm, P. A. Larsson,T. Krok, H. E. Ahrenberg, och Hierta-Retzius.

Illustration: Ingela Sandberg