3.4: conservation of biodiversity Flashcards
reasons for preserving biodiversity -
- ecological reasons
- economic reasons
- aesthetic reasons
- social reasons
- moral/ethical reasons
- environmental reasons
- agricultural reasons
ecological reasons -
biodiversity has a major effect on the stability of an ecosystem
more diverse ecosystem = better chance of survive and adaptation to environmental changes or threats
for eg. if the temperature of a species-rich lake rises due to global warming:
some species of fish in the ecosystem are unable to cope with the change while others can
the fish that are able to cope will survive, reproduce and keep contributing to the ecosystem
within communities there are keystone species that have a larger impact on the ecosystem than others
when these species are lost there are several knock-on effects
Bush elephants in the African savannah are a keystone species
- they graze in a very extreme way, knocking over and eating several species of tree. this destruction of vegetation actually helps to maintain the ecosystem
- elephant dung also provides a habitat for many important fungi and insect species
- when elephants were illegally hunted for their ivory, their numbers were reduced and scientists observed a major negative impact on the savannah
economic value -
many of the medicines used today have originated from plants, fungi and bacteria
for eg. cancer-fighting drug paclitaxel is sourced from Pacific and Himalayan Yew Trees.
due to the large number of drugs that have already been sourced from nature it is reasonable to assume that there are other drugs, yet to be found in nature, that could be used in the future
ecotourism is a major source of income for many countries -> contributes to the economy & jobs
many tourists travel to and spend money in National parks so they can see wildlife
ecosystems have also made major contributions to the field of science and technology
eg. specific enzyme used in DNA sequencing was first discovered in thermophilic bacterium found in a hot spring in Yellowstone National Park, USA
aesthetic, social & moral reasons
- humans find great joy and pleasure in the beauty of nature
- it provides inspiration for creatives such as photographers, poets, musicians and artists
there is a strong argument for preserving biodiversity because of its aesthetic benefits - many people enjoy spending time in the natural environment
- there are many activities that people can do together in nature, e.g. birdwatching, walking, climbing
- such environments may be lost if they are not conserved, with the loss of the social benefits that they can bring
- many people believe that humans have a moral obligation to prevent the loss of biodiversity that results from human activities
- humans share the planet with millions of other species and they have no right to cause the extinction of other species
- as humans are the most intelligent species on the planet the responsibility falls upon their shoulders to protect and value all of the organisms on the planet
environmental reasons
- humans need diverse ecosystems because of the essential environmental services they provide
- plants absorb carbon dioxide from the atmosphere and help to reduce the greenhouse effect and climate change
- microorganisms digest and break down the masses of organic waste that are produced by larger organisms
- humans have irrigation and drinking water thanks to the transpiration of plants and their contribution to the water cycle
- different fungi and bacteria species are a major part of the nutrient cycle that allows for nutrients to reenter the soil for further plant growth
- plants are producers in food webs. they are both a direct and indirect energy source for humans through fruit, vegetables and meat
agricultural reasons -
- most of the crops that humans grow are very uniform with low genetic diversity
- the wild relatives of crops can provide a source of genetic diversity to rescue crops that are affected by disease or other disasters
- many of the wild relative species are under threat due to habitat destruction and climate change
all of the world’s potato crop comes from a single species this lack of species diversity makes the crop highly susceptible to disease - there are over 100 species of wild potatoes that grow in the Andes - these Andean species act as a source of alleles for disease resistance & have been introduced to the potato crop through gene technology and interbreeding
protected areas:
defined geographical space, such as a national park, wildlife sanctuary, or nature reserve, that is managed and protected for the conservation of its natural resources, biodiversity, and cultural heritage.
they can be established by national governments, international organisations, or private entities, and are designed to conserve natural and cultural resources for future generations, as well as provide opportunities for scientific research, education, and recreation.
protected areas can have various levels of protection and management, from nature reserves where human activities are strictly prohibited, to multiple-use areas where certain human activities are permitted (e.g. wild camping)
they provide critical habitat for endangered and threatened species, protect important ecosystems and ecological processes, and provide opportunities for ecotourism and other sustainable economic activities
criteria for consideration when designing protected areas include:
- size (larger areas, support more biodiversity & provides a greater range of ecosystems)
- shape (complex shape increases edge-effect while a simple shape may not provide enough habitat variety. irregular shapes following natural features like rivers or ridges provide connectivity)
corridors (narrow strips of land that facilitate the movement of organisms and allow for gene flow b/w populations by connecting otherwise isolated areas)
- edge effects (refers to the changes that occur at the boundary b/w diff habitats. high edge-to-interior ratio = increased exposure to human disturbances, invasive species & altered microclimates. minimise by using buffer zones around edges & by creating areas w/ simple shapes)
- proximity to potential human influence (areas close to human settlement may be subject to habitat destruction, pollution & hunting)
CITES -
CITES is an international agreement that regulates the trade of endangered species and their products
goal is to ensure that international trade does not threaten the survival of the species
provides a framework for cooperation between countries and sets up a system of permits and regulations to control the trade of endangered species
CITES has helped to protect many species, including elephants, rhinos, and tigers
captive breeding, reintroduction programmes and zoos -
captive breeding is the process of breeding animals in controlled environments, such as zoos, aquariums, or wildlife sanctuaries.
it is often used to help restore populations of endangered species that have declined in the wild
reintroduction is the process of releasing captive-bred animals into the wild
zoos also play a role in conservation by raising public awareness and funding conservation efforts
eg. of a successful captive breeding and reintroduction program is the California condor recovery program in the United States
flagship species:
charismatic species that are well-known and popular with the public, such as elephants, pandas, or tigers
they can be used as symbols for conservation efforts and can help to raise awareness and support for conservation efforts
by protecting charismatic species, their habitats and other species in the same ecosystem may also be protected
eg. mountain gorillas found in the Virunga Mountains has faced threats from habitat destruction, poaching & human conflict. by focusing on the conservation of mountain gorillas and their habitat, conservation organisations have been able to protect not only this species but also the many other plants and animals that share their ecosystem
keystone species:
species that have a disproportionate effect on the structure and function of their ecosystem.
their removal can cause significant changes in the ecosystem, including the loss of other species
by protecting keystone species, the integrity of the ecosystem can be maintained, which can in turn benefit other species in the ecosystem
for eg. the sea otter is a keystone species in the kelp forest ecosystem in the Pacific Northwest of the United States, as it helps to control the population of sea urchins, which are herbivores that can damage the kelp forests
evaluating conservation approaches (pt.1) -
protected areas:
- provides direction protection to habitats & species
- promotes ecotourism & research opportunities
- can aid restoration & ecological rehabilitation efforts
- may offer ecosystem services to surrounding areas
- limited land availability
- may require displacing indigenous populations
- limited enforcement of regulations
- can be subject to illegal poaching & logging
- can be expensive to manage & maintain
CITES:
- regulates international trade of endangered species
- provides a framework for international cooperation
- protects biodiversity by preventing over-exploitation
- supports sustainable use of resources
- difficult to enforce & monitor trade in remote areas
- can be resource-intensive to implement
- some countries may not prioritise enforcement/ doesn’t have the resources to do so
- does not address habitat loss or other threats to species
evaluating conservation approaches (pt.2) -
zoos:
- can serve as a last resort for critically endangered species
- can raise awareness & educate the public
- allows for research & educational opportunities
- can provide a safe and controlled environment for breeding
- limited genetic diversity due to small population size
- animals may experience stress & health issues in captivity
- some species may not be suitable for captive breeding
- limited capacity for large, wide ranging species
- can be expensive to operate & maintain
captive breeding & reintroduction programmes:
- can increase population size of endangered species
- can aid in the restoration of ecosystems & food webs
- can increase genetic diversity in populations
- can serve as a way to study species’ behaviour
- may not address underlying threats to species
- high costs associated with breeding & reintroduction
- success may depend on habitat availability & quality
