Species and Landscape Approaches - Introduction to Conservation Biology - Lecture Slides, Slides of Biology

Download Species and Landscape Approaches - Introduction to Conservation Biology - Lecture Slides and more Slides Biology in PDF only on Docsity! Species & Landscape Approaches to Conservation “The last word in ignorance is the man who says of an animal or plant: ‘What good is it?’ If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering.” Aldo Leopold (1949, A Sand County Almanac) Docsity.com Species-Level Conservation Most conservation efforts target species (or populations), usually through conservation of habitat (Groom et al. 2006) Docsity.com Species-Level Conservation Efforts World Wide Fund for Nature (Formerly the World Wildlife Fund) World’s largest conservation non- governmental organization (NGO), by membership 5 million members Operating budget > $100,000,000/yr Initially focused on endangered species, but its mission has expanded Docsity.com Feb. 14, 2010 began the Year of the Tiger, according to the Chinese lunar calendar WWF launched a major campaign for tiger conservation Species-Level Conservation Efforts World Wide Fund for Nature (Formerly the World Wildlife Fund) Docsity.com Pop. A Pop. B Pop. C Pop. D More Population Biology… Species often occur in nature as networks of populations whose temporal and spatial dynamics are interconnected by dispersing individuals (Groom et al. 2006) Docsity.com Pop. or Habitat A Pop. or Habitat B Pop. or Habitat C Pop. or Habitat D The populations inhabit habitats of differing quality Which may change from year to year Source  (b-d)>0 Sink  (b-d)<0 More Population Biology… Source & Sink Habitats or Populations Docsity.com Pop. or Habitat A Pop. or Habitat B Pop. or Habitat C As originally conceived by Levins (1969), many populations or suitable habitat patches are connected by dispersal across intervening matrix of unsuitable habitat (i.e., no necessary variability of habitat quality among patches) Unoccupied Habitat D More Population Biology… Meta-Population Dynamics Docsity.com Pop. or Habitat B Pop. or Habitat C More Population Biology… Meta-Population Dynamics Finite chance of extinction in all patches; at any given time some are occupied and some are unoccupied; meta-population is maintained by dispersal and recolonization of temporarily empty patches Pop. or Habitat D Unoccupied Habitat A Docsity.com Population Viability Analysis (PVA) Often computer-intensive simulation estimates of Minimum Viable Population Sizes (MVPs) Docsity.com Population Viability Analysis (PVA) “… for declining species, spatially explicit individual-based models can be used to understand both population demography and the impacts of habitat destruction, and to guide management practices to increase the chances of species survival.” “Mean (solid line) and 95% CI (dashed lines) for a single set of 150-year simulation runs (n = 100) using the field- derived estimates of the base model parameters… Simulation results prior to the dark grey line in the figure constitute the burn-in phase of the model and were discarded.” Docsity.com Ecologically Functional Populations (EFPs) As density of a species decreases, so does its “functionality,” i.e., its interactions with other species Some have criticized the focus on MVPs, arguing that we should be concerned about EFPs, and only focus on MVPs as a last resort Redford (1992) The Empty Forest Argued that a forest may still look like a forest soon after its mammals & birds have been lost, but without pollinators & seed dispersers the forest’s foundation species (the trees) and ecosystem services are doomed Docsity.com Ecologically Functional Populations (EFPs) “… a challenging trade-off exists between preserving the relict trees, which have a high genetic diversity and a key ecological role in these savannah-like ecosystems, and maintaining the current nesting area for these protected, but expanding, wading birds.” Docsity.com Landscape-Level Conservation Wild organisms do not recognize anthropogenic borders Wild organisms often require more than one habitat type These and other considerations motivate landscape-level conservation Docsity.com Landscape-Level Conservation Efforts The Nature Conservancy U.S.’s largest conservation non- governmental organization (NGO) – by revenue Operating budget > $1,000,000,000 / yr Especially well-managed charitable organization, ~ 88% efficiency (i.e., 88% of $$ go to conservation, as opposed to overhead and fundraising) Docsity.com