Landscape fragmentation

Transcription

1 Landscape fragmentation due to transportation infrastructure and urban development Dr. Jochen Jaeger ETH Zurich, Switzerland,, May 2004

2 Landscape in the vicinity of Singen (Baden-Wurttemberg, Germany) in 1969

3 20 years later: Motorway intersection Singen in

4 BadenWurttemberg (Jaeger et al. 2001) Black Forest How much has the degree of landscape fragmentation increased? How can the consequences be assessed?

5 Structure of this talk Measuring landscape fragmentation Effective mesh size Time series Use as environmental indicator Effects of roads on animal populations Road-density density threshold Suitability of fencing Future research

6 How to measure the degree of landscape fragmentation 9 suitability criteria Serious problems with existing landscape indices New measure: effective mesh size, m eff Based on the probability that two randomly chosen points can be connected: Jaeger (2000), Landscape Ecology m eff eff now available in FRAGSTATSF (on the www)

7 Spatial comparisons m eff in the 44 rural districts in Baden- Wurttemberg Jaeger et al. (2001) Ortenaukreis Emmendingen Freudenstadt Breisgau-Hochschw. Rastatt Reutlingen Zollernalbkreis Tübingen Calw Baden-Baden Lörrach Tuttlingen Schwarzwald-Baar-Kreis Heidenheim Alb-Donau-Kreis Ostalbkreis Waldshut Main-Tauber-Kreis Rottweil Neckar-Odenwald-Kreis Göppingen Freiburg i. B., St. Böblingen Karlsruhe Esslingen Biberach Sigmaringen Heilbronn Rhein-Neckar-Kreis Rems-Murr-Kreis Ravensburg Schwäbisch Hall Enzkreis Hohenlohekreis Konstanz Heidelberg, Stadt Ludwigsburg Bodenseekreis Heilbronn, Stadt Pforzheim Karlsruhe, Stadt Ulm Mannheim Stuttgart km 2

8 Landscape change: Time series m eff [km 2 ] Baden-Wurttemberg m eff [km 2 ] Hohenlohekreis P L Ravensburg U K B Konstanz R Bodenseekreis Ludwigsburg H 2.00 Ulm Year Year Pforzheim Used as indicator (impact on biodiversity) in the Environmental Report of Baden-Wu Wurttemberg (2003)

9 Useful for measurementsm and assessments: time series (environmental indicator) setting environmental standards management and regulation for the future Results published in: Jaeger, J. 2002: Landschaftszerschneidung. Ulmer, Stuttgart. (English translation in planning)

10 m currently eff used in 5 states of Germany: Baden-Wu Wurttemberg, Hesse, Bavaria, Thuringia ringia, Schleswig-Holstein. Ongoing discussion about using it in all states of Germany as one of 24 core indicators of sustainability. European Environmental Agency (EEA) Switzerland: Project proposal in progress

11 Collaboration with the European Environmental Agency (EEA) since Nov European countries Finland Esto nia Sweden Lithuania Norway Latvia Albania Greece Ro mania M acedonia Bosnia and Herzegowina Italy Spain Yugo slavia United Kingdo m Poland Ireland Bulgaria France Slo vakia Switzerland Portugal Croatia Austria Slo venia Hugary Czech Republic Jaeger et al., in prep. Germany Luxembo urg Netherlands Denmark Belgium m eff [km 2 ]

12 Effects of roads and railroads Road Ecology: : an emerging new and relevant discipline Road Ecology is the sleeping giant of conservation biology (Forman 2002) Buch Forman et al. (2003) scannen hier 2003

13 Roads and Traffic Habitat Loss Traffic Mortality Road Avoidance R.I.P. Population Subdivision Reduced Population Size Reduced Population Persistence

14 Increasing road density... reduces probability of population persistence: Linearly or with a threshold??

15 The road density threshold 1 Probability of population persistence Number of roads Jaeger, J., Fahrig, L., Ewald, K., in prep. Artwork thanks to Cristina Boschi.

16 Behavior at the road road avoidance = animals don t t try to cross traffic mortality = percent of animals killed on the road 100% 1- R R proportion of animals avoiding the road 1- K K road proportion of animals killed proportion of succeeding animals

17 Spatially explicit individual- based simulation model road

18 Persistence probability Pers. prob effect of a fence road avoidance traffic mortality

19 Persistence probability Pers. prob road avoidance traffic mortality

20 When do fences enhance population survival? Fence Fence threshold line road avoidance traffic mortality fence reduces survival fence enhances survival Jaeger and Fahrig (2004), Conservation Biology

21 Future research questions Bundling of roads Relative importance of road configuration and road length Response times to new roads Landscape connectivity Effect of different matrix types Time series of landscape fragmentation in Switzerland Comparison with metapopulation models Empirical data Effects of overpasses and underpasses

22 Collaboration L. Fahrig,, Carleton University, Ottawa, ON, Canada A. Clevenger,, Montana State Univ., USA A. Seiler,, Univ. of Uppsala, Sweden S. Kleeschulte,, EEA, Univ. Auton.. de Barcelona, Spain K. Frank,, UFZ Leipzig, Germany H.-G. Schwarz-von Raumer,, Univ. of Stuttgart, Germany R. Serrouya, Kokanee Forest Consulting, BC, Canada S. Alexander,, Univ. of Calgary, AB, Canada M. Percy,, Banff National Park, BC, Canada S. Saura,, Univ. de Lleida,, Spain

23 Summary Monitoring landscape fragmentation (as environmental indicator) Effects of roads: Thresholds in response to road density and suitability of fences Individual-based population models