ObjectivesSlide 2Conservation Planning: Approach 2Endemic species: restricted to small geographic area; especially prominent on islandsDeterministic causes of extinctions: the ‘evil quintet’Habitat changes caused by human land use limit conservation strategies.Habitat reduction and fragmentation lead to endangered speciesHabitat reduction and eliminationSmaller fragments support fewer animals.*** What is the pattern? What explains it?Slide 11Principles for design of nature preserves: If create preserve from large expanse of uniform habitat:Why are larger areas better?***Summarize two major results. Corridors enhance migration between patches and maintain population cohesion.***What are advantages of corridors?If creating preserve out of diverse habitat:Consider community structureHow does species (and functional) diversity affect community response to disturbance?Population models assume: large size (> minimum viable population size); no variation in average birth and death rates.Slide 20***Summarize the two main results. Provide a reason for each result. What traits enable a population to rescue a small population from extinction? Figure 5Rescue effect:Mainland-island model: Source provides emigrants to sink.Sample exam ?Restoration EcologySlide 26Illinois in Need of RestorationSlide 28Goals: Improve the ecology of a disturbed area by:Slide 30What aspects of Population Ecology are relevant to Restoration Ecology?What aspects of Community Ecology are relevant to Restoration Ecology?How is the Species-Area curve relevant?How is Island Biogeography Theory relevant?Patch relationships: What are 2 take-home messages?Ecological Disturbance: What are its dimensions? How relate to restoration?Intermediate Disturbance Hypothesis: at which level does disturbance aid restoration? Why?Selected Natural & Anthropogenic Disturbances: reversible vs. permanent change?SuccessionSuccession: Species-Species InteractionsCommunity AssemblyWhich orientation to follow? Succession vs. Community AssemblyHow can succession be managed to aid restoration?Restoration: Managing SuccessionManaging Succession: in PracticeHow can community structure influence stability of restored community?How can Diversity Complexity Stability be enhanced?Landscape EcologySpatial PrinciplesMinimum Dynamic Area in Restoration DesignHow is Ecosystem Ecology relevant?Objectives•Conservation approaches: • populations/species• entire habitats •Habitat destruction/fragmentation causes much extinction•Conservation biology relates to landscape and community ecology•Plans for preserves• Size, number, shape, pattern• Stepping stones, corridors• Preserve community structureConservation Planning: Approach 2•Preserve habitats/areas,• especially ‘biodiversity hotspots’• high species number• high endemismEndemic species: restricted to small geographic area; especially prominent on islandsDeterministic causes of extinctions:the ‘evil quintet’1 habitat destruction and fragmentation (67% of cases)2 overkill (overexploit)3 chains of extinction•introduced species•emerging diseasesHabitat changes caused by human land use limit conservation strategies.Habitat reduction and fragmentationlead to endangered speciesHabitat reduction and elimination•Some habitats are eliminated altogether.•Fragmentation causes other problems:• reduced total area• reduced interior/edge ratio• reduced habitat heterogeneity• reduced connectivity• greater inter-fragment distance• unable to migrate with changing climateSmaller fragments support fewer animals.Figure 1*** What is the pattern? What explains it? Figure 2Which sizeof area isneeded?Will a park beSufficient?Principles for design of nature preserves:If create preserve from large expanse of uniform habitat:•larger is better than smaller •SLOSS: single large or several small?•one large area is better than several small that sum to same size•add corridors or ‘stepping stones’•circular is better than elongate with more edgeWhy are larger areas better?• support more species by reducing likelihood of stochastic extinction• promote genetic diversity• buffer populations against disturbance • avoid ‘edge effects’• offer freedom to migrate***Summarize two major results.Corridors enhance migration between patches and maintain population cohesion.Figure 3***What are advantages of corridors?•Are there disadvantages?If creating preserve out of diverse habitat:•Several small in different habitats better than one large in uniform habitat•Plan for migration ---> • use corridors stepping stones to link habitats• bridge roads and pipelines that impede movementConsider community structure• Top-down control of trophic abundances• Cascade effects: indirect effects extended through multiple levels• Can have chain of extinctions if highly dependent• Keystone organisms must be preserved• Non-redundant species, key species that maintain stability/diversityHow does species (and functional) diversity affect community response to disturbance?Population models assume: large size (> minimum viable population size); no variation in average birth and death rates. • In reality, randomness affects populations, especially small ones: • Catastrophe• Variation in environment• Stochastic (random sampling) processes• Chance events may cause small populations to go extinct.• Minimum viable population size = >500Probability of extinction increases over time; increases with smaller initial population size.Small populations are more likely to go extinctdue to random fluctuation in population size.Figure 4***Summarize the two main results. Provide a reason for each result. What traits enable a population to rescue asmall population from extinction? Figure 5Rescue effect:•Immigration from a large subpopulation can keep a declining subpopulation from inbreeding and going extinct.•Can produce positive density-dependence: survival of subpopulations increases with more subpopulations.Mainland-island model:Source provides emigrants to sink.sourcesinksFigure 6Sample exam ?You are asked to design a national park system for a tropical country.1) How will the concept of ‘hot spots’ of diversity influence your choice of areas to conserve?•You have defined your locations. What