Habitat conservation is a management practice that seeks to conserve, protect and restore habitats and prevent species extinction, fragmentation or reduction in range. It is a priority of many groups that cannot be easily characterized in terms of any one ideology.
History of the conservation movement
For much of human history, nature was seen as a resource that could be controlled by the government and used for personal and economic gain. The idea was that plants only existed to feed animals and animals only existed to feed humans. The value of land was limited only to the resources it provided such as fertile soil, timber, and minerals.
Throughout the 18th and 19th centuries, social views started to change and conservation principles were first practically applied to the forests of British India. The conservation ethic that began to evolve included three core principles: 1) human activities damage the environment, 2) there was a civic duty to maintain the environment for future generations, and 3) scientific, empirically based methods should be applied to ensure this duty was carried out. Sir James Ranald Martin was prominent in promoting this ideology, publishing numerous medico-topographical reports that demonstrated the damage from large-scale deforestation and desiccation, and lobbying extensively for the institutionalization of forest conservation activities in British India through the establishment of Forest Departments.Stebbing, E.P (1922)The forests of India vol. 1, pp. 72–81
The Madras Board of Revenue started local conservation efforts in 1842, headed by Alexander Gibson, a professional botanist who systematically adopted a forest conservation program based on scientific principles. This was the first case of state conservation management of forests in the world. Governor-General Lord Dalhousie introduced the first permanent and large-scale forest conservation program in 1855, a model that soon spread to other colonies, as well to the United States,America has been the context for both the origins of conservation history and its modern form, environmental history . Asiaticsociety.org.bd. Retrieved on 2011-09-01. where Yellowstone National Park was opened in 1872 as the world's first national park.
Rather than focusing on the economic or material benefits from nature, humans began to appreciate the value of nature itself and the need to protect it. By the mid-20th century, countries such as the United States, Canada, and Britain instigated laws and legislation in order to ensure that the most fragile and beautiful environments would be protected for posterity.
Today, with the help of NGO's and governments worldwide, a movement is mobilizing with the goal of protecting habitats and preserving biodiversity on a global scale.
Values of natural habitat
Natural habitats can provide Ecosystem services to humans, which are "any positive benefit that wildlife or ecosystems provide to people." The natural environment is a source for a wide range of resources that can be exploited for economic profit, for example timber is harvested from forests and clean water is obtained from natural streams. However, land development from anthropogenic economic growth often causes a decline in the ecological integrity of nearby natural habitat. For instance, this was an issue in the northern Rocky Mountains of the US.
However, there is also the economic value in conserving natural habitats. Financial profit can be made from tourist revenue, for example in the tropics where species diversity is high, or in recreational sports which take place in natural environments such as hiking and mountain biking. The cost of repairing damaged ecosystems is considered to be much higher than the cost of conserving natural ecosystems.
Measuring the worth of conserving different habitat areas is often criticized as being too utilitarian from a philosophical point of view.
Biodiversity Habitat conservation is important in maintaining biodiversity, which refers to the variability in populations, organisms, and gene pools, as well as habitats and ecosystems. Biodiversity is also an essential part of global food security. There is evidence to support a trend of accelerating erosion of the genetic resources of agricultural plants and animals. An increase in genetic similarity of agricultural plants and animals means an increased risk of food loss from major epidemics. Wild species of agricultural plants have been found to be more resistant to disease, for example the wild corn species Teosinte is resistant to 4 corn diseases that affect human grown crops. A combination of seed banking and habitat conservation has been proposed to maintain plant diversity for food security purposes. It has been shown that focusing conversation efforts on ecosystems "within multiple trophic levels" can lead to a better functioning ecosystem with more biomass.
Classifying environmental values Pearce and Moran outlined the following method for classifying environmental uses: Direct extractive uses: e.g. timber from forests, food from plants and animals Indirect uses: e.g. ecosystem services like flood control, pest control, erosion protection Optional uses: future possibilities e.g. unknown but potential use of plants in chemistry/medicine Non-use values: Bequest value (benefit of an individual who knows that others may benefit from it in future) Passive use value (sympathy for natural environment, enjoyment of the mere existence of a particular species)
Impacts
Natural causes Habitat loss and destruction can occur both naturally and through anthropogenic causes. Events leading to natural habitat loss include climate change, catastrophic events such as volcanic explosions and through the interactions of invasive and non-invasive species. Natural climate change, events have previously been the cause of many widespread and large scale losses in habitat. For example, some of the mass extinction events generally referred to as the "Big Five" have coincided with large scale such as the Earth entering an ice age, or alternate warming events. Other events in the big five also have their roots in natural causes, such as volcanic explosions and meteor collisions.
The Chicxulub impact is one such example, which has previously caused widespread losses in habitat as the Earth either received less sunlight or grew colder, causing certain fauna and flora to flourish whilst others perished. Previously known warm areas in the tropics, the most sensitive habitats on Earth, grew colder, and areas such as Australia developed radically different flora and fauna to those seen today. The big five mass extinction events have also been linked to sea level changes, indicating that large scale marine species loss was strongly influenced by loss in marine habitats, particularly shelf habitats. Methane-driven oceanic eruptions have also been shown to have caused smaller mass extinction events.
Human impacts
Humans have been the cause of many species’ extinction. Due to humans’ changing and modifying their environment, the habitat of other species often become altered or destroyed as a result of human actions. The altering of habitats will cause habitat fragmentation, reducing the species' habitat and decreasing their dispersal range. This increases species isolation which then causes their population to decline. Even before the modern industrial era, humans were having widespread, and major effects on the environment. A good example of this is found in Aboriginal Australians and Australian megafauna. Aboriginal hunting practices, which included burning large sections of forest at a time, eventually altered and changed Australia's vegetation so much that many herbivorous megafauna species were left with no habitat and were driven into extinction. Once herbivorous megafauna species became extinct, carnivorous megafauna species soon followed.
In the recent past, humans have been responsible for causing more extinctions within a given period of time than ever before. Deforestation, pollution, anthropogenic climate change and human settlements have all been driving forces in altering or destroying habitats. The destruction of ecosystems such as rainforests has resulted in countless habitats being destroyed. These biodiversity hotspots are home to millions of habitat specialists, which do not exist beyond a tiny area. Once their habitat is destroyed, they cease to exist. This destruction has a follow-on effect, as species which coexist or depend upon the existence of other species also become extinct, eventually resulting in the collapse of an entire ecosystem. These time-delayed extinctions are referred to as the extinction debt, which is the result of destroying and fragmenting habitats.
As a result of anthropogenic modification of the environment, the extinction rate has climbed to the point where the Earth is now within a sixth mass extinction event, as commonly agreed by biologists. This has been particularly evident, for example, in the rapid decline in the number of amphibian species worldwide.
Approaches and methods of habitat conservation Adaptive management addresses the challenge of scientific uncertainty in habitat conservation plans by systematically gathering and applying reliable information to enhance conservation strategies over time. This approach allows for adjustments in management practices based on new insights, making conservation efforts more effective. Determining the size, type and location of habitat to conserve is a complex area of conservation biology. Although difficult to measure and predict, the conservation value of a habitat is often a reflection of the quality (e.g. species abundance and diversity), endangerment of encompassing ecosystems, and spatial distribution of that habitat.
Habitat Restoration
Habitat restoration is a subset of habitat conservation and its goals include improving the habitat and resources ranging from one species to several species The Society for Ecological Restoration's International Science and Policy Working Group define restoration as "the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed." The scale of habitat restoration efforts can range from small to large areas of land depending on the goal of the project. Elements of habitat restoration include developing a plan and embedding goals within that plan, and monitoring and evaluating species. Considerations such as the species type, environment, and context are aspects of planning a habitat restoration project.
Efforts to restore habitats that have been altered by anthropogenic activities has become a global endeavor, and is used to counteract the effects of habitat destruction by humans. Miller and Hobbs state three constraints on restoration: "ecological, economic, and social" constraints. Habitat restoration projects include Marine Debris Mitigation for Navassa Island National Wildlife Refuge in Haiti and Lemon Bay Preserve Habitat Restoration in Florida.
Identifying priority habitats for conservation