Conservation biology is the scientific study of the
nature and status of Earth's
biodiversity
with the aim of protecting species, their habitats, and ecosystems
from excessive rates of extinction and the erosion of biotic interactions. It is
an interdisciplinary subject drawing on natural and social sciences, and the
practice of natural resource management.
The conservation ethic is based on the findings of
conservation biology.
Use of the term
This term conservation biology was introduced as the
title of a conference held at the University of California, San Diego
in La Jolla, California in 1978 organized by biologists Bruce Wilcox and Michael E. Soulé. The meeting was prompted by the
concern among scientists over tropical deforestation, disappearing species,
eroding genetic diversity within species. The conference and proceedings that
resulted sought to bridge a gap existing at the time between theory in ecology
and population biology on the one hand and conservation policy and practice on
the other. Conservation biology and the concept of biological diversity (biodiversity)
emerged together, helping crystallize the modern era of conservation science
and policy. The inherent
multidisciplinary basis for conservation biology has led to the development of
several new subdisciplines including conservation genetics, conservation social
science, conservation behavior and conservation physiology.
Description
The rapid decline of established biological systems around
the world means that conservation biology is often referred to as a
"Discipline with a deadline". Conservation biology is tied closely to
ecology in
researching the dispersal, migration,
demographics,
effective population size, inbreeding depression, and minimum population viability of rare
or endangered species. To better understand the restoration ecology of native plant and animal
communities, the conservation biologist closely studies both their polytypic
and monotypic habitats that are affected by a wide
range of benign and hostile factors. Conservation biology is concerned with
phenomena that affect the maintenance, loss, and restoration of biodiversity
and the science of sustaining evolutionary processes that engender genetic, population,
species, and
ecosystem diversity. The concern stems from estimates suggesting that up to 50%
of all species on the planet will disappear within the next 50 years, which has
contributed to poverty, starvation, and will reset the course of evolution on
this planet.
Conservation biologists research and educate on the trends
and process of biodiversity loss, species extinctions,
and the negative effect these are having on our capabilities to sustain
the well-being of human society. Conservation biologists work in the field and
office, in government, universities, non-profit organizations and industry.
They are funded to research, monitor, and catalog every angle of the earth and
its relation to society. The topics are diverse, because this is an
interdisciplinary network with professional alliances in the biological as well
as social sciences. Those dedicated to the cause and profession advocate for a
global response to the current biodiversity crisis based on morals, ethics, and
scientific reason.
Organizations and citizens are responding to the biodiversity crisis through
conservation action plans that direct research, monitoring, and education
programs that engage concerns at local through global scales.
History
The conservation of natural indian resources is the
fundamental problem. Unless we solve that problem, it will avail us little to
solve all others.
– Theodore Roosevelt
Natural resource conservation
Conscious efforts to conserve and protect global
biodiversity are a recent phenomenon. Natural resource conservation, however,
has a history that extends prior to the age of conservation. Resource ethics
grew out of necessity through direct relations with nature. Regulation or
communal restraint became necessary to prevent selfish motives from taking more
than could be locally sustained, therefore compromising the long-term supply
for the rest of the community.This social dilemma with respect to natural
resource management is often called the "Tragedy of the Commons".
From this principle, conservation biologists can trace
communal resource based ethics throughout cultures as a solution to communal
resource conflict. For example, the Alaskan Tlingit
peoples and the Haida of the Pacific
Northwest had resource boundaries, rules, and restrictions among clans with
respect to the fishing of Sockeye Salmon. These rules were guided by clan
elders who knew lifelong details of each river and stream they managed.There
are numerous examples in history where cultures have followed rules, rituals,
and organized practice with respect to communal natural resource management.
Conservation ethics are also found in early religious and
philosophical writings. There are examples in the Tao, Shinto, Hindu, Islamic and Buddhist
traditions.In Greek philosophy, Plato lamented about pasture land degradation:
"What is left now is, so to say, the skeleton of a body wasted by disease;
the rich, soft soil has been carried off and only the bare framework of the
district left." In the bible, through Moses, God commanded to let the land
rest from cultivation every seventh year. Before the 18th century, however,
much of European culture considered it a pagan
view to admire nature. Wilderness was denigrated while agricultural
development was praised. However, as early as AD 680 a wildlife sanctuary was
founded on the Farne Islands by St Cuthbert
in response to his religious beliefs.
Early naturalists
Natural history was a major preoccupation in the
18th century, with grand expeditions and the opening of popular public displays
in Europe and North
America. By 1900 there were 150 natural history museums in Germany, 250 in Great
Britain, 250 in the United States, and 300 in France. Preservationist
or conservationist sentiments are a development of the late 18th to early 20th
centuries.
By the early 19th century biogeography
was ignited through the efforts of Alexander von Humboldt, Charles
Lyell and Charles Darwin.The 19th-century fascination with
natural history engendered a fervor to be the first to collect rare specimens
with the goal of doing so before they became extinct by other such collectors.
Although the work of many 18th and 19th century naturalists were to inspire
nature enthusiasts and conservation organizations, their
writings, by modern standards, showed insensitivity towards conservation as
they would kill hundreds of specimens for their collections.
Conservation movement
The modern roots of conservation biology can be found in the
late 18th-century Enlightenment period particularly in England and Scotland. A
number of thinkers, among them notably Lord
Monboddo,described the importance of "preserving nature"; much of
this early emphasis had its origins in Christian theology.
Scientific conservation principles were first practically
applied to the forests of British India. The conservation ethic that began to
evolve included three core principles: that human activity damaged the environment, that there was a civic duty
to maintain the environment for future generations, and that 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 many medico-topographical reports that demonstrated
the scale of damage wrought through large-scale deforestation and desiccation,
and lobbying extensively for the institutionalization of forest conservation
activities in British India through the establishment of Forest Departments.
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
the world in 1855, a model that soon spread to other
colonies, as well the United States, where Yellowstone National Park was opened in
1872 as the world’s first national park.
The term conservation came into widespread use in the
late 19th century and referred to the management, mainly for economic reasons,
of such natural resources as timber, fish, game, topsoil, pastureland, and
minerals. In addition it referred to the preservation of forests (forestry),
wildlife (wildlife refuge), parkland, wilderness,
and watersheds.
This period also saw the passage of the first conservation legislation and the
establishment of the first nature conservation societies. The Sea Birds Preservation Act of 1869
was passed in Britain as the first nature protection law in the world[35]
after extensive lobbying from the Association for the Protection of Seabirds
and the respected ornithologist
Alfred
Newton. Newton was also instrumental in the passage of the first Game laws
from 1872, which protected animals during their breeding season so as to
prevent the stock from being brought close to extinction.
One of the first conservation societies was the Royal Society for the
Protection of Birds, founded in 1889 in Manchester
as a protest group campaigning against the use of great crested grebe and kittiwake skins and feathers in fur clothing.
Originally known as "the Plumage League". the group gained popularity
and eventually amalgamated with the Fur and Feather League in Croydon, and
formed the RSPB.The National Trust formed in 1895 with the manifesto to
"...promote the permanent preservation, for the benefit of the nation, of
lands, ...to preserve (so far practicable) their natural aspect."
In the United States, the Forest Reserve Act of 1891 gave the
President power to set aside forest reserves from the land in the public domain.
John Muir
founded the Sierra Club in 1892, and the New York Zoological Society was set up
in 1895. A series of national forests and preserves were established by Theodore Roosevelt from 1901 to 1909. The 1916
National Parks Act, included a 'use without impairment' clause, sought by John
Muir, which eventually resulted in the removal of a proposal to build a dam in
Dinosaur National Monument in 1959.
In the 20th century, Canadian civil
servants, including Charles Gordon Hewitt and James
Harkin spearheaded the movement toward wildlife conservation.
Global conservation efforts
In the mid-20th century, efforts arose to target individual
species for conservation, notably efforts in big cat
conservation in South America led by the New York Zoological Society.
In the early 20th century the New York Zoological Society was instrumental in
developing concepts of establishing preserves for particular species and
conducting the necessary conservation studies to determine the suitability of
locations that are most appropriate as conservation priorities; the work of
Henry Fairfield Osborn Jr., Carl
E. Akeley, Archie Carr and Archie Carr III is notable in
this era. Akeley for example, having led expeditions to the Virunga
Mountains and observed the mountain
gorilla in the wild, became convinced that the species and the area were
conservation priorities. He was instrumental in persuading Albert I of Belgium to act in defense of the mountain
gorilla and establish Albert National Park (since renamed Virunga National Park) in what is now Democratic Republic of Congo.
By the 1970s, led primarily by work in the United States
under the Endangered Species Act along with the Species at Risk Act (SARA) of Canada, Biodiversity Action Plans developed in Australia, Sweden, the United
Kingdom, hundreds of species specific protection plans ensued. Notably the
United Nations acted to conserve sites of outstanding cultural or natural
importance to the common heritage of mankind. The programme was adopted by the
General Conference of UNESCO in 1972. As of 2006, a total of 830 sites are listed:
644 cultural, 162 natural. The first country to pursue aggressive biological
conservation through national legislation was the United States, which passed
back to back legislation in the Endangered Species Act (1966) and National Environmental Policy Act
(1970), which together injected major funding and protection measures to
large-scale habitat protection and threatened species research. Other
conservation developments, however, have taken hold throughout the world.
India, for example, passed the Wildlife Protection Act of 1972 .
In 1980 a significant development was the emergence of the urban
conservation movement. A local organization was established in Birmingham,
UK, a development
followed in rapid succession in cities across the UK, then overseas. Although
perceived as a grassroots movement, its early development was
driven by academic research into urban wildlife. Initially perceived as
radical, the movement's view of conservation being inextricably linked with
other human activity has now become mainstream in conservation thought.
Considerable research effort is now directed at urban conservation biology. The
Society for Conservation Biology
originated in 1985.
By 1992 most of the countries of the world had become
committed to the principles of conservation of biological diversity with the Convention on Biological Diversity;
subsequently many countries began programmes of Biodiversity Action Plans to identify and
conserve threatened species within their borders, as well as protect associated
habitats. The late 1990s saw increasing professionalism in the sector, with the
maturing of organisations such as the Institute of Ecology
and Environmental Management and the Society for the Environment.
Since 2000 the concept of landscape scale conservation has risen
to prominence, with less emphasis being given to single-species or even
single-habitat focused actions. Instead an ecosystem approach is advocated by
most mainstream conservationist, although concerns have been expressed by those
working to protect some high-profile species.
Ecology has clarified the workings of the biosphere;
i.e., the complex interrelationships among humans, other species, and the
physical environment. The burgeoning human population and associated agriculture,
industry,
and the ensuing pollution, have demonstrated how easily ecological
relationships can be disrupted.
Extinction rates are measured in a variety of ways.
Conservation biologists measure and apply statistical measures of fossil
records, rates of habitat loss, and a multitude of other variables such
as loss of biodiversity as a function of the rate of habitat loss and site
occupancy to obtain such
estimates. The Theory of Island Biogeography
is possibly the most significant contribution toward the scientific
understanding of both the process and how to measure the rate of species
extinction. The current background extinction rate is estimated
to be one species every few years.
The measure of ongoing species loss is made more complex by
the fact that most of the Earth's species have not been described or evaluated.
Estimates vary greatly on how many species actually exist (estimated range:
3,600,000-111,700,000) to how many have received a species binomial (estimated range: 1.5-8
million). Less than 1% of all species that have been described have been studied
beyond simply noting its existence. From these figures, the IUCN reports that
23% of vertebrates,
5% of invertebrates
and 70% of plants that have been evaluated are designated as endangered
or threatened.
Better knowledge is being constructed by The
Plant List for actual numbers of species.
Systematic conservation planning
Systematic conservation planning is an effective way to seek
and identify efficient and effective types of reserve design to capture or
sustain the highest priority biodiversity values and to work with communities
in support of local ecosystems. Margules and Pressey identify six interlinked
stages in the systematic planning approach:
- Compile data on the biodiversity of the planning region
- Identify conservation goals for the planning region
- Review existing conservation areas
- Select additional conservation areas
- Implement conservation actions
- Maintain the required values of conservation areas
Conservation biologists regularly prepare detailed
conservation plans for grant proposals or to effectively coordinate their
plan of action and to identify best management practices (e.g.). Systematic
strategies generally employ the services of Geographic Information Systems to
assist in the decision making process.
Conservation physiology: a mechanistic approach to
conservation
Conservation physiology was defined by Steven
J. Cooke and colleagues as: ‘An integrative scientific discipline applying
physiological concepts, tools, and knowledge to characterizing biological
diversity and its ecological implications; understanding and predicting how
organisms, populations, and ecosystems respond to environmental change and stressors;
and solving conservation problems across the broad range of taxa (i.e.
including microbes, plants, and animals). Physiology is considered in the
broadest possible terms to include functional and mechanistic responses at all
scales, and conservation includes the development and refinement of strategies
to rebuild populations, restore ecosystems, inform conservation policy,
generate decision-support tools, and manage natural resources.’ Conservation physiology is particularly
relevant to practitioners in that it has the potential to generate
cause-and-effect relationships and reveal the factors that contribute to
population declines.
Conservation biology as a profession
The Society for Conservation Biology
is a global community of conservation professionals dedicated to advancing the
science and practice of conserving biodiversity. Conservation biology as a
discipline reaches beyond biology, into subjects such as philosophy,
law, economics, humanities,
arts, anthropology,
and education.
Within biology, conservation genetics and evolution are
immense fields unto themselves, but these disciplines are of prime importance
to the practice and profession of conservation biology.
Is conservation biology an objective science when biologists advocate for an
inherent value in nature? Do conservationists introduce bias when they support
policies using qualitative description, such as habitat degradation, or healthy ecosystems?
As all scientists hold values, so do conservation biologists. Conservation
biologists advocate for reasoned and sensible management of natural resources
and do so with a disclosed combination of science, reason, logic, and values in their conservation
management plans. This sort of advocacy is similar to the medical profession
advocating for healthy lifestyle options, both are beneficial to human
well-being yet remain scientific in their approach.
There is a movement in conservation biology suggesting a new
form of leadership is needed to mobilize conservation biology into a more
effective discipline that is able to communicate the full scope of the problem
to society at large. The movement proposes an adaptive leadership approach that
parallels an adaptive management approach. The concept is based on a new
philosophy or leadership theory steering away from historical notions of power,
authority, and dominance. Adaptive conservation leadership is reflective and
more equitable as it applies to any member of society who can mobilize others
toward meaningful change using communication techniques that are inspiring,
purposeful, and collegial. Adaptive conservation leadership and mentoring
programs are being implemented by conservation biologists through organizations
such as the Aldo Leopold Leadership Program
Approaches
Conservation may be classified as either in-situ conservation, which is protecting an
endangered species in its natural habitat, or ex-situ conservation, which occurs outside the
natural habitat. In-situ conservation involves protecting or cleaning up the
habitat itself which may include a great deal of environmental preservation, or by
defending the species from predators. Ex-situ conservation may be used on some or all
of the population, when in-situ conservation is too difficult, or impossible.
Also, non-interference may be used, which is termed a preservationist
method. Preservationists advocate for giving areas of nature and species a
protected existence that halts interference from the humans. In this regard,
conservationists differ from preservationists in the social dimension, as
conservation biology engages society and seeks equitable solutions for both
society and ecosystems.
Some preservationists emphasize the potential of
biodiversity in a world without humans
"Animals have not yet invaded 2/3 of Earth's habitats,
and it could be that without human influence the diversity of tetrapods will
continue to increase in an exponential fashion."
—Sahney et al.
Ethics and values
Conservation biologists are interdisciplinary
researchers that practice ethics in the biological and social sciences. Chan
states that conservationists must advocate for biodiversity and can do so in a
scientifically ethical manner by not promoting simultaneous advocacy against
other competing values. A conservationist researches biodiversity and reasons
through a Resource Conservation Ethic , which identify what measures will
deliver "the greatest good for the greatest number of people for the
longest time."
Some conservation biologists argue that nature has an intrinsic value that is independent of anthropocentric
usefulness or utilitarianism. Intrinsic value advocates that a gene,
or species, be valued because they have a utility for the ecosystems they
sustain. Aldo Leopold was a classical thinker and writer on
such conservation ethics whose philosophy, ethics and writings are still valued
and revisited by modern conservation biologists. His writing is often required
reading for those in the profession.
Conservation priorities
A pie chart image showing the relative biomass
representation in a rain forest through a summary of children's perceptions
from drawings and artwork (left), through a scientific estimate of actual
biomass (middle), and by a measure of biodiversity (right). Notice that the
biomass of social insects (middle) far outweighs the number of species (right).
The International Union for the Conservation of Nature
(IUCN) has organized a global assortment of scientists and research stations
across the planet to monitor the changing state of nature in an effort to
tackle the extinction crisis. The IUCN provides annual updates on the status of
species conservation through its Red List. The IUCN Red List serves as an
international conservation tool to identify those species most in need of
conservation attention and by providing a global index on the status of
biodiversity. More than the dramatic rates of species loss, however,
conservation scientists note that the sixth mass extinction is a biodiversity
crisis requiring far more action than a priority focus on rare,
endemic or endangered species. Concerns for biodiversity
loss covers a broader conservation mandate that looks at ecological processes,
such as migration, and a holistic examination of biodiversity at levels beyond
the species, including genetic, population and ecosystem diversity. Extensive,
systematic, and rapid rates of biodiversity loss threatens the sustained
well-being of humanity by limiting supply of ecosystem services that are
otherwise regenerated by the complex and evolving holistic network of genetic
and ecosystem diversity. While the conservation status of species is employed
extensively in conservation management, some scientists highlight that it is
the common species that are the primary source of exploitation and habitat
alteration by humanity. Moreover, common species are often undervalued despite
their role as the primary source of ecosystem services.
While most in the community of conservation science
"stress the importance" of sustaining
biodiversity, there is debate on how to prioritize genes, species, or
ecosystems, which are all components of biodiversity (e.g. Bowen, 1999). While
the predominant approach to date has been to focus efforts on endangered
species by conserving biodiversity hotspots, some scientists
(e.g) and conservation organizations, such as the Nature Conservancy, argue that it is more
cost-effective, logical, and socially relevant to invest in biodiversity
coldspots. The costs of discovering, naming, and mapping out the
distribution every species, they argue, is an ill advised conservation venture.
They reason it is better to understand the significance of the ecological roles
of species.
Biodiversity hotspots and coldspots are a way of recognizing
that the spatial concentration of genes, species, and ecosystems is not
uniformly distributed on the Earth's surface. For example, "[...] 44% of
all species of vascular plants and 35% of all species in four vertebrate groups
are confined to 25 hotspots comprising only 1.4% of the land surface of the
Earth."
Those arguing in favor of setting priorities for coldspots
point out that there are other measures to consider beyond biodiversity. They
point out that emphasizing hotspots downplays the importance of the social and
ecological connections to vast areas of the Earth's ecosystems where biomass, not
biodiversity, reigns supreme. It is estimated that 36% of the Earth's surface,
encompassing 38.9% of the worlds vertebrates, lacks the endemic
species to qualify as biodiversity hotspot. Moreover, measures show that
maximizing protections for biodiversity does not capture ecosystem services any
better than targeting randomly chosen regions. Population level biodiversity
(i.e. coldspots) are disappearing at a rate that is ten times that at the
species level.The level of importance in addressing biomass versus endemism as
a concern for conservation biology is highlighted in literature measuring the
level of threat to global ecosystem carbon stocks that do not necessarily
reside in areas of endemism. A hotspot priority approach would not
invest so heavily in places such as steppes, the Serengeti,
the Arctic, or taiga. These areas
contribute a great abundance of population (not species) level biodiversity and
ecosystem services, including cultural value and
planetary nutrient cycling..
Those in favor of the hotspot approach point out that
species are irreplaceable components of the global ecosystem, they are
concentrated in places that are most threatened, and should therefore receive
maximal strategic protections. The IUCN
Red List categories, which appear on Wikipedia species articles, is an
example of the hotspot conservation approach in action; species that are not
rare or endemic are listed the least concern and their Wikipedia articles tend
to be ranked low on the importance scale. This is a hotspot approach because
the priority is set to target species level concerns over population level or
biomass. Species richness and genetic biodiversity contributes to and engenders
ecosystem stability, ecosystem processes, evolutionary adaptability,
and biomass. Both sides agree, however, that conserving biodiversity
is necessary to reduce the extinction rate and identify an inherent value in
nature; the debate hinges on how to prioritize limited conservation resources
in the most cost-effective way.
Economic values and natural capital
Conservation biologists have started to collaborate with
leading global economists to determine how to measure the wealth and services of nature and to make these values
apparent in global market transactions. This system of
accounting is called natural capital and would, for example,
register the value of an ecosystem before it is cleared to make way for
development.The WWF publishes its Living Planet Report and provides a
global index of biodiversity by monitoring approximately 5,000 populations
in 1,686 species of vertebrate (mammals, birds, fish, reptiles, and
amphibians) and report on the trends in much the same way that the stock market
is tracked.
This method of measuring the global economic benefit of
nature has been endorsed by the G8+5 leaders and the European Commission. Nature sustains many ecosystem services that benefit humanity.Many of
the earths ecosystem services are public
goods without a market and therefore no price or value. When the stock market registers a
financial crisis, traders on Wall Street are not in the business of trading stocks
for much of the planet's living natural capital stored in ecosystems. There is
no natural stock market with investment portfolios into sea horses, amphibians,
insects, and other creatures that provide a sustainable supply of ecosystem
services that are valuable to society. The ecological footprint of society has
exceeded the bio-regenerative capacity limits of the planet's ecosystems by
about 30 percent, which is the same percentage of vertebrate populations
that have registered decline from 1970 through 2005.
The ecological credit crunch is a global challenge. The
Living Planet Report 2008 tells us that more than three-quarters of the world's
people live in nations that are ecological debtors – their national consumption
has outstripped their country's biocapacity. Thus, most of us are propping up
our current lifestyles, and our economic growth, by drawing (and increasingly
overdrawing) upon the ecological capital of other parts of the world.
WWF Living Planet Report
The inherent natural
economy plays an essential role in sustaining humanity, including the
regulation of global atmospheric chemistry, pollinating crops, pest
control, cycling soil nutrients, purifying our water
supply, supplying medicines and health benefits, and unquantifiable quality
of life improvements. There is a relationship, a correlation,
between markets
and natural capital, and social income inequity and biodiversity
loss. This means that there are greater rates of biodiversity loss in places
where the inequity of wealth is greatest
Although a direct market comparison of natural
capital is likely insufficient in terms of human value,
one measure of ecosystem services suggests the contribution amounts to
trillions of dollars yearly. For example, one segment of North
American forests has been assigned an annual value of 250 billion dollars;
as another example, honey-bee pollination is estimated to provide between 10
and 18 billion dollars of value yearly. The value of ecosystem services on one New Zealand
island has been imputed to be as great as the GDP of that region. This
planetary wealth is being lost at an incredible rate as the demands of human
society is exceeding the bio-regenerative capacity of the Earth. While
biodiversity and ecosystems are resilient, the danger of losing them is that
humans cannot recreate many ecosystem functions through technological innovation.
Strategic species concepts
Keystone species
Some species, called a keystone species, form a
central supporting hub in the ecosystem. The loss of such a species results in
a collapse in ecosystem function, as well as the loss of coexisting species.
The importance of a keystone species was shown by the extinction of the Steller's Sea Cow (Hydrodamalis gigas)
through its interaction with sea otters, sea urchins,
and kelp. Kelp beds
grow and form nurseries in shallow waters to shelter creatures that support the
food chain.
Sea urchins feed on kelp, while sea otters feed on sea urchins. With the rapid
decline of sea otters due to overhunting, sea urchin populations grazed
unrestricted on the kelp beds and the ecosystem collapsed. Left unchecked,
the urchins destroyed the shallow water kelp communities that supported the
Steller's Sea Cow's diet and hastened their demise. The sea otter was thought
to be a keystone species because the coexistence of many ecological associates
in the kelp beds relied upon otters for their survival. However this was later
questioned by Turvey and Risley, who showed that hunting alone would have
driven the Steller's sea cow extinct.
Indicator species
The NAMOS BC logo is an example of an ecosystem umbrella
concept (forests and wetlands) combined with amphibians as indicator and
flagship species.
An indicator species has a narrow set of ecological
requirements, therefore they become useful targets for observing the health of
an ecosystem. Some animals, such as amphibians
with their semi-permeable skin and linkages to wetlands, have an
acute sensitivity to environmental harm and thus may serve as a miner's canary. Indicator species are
monitored in an effort to capture environmental degradation through pollution
or some other link to proximate human activities. Monitoring an indicator
species is a measure to determine if there is a significant environmental
impact that can serve to advise or modify practice, such as through different
forest silviculture
treatments and management scenarios, or to measure the degree of harm that a pesticide may
impart on the health of an ecosystem.
Government regulators, consultants, or NGOs regularly monitor
indicator species, however, there are limitations coupled with many practical
considerations that must be followed for the approach to be effective. It is
generally recommended that multiple indicators (genes, populations, species,
communities, and landscape) be monitored for effective conservation measurement
that prevents harm to the complex, and often unpredictable, response from
ecosystem dynamics (Noss, 1997).
Umbrella and flagship species
An example of an umbrella species is the Monarch butterfly, because of its lengthy migrations
and aesthetic
value. The Monarch migrates across North America, covering multiple ecosystems
and so requires a large area to exist. Any protections afforded to the Monarch
butterfly will at the same time umbrella many other species and habitats. An
umbrella species is often used as flagship species, which are species,
such as the Giant Panda, the Blue Whale,
the tiger, the mountain
gorilla and the Monarch butterfly, that capture the public's attention and
attract support for conservation measures.
Context and trends
Conservation biologists study trends and process from the paleontological
past to the ecological
present as they gain an understanding of the context related to species extinction. It is generally accepted
that there have been five major global mass extinctions that register in
Earth's history. These include: the Ordovician (440 mya),
Devonian (370 mya), Permian–Triassic (245 mya), Triassic–Jurassic (200 mya), and
Cretaceous–Paleogene extinction
event (66 mya) extinction spasms. Within the last 10,000 years, human
influence over the Earth's ecosystems has been so extensive that scientists
have difficulty estimating the number of species lost; that is to say the rates
of deforestation,
reef destruction, wetland
draining and other human acts are proceeding much faster than human
assessment of species. The latest Living Planet Report by the World Wide Fund for Nature estimates
that we have exceeded the bio-regenerative capacity of the planet, requiring
1.5 Earths to support the demands placed on our natural resources.
Sixth extinction
An art scape image showing the relative importance of
animals in a rain forest through a summary of (a) child's perception compared
with (b) a scientific estimate of the importance. The size of the animal
represents its importance. The child's mental image places importance on big
cats, birds, butterflies, and then reptiles versus the actual dominance of
social insects (such as ants).
Conservation biologists are dealing with and have published evidence from
all corners of the planet indicating that humanity may be causing the sixth and
fastest planetary extinction event. It has been suggested that we
are living in an era of unprecedented numbers of species extinctions, also
known as the Holocene extinction event. The global
extinction rate may be approximately 100,000 times higher than the natural background extinction rate. It is
estimated that two-thirds of all mammal genera and one-half of all mammal species weighing
at least 44 kilograms (97 lb) have gone extinct in the last 50,000 years.The
Global Amphibian Assessment reports that amphibians are declining on a
global scale faster than any other vertebrate
group, with over 32% of all surviving species being threatened with extinction.
The surviving populations are in continual decline in 43% of those that are
threatened. Since the mid-1980s the actual rates of extinction have exceeded
211 times rates measured from the fossil
record.However, "The current amphibian extinction rate may range from
25,039 to 45,474 times the background extinction rate for amphibians." The
global extinction trend occurs in every major vertebrate
group that is being monitored. For example, 23% of all mammals and 12%
of all birds are Red
Listed by the International Union for Conservation
of Nature (IUCN), meaning they too are threatened with extinction.
Status of oceans and reefs
Global assessments of coral reefs of the world continue to
report drastic and rapid rates of decline. By 2000, 27% of the world's coral
reef ecosystems had effectively collapsed. The largest period of decline
occurred in a dramatic "bleaching" event in 1998, where approximately
16% of all the coral reefs in the world disappeared in less than a year. Coral
bleaching is caused by a mixture of environmental stresses, including increases in
ocean temperatures and acidity, causing both the release of symbiotic algae and death of
corals. Decline and extinction risk in coral reef biodiversity has risen
dramatically in the past ten years. The loss of coral reefs, which are
predicted to go extinct in the next century, will have huge economic impacts,
threatens the balance of global biodiversity, and endangers food security for
hundreds of millions of people. Conservation biology plays an important role in
international agreements covering the world's oceans(and other issues
pertaining to biodiversity, e.g.).
These predictions will undoubtedly appear extreme, but it
is difficult to imagine how such changes will not come to pass without
fundamental changes in human behavior.
The oceans are threatened by acidification due to an
increase in CO2 levels. This is a most serious threat to societies
relying heavily upon oceanic natural
resources. A concern is that the majority of all marine
species will not be able to evolve or acclimate in response to the changes in the ocean
chemistry.
The prospects of averting mass extinction seems unlikely
when "[...] 90% of all of the large (average approximately ≥50 kg), open
ocean tuna, billfishes, and sharks in the ocean" are reportedly gone.
Given the scientific review of current trends, the ocean is predicted to have
few surviving multi-cellular organisms with only microbes left
to dominate marine ecosystems.
Groups other than vertebrates
Serious concerns also being raised about taxonomic
groups that do not receive the same degree of social attention or attract
funds as the vertebrates. These include fungal (including lichen-forming
species), invertebrate (particularly insect) and plant communities where the vast majority of
biodiversity is represented. Conservation of fungi and conservation of insects,
in particular, are both of pivotal importance for conservation biology. As
mycorrhizal symbionts, and as decomposers and recyclers, fungi are essential
for sustainability of forests. The value of insects in the biosphere is
enormous because they outnumber all other living groups in measure of species
richness. The greatest bulk of biomass on land
is found in plants, which is sustained by insect relations. This great
ecological value of insects is countered by a society that often reacts
negatively toward these aesthetically 'unpleasant' creatures.
One area of concern in the insect world that has caught the
public eye is the mysterious case of missing honey bees
(Apis mellifera). Honey bees provide an indispensable ecological
services through their acts of pollination supporting a huge variety of
agriculture crops. The sudden disappearance of bees leaving empty hives or colony collapse disorder (CCD) is not
uncommon. However, in 16-month period from 2006 through 2007, 29% of 577 beekeepers
across the United States reported CCD losses in up to 76% of their colonies.
This sudden demographic loss in bee numbers is placing a strain on the
agricultural sector. The cause behind the massive declines is puzzling
scientists. Pests, pesticides,
and global
warming are all being considered as possible causes.
Another highlight that links conservation biology to
insects, forests, and climate change is the mountain pine beetle (Dendroctonus
ponderosae) epidemic
of British Columbia, Canada, which has infested
470,000 km2 (180,000 sq mi) of forested land since
1999. An action plan has been prepared by the Government of British Columbia to
address this problem.
This impact [pine beetle epidemic] converted the
forest from a small net carbon sink to a large net carbon source both during
and immediately after the outbreak. In the worst year, the impacts resulting
from the beetle outbreak in British Columbia were equivalent to 75% of the
average annual direct forest fire emissions from all of Canada during
1959–1999.
—Kurz et al.
Conservation biology of parasites
Main article: Conservation biology of parasites
A large proportion of parasite species are threatened by
extinction. A few of them are being eradicated as pests of humans or domestic
animals, however, most of them are harmless. Threats include the decline or
fragmentation of host populations, or the extinction of host species.
Threats to biodiversity
Many of the threats to biodiversity, including disease and
climate change, are reaching inside borders of protected areas, leaving them
'not-so protected' (e.g. Yellowstone National Park). Climate
change, for example, is often cited as a serious threat in this regard,
because there is a feedback loop between species extinction and the
release of carbon dioxide into the atmosphere.
Ecosystems store and cycle large amounts of carbon which regulates global
conditions. The effects of global warming adds a catastrophic threat toward a
mass extinction of global biological diversity. The extinction threat is
estimated to range from 15 to 37 percent of all species by 2050, or 50 percent
of all species over the next 50 years.
Some of the most significant and insidious threats to
biodiversity and ecosystem processes include climate change, mass
agriculture, deforestation, overgrazing,
slash-and-burn
agriculture, urban development, wildlife
trade, light pollution and pesticide
use. Habitat fragmentation poses one of the more
difficult challenges, because the global network of protected areas only covers
11.5% of the Earth's surface. Roads are one cause of fragmentation, as well as a direct
source of mortality
for many types of animals,
but they can also have some beneficial effects. A significant consequence of
fragmentation and lack of linked
protected areas is the reduction of animal migration on a global scale.
Considering that billions of tonnes of biomass are responsible for nutrient
cycling across the earth, the reduction of migration is a serious matter
for conservation biology.
Human activities are associated directly or indirectly with
nearly every aspect of the current extinction spasm.
Wake and Vredenburg
These figures do not imply, however, that human activities
must necessarily cause irreparable harm to the biosphere. With conservation management and planning
for biodiversity at all levels, from genes to ecosystems, there are examples where humans mutually
coexist in a sustainable way with nature. However, it may be too late for human
intervention to reverse the current mass extinction.
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