A renewable resource is a natural resource which replenishes to overcome resource depletion
caused by usage and consumption, either through biological reproduction
or other naturally recurring processes in a finite amount of time in a
human time scale. Renewable resources are a part of Earth's natural
environment and the largest components of its ecosphere. A positive life cycle assessment is a key indicator of a resource's sustainability.
Definitions of renewable resources may also include agricultural production, as in sustainable agriculture and to an extent water resources. In 1962, Paul Alfred Weiss defined Renewable Resources as: "The total range of living organisms providing man with food, fibres, etc...". Another type of renewable resources is renewable energy
resources. Common sources of renewable energy include solar, geothermal
and wind power, which are all categorised as renewable resources.
Global vegetation
oceans and seas often act as renewable resources
Sawmill near Fügen, Zillertal, Austria
Air, food and water
Water resources
Water can be considered a renewable
material when carefully controlled usage, treatment, and release are
followed. If not, it would become a non-renewable resource at that
location. For example, groundwater is usually removed from an aquifer
at a rate much greater than its very slow natural recharge, and so
groundwater is considered non-renewable. Removal of water from the pore
spaces may cause permanent compaction (subsidence) that cannot be renewed. 97.5% of the water on the Earth is salt water, and 3% is fresh water; slightly over two thirds of this is frozen in glaciers and polarice caps.
The remaining unfrozen freshwater is found mainly as groundwater, with
only a small fraction (0.008%) present above ground or in the air.
Water pollution is one of the main concerns regarding water resources. It is estimated that 22% of worldwide water is used in industry. Major industrial users include hydroelectric dams, thermoelectric power plants (which use water for cooling), ore and oil refineries (which use water in chemical processes) and manufacturing plants (which use water as a solvent).
Desalination
of seawater is considered a renewable source of water, although
reducing its dependence on fossil fuel energy is needed for it to be
fully renewable.
Food is any substance consumed to provide nutritional support for the body. Most food has its origin in renewable resources. Food is obtained directly from plants and animals.
Hunting may not be the first source of meat in the modernised
world, but it is still an important and essential source for many rural
and remote groups. It is also the sole source of feeding for wild
carnivores.
Sustainable agriculture
The phrase sustainable agriculture was coined by Australian agricultural scientist Gordon McClymont.
It has been defined as "an integrated system of plant and animal
production practices having a site-specific application that will last
over the long term". Expansion of agricultural land reduces biodiversity and contributes to deforestation. The Food and Agriculture Organisation
of the United Nations estimates that in coming decades, cropland will
continue to be lost to industrial and urban development, along with
reclamation of wetlands, and conversion of forest to cultivation,
resulting in the loss of biodiversity and increased soil erosion.
Although air and sunlight are available everywhere on Earth, crops also depend on soilnutrients and the availability of water. Monoculture
is a method of growing only one crop at a time in a given field, which
can damage land and cause it to become either unusable or suffer from
reduced yields. Monoculture can also cause the build-up of pathogens and pests that target one specific species. The Great Irish Famine (1845–1849) is a well-known example of the dangers of monoculture.
Crop rotation and long-term crop rotations confer the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops, and can improve soil structure and fertility
by alternating deep-rooted and shallow-rooted plants. Other methods to
combat lost soil nutrients are returning to natural cycles that annually
flood cultivated lands (returning lost nutrients indefinitely) such as
the Flooding of the Nile, the long-term use of biochar, and use of crop and livestock landraces that are adapted to less than ideal conditions such as pests, drought, or lack of nutrients.
Agricultural practices are the single greatest contributor to the global increase in soil erosion rates.
It is estimated that "more than a thousand million tonnes of southern
Africa's soil are eroded every year. Experts predict that crop yields
will be halved within thirty to fifty years if erosion continues at
present rates." The Dust Bowl phenomenon in the 1930s was caused by severe drought combined with farming methods that did not include crop rotation, fallow fields, cover crops, soil terracing and wind-breaking trees to prevent wind erosion.
The tillage
of agricultural lands is one of the primary contributing factors to
erosion, due to mechanised agricultural equipment that allows for deep
plowing, which severely increases the amount of soil that is available
for transport by water erosion.
The phenomenon called peak soil describes how large-scale factory farming techniques are affecting humanity's ability to grow food in the future. Without efforts to improve soil management practices, the availability of arable soil may become increasingly problematic.
Methods to combat erosion include no-till farming, using a keyline design, growing wind breaks to hold the soil, and widespread use of compost. Fertilizers and pesticides can also have an effect of soil erosion, which can contribute to soil salinity and prevent other species from growing. Phosphate
is a primary component in the chemical fertiliser applied most commonly
in modern agricultural production. However, scientists estimate that
rock phosphate reserves will be depleted in 50–100 years and that Peak Phosphate will occur in about 2030.
Industrial processing and logistics also have an effect on agriculture's sustainability. The way and locations crops are sold requires energy for transportation, as well as the energy cost for materials, labour, and transport. Food sold at a local location, such a farmers' market, have reduced energy overheads.
Illegal slash and burn practice in Madagascar, 2010
An important renewable resource is wood provided by means of forestry, which has been used for construction, housing and firewood since ancient times.
Plants provide the main sources for renewable resources, the main distinction is made between energy crops and non-food crops. A large variety of lubricants, industrially used vegetable oils, textiles and fibre made e.g. of cotton, copra or hemp, paper derived from wood, rags or grasses, bioplastic are based on plant renewable resources. A large variety of chemical based products like latex, ethanol, resin, sugar and starch can be provided with plant renewables. Animal based renewables include fur, leather, technical fat and lubricants and further derived products, as e.g. animal glue, tendons, casings or in historical times ambra and baleen provided by whaling.
With regard to pharmacy ingredients and legal and illegal drugs,
plants are important sources, however e.g. venom of snakes, frogs and
insects has been a valuable renewable source of pharmacological
ingredients. Before GMO production set in, insulin and important hormones were based on animal sources. Feathers, an important byproduct of poultry farming for food, is still being used as filler and as base for keratin in general. Same applies for the chitin produced in farming Crustaceans which may be used as base of chitosan. The most important part of the human body used for non-medical purposes is human hair as for artificial hair integrations, which is being traded worldwide.
Historical role
An adult and sub-adult Minke whale are dragged aboard the Nisshin Maru, a Japanese whaling vessel
Historically, renewable resources like firewood, latex, guano, charcoal, wood ash, plant colors as indigo, and whale products have been crucial for human needs but failed to supply demand in the beginning of the industrial era. Early modern times faced large problems with overuse of renewable resources as in deforestation, overgrazing or overfishing.
Besides fresh meat and milk, which is as a food item not topic of this section, livestock farmers and artisans used further animal ingredients as tendons, horn, bones, bladders. Complex technical constructions as the composite bow
were based on combination of animal and plant based materials. The
current distribution conflict between biofuel and food production is
being described as Food vs. fuel. Conflicts between food needs and usage, as supposed by fief obligations were in so far common in historical times as well. However, a significant percentage of (middle European) farmers yields went into livestock, which provides as well organic fertiliser. Oxen and horses were important for transportation purposes, drove engines as e.g. in treadmills.
Other regions solved the transportation problem with terracing, urban and garden agriculture.
Further conflicts as between forestry and herding, or (sheep) herders
and cattle farmers led to various solutions. Some confined wool
production and sheep to large state and nobility domains or outsourced
to professional shepherds with larger wandering herds.
The British Agricultural Revolution was mainly based on a new system of crop rotation, the four-field rotation. British agriculturist Charles Townshend recognised the invention in Dutch Waasland and popularised it in the 18th century UK, George Washington Carver in the USA. The system used wheat, turnips and barley and introduced as well clover.
Clover is able to fix nitrogen from air, a practically non exhaustive
renewable resource, into fertilizing compounds to the soil and allowed
to increase yields by large. Farmers opened up a fodder crop and grazing
crop. Thus livestock could to be bred year-round and winter culling was avoided. The amount of manure rose and allowed more crops but to refrain from wood pasture.
Early modern times and the 19th century saw the previous resource
base partially replaced respectively supplemented by large scale
chemical synthesis and by the use of fossil and mineral resources
respectively.
Besides the still central role of wood, there is a sort of renaissance
of renewable products based on modern agriculture, genetic research and
extraction technology. Besides fears about an upcoming global shortage of fossil fuels,
local shortages due to boycotts, war and blockades or just
transportation problems in remote regions have contributed to different
methods of replacing or substituting fossil resources based on
renewables.
Challenges
The use of certain basically renewable products as in TCMendangers various species. Just the black market in rhinoceros horn reduced the world's rhino population by more than 90 percent over the past 40 years.
However the former Plant breeding research institutes took a different approach. After the loss of the German colonial empire, important players in the field as Erwin Baur and Konrad Meyer switched to using local crops as base for economic autarky. Meyer as a key agricultural scientist and spatial planner of the Nazi era managed and lead Deutsche Forschungsgemeinschaft
resources and focused about a third of the complete research grants in
Nazi Germany on agricultural and genetic research and especially on
resources needed in case of a further German war effort.
A wide array of agrarian research institutes still existing today and
having importance in the field was founded or enlarged in the time.
There were some major failures as trying to e.g. grow frost resistant olive species, but some success in the case of hemp, flax, rapeseed, which are still of current importance. During World War 2, German scientists tried to use Russian Taraxacum (dandelion) species to manufacture natural rubber.
Rubber dandelions are still of interest, as scientists in the
Fraunhofer Institute for Molecular Biology and Applied Ecology (IME)
announced 2013 to have developed a cultivar that is suitable for
commercial production of natural rubber.
Legal situation and subsidies
Several legal and economic means have been used to enhance the market share of renewables.
The UK uses Non-Fossil Fuel Obligations (NFFO), a collection of orders requiring the electricity Distribution Network Operators in England and Wales to purchase electricity from the nuclear power and renewable energy sectors. Similar mechanisms operate in Scotland (the Scottish Renewable Orders under the Scottish Renewables Obligation) and Northern Ireland (the Northern Ireland Non-Fossil Fuel Obligation). In the USA, Renewable Energy Certificates (RECs), use a similar approach. German Energiewende
is using fed-in tariffs. An unexpected outcome of the subsidies was the
quick increase of pellet byfiring in conventional fossil fuel plants
(compare Tilbury power stations) and cement works, making wood respectively biomass accounting for about half of Europe’s renewable-energy consumption.
Examples of industrial use
Biorenewable chemicals
Biorenewable chemicals are chemicals created by biological organisms that provide feedstocks for the chemical industry.
Biorenewable chemicals can provide solar-energy-powered substitutes for
the petroleum-based carbon feedstocks that currently supply the
chemical industry. The tremendous diversity of enzymes in biological
organisms, and the potential for synthetic biology
to alter these enzymes to create yet new chemical functionalities, can
drive the chemical industry. A major platform for creation of new
chemicals is the polyketide biosynthetic pathway, which generates chemicals containing repeated alkyl chain units with potential for a wide variety of functional groups at the different carbon atoms.
The production and use of bioplastics is generally regarded as a more sustainable activity
when compared to plastic production from petroleum (petroplastic);
however, manufacturing of bioplastic materials is often still reliant
upon petroleum as an energy and materials source. Because of the
fragmentation in the market and ambiguous definitions it is difficult to
describe the total market size for bioplastics, but the global
production capacity is estimated at 327,000 tonnes. In contrast, global consumption of all flexible packaging is estimated at around 12.3 million tonnes.
Bioasphalt
Bioasphalt is an asphalt alternative made from non-petroleum based renewable resources. Manufacturing sources of bioasphalt include sugar, molasses and rice, corn and potatostarches, and vegetable oil based waste. Asphalt made with vegetable oil based binders was patented by Colas SA in France in 2004.
Biomass is referring to biological material from living, or recently living organisms, most often referring to plants or plant-derived materials.
Sustainable harvesting and use of renewable resources (i.e., maintaining a positive renewal rate) can reduce air pollution, soil contamination, habitat destruction and land degradation. Biomass energy is derived from six distinct energy sources: garbage, wood, plants, waste, landfill gases, and alcohol fuels.
Historically, humans have harnessed biomass-derived energy since the
advent of burning wood to make fire, and wood remains the largest
biomass energy source today.
However, low tech use of biomass, which still amounts for more than 10% of world energy needs may induce indoor air pollution in developing nations and results in between 1.5 million and 2 million deaths in 2000.
The biomass used for electricity generation varies by region. Forest by-products, such as wood residues, are common in the United States. Agricultural waste is common in Mauritius (sugar cane residue) and Southeast Asia (rice husks). Animal husbandry residues, such as poultry litter, are common in the UK. The biomass power generating industry in the United States, which consists of approximately 11,000 MW of summer operating capacity actively supplying power to the grid, produces about 1.4 percent of the U.S. electricity supply.
Natural fibres are a class of hair-like materials that are continuous
filaments or are in discrete elongated pieces, similar to pieces of thread. They can be used as a component of composite materials. They can also be matted into sheets to make products such as paper or felt.
Fibres are of two types: natural fibre which consists of animal and
plant fibres, and man made fibre which consists of synthetic fibres and
regenerated fibres.
Threats to renewable resources
Renewable resources are endangered by non-regulated industrial developments and growth. They must be carefully managed to avoid exceeding the natural world's capacity to replenish them.
A life cycle assessment provides a systematic means of evaluating
renewability. This is a matter of sustainability in the natural
environment.
Overfishing
Atlantic cod stocks severely overfished leading to abrupt collapse
National Geographic
has described ocean over fishing as "simply the taking of wildlife from
the sea at rates too high for fished species to replace themselves."
Tuna
meat is driving overfishing as to endanger some species like the
bluefin tuna. The European Community and other organisations are trying
to regulate fishery as to protect species and to prevent their
extinctions. The United Nations Convention on the Law of the Sea treaty deals with aspects of overfishing in articles 61, 62, and 65.
Besides their role as a resource for fuel and building material,
trees protect the environment by absorbing carbon dioxide and by
creating oxygen. The destruction of rain forests is one of the critical causes of climate change.
Deforestation causes carbon dioxide to linger in the atmosphere. As
carbon dioxide accrues, it produces a layer in the atmosphere that traps
radiation from the sun. The radiation converts to heat which causes global warming, which is better known as the greenhouse effect.
Deforestation also affects the water cycle. It reduces the content of water in the soil and groundwater as well as atmospheric moisture. Deforestation reduces soil cohesion, so that erosion, flooding and landslides ensue.
Rain forests house many species and organisms providing people
with food and other commodities. In this way biofuels may well be
unsustainable if their production contributes to deforestation.
Some renewable resources, species and organisms are facing a very
high risk of extinction caused by growing human population and
over-consumption. It has been estimated that over 40% of all living
species on Earth are at risk of going extinct.
Many nations have laws to protect hunted species and to restrict the
practice of hunting. Other conservation methods include restricting land
development or creating preserves. The IUCN Red List of Threatened Species is the best-known worldwide conservation status listing and ranking system. Internationally, 199 countries have signed an accord agreeing to create Biodiversity Action Plans to protect endangered and other threatened species.
Efforts are made to preserve the natural characteristics of Hopetoun Falls, Australia, without affecting visitors' access.
Conservation biology is the management of nature and 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.
Origins
The
term conservation biology and its conception as a new field originated
with the convening of "The First International Conference on Research in
Conservation Biology" held at the University of California, San Diego in La Jolla, California in 1978 led by American biologists Bruce A. Wilcox and Michael E. Soulé with a group of leading university and zoo researchers and conservationists including Kurt Benirschke, Sir Otto Frankel, Thomas Lovejoy, and Jared Diamond. The meeting was prompted by the concern over tropical deforestation, disappearing species, eroding genetic diversity within species. The conference and proceedings that resulted
sought to initiate the bridging of a gap between theory in ecology and
evolutionary genetics 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 new subdisciplines including conservation social science, conservation behavior and conservation physiology. It stimulated further development of conservation genetics which Otto Frankel had originated first but is now often considered a subdiscipline as well.
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. The topics of their research 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 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.[7][21]
There are numerous examples in history where cultures have followed
rules, rituals, and organized practice with respect to communal natural
resource management.
The Mauryan emperor Ashoka
around 250 B.C. issued edicts restricting the slaughter of animals and
certain kinds of birds, as well as opened veterinary clinics.
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.
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.
Before Charles Darwin set sail on HMS Beagle, most people in the world, including Darwin, believed in special creation and that all species were unchanged.
George-Louis Leclerc was one of the first naturalist that questioned
this belief. He proposed in his 44 volume natural history book that
species evolve due to environmental influences.
Erasmus Darwin was also a naturalist who also suggested that species
evolved. Erasmus Darwin noted that some species have vestigial
structures which are anatomical structures that have no apparent
function in the species currently but would have been useful for the
species' ancestors.
The thinking of these early 18th century naturalist helped to change
the mindset and thinking of the early 19th century naturalist.
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-GeneralLord 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[38] after extensive lobbying from the Association for the Protection of Seabirds[39] and the respected ornithologistAlfred Newton.[40] 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 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 his son 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 conservationists,
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.
“
The
last word in ignorance is the man who says of an animal or plant: "What
good is it?" If the land mechanism as a whole is good, then every part
is good, whether we understand it or not. If the biota, in the course of
aeons, has built something we like but do not understand, then who but a
fool would discard seemingly useless parts? To keep every cog and wheel
is the first precaution of intelligent tinkering.
The blue graph shows the apparent percentage (not the absolute number) of marine animalgenera
becoming extinct during any given time interval. It does not represent
all marine species, just those that are readily fossilized. The labels
of the traditional "Big Five" extinction events and the more recently
recognised End-Capitanian extinction event are clickable hyperlinks; see Extinction event for more details.
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 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 healthyecosystems?
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 restoring the habitat.
Ex-situ conservation, on the other hand, involves protection outside of
an organism's natural habitat, such as on reservations or in gene banks,
in circumstances where viable populations may not be present in the
natural habitat.
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.
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 may be inspired by the resource conservation ethic, which seeks to identify what measures will deliver "the greatest good for the greatest number of people for the longest time." In contrast, 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.
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 of
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.
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 Earth's 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.
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 unique to their ecosystem. The loss of such a species results in a collapse in ecosystem function, as well as the loss of coexisting species. Keystone species are usually predators due to their ability to control the population of prey in their ecosystem. 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
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.
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. Paradoxically, however, conservation bias towards flagship species sometimes threatens other species of chief concern.
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 1.6 Earths to support the demands placed on our
natural resources.
Holocene 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 1,000 times higher than the natural background extinction rate. It is estimated that two-thirds of all mammalgenera 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. Even though
extinction is natural, the decline in species is happening at such an
incredible rate that evolution can simply not match, therefore, leading
to the greatest continual mass extinction on Earth.
Humans have dominated the planet and our high consumption of resources,
along with the pollution generated is affecting the environments in
which other species live.
There are a wide variety of species that humans are working to protect
such as the Hawaiian Crow and the Whooping Crane of Texas.
People can also take action on preserving species by advocating and
voting for global and national policies that improve climate, under the
concepts of climate mitigation and climate restoration.
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 symbioticalgae 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, threatens the balance of
global biodiversity, will have huge economic impacts, 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).
The oceans are threatened by acidification due to an increase in CO2 levels (DJS: acidification should be defined here -- e.g., it does not mean the oceans are becoming or will become acidic (pH < 7)). 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 plantcommunities
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
use of honey and wax have become vastly used throughout the world. 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. (DJS: honey bee populations have rebounded significantly since then.)
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
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
Today, many threats to Biodiversity exist. An acronym that can be
used to express the top threats of present-day H.I.P.P.O stands for
Habitat Loss, Invasive Species, Pollution, Human Population, and
Overharvesting. The primary threats to biodiversity are habitat destruction (such as deforestation, agricultural expansion, urban development), and overexploitation (such as wildlife trade). Habitat fragmentation also poses challenges, because the global network of protected areas only covers 11.5% of the Earth's surface. 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.
However, human activities need not 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. Even with the current threats to biodiversity there are ways we can improve the current condition and start anew.
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. In present day, there have been major climate shifts with temperature changes making survival of some species difficult. The effects of global warming add a catastrophic threat toward a mass extinction of global biological diversity.
Conservationists have claimed that not all the species can be saved,
and they have to decide which their efforts should be used to protect.
This concept is known as the Conservation Triage. 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. The current extinction rate is 100-100,000 times more rapid today than the last several billion years.
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