Ch 55 Conservation Biology and Restoration Ecology Human activities threaten Earth's biodiversity Population conservation focuses on population size, genetic diversity, and critical habitat Landscape and regional conservation aim to sustain entire biotas Restoration ecology attempts to restore degraded ecosystems to a more natural state Sustainable development seeks to improve the human condition while conserving biodiversity

Conservation biology integrates the following fields to conserve biological diversity at all levels: Ecology Evolutionary biology Physiology Molecular biology Genetics

Restoration ecology - applies ecological principles in an effort to return degraded ecosystems to conditions as similar as possible to their natural state

3 Levels of Biodiversity: Genetic Diversity - individual genetic variation within a population and genetic variation between populations that is associated with adaptations to local conditions Species Diversity - variety of species in an ecosystem or throughout the entire biosphere (species richness) Ecosystem Diversity - variety of biosphere's ecosystems

Why should we care about the loss of biodiversity? Biophilia - our sense of connection to nature and other forms of life

Benefits of Species and Genetic Diversity Could provide crops, fibers, and medicines, unique genes, "bioprospecting" - new medicines, foods, petroleum substitutes, chemicals, etc

Ecosystem services include: Purification of air and water Preserving and generation of fertile soil Detoxification and decomposition of wastes Cycling of nutrients Moderation of weather extremes Protection from UV rays, Etc.

4 Major Threats to Biodiversity: 1. Habitat destruction 2. Introduced Species 3. Overexploitation 4. Disruption of "interaction networks" (food webs)

Habitat destruction is the single greatest threat to biodiversity Agriculture, urban development, forestry, mining and pollution Habitat fragmentation - breaking up habitats into small patches Aquatic habitats destroyed by: dams, reservoirs, channel modification and flow regulation

Introduced species - those that humans move, intentionally or accidentally, from the species' native locations to new geographic regions No natural predators Competition with native species - native species usually loses Ex: kudzu, zebra mussels

Overexploitation - human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound Commercial fishing, hunting, collecting and trading of animals Ex: elephants, North American tuna, northern cod

Disruption of Interaction Networks When one species goes extinct, the rest fall like dominoes Keystone species: sea otters Engineers: beavers Pollinators: "flying foxes" bats

Extinction vortex - a small population is prone to positive feedback loops of interbreeding and genetic drift, causing smaller and smaller populations until its extinct Key: loss of genetic variation to enable evolutionary changes

Minimum viable population (MVP) - minimum population size at which a species is able to sustain its numbers and survive Population Viability Analysis (PVA) - population's chances for survival

Declining-population approach: Focuses on threatened and endangered populations that show a downward trend, regardless of population size Emphasizes the environmental factors that caused a population to decline in the first place

Determining population numbers and habitat needs are only part of the effort Also need to examine species' biological and ecological needs against other conflicting demands Trade-offs Identifying keystone species and finding ways to sustain their populations can be central to survival of whole communities

Edges - between ecosystems Some species thrive here Human created edges often have negative impact because the interior gets smaller, less species Movement corridor - narrow strip or small clumps of quality habitat that connect isolated patches, can help preserve biodiversity

Protected Areas Lots of questions? Biodiversity Hot Spots - relatively small area with an exceptional concentration of endemic species and a large number of endangered and threatened species Good places for nature reserves but hard to identify Too small Zoned reserve - an extensive region of land that includes one or more areas undisturbed by humans surrounded by lands that have been changed by human activity and used for economic gain

Bioremediation - using living organisms to detoxify polluted areas Biological augmentation - uses organisms to add essential materials to a degraded ecosystem Learn as you go

Sustainable development - long-term prosperity of human societies and the ecosystems that support them Sustainable Biosphere Initiative: everyone must work together for this to be effective Costa Rica: zoned reserves, ecotourism Increased literacy Increased life expectancy Lower infant mortality

Biophilia Conservation because it is the ethical thing to do