Introduction – Landscape Ecology

1. Introduction – Landscape Ecology • Landscape Ecology: Study of landscape structure and processes. • Landscape: Heterogeneous area composed of several ecosystems. • Landscape Elements: Visually distinctive patches in an ecosystem.

2. Vancouver Island marmot(Marmota vancouverensis) ~100 left Isolated from hoary and Olympic marmots

3. Vancouver Island marmot(Marmota vancouverensis) Natural tree succession

4. Vancouver Island marmot(Marmota vancouverensis) • Logging – disjunct patches • - max. dispersal = 7 km • Climate • Prey-Predator Dynamics

5. Human Land Use Practices • Agriculture • Suburban Development • Let’s pick on Indiana: • 97% of land in state = privately-owned • In central Indiana, • 70+% of land in row crop • <10% in forest • Urban sprawl intensifying

6. Human Impacts • Ecosystem simplification: elimination of species from food webs via human alterations to land • Example: vertebrate communities in ag. landscapes

8. Intensive Agriculture & Clean Farming

9. Timber Extraction & Fragmentation

10. Formation of Terrestrial “Islands”

11. Habitat Fragmentation • Process of breaking contiguous unit into smaller pieces; area & distance components • Leads to: • < remnant patch size • > edge:interior ratios • > patch isolation • < connectivity • Community & Ecosystem processes altered

12. Formation of Terrestrial “Islands”

14. Habitat Loss vs. Habitat Fragmentation

15. Patch size #patches Patch isolation Edge

17. What about aquatic systems?

18. What about aquatic systems? Con.Bio 12(6)

19. Habitat Fragmentation • area-sensitive species: species that require minimum patch size for daily life requirements • Edge effects: influence of factors from outside of a patch

20. Increased Edge Habitat

21. Increased Edge Habitat

22. Edge Effects • Habitat surrounding a patch can: • change abiotic conditions; e.g., temp. • change biotic interactions, e.g., predation • Example of nest predation = edge effect of approximately 50 m into forest patch

23. Habitat Fragmentation • First-Order Effects: fragmentation leads to change in a species’ abundance and/or distribution

24. Habitat Fragmentation • Higher-Order Effects: fragmentation indirectly leads to change in a species abundance and/or distribution via altered species interactions

25. HABITAT FRAGMENTATION Predators - Abundance - Distribution - Foraging Behaviors + Ground-Nesting Birds - Abundance - Distribution – – – Avian Competitors Avian Prey Brood Parasites + + Parasites - Abundance - Distribution REPRODUCTIVE SUCCESS

26. Habitat Fragmentation: Species-Specific Sensitivity? • Rare species = more vulnerable • Wide ranging species = large-area requirements • Species with reduced mobility = more vulnerable • Species with low fecundity (related to rarity?) • Species with short life cycle (or multi-stage life cycle?)

27. Habitat Fragmentation: Species-Specific Sensitivity? • Ground-nesting birds may be more vulnerable (30-60% reduction in last 25 yrs) • Interior-dependent species • Species vulnerable to human exploitation or disturbance • Specialist species?

28. Habitat Fragmentation: Species-Specific Sensitivity? • Generalizations are a good start • (= hypotheses?), but a little more complex than that……

29. Gehring and Swihart. 2003. Biological Conservation 109:283-295

30. Spatial and Temporal Ecology of Raccoons Gehring et al. In prep.

31. Swihart et al. 2003. Diversity and Distributions 9:1-8.

32. Brown and Litvaitis. 1995. Canadian Journal of Zoology 73:1005-1011

33. Implications of Changes in Scale Insects sampled at 10-m intervals for 100 m

34. Implications of Changes in Scale Insects sampled at 2000-m intervals for 20,000 m

35. Landscape Pattern • Landscape Components (attributes of features or spatial elements) • Composition • Configuration • Connectivity Relative to landscape spatial elements….

36. How much of the area is comprised of each type of spatial element? How are spatial elements arranged in space? How do these attributes change through time?

37. How does one quantify landscape pattern? How do biotic communities interact with pattern?

38. Causes of Landscape Pattern • Abiotic Factors • Biotic Factors • Human Landuse • Disturbance & Succession

39. Causes of Landscape Pattern • Abiotic Factors • Variance in climate (biogeographic influences) • Variance in landform (more localized constraints; microclimates)

41. Common N.A. trees – contractions & radiations in distribution

42. Influence of landform – spatial pattern of species distribution

43. Causes of Landscape Pattern • Biotic Factors • Competition • Predation

44. Causes of Landscape Pattern • Human Land Use • Prehistoric, Historic, Present Effects • Shift from nomadic hunter-gatherer to farming systems

45. Human Land Use Practices • Agriculture • Suburban Development • *Landuse / Landcover Data from USGS sources (typically resolution to 30 m)

46. Causes of Landscape Pattern • Human Land Use • Present Effects • Extraction of natural resources • Patterns of development • Transportation networks

47. Roads: Formation of Barriers in Landscapes

48. Clearcuts and National Forest Management

49. Patch Clearcuts

50. Landscape Processes • Landscape structure influences processes such as the flow of energy, materials, and species between the ecosystem within a landscape.