Conservation Biology and Global Change (Earth is changing rapidly as a…
Conservation Biology and Global Change
Sustainable development seeks to improve human lives while conserving biodiversity
Modern lives reflect remnants of our ancestral attachment to nature and the diversity of life—the concept of biophilia.
By reducing our orientation toward short-term gain, we can learn to value the natural processes that sustain us.
Many nations, scientific societies, and other groups have embraced the concept of sustainable development, meeting the needs of people today without limiting the ability of future generations to meet their needs.
Earth is changing rapidly as a result of human actions
Ecologists are debating assisted migration, the translocation a species to a favorable habitat beyond its native range to protect the species from human-caused threats.
If it were not for this greenhouse effect, the average air temperature at Earth’s surface would be a frigid –18°C (–2.4°F), and most life as we know it could not exist.
Toxins may become more concentrated in successive trophic levels of a food web, a process called biological magnification.
Humans release an immense variety of toxic chemicals, including thousands of synthetic compounds previously unknown in nature.
The nutrient level in an ecosystem may exceed the critical load, the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity.
Landscape ecology and regional conservation help sustain biodiversity
The key challenge of the zoned reserve approach is to develop a social and economic climate in the surrounding lands that is compatible with the long-term viability of the protected core area.
A zoned reserve is a large region that includes areas undisturbed by humans surrounded by lands that are used for economic gain and have been changed by humans.
Much of the focus has been on biodiversity hot spots, relatively small areas with numerous endemic species and a large number of threatened or endangered species.
Movement corridors, narrow strips or series of small clumps of habitat connecting otherwise isolated patches, can be deciding factors in conserving biodiversity.
One goal of landscape ecology is to understand past, present, and future patterns of landscape use and to make biodiversity conservation part of land-use planning.
Population conservation focuses on population size, genetic diversity, and critical habitat
A meaningful estimate of the MVP requires the researcher to determine the effective population size (N e) based on the breeding potential of a population, incorporating information about the sex ratio of breeding individuals.
The minimum population size at which a species is able to sustain its numbers and survive is the minimum viable population size (MVP).
A small population is vulnerable to inbreeding and genetic drift which draw the population down an extinction vortex toward smaller and smaller numbers until extinction is inevitable.
Human activities threaten Earth’s biodiversity
The fourth threat to biodiversity, global change, includes alterations in climate, atmospheric chemistry, and broad ecological systems that reduce the capacity of Earth to sustain life.
Introduced species, also called nonnative or exotic species, are those that humans move, intentionally or accidentally, from native locations to new geographic regions.
Ecosystem services encompass all the processes through which natural ecosystems and the species they contain help sustain human life on Earth.
The U.S. Endangered Species Act (ESA) defines an endangered species as one that is “in danger of extinction throughout all or a significant portion of its range,” and a threatened species as one likely to become endangered in the foreseeable future.
Genetic diversity comprises not only the individual genetic variation within a population but also genetic variation between populations associated with adaptations to local conditions.