What is a protected area? - Management plan is needed to qualify - Wild vs managed protection - Regional, local level nature reserves - National parks - Natura 2000 - EU - Marine protected areas - "De facto" protection (e.g. military, power plants etc) What is the main driver of the biodiversity crisis? - Habitat loss and fragmentation - 85 % of species on the IUCN red list are threatened due to habitat loss - 23 % median habitat range reduction potentially by the end of the century What is the Island Biogeography Theory? - Immigration/Extinction balance regulates species biodiversity - Larger islands -> less extinction -> more species - Closer to mainland -> more immigration -> more species Habitat loss = Habitat fragmentation? - When habitat is lost, it is also fragmented - What is the effect of fragmentation? - Local effects on patches: ○ Connectivity loss ○ Habitat degradation ○ Edge effects ○ Population size in reductions ○ Inbreeding - Overall effects on the landscape? Depends! - Patch level effect vs. Overall landscape effect Explain the habitat amount hypothesis - Patch area alone explains species diversity - Driven by the sample area effect - larger sample are, more species - Makes it possible to test for a fragmentation effect What is the Savannah River Site Corridors Experiment? - Long time experiment (since 1993) testing effect of isolation on species diversity independent of patch size - Has found both an effect of habitat size and fragmentation - Fragmentation effect has increased with time What are negative effects of habitat fragmentation on diversity? - Decrease in alpha diversity (due to stronger edge effects and habitat degradation) - Population size reductions, leading to lower adaptive potential and inbreeding - Loss of habitat-dependent species - Changes in host-parasite dynamics What are positive effects of habitat fragmentation on diversity? - Increased Beta diversity - Increased specialisation across patches due to habitat heterogeneity - More "vagrants" around the edges What combined effects does habitat fragmentation have on Gamma diversity? - Scale matters! Patch vs. Landscape effect - Species dispersal distances are important Is it better to conserve one large patch or many small ones? - Many small patches increase gamma diversity - In practice, habitat loss and fragmentation act together - most important is to minimise loss - Distance between patches is often not considered in theoretical frameworks - important for connectivity What are the key global targets in the Kunming-Montreal biodiversity agreement? (COP15) - Restore 30% degraded ecosystems globally (on land and sea) by 2030 - Conserve and manage 30% areas (terrestrial, inland water, and coastal and marine)by 2030 What is included in the Marine Protected Area Network Design? - Should protect biodiversity - Should protect connectivity - Should protect suitable habitat under climate change scenarios - Local impacts and changes in source-sink dynamics must be considered What is the source-sink dynamic? - Definition: The source-sink model describes how populations interact across different habitats. Source habitats have a surplus of individuals due to high birth rates and low death rates, allowing them to "export" individuals. Sink habitats depend on immigration from sources to sustain their populations because local conditions can't support a viable population. - Example: A forest with abundant food and shelter (source) supports high bird reproduction, while an adjacent urban park (sink) relies on birds migrating from the forest to maintain its population. What is climate velocity? - With climate change, habitats will "move" (generally poleward) - The velocity of this movement (in the horizontal plane) has been called "velocity of climate change" - Estimated 0.42 km/year, but differs between habitats - Lowest mountain regions due to large changes in habitat with altitude - A species will need to be able to disperse at this rate to avoid extinction - Depends on available habit / barriers to gene flow (e.g. Alpes are a barrier) - Thus, dispersal ability oof ecosystem engineers (e.g. plants, corals) will be key to others - Only 8% of MPAs (Marine Protected Areas) worldwide have residence times >100 years Tundra most stable