LECTURE 23 CONSERVATION BIOLOGY 2 + RESTORATION ECOLOGYMAJOR CONCEPTS1. Conservation Biology relates to land use and landscape structure.2. Habitat destruction and fragmentation cause 67% of all cases of recent extinctions.3. Hotspots for immediate conservation: high # species + high # endemic species4. Plan areas/habitats to preserve: A) if large uniform area available: SLOSS: single large better than equal size of separate small5. Plan areas/habitats to preserve: B) if diversity of area available: Several small diverse better than one large uniform.6. Plan for migration via corridors and ‘stepping stones’ in both types.7. Consider community structure (e.g. top-down control, cascade effects, keystone sp.).8. Large nearby subpopulations may rescue a small population from going extinct.9. Chance events may cause small populations to go extinct.Conservation Biology: Relate to Land Use and Landscape StructureI. Conservation Planning: Approach 1: Single Species Focus on rare, endangered species. Focus on dynamics and genetics of small populationsII. Conservation Planning: Approach 2 Preserve areas/habitats Hotspots: high # species + high # endemic species (only found there)III. Principles of design planning 1: for large expanse of uniform habitat A. Larger area better than small Why larger better? see ICA 8 from Part 2 1. Support more species by reducing chance of stochastic extinction. 2. Promote genetic diversity. 3. Buffer populations against disturbance. 4. Avoid ‘edge effects’. 5. Offer freedom to migrate without going outside of normal habitat B. SLOSS: single large better than equal size of separate small C. Fragmentation into small patches brings: reductions in: total area, interior/edge ratio, habitat heterogeneity, connectivity makes migration difficult with changing climate D.Plan for migration via corridors and ‘stepping stones’ Advantages: 1. Increase migration a. increase species richness b. provide a ‘rescue effect’ c. prevent inbreeding; add genetic diversity 2. Increase foraging area for widespread species 3. Provide cover for escape from predator when moving 4. Alternative refuges form large disturbances 5. Offers mix of habitats for species requiring themDisadvantages: 1. Risk spread of disease, weeds, invasive species between patches. 2. Predators learn corridor route. 3. Disrupt local adaptations and cause outbreeding depression. E. Circular (> interior/edge ratio) better than rectangularIV. Principles of design planning 2: for creating out of diverse area Several small diverse better than one large uniform Plan for migration via corridors and ‘stepping stones’ V. Consider 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/diversity Greater species diversity enhances chance of recovery from disturbance VI. Consider population ecology A. Small populations: greater risk of extinction due to Stochastic events Subpopulations more isolated Subpopulations with more synchronized fluctuations B. Deterministic models Based on large size; no variation in average birth and death rates C. Stochastic (random) models Randomness affects populations Catastrophe Temporal variation in environment Stochastic (random sampling) processes Chance events may cause small populations to go extinct Probability of extinction increases over time decreases with larger initial population size Small populations can go extinct due to random fluctuations in population size. D.Rescue effect: immigration from large subpopulation keeps a declining population from inbreeding and going extinct (source provides emigrants to sink) Need corridors to connect source and sinkSummary 6-16IRESTORATION ECOLOGYMAJOR CONCEPTS1. Restoration ecology is an applied discipline dependent on firm understanding of basic ecological processes.2. It also is tightly embedded in a social context.3. All subdisciplines of ecology from population through ecosytem contain principles relevant for enhancing success of restoration projects.I. Restoration Ecology: A Use research to understand ecological processes in highly disturbed ecosystems  B Apply understanding to: enhance their complexity and long-term persistence increase diversity reintroduce ecosystem function biomass (energy flow; productivity) + nutrient content (cycles) reestablish characteristic species, community structure + function C Relevant disciplines: Population, Community, Landscape, Ecosystem Ecology D Intertwined dimensions: Society, Politics, Economics, PolicyEcological Theory Relevant to Restoration:II. Population level – A Vulnerability of small populations Stochastic extinction Genetic variation/inbreeding depression B Minimum population viable size C Metapopulation dynamics D Use of locally adapted genotypesIII.Community Ecology A Species-Area relationship B Island Biogeography Theory C Fragmentation and patch size requirements of different groups of organims D Disturbance dimensions + Intermediate disturbance hypothesis E Succession 1 Species-species Iinteractions as they influence community development Facilitation InhibitionTolerance 2 Causes of succession: site availability species availability species performance 3 Contributing processes: disturbance dispersal ecophysiology propagules life history resources stress competition allelopathy