1. Large-scale Ecology Interacting ecosystems

2. Key terms
Ecosystem- A specific biological community defined by the the composition of the community and the interacting physical environment.
Landscape Ecology- The study of heterogeneous land area comprised of interacting patches of ecosystems.

4. Landscape Ecology terms
Patch- a geographic area that is relatively homogenous with respect to its surroundings (uniform habitat).
Ecotype- A specific ecosystem/habitat patch.
Matrix- most extensive ecotype present with in the landscape.
Patches are often said to be embedded within the matrix.

6. Scale Scale- the unit of measure of perception (spatial or temporal).
The scale one observes a landscape at greatly influences the perception of the landscape.
Different organisms perceive the ecosystem at different scales

7. Landscape ecologists study landscape structure and how that relates to functional processes.
 Structure focuses on aspects of the patches: their density, size, shape, orientation to each other, contrast between each other, etc. (overhead Fig 2)
 Landscape ecologist attempt to understand how neighboring ecosystems influence each other. Also address the impact of human landscapes on natural ecosystems.

9. The Edge Effect:
 Ecotones- boundaries between different adjacent communities.
Edge habitats often differ from both adjacent communities due to mixed species composition, temp., light, humidity, etc.
Patch shape influences the amount of edge (Fig 4.21 text)

10. EDGES CAN HAVE DISTINCT PHYSICAL CONDITIONS
Increased light:-
Raises temperature
Increases air flow
Increases evaporation

11. EDGES ARE DYNAMIC This is an edge succession
Trees at the edge extend their canopies and develop epicormic branches
The gap between ground level and the canopy is filled.
Shade intolerant plants e.g. blackberries become established in the new high light zone
This is an edge succession

12. The Edge Effect:
Edges show greater diversity than the communities that bound them.
The degree of diversity is greatest when:
the adjoining communities are highly contrasting (forest - grassland),
the edge is long and wide,
patches are large enough to sustain the members of the original community.

13. Fig
Habitat fragmentation our environment is increasingly becoming edge habitat. Our most threatened organisms are those that require core habitat.

14. Habitat Fragmentation – Cadiz Township, WI

15. Edge effect
Edges can often be more diverse, but at the same time can act as “traps” with greater risks of predation, parasitism, and or disease.
A large amount of preserved habitat doesn’t mean much if most of it is edge habitat. We must preserve large area with core habitat.

16. Source-sink dynamics
 Metapopulations- set of spatially isolated subpopulations of a particular species living in patches.
 Because of patch heterogeneity- some subpopulations are more productive than others.
some produce a surplus of individuals- sources
some produce insufficient offspring to sustain the subpopulation- sinks
Patch conditions vary between different species.

17. source-sink dynamics- source populations supply individuals to sink population through emigration and immigration via corridors.
Sink
Source

18. Corridors
Fig
* Harrison Ford and Conservation International

19. Island Biogeography
 Total species diversity of a isolated ecosystem (island) can be predicted based on: area, distance to nearest colonizing source, and extinction rate.
 Tenets:
A larger area of land can sustain more species (More niche space)
Larger areas have lower local extinction rates

20. Diversity increases with land area: (See handout)

21. Island Biogeography
Areas closer to source populations have a higher rate of colonization.
Areas with greater species diversity correspondingly have greater local extinction rates. Why?
Colonization rates decline as diversity increases. Why?

22. Equilibrium amount of species diversity is determined by the balance of these relationships (Fig text):
Fig

23. Restoration Ecology Goals: Replace a species- Endangered Species Act
Restore structure- species composition (but not function)
Restore function- water filtration, flood control, food web.
Restore all the above: synthesis

24. Restoration Ecology
Focus is usually specific- Population recovery or restoring habitat of endangered species. But increasingly efforts to restore large-scale ecosystems are underway- e.g. Florida Everglades.
Complications: natural disturbance regimes (fire, floods, etc), alien species, pollution, resources (space), erosion, cost, public support, long-term maintenance and monitoring.

25. Fig. 5.21

26. Fig. 5.22

27. Population Viability Analysis (PVA)-
modeling technique that incorporates life history, habitat requirements, metapopulation dynamics, species interactions, etc. to predict the probability of persistence of a population for a given time and space.
-        Minimum viable population- population size necessary for long-term persistence in an area.
-        Technique is used for restoration planning and for endangered species recovery plans.

28. Adaptive management
apply a management approach to restoration that experimentally evaluates the success of an ongoing project and modifies the strategy accordingly. Marries applied science with pure science.

29. Fig. 5.25