Ecological Restoration - Introduction to Conservation Biology - Lecture Slides, Slides of Biology

Download Ecological Restoration - Introduction to Conservation Biology - Lecture Slides and more Slides Biology in PDF only on Docsity! Ecological Restoration Docsity.com Crissy Field, San Francisco Before restoration Crissy Field, San Francisco After restoration Ecological Restoration “…the process of intentionally altering a site to establish a defined, indigenous, historic ecosystem. The goal of the process is to emulate the structure, function, diversity and dynamics of the specified ecosystem…” (Society for Ecological Restoration 1991) Docsity.com Ecological Restoration Additional sub-categories from Groom et al. (2006) & other texts: Remediation (similar to reclamation) – removes chemical contaminants from polluted areas – by biotic, chemical or physical means – especially to protect human & ecosystem health Re-creation (similar to replacement) – constructs a new biological community on a site in which anthropogenic disturbance essentially removed the entire native community, often in an attempt to match a particular historic condition Docsity.com Ecological Restoration U. S. Legislation – e.g., Clean Water Act (1972) “to restore & maintain the chemical, physical & biological integrity of the Nation’s [surface] waters” Requires mitigation: if unavoidable impacts to waters & wetlands occur, those responsible must restore / re-create comparable ecosystems elsewhere Docsity.com Ecological Restoration U. S. Legislation – e.g., Surface Mining Control & Reclamation Act (1977) Aims to prevent adverse effects of surface mining (especially coal) & requires mining companies to restore mined sites (usually initiated through reclamation) Docsity.com “Restoring Yellowstone’s Aspen with Wolves” “combined effects of a behaviorally- mediated and density-mediated trophic cascade” Density-mediated – indirect carnivore effect on plants owing to lethal direct carnivore effect on herbivore density Behaviorally-mediated – indirect carnivore effect on plants owing to non-lethal carnivore effect on herbivore behavior Docsity.com Re-wilding North America with Pleistocene Megafauna Some Conservation Biologists have made a serious proposal that we should re- create the N. Am. Pleistocene fauna with modern analogs e.g., African elephants, South American camelids… Docsity.com Re-wilding North America with Pleistocene Megafauna … and carnivores, such as African lions & Siberian tigers (modern analogs of Smilodon [Saber- toothed cat]) It’s a serious proposal, but is it a good idea? Docsity.com “Rapid Recovery of Damaged Ecosystems” Meta-analysis “We provide startling evidence that most ecosystems globally can, given human will, recover from very major perturbations [a.k.a. disturbances] on timescales of decades to half-centuries.” “The message of our paper is that recovery is possible and can be rapid for many ecosystems, giving much hope for humankind to transition to sustainable management of global ecosystems.” Docsity.com Figure & quote from J. M. Rey Benayas et al. (2009) Science “Enhancement of Biodiversity & Ecosystem Services by Ecological Restoration” Meta-analysis (89 restoration assessments; response ratio = ln[Restored / Degraded or Reference]) Provisioning = e.g., fish, food crops, timber Supporting = e.g., nutrient cycling, primary production Regulating = e.g., climate, water supply, soil characteristics Docsity.com “Enhancement of Biodiversity & Ecosystem Services by Ecological Restoration” “Ecological restoration increased provision of biodiversity and ecosystem services by 44 and 25%, respectively. However, values of both remained lower in restored versus intact reference ecosystems.” Meta-analysis (89 restoration assessments; response ratio = ln[Restored / Degraded or Reference]) Docsity.com