Chapter 56 | biologyapecology

CHAPTER 56: CONSERVATION AND RESTORATION

What are Conservation biology and Restoration ecology?

Conservation biology integrates ecology, physiology, molecular biology, genetics, and evolutionary biology to conserve biological diversity and sustain ecosystem processes around the globe at all levels. Resoration ecology refers to ecological principles which are able to return an ecosystem back to their natural state after human disturbance.

General Review

Biodiversity — The variety of life in the world or in a particular habitat or ecosystem. Biodiversity is considered at three different levels:

Genetic diversity is the source of variation within and between populations that allow them to adapt to environmental changes.
Species diversity maintains the structure of communities and food webs
Ecosystem diversity provides life-sustaining services such as nutrient cycling.

Ecosystem services — All the processes performed by ecosystems which help sustain humans, including purifying air and water, pollination, and decomposition of wastes.

Endangered species — Most or all of the populations of a species are In danger of becoming extinct

Threatened species — A species which has a high chance of becoming endangered in the near future.

Small-Population Approach — Emphasizes the small size of populations as the ultimate cause of extinction. Features the extinction vortex.

Declining-Population Approach — Focuses on threatened and endangered populations that show a downward trend, and the environmental factors that cause this decline. This approach is usually done via the following steps:

Confirmation of data
Study of natural history and the needs of the species
Development of a hypotheses for the causes of decline
Test the hypotheses'
Apply the results of the diagnosis

Biodiversity hotspot — A relatively small area with an extraordinary concentration of different natural species and a large number of threatened or endangered species.

Above is a map of Earth's terrestrial hotspots. Over a third of all species of plants, amphibians, reptiles, birds, and mammals inhabit only 1.5% of the earth's land.

Bioremediation — The use of organisms (usually prokaryotes, fungi, or plants) to detoxify polluted ecosystems. Some organisms are able to revegetate old mine sites, or degrade toxins into less harmful or insoluble forms. For instance, sunflowers are known to take up certain radioactive isotopes from nuclear waste.

Biological augmentation — Using organisms to add essential materials and chemical nutriends to a damaged ecosystem so that recovery can occur sooner.

Threats to Biodiversity

There are three major types of ways that human activities threaten biodiversity across the globe:

Habitat loss — Destruction of physical habitat is the single greatest threat to organisms. This can be caused by pollution, or clearing land for agriculture, urban development, forestry, and mining.

Introduced species — Non-native species which humans transfer intentionally or accidentally to new geographic regions. Introduced species can become invasive, having no natural predators and prey on or outcompete native species.

Overexploitation — The harvesting of wild organisms (both aquatic and terrestrail) to an extent beyond their capacity to reproduce and replenish their populations.

The Extinction Vortex

An extinction vortex describes when low genetic variation and other factors cause a small population shrink until no individuals exist. This does not always occur.

The minimum viable population (MVP) is the minimal population size that a species needs in order to survive and sustain its numbers. Conservation programs attempt to sustain the minimum viable number of reproductively active individuals.

A meaningful MVP estimate often requries the effective population size, which is the number of individuals in an ideal population, as based on the breeding potential of that population.

Above is the formulat to find the effective population size. Nf and Nm refer to the number of females and males respectively.

Regional Conservation

Natural boundaries or edges between ecosystems can have a positive effect on species while human alterated edges do not.

Shown above is an artificial movement corridor. Movement corridors are small fragments of land connecting otherwise isolated habitats. They are very important for promoting dispersal and expansion of populations, as well as the reduction of inbreeding within a declining population.

A zoned reserve is a large are of undisturbed land surrounded by areas that have been modified by humans. Strict regulations prevent alterations to the reserve.

Future of the Biosphere

Sustainable development meets the needs of people today without harming the environment and indirectly harming future generations. The Ecological Society of America is in favour of a research agenda called the Sustainable Biosphere Initiative.

This initiative aims to collect the ecological information needed for us to manage and conserve Earth's resources as responsibly as possible. This requires the partnership between national governments, nongovernment organizations and individuals.

Notable Experiment

A population collapse of Jasper County's Illinois greater prairie chicken was observed. Ronald Westemeier, Jeffrey Brawn, and colleagues began to transplant chickens from other areas and found that the reduced genetic variation had begun to pull the Jasper County chickens down the extinction vortex.

Prominent Figure

Edward Osborne Wilson is an American biologist, researcher, theorist, naturalist, and author. He introduced the term biophilia, which he defines as "the urge to affiliate with other forms of life." This sense of man's connection to nature and other forms of life may be the purest reason as to why we should care about the loss of biodiversity in the world today.