Biodiversity refers to the variety and variability
of life on Earth. Biodiversity typically measures
variation at the genetic, species, and ecosystem
level. Terrestrial biodiversity is usually
greater near the equator, which is the result
of the warm climate and high primary productivity.
Biodiversity is not distributed evenly on
Earth, and is richest in the tropics. These
tropical forest ecosystems cover less than
10 percent of earth's surface, and contain
about 90 percent of the world's species. Marine
biodiversity is usually highest along coasts
in the Western Pacific, where sea surface
temperature is highest, and in the mid-latitudinal
band in all oceans. There are latitudinal
gradients in species diversity. Biodiversity
generally tends to cluster in hotspots, and
has been increasing through time, but will
be likely to slow in the future.Rapid environmental
changes typically cause mass extinctions.
More than 99.9 percent of all species that
ever lived on Earth, amounting to over five
billion species, are estimated to be extinct.
Estimates on the number of Earth's current
species range from 10 million to 14 million,
of which about 1.2 million have been documented
and over 86 percent have not yet been described.
More recently, in May 2016, scientists reported
that 1 trillion species are estimated to be
on Earth currently with only one-thousandth
of one percent described. The total amount
of related DNA base pairs on Earth is estimated
at 5.0 x 1037 and weighs 50 billion tonnes.
In comparison, the total mass of the biosphere
has been estimated to be as much as 4 TtC
(trillion tons of carbon). In July 2016, scientists
reported identifying a set of 355 genes from
the Last Universal Common Ancestor (LUCA)
of all organisms living on Earth.The age of
the Earth is about 4.54 billion years. The
earliest undisputed evidence of life on Earth
dates at least from 3.5 billion years ago,
during the Eoarchean Era after a geological
crust started to solidify following the earlier
molten Hadean Eon. There are microbial mat
fossils found in 3.48 billion-year-old sandstone
discovered in Western Australia. Other early
physical evidence of a biogenic substance
is graphite in 3.7 billion-year-old meta-sedimentary
rocks discovered in Western Greenland. More
recently, in 2015, "remains of biotic life"
were found in 4.1 billion-year-old rocks in
Western Australia. According to one of the
researchers, "If life arose relatively quickly
on Earth .. then it could be common in the
universe."Since life began on Earth, five
major mass extinctions and several minor events
have led to large and sudden drops in biodiversity.
The Phanerozoic eon (the last 540 million
years) marked a rapid growth in biodiversity
via the Cambrian explosion—a period during
which the majority of multicellular phyla
first appeared. The next 400 million years
included repeated, massive biodiversity losses
classified as mass extinction events. In the
Carboniferous, rainforest collapse led to
a great loss of plant and animal life. The
Permian–Triassic extinction event, 251 million
years ago, was the worst; vertebrate recovery
took 30 million years. The most recent, the
Cretaceous–Paleogene extinction event, occurred
65 million years ago and has often attracted
more attention than others because it resulted
in the extinction of the dinosaurs.The period
since the emergence of humans has displayed
an ongoing biodiversity reduction and an accompanying
loss of genetic diversity. Named the Holocene
extinction, the reduction is caused primarily
by human impacts, particularly habitat destruction.
Conversely, biodiversity positively impacts
human health in a number of ways, although
a few negative effects are studied.The United
Nations designated 2011–2020 as the United
Nations Decade on Biodiversity.
== History of terminology ==
1968 - The term biological diversity was used
first by Dasmann.
1975 - The term natural diversity was introduced
(by The Science Division of The Nature Conservancy
in a 1975 study, "The Preservation of Natural
Diversity.")Template:Citation needed=January2019
1980 - Thomas Lovejoy introduced the term
biological diversity to the scientific community
in a book.. It rapidly became commonly used.
1985 -The contracted form biodiversity was
coined by W. G. Rosen
1985 - The term "biodiversity" appears in
the article, "A New Plan to Conserve the Earth's
Biota" by Laura Tangley.
1988 - The term biodiversity first appeared
in a publication.
The present - the term has achieved widespread
use.
== Definitions ==
=== Prior term ===
"Biodiversity" is most commonly used to replace
the more clearly defined and long established
terms, species diversity and species richness.
=== Alternate terms ===
Biologists most often define biodiversity
as the "totality of genes, species and ecosystems
of a region". An advantage of this definition
is that it seems to describe most circumstances
and presents a unified view of the traditional
types of biological variety previously identified:
taxonomic diversity (usually measured at the
species diversity level)
ecological diversity (often viewed from the
perspective of ecosystem diversity)
morphological diversity (which stems from
genetic diversity and molecular diversity)
functional diversity (which is a measure of
the number of functionally disparate species
within a population (e.g. different feeding
mechanism, different motility, predator vs
prey, etc.)) This multilevel construct is
consistent with Datman and Lovejoy.
=== Wilcox 1982 ===
An explicit definition consistent with this
interpretation was first given in a paper
by Bruce A. Wilcox commissioned by the International
Union for the Conservation of Nature and Natural
Resources (IUCN) for the 1982 World National
Parks Conference. Wilcox's definition was
"Biological diversity is the variety of life
forms...at all levels of biological systems
(i.e., molecular, organismic, population,
species and ecosystem)...".
=== Genetic: Wilcox 1984 ===
Biodiversity can be defined genetically as
the diversity of alleles, genes and organisms.
They study processes such as mutation and
gene transfer that drive evolution.
=== United Nations 1992 ===
The 1992 United Nations Earth Summit defined
"biological diversity" as "the variability
among living organisms from all sources, including,
'inter alia', terrestrial, marine and other
aquatic ecosystems and the ecological complexes
of which they are part: this includes diversity
within species, between species and of ecosystems".
This definition is used in the United Nations
Convention on Biological Diversity.
=== Gaston and Spicer 2004 ===
Gaston & Spicer's definition in their book
"Biodiversity: an introduction" is "variation
of life at all levels of biological organization".
== Distribution ==
Biodiversity is not evenly distributed, rather
it varies greatly across the globe as well
as within regions. Among other factors, the
diversity of all living things (biota) depends
on temperature, precipitation, altitude, soils,
geography and the presence of other species.
The study of the spatial distribution of organisms,
species and ecosystems, is the science of
biogeography.
Diversity consistently measures higher in
the tropics and in other localized regions
such as the Cape Floristic Region and lower
in polar regions generally. Rain forests that
have had wet climates for a long time, such
as Yasuní National Park in Ecuador, have
particularly high biodiversity.Terrestrial
biodiversity is thought to be up to 25 times
greater than ocean biodiversity. A new method
used in 2011, put the total number of species
on Earth at 8.7 million, of which 2.1 million
were estimated to live in the ocean. However,
this estimate seems to under-represent the
diversity of microorganisms.
=== Latitudinal gradients ===
Generally, there is an increase in biodiversity
from the poles to the tropics. Thus localities
at lower latitudes have more species than
localities at higher latitudes. This is often
referred to as the latitudinal gradient in
species diversity. Several ecological factors
may contribute to the gradient, but the ultimate
factor behind many of them is the greater
mean temperature at the equator compared to
that of the poles.Even though terrestrial
biodiversity declines from the equator to
the poles, some studies claim that this characteristic
is unverified in aquatic ecosystems, especially
in marine ecosystems. The latitudinal distribution
of parasites does not appear to follow this
rule.In 2016, an alternative hypothesis ("the
fractal biodiversity") was proposed to explain
the biodiversity latitudinal gradient. In
this study, the species pool size and the
fractal nature of ecosystems were combined
to clarify some general patterns of this gradient.
This hypothesis considers temperature, moisture,
and net primary production (NPP) as the main
variables of an ecosystem niche and as the
axis of the ecological hypervolume. In this
way, it is possible to build fractal hypervolumes,
whose fractal dimension rises up to three
moving towards the equator.
=== Hotspots ===
A biodiversity hotspot is a region with a
high level of endemic species that have experienced
great habitat loss. The term hotspot was introduced
in 1988 by Norman Myers. While hotspots are
spread all over the world, the majority are
forest areas and most are located in the tropics.
Brazil's Atlantic Forest is considered one
such hotspot, containing roughly 20,000 plant
species, 1,350 vertebrates and millions of
insects, about half of which occur nowhere
else. The island of Madagascar and India are
also particularly notable. Colombia is characterized
by high biodiversity, with the highest rate
of species by area unit worldwide and it has
the largest number of endemics (species that
are not found naturally anywhere else) of
any country. About 10% of the species of the
Earth can be found in Colombia, including
over 1,900 species of bird, more than in Europe
and North America combined, Colombia has 10%
of the world's mammals species, 14% of the
amphibian species and 18% of the bird species
of the world. Madagascar dry deciduous forests
and lowland rainforests possess a high ratio
of endemism. Since the island separated from
mainland Africa 66 million years ago, many
species and ecosystems have evolved independently.
Indonesia's 17,000 islands cover 735,355 square
miles (1,904,560 km2) and contain 10% of the
world's flowering plants, 12% of mammals and
17% of reptiles, amphibians and birds—along
with nearly 240 million people. Many regions
of high biodiversity and/or endemism arise
from specialized habitats which require unusual
adaptations, for example, alpine environments
in high mountains, or Northern European peat
bogs.Accurately measuring differences in biodiversity
can be difficult. Selection bias amongst researchers
may contribute to biased empirical research
for modern estimates of biodiversity. In 1768,
Rev. Gilbert White succinctly observed of
his Selborne, Hampshire "all nature is so
full, that that district produces the most
variety which is the most examined."
== 
Evolution ==
=== 
Chronology ===
Biodiversity is the result of 3.5 billion
years of evolution. The origin of life has
not been definitely established by science,
however some evidence suggests that life may
already have been well-established only a
few hundred million years after the formation
of the Earth. Until approximately 600 million
years ago, all life consisted of microorganisms
– archaea, bacteria, and single-celled protozoans
and protists.
The history of biodiversity during the Phanerozoic
(the last 540 million years), starts with
rapid growth during the Cambrian explosion—a
period during which nearly every phylum of
multicellular organisms first appeared. Over
the next 400 million years or so, invertebrate
diversity showed little overall trend and
vertebrate diversity shows an overall exponential
trend. This dramatic rise in diversity was
marked by periodic, massive losses of diversity
classified as mass extinction events. A significant
loss occurred when rainforests collapsed in
the carboniferous. The worst was the Permian-Triassic
extinction event, 251 million years ago. Vertebrates
took 30 million years to recover from this
event.The fossil record suggests that the
last few million years featured the greatest
biodiversity in history. However, not all
scientists support this view, since there
is uncertainty as to how strongly the fossil
record is biased by the greater availability
and preservation of recent geologic sections.
Some scientists believe that corrected for
sampling artifacts, modern biodiversity may
not be much different from biodiversity 300
million years ago., whereas others consider
the fossil record reasonably reflective of
the diversification of life. Estimates of
the present global macroscopic species diversity
vary from 2 million to 100 million, with a
best estimate of somewhere near 9 million,
the vast majority arthropods. Diversity appears
to increase continually in the absence of
natural selection.
=== Diversification ===
The existence of a global carrying capacity,
limiting the amount of life that can live
at once, is debated, as is the question of
whether such a limit would also cap the number
of species. While records of life in the sea
shows a logistic pattern of growth, life on
land (insects, plants and tetrapods) shows
an exponential rise in diversity. As one author
states, "Tetrapods have not yet invaded 64
per cent of potentially habitable modes and
it could be that without human influence the
ecological and taxonomic diversity of tetrapods
would continue to increase in an exponential
fashion until most or all of the available
ecospace is filled."It also appears that the
diversity continue to increase over time,
especially after mass extinctions.On the other
hand, changes through the Phanerozoic correlate
much better with the hyperbolic model (widely
used in population biology, demography and
macrosociology, as well as fossil biodiversity)
than with exponential and logistic models.
The latter models imply that changes in diversity
are guided by a first-order positive feedback
(more ancestors, more descendants) and/or
a negative feedback arising from resource
limitation. Hyperbolic model implies a second-order
positive feedback. The hyperbolic pattern
of the world population growth arises from
a second-order positive feedback between the
population size and the rate of technological
growth. The hyperbolic character of biodiversity
growth can be similarly accounted for by a
feedback between diversity and community structure
complexity. The similarity between the curves
of biodiversity and human population probably
comes from the fact that both are derived
from the interference of the hyperbolic trend
with cyclical and stochastic dynamics.Most
biologists agree however that the period since
human emergence is part of a new mass extinction,
named the Holocene extinction event, caused
primarily by the impact humans are having
on the environment. It has been argued that
the present rate of extinction is sufficient
to eliminate most species on the planet Earth
within 100 years.In 2011, in his Biodiversity-related
Niches Differentiation Theory, Roberto Cazzolla
Gatti proposed that species themselves are
the architects of biodiversity, by proportionally
increasing the number of potentially available
niches in a given ecosystem. This study led
to the idea that biodiversity is autocatalytic.
An ecosystem of interdependent species can
be, therefore, considered as an emergent autocatalytic
set (a self-sustaining network of mutually
"catalytic" entities), where one (group of)
species enables the existence of (i.e., creates
niches for) other species. This view offers
a possible answer to the fundamental question
of why so many species can coexist in the
same ecosystem.
New species are regularly discovered (on average
between 5–10,000 new species each year,
most of them insects) and many, though discovered,
are not yet classified (estimates are that
nearly 90% of all arthropods are not yet classified).
Most of the terrestrial diversity is found
in tropical forests and in general, land has
more species than the ocean; some 8.7 million
species may exists on Earth, of which some
2.1 million live in the ocean.
== Ecosystem services ==
=== 
The balance of evidence ===
"Ecosystem services are the suite of benefits
that ecosystems provide to humanity." The
natural species, or biota, are the caretakers
of all ecosystems. It is as if the natural
world is an enormous bank account of capital
assets capable of paying life sustaining dividends
indefinitely, but only if the capital is maintained.These
services come in three flavors:
Provisioning services which involve the production
of renewable resources (e.g.: food, wood,
fresh water)
Regulating services which are those that lessen
environmental change (e.g.: climate regulation,
pest/disease control)
Cultural services represent human value and
enjoyment (e.g.: landscape aesthetics, cultural
heritage, outdoor recreation and spiritual
significance)There have been many claims about
biodiversity's effect on these ecosystem services,
especially provisioning and regulating services.
After an exhaustive survey through peer-reviewed
literature to evaluate 36 different claims
about biodiversity's effect on ecosystem services,
14 of those claims have been validated, 6
demonstrate mixed support or are unsupported,
3 are incorrect and 13 lack enough evidence
to draw definitive conclusions.
==== Services enhanced ====
===== 
Provisioning services =====
Greater species diversity
of plants increases fodder yield (synthesis
of 271 experimental studies).
of plants (i.e. diversity within a single
species) increases overall crop yield (synthesis
of 575 experimental studies). Although another
review of 100 experimental studies reports
mixed evidence.
of trees increases overall wood production
(Synthesis of 53 experimental studies). However,
there is not enough data to draw a conclusion
about the effect of tree trait diversity on
wood production.
===== Regulating services =====
Greater species diversity
of fish increases the stability of fisheries
yield (Synthesis of 8 observational studies)
of natural pest enemies decreases herbivorous
pest populations (Data from two separate reviews;
Synthesis of 266 experimental and observational
studies; Synthesis of 18 observational studies.
Although another review of 38 experimental
studies found mixed support for this claim,
suggesting that in cases where mutual intraguild
predation occurs, a single predatory species
is often more effective
of plants decreases disease prevalence on
plants (Synthesis of 107 experimental studies)
of plants increases resistance to plant invasion
(Data from two separate reviews; Synthesis
of 105 experimental studies; Synthesis of
15 experimental studies)
of plants increases carbon sequestration,
but note that this finding only relates to
actual uptake of carbon dioxide and not long
term storage, see below; Synthesis of 479
experimental studies)
plants increases soil nutrient remineralization
(Synthesis of 103 experimental studies)
of plants increases soil organic matter (Synthesis
of 85 experimental studies)
==== Services with mixed evidence ====
===== 
Provisioning services =====
None to date
===== Regulating services =====
Greater species diversity of plants may or
may not decrease herbivorous pest populations.
Data from two separate reviews suggest that
greater diversity decreases pest populations
(Synthesis of 40 observational studies; Synthesis
of 100 experimental studies). One review found
mixed evidence (Synthesis of 287 experimental
studies), while another found contrary evidence
(Synthesis of 100 experimental studies)
Greater species diversity of animals may or
may not decrease disease prevalence on those
animals (Synthesis of 45 experimental and
observational studies), although a 2013 study
offers more support showing that biodiversity
may in fact enhance disease resistance within
animal communities, at least in amphibian
frog ponds. Many more studies must be published
in support of diversity to sway the balance
of evidence will be such that we can draw
a general rule on this service.
Greater species and trait diversity of plants
may or may not increase long term carbon storage
(Synthesis of 33 observational studies)
Greater pollinator diversity may or may not
increase pollination (Synthesis of 7 observational
studies), but a publication from March 2013
suggests that increased native pollinator
diversity enhances pollen deposition (although
not necessarily fruit set as the authors would
have you believe, for details explore their
lengthy supplementary material).
==== Services hindered ====
===== 
Provisioning services =====
Greater species diversity of plants reduces
primary production (Synthesis of 7 experimental
studies)
===== Regulating services =====
greater genetic and species diversity of a
number of organisms reduces freshwater purification
(Synthesis of 8 experimental studies, although
an attempt by the authors to investigate the
effect of detritivore diversity on freshwater
purification was unsuccessful due to a lack
of available evidence (only 1 observational
study was found
===== 
Provisioning services =====
Effect of species diversity of plants on biofuel
yield (In a survey of the literature, the
investigators only found 3 studies)
Effect of species diversity of fish on fishery
yield (In a survey of the literature, the
investigators only found 4 experimental studies
and 1 observational study)
===== Regulating services =====
Effect of species diversity on the stability
of biofuel yield (In a survey of the literature,
the investigators did not find any studies)
Effect of species diversity of plants on the
stability of fodder yield (In a survey of
the literature, the investigators only found
2 studies)
Effect of species diversity of plants on the
stability of crop yield (In a survey of the
literature, the investigators only found 1
study)
Effect of genetic diversity of plants on the
stability of crop yield (In a survey of the
literature, the investigators only found 2
studies)
Effect of diversity on the stability of wood
production (In a survey of the literature,
the investigators could not find any studies)
Effect of species diversity of multiple taxa
on erosion control (In a survey of the literature,
the investigators could not find any studies
– they did however find studies on the effect
of species diversity and root biomass)
Effect of diversity on flood regulation (In
a survey of the literature, the investigators
could not find any studies)
Effect of species and trait diversity of plants
on soil moisture (In a survey of the literature,
the investigators only found 2 studies)Other
sources have reported somewhat conflicting
results and in 1997 Robert Costanza and his
colleagues reported the estimated global value
of ecosystem services (not captured in traditional
markets) at an average of $33 trillion annually.Since
the stone age, species loss has accelerated
above the average basal rate, driven by human
activity. Estimates of species losses are
at a rate 100-10,000 times as fast as is typical
in the fossil record.
Biodiversity also affords many non-material
benefits including spiritual and aesthetic
values, knowledge systems and education.
=== Agriculture ===
Agricultural diversity can be divided into
two categories: intraspecific diversity, which
includes the genetic variety within a single
species, like the potato (Solanum tuberosum)
that is composed of many different forms and
types (e.g. in the U.S. they might compare
russet potatoes with new potatoes or purple
potatoes, all different, but all part of the
same species, S. tuberosum).
The other category of agricultural diversity
is called interspecific diversity and refers
to the number and types of different species.
Thinking about this diversity we might note
that many small vegetable farmers grow many
different crops like potatoes and also carrots,
peppers, lettuce etc.
Agricultural diversity can also be divided
by whether it is ‘planned’ diversity or
‘associated’ diversity. This is a functional
classification that we impose and not an intrinsic
feature of life or diversity. Planned diversity
includes the crops which a farmer has encouraged,
planted or raised (e.g. crops, covers, symbionts
and livestock, among others), which can be
contrasted with the associated diversity that
arrives among the crops, uninvited (e.g. herbivores,
weed species and pathogens, among others).The
control of associated biodiversity is one
of the great agricultural challenges that
farmers face. On monoculture farms, the approach
is generally to eradicate associated diversity
using a suite of biologically destructive
pesticides, mechanized tools and transgenic
engineering techniques, then to rotate crops.
Although some polyculture farmers use the
same techniques, they also employ integrated
pest management strategies as well as strategies
that are more labor-intensive, but generally
less dependent on capital, biotechnology and
energy.
Interspecific crop diversity is, in part,
responsible for offering variety in what we
eat. Intraspecific diversity, the variety
of alleles within a single species, also offers
us choice in our diets. If a crop fails in
a monoculture, we rely on agricultural diversity
to replant the land with something new. If
a wheat crop is destroyed by a pest we may
plant a hardier variety of wheat the next
year, relying on intraspecific diversity.
We may forgo wheat production in that area
and plant a different species altogether,
relying on interspecific diversity. Even an
agricultural society which primarily grows
monocultures, relies on biodiversity at some
point.
The Irish potato blight of 1846 was a major
factor in the deaths of one million people
and the emigration of about two million. It
was the result of planting only two potato
varieties, both vulnerable to the blight,
Phytophthora infestans, which arrived in 1845
When rice grassy stunt virus struck rice fields
from Indonesia to India in the 1970s, 6,273
varieties were tested for resistance. Only
one was resistant, an Indian variety and known
to science only since 1966. This variety formed
a hybrid with other varieties and is now widely
grown.
Coffee rust attacked coffee plantations in
Sri Lanka, Brazil and Central America in 1970.
A resistant variety was found in Ethiopia.
The diseases are themselves a form of biodiversity.Monoculture
was a contributing factor to several agricultural
disasters, including the European wine industry
collapse in the late 19th century and the
US southern corn leaf blight epidemic of 1970.Although
about 80 percent of humans' food supply comes
from just 20 kinds of plants, humans use at
least 40,000 species. Many people depend on
these species for food, shelter and clothing.
Earth's surviving biodiversity provides resources
for increasing the range of food and other
products suitable for human use, although
the present extinction rate shrinks that potential.
=== Human health ===
Biodiversity's relevance to human health is
becoming an international political issue,
as scientific evidence builds on the global
health implications of biodiversity loss.
This issue is closely linked with the issue
of climate change, as many of the anticipated
health risks of climate change are associated
with changes in biodiversity (e.g. changes
in populations and distribution of disease
vectors, scarcity of fresh water, impacts
on agricultural biodiversity and food resources
etc.). This is because the species most likely
to disappear are those that buffer against
infectious disease transmission, while surviving
species tend to be the ones that increase
disease transmission, such as that of West
Nile Virus, Lyme disease and Hantavirus, according
to a study done co-authored by Felicia Keesing,
an ecologist at Bard College and Drew Harvell,
associate director for Environment of the
Atkinson Center for a Sustainable Future (ACSF)
at Cornell University.The growing demand and
lack of drinkable water on the planet presents
an additional challenge to the future of human
health. Partly, the problem lies in the success
of water suppliers to increase supplies and
failure of groups promoting preservation of
water resources. While the distribution of
clean water increases, in some parts of the
world it remains unequal. According to the
World Health Organisation (2018) only 71%
of the global population used a safely managed
drinking-water service.Some of the health
issues influenced by biodiversity include
dietary health and nutrition security, infectious
disease, medical science and medicinal resources,
social and psychological health. Biodiversity
is also known to have an important role in
reducing disaster risk and in post-disaster
relief and recovery efforts.Biodiversity provides
critical support for drug discovery and the
availability of medicinal resources. A significant
proportion of drugs are derived, directly
or indirectly, from biological sources: at
least 50% of the pharmaceutical compounds
on the US market are derived from plants,
animals and micro-organisms, while about 80%
of the world population depends on medicines
from nature (used in either modern or traditional
medical practice) for primary healthcare.
Only a tiny fraction of wild species has been
investigated for medical potential. Biodiversity
has been critical to advances throughout the
field of bionics. Evidence from market analysis
and biodiversity science indicates that the
decline in output from the pharmaceutical
sector since the mid-1980s can be attributed
to a move away from natural product exploration
("bioprospecting") in favor of genomics and
synthetic chemistry, indeed claims about the
value of undiscovered pharmaceuticals may
not provide enough incentive for companies
in free markets to search for them because
of the high cost of development; meanwhile,
natural products have a long history of supporting
significant economic and health innovation.
Marine ecosystems are particularly important,
although inappropriate bioprospecting can
increase biodiversity loss, as well as violating
the laws of the communities and states from
which the resources are taken.
=== Business and industry ===
Many industrial materials derive directly
from biological sources. These include building
materials, fibers, dyes, rubber and oil. Biodiversity
is also important to the security of resources
such as water, timber, paper, fiber and food.
As a result, biodiversity loss is a significant
risk factor in business development and a
threat to long term economic sustainability.
=== Leisure, cultural and aesthetic value
===
Biodiversity enriches leisure activities such
as hiking, birdwatching or natural history
study. Biodiversity inspires musicians, painters,
sculptors, writers and other artists. Many
cultures view themselves as an integral part
of the natural world which requires them to
respect other living organisms.
Popular activities such as gardening, fishkeeping
and specimen collecting strongly depend on
biodiversity. The number of species involved
in such pursuits is in the tens of thousands,
though the majority do not enter commerce.
The relationships between the original natural
areas of these often exotic animals and plants
and commercial collectors, suppliers, breeders,
propagators and those who promote their understanding
and enjoyment are complex and poorly understood.
The general public responds well to exposure
to rare and unusual organisms, reflecting
their inherent value.
Philosophically it could be argued that biodiversity
has intrinsic aesthetic and spiritual value
to mankind in and of itself. This idea can
be used as a counterweight to the notion that
tropical forests and other ecological realms
are only worthy of conservation because of
the services they provide.
=== Ecological services ===
Biodiversity supports many ecosystem services:
"There is now unequivocal evidence that biodiversity
loss reduces the efficiency by which ecological
communities capture biologically essential
resources, produce biomass, decompose and
recycle biologically essential nutrients...
There is mounting evidence that biodiversity
increases the stability of ecosystem functions
through time... Diverse communities are more
productive because they contain key species
that have a large influence on productivity
and differences in functional traits among
organisms increase total resource capture...
The impacts of diversity loss on ecological
processes might be sufficiently large to rival
the impacts of many other global drivers of
environmental change... Maintaining multiple
ecosystem processes at multiple places and
times requires higher levels of biodiversity
than does a single process at a single place
and time."
It plays a part in regulating the chemistry
of our atmosphere and water supply. Biodiversity
is directly involved in water purification,
recycling nutrients and providing fertile
soils. Experiments with controlled environments
have shown that humans cannot easily build
ecosystems to support human needs; for example
insect pollination cannot be mimicked, though
there have been attempts to create artificial
pollinators using unmanned aerial vehicles.
The economic activity of pollination alone
represented between $2.1-14.6 billions in
2003.
== Number of species ==
According to Mora and colleagues, the total
number of terrestrial species is estimated
to be around 8.7 million while the number
of oceanic species is much lower, estimated
at 2.2 million. The authors note that these
estimates are strongest for eukaryotic organisms
and likely represent the lower bound of prokaryote
diversity. Other estimates include:
220,000 vascular plants, estimated using the
species-area relation method
0.7-1 million marine species
10–30 million insects; (of some 0.9 million
we know today)
5–10 million bacteria;
1.5-3 million fungi, estimates based on data
from the tropics, long-term non-tropical sites
and molecular studies that have revealed cryptic
speciation. Some 0.075 million species of
fungi had been documented by 2001)
1 million mites
The number of microbial species is not reliably
known, but the Global Ocean Sampling Expedition
dramatically increased the estimates of genetic
diversity by identifying an enormous number
of new genes from near-surface plankton samples
at various marine locations, initially over
the 2004-2006 period. The findings may eventually
cause a significant change in the way science
defines species and other taxonomic categories.Since
the rate of extinction has increased, many
extant species may become extinct before they
are described. Not surprisingly, in the animalia
the most studied groups are birds and mammals,
whereas fishes and arthropods are the least
studied animals groups.
== Measuring biodiversity ==
== 
Species loss rates ==
No longer do we have to justify the existence
of humid tropical forests on the feeble grounds
that they might carry plants with drugs that
cure human disease. Gaia theory forces us
to see that they offer much more than this.
Through their capacity to evapotranspirate
vast volumes of water vapor, they serve to
keep the planet cool by wearing a sunshade
of white reflecting cloud. Their replacement
by cropland could precipitate a disaster that
is global in scale.
During the last century, decreases in biodiversity
have been increasingly observed. In 2007,
German Federal Environment Minister Sigmar
Gabriel cited estimates that up to 30% of
all species will be extinct by 2050. Of these,
about one eighth of known plant species are
threatened with extinction. Estimates reach
as high as 140,000 species per year (based
on Species-area theory). This figure indicates
unsustainable ecological practices, because
few species emerge each year. Almost all scientists
acknowledge that the rate of species loss
is greater now than at any time in human history,
with extinctions occurring at rates hundreds
of times higher than background extinction
rates. As of 2012, some studies suggest that
25% of all mammal species could be extinct
in 20 years.In absolute terms, the planet
has lost 58% of its biodiversity since 1970
according to a 2016 study by the World Wildlife
Fund. The Living Planet Report 2014 claims
that "the number of mammals, birds, reptiles,
amphibians and fish across the globe is, on
average, about half the size it was 40 years
ago". Of that number, 39% accounts for the
terrestrial wildlife gone, 39% for the marine
wildlife gone and 76% for the freshwater wildlife
gone. Biodiversity took the biggest hit in
Latin America, plummeting 83 percent. High-income
countries showed a 10% increase in biodiversity,
which was canceled out by a loss in low-income
countries. This is despite the fact that high-income
countries use five times the ecological resources
of low-income countries, which was explained
as a result of process whereby wealthy nations
are outsourcing resource depletion to poorer
nations, which are suffering the greatest
ecosystem losses.A 2017 study published in
PLOS One found that the biomass of insect
life in Germany had declined by three-quarters
in the last 25 years. Dave Goulson of Sussex
University stated that their study suggested
that humans "appear to be making vast tracts
of land inhospitable to most forms of life,
and are currently on course for ecological
Armageddon. If we lose the insects then everything
is going to collapse."
== Threats ==
In 2006, many species were formally classified
as rare or endangered or threatened; moreover,
scientists have estimated that millions more
species are at risk which have not been formally
recognized. About 40 percent of the 40,177
species assessed using the IUCN Red List criteria
are now listed as threatened with extinction—a
total of 16,119.Jared Diamond describes an
"Evil Quartet" of habitat destruction, overkill,
introduced species and secondary extinctions.
Edward O. Wilson prefers the acronym HIPPO,
standing for Habitat destruction, Invasive
species, Pollution, human over-Population
and Over-harvesting. The most authoritative
classification in use today is IUCN's Classification
of Direct Threats (version 2.0 released in
2016) which has been adopted by major international
conservation organizations such as the US
Nature Conservancy, the World Wildlife Fund,
Conservation International and BirdLife International.
The 11 main direct threats to conservation
are:
1. residential & commercial development
housing & urban areas (urban areas, suburbs,
villages, vacation homes, shopping areas,
offices, schools, hospitals)
commercial & industrial areas (manufacturing
plants, shopping centers, office parks, military
bases, power plants, train & ship yards, airports)
tourism & recreational areas (skiing, golf
courses, sports fields, parks, campgrounds)2.
farming activities
agriculture (crop farms, orchards, vineyards,
plantations, ranches)
aquaculture (shrimp or fin fish aquaculture,
fish ponds on farms, hatchery salmon, seeded
shellfish beds, artificial algal beds)3. energy
production & mining
renewable energy production (geothermal, solar,
wind, & tidal farms)
non-renewable energy production (oil and gas
drilling)
mining (fuel and minerals)4. transportation
& service corridors
service corridors (electrical & phone wires,
aqueducts, oil & gas pipelines)
transport corridors (roads, railroads, shipping
lanes, and flight paths)
collisions with the vehicles using the corridors
associated accidents and catastrophes (oil
spills, electrocution, fire)5. biological
resource usages
hunting (bushmeat, trophy, fur)
persecution (predator control and pest control,
superstitions)
plant destruction or removal (human consumption,
free range livestock foraging, battling timber
disease, orchid collection)
logging or wood harvesting (selective or clear
cutting, firewood collection, charcoal production)
fishing (trawling, whaling, live coral or
seaweed or egg collection)6. human intrusions
& activities that alter, destroy, simply disturb
habitats and species from exhibiting natural
behaviors
recreational activities (off-road vehicles,
motorboats, jet-skis, snowmobiles, ultralight
planes, dive boats, whale watching, mountain
bikes, hikers, birdwatchers, skiers, pets
in recreational areas, temporary campsites,
caving, rock-climbing)
war, civil unrest, & military exercises (armed
conflict, mine fields, tanks & other military
vehicles, training exercises & ranges, defoliation,
munitions testing)
illegal activities (smuggling, immigration,
vandalism)7. natural system modifications
fire suppression or creation (controlled burns,
inappropriate fire management, escaped agricultural
and campfires, arson)
water management (dam construction & operation,
wetland filling, surface water diversion,
groundwater pumping)
other modifications (reclamation projects,
shoreline rip-rap, lawn cultivation, beach
construction and maintenance, tree-thinning
in parks)
removing/reducing human maintenance (mowing
meadows, reduction in controlled burns, lack
of indigenous management of key ecosystems,
ceasing supplimental feeding of condors)8.
invasive & problematic species, pathogens
& genes
invasive species (feral horses & household
pets, zebra mussels, Miconia tree, kudzu,
introduction for biocontrol)
problematic native species (overabundant native
deer or kangaroo, overabundant algae due to
loss of native grazing fish, locust-type plagues)
introduced genetic material (pesticide-resistant
crops, genetically modified insects for biocontrol,
genetically modified trees or salmon, escaped
hatchery salmon, restoration projects using
non-local seed stock)
pathogens & microbes (plague affecting rodents
or rabbits, Dutch elm disease or chestnut
blight, Chytrid fungus affecting amphibians
outside of Africa)9. pollution
household sewage & urban waste water (discharge
from municipal waste treatment plants, leaking
septic systems, untreated sewage, outhouses,
oil or sediment from roads, fertilizers and
pesticides from lawns and golf-courses, road
salt)
industrial & military effluents (toxic chemicals
from factories, illegal dumping of chemicals,
mine tailings, arsenic from gold mining, leakage
from fuel tanks, PCBs in river sediments)
agricultural & forestry effluents (nutrient
loading from fertilizer run-off, herbicide
run-off, manure from feedlots, nutrients from
aquaculture, soil erosion)
garbage & solid waste (municipal waste, litter
& dumped possessions, flotsam & jetsam from
recreational boats, waste that entangles wildlife,
construction debris)
air-borne pollutants (acid rain, smog from
vehicle emissions, excess nitrogen deposition,
radioactive fallout, wind dispersion of pollutants
or sediments from farm fields, smoke from
forest fires or wood stoves)
excess energy (noise from highways or airplanes,
sonar from submarines that disturbs whales,
heated water from power plants, lamps attracting
insects, beach lights disorienting turtles,
atmospheric radiation from ozone holes)10.
catastrophic geological events
earthquakes, tsunamis, avalanches, landslides,
& volcanic eruptions and gas emissions11.
climate changes
ecosystem encroachment (inundation of shoreline
ecosystems & drowning of coral reefs from
sea level rise, sand dune encroachment from
desertification)
changes in geochemical regimes (ocean acidification,
changes in atmospheric CO2 affecting plant
growth, loss of sediment leading to broad-scale
subsidence)
changes in temperature regimes (heat waves,
cold spells, oceanic temperature changes,
melting of glaciers/sea ice)
changes in precipitation & hydrological regimes
(droughts, rain timing, loss of snowcover,
increased severity of floods)
severe weather events (thunderstorms, tropical
storms, hurricanes, cyclones, tornadoes, hailstorms,
ice storms or blizzards, dust storms, erosion
of beaches during storms)
=== Habitat destruction ===
Habitat destruction has played a key role
in extinctions, especially in relation to
tropical forest destruction. Factors contributing
to habitat loss include: overconsumption,
overpopulation, land use change, deforestation,
pollution (air pollution, water pollution,
soil contamination) and global warming or
climate change.Habitat size and numbers of
species are systematically related. Physically
larger species and those living at lower latitudes
or in forests or oceans are more sensitive
to reduction in habitat area. Conversion to
"trivial" standardized ecosystems (e.g., monoculture
following deforestation) effectively destroys
habitat for the more diverse species that
preceded the conversion. Even the simplest
forms of agriculture affect diversity – through
clearing/draining land, discouraging weeds
and "pests", and encouraging just a limited
set of domesticated plant and animal species.
In some countries lack of property rights
or lax law/regulatory enforcement necessarily
leads to biodiversity loss (degradation costs
having to be supported by the community).A
2007 study conducted by the National Science
Foundation found that biodiversity and genetic
diversity are codependent—that diversity
among species requires diversity within a
species and vice versa. "If any one type is
removed from the system, the cycle can break
down and the community becomes dominated by
a single species."
At present, the most threatened ecosystems
occur in fresh water, according to the Millennium
Ecosystem Assessment 2005, which was confirmed
by the "Freshwater Animal Diversity Assessment"
organised by the biodiversity platform and
the French Institut de recherche pour le développement
(MNHNP).Co-extinctions are a form of habitat
destruction. Co-extinction occurs when the
extinction or decline in one species accompanies
similar processes in another, such as in plants
and beetles.
=== Introduced and invasive species ===
Barriers such as large rivers, seas, oceans,
mountains and deserts encourage diversity
by enabling independent evolution on either
side of the barrier, via the process of allopatric
speciation. The term invasive species is applied
to species that breach the natural barriers
that would normally keep them constrained.
Without barriers, such species occupy new
territory, often supplanting native species
by occupying their niches, or by using resources
that would normally sustain native species.
The number of species invasions has been on
the rise at least since the beginning of the
1900s. Species are increasingly being moved
by humans (on purpose and accidentally). In
some cases the invaders are causing drastic
changes and damage to their new habitats (e.g.:
zebra mussels and the emerald ash borer in
the Great Lakes region and the lion fish along
the North American Atlantic coast). Some evidence
suggests that invasive species are competitive
in their new habitats because they are subject
to less pathogen disturbance. Others report
confounding evidence that occasionally suggest
that species-rich communities harbor many
native and exotic species simultaneously while
some say that diverse ecosystems are more
resilient and resist invasive plants and animals.
An important question is, "do invasive species
cause extinctions?" Many studies cite effects
of invasive species on natives, but not extinctions.
Invasive species seem to increase local (i.e.:
alpha diversity) diversity, which decreases
turnover of diversity (i.e.: beta diversity).
Overall gamma diversity may be lowered because
species are going extinct because of other
causes, but even some of the most insidious
invaders (e.g.: Dutch elm disease, emerald
ash borer, chestnut blight in North America)
have not caused their host species to become
extinct. Extirpation, population decline and
homogenization of regional biodiversity are
much more common. Human activities have frequently
been the cause of invasive species circumventing
their barriers, by introducing them for food
and other purposes. Human activities therefore
allow species to migrate to new areas (and
thus become invasive) occurred on time scales
much shorter than historically have been required
for a species to extend its range.
Not all introduced species are invasive, nor
all invasive species deliberately introduced.
In cases such as the zebra mussel, invasion
of US waterways was unintentional. In other
cases, such as mongooses in Hawaii, the introduction
is deliberate but ineffective (nocturnal rats
were not vulnerable to the diurnal mongoose).
In other cases, such as oil palms in Indonesia
and Malaysia, the introduction produces substantial
economic benefits, but the benefits are accompanied
by costly unintended consequences.
Finally, an introduced species may unintentionally
injure a species that depends on the species
it replaces. In Belgium, Prunus spinosa from
Eastern Europe leafs much sooner than its
West European counterparts, disrupting the
feeding habits of the Thecla betulae butterfly
(which feeds on the leaves). Introducing new
species often leaves endemic and other local
species unable to compete with the exotic
species and unable to survive. The exotic
organisms may be predators, parasites, or
may simply outcompete indigenous species for
nutrients, water and light.
At present, several countries have already
imported so many exotic species, particularly
agricultural and ornamental plants, that their
own indigenous fauna/flora may be outnumbered.
For example, the introduction of kudzu from
Southeast Asia to Canada and the United States
has threatened biodiversity in certain areas.
==== Genetic pollution ====
Endemic species can be threatened with extinction
through the process of genetic pollution,
i.e. uncontrolled hybridization, introgression
and genetic swamping. Genetic pollution leads
to homogenization or replacement of local
genomes as a result of either a numerical
and/or fitness advantage of an introduced
species.
Hybridization and introgression are side-effects
of introduction and invasion. These phenomena
can be especially detrimental to rare species
that come into contact with more abundant
ones. The abundant species can interbreed
with the rare species, swamping its gene pool.
This problem is not always apparent from morphological
(outward appearance) observations alone. Some
degree of gene flow is normal adaptation and
not all gene and genotype constellations can
be preserved. However, hybridization with
or without introgression may, nevertheless,
threaten a rare species' existence.
=== Overexploitation ===
Overexploitation occurs when a resource is
consumed at an unsustainable rate. This occurs
on land in the form of overhunting, excessive
logging, poor soil conservation in agriculture
and the illegal wildlife trade.
About 25% of world fisheries are now overfished
to the point where their current biomass is
less than the level that maximizes their sustainable
yield.The overkill hypothesis, a pattern of
large animal extinctions connected with human
migration patterns, can be used explain why
megafaunal extinctions can occur within a
relatively short time period.
=== Hybridization, genetic pollution/erosion
and food security ===
In agriculture and animal husbandry, the Green
Revolution popularized the use of conventional
hybridization to increase yield. Often hybridized
breeds originated in developed countries and
were further hybridized with local varieties
in the developing world to create high yield
strains resistant to local climate and diseases.
Local governments and industry have been pushing
hybridization. Formerly huge gene pools of
various wild and indigenous breeds have collapsed
causing widespread genetic erosion and genetic
pollution. This has resulted in loss of genetic
diversity and biodiversity as a whole.Genetically
modified organisms contain genetic material
that is altered through genetic engineering.
Genetically modified crops have become a common
source for genetic pollution in not only wild
varieties, but also in domesticated varieties
derived from classical hybridization.Genetic
erosion and genetic pollution have the potential
to destroy unique genotypes, threatening future
access to food security. A decrease in genetic
diversity weakens the ability of crops and
livestock to be hybridized to resist disease
and survive changes in climate.
=== Climate change ===
Global warming is also considered to be a
major potential threat to global biodiversity
in the future. For example, coral reefs – which
are biodiversity hotspots – will be lost
within the century if global warming continues
at the current trend.Climate change has seen
many claims about potential to affect biodiversity
but evidence supporting the statement is tenuous.
Increasing atmospheric carbon dioxide certainly
affects plant morphology and is acidifying
oceans, and temperature affects species ranges,
phenology, and weather, but the major impacts
that have been predicted are still just potential
impacts. We have not documented major extinctions
yet, even as climate change drastically alters
the biology of many species.
In 2004, an international collaborative study
on four continents estimated that 10 percent
of species would become extinct by 2050 because
of global warming. "We need to limit climate
change or we wind up with a lot of species
in trouble, possibly extinct," said Dr. Lee
Hannah, a co-author of the paper and chief
climate change biologist at the Center for
Applied Biodiversity Science at Conservation
International.A recent study predicts that
up to 35% of the world terrestrial carnivores
and ungulates will be at higher risk of extinction
by 2050 because of the joint effects of predicted
climate and land-use change under business-as-usual
human development scenarios.
=== Human overpopulation ===
The world's population numbered nearly 7.6
billion as of mid-2017 (which is approximately
one billion more inhabitants compared to 2005)
and is forecast to reach 11.1 billion in 2100.
Sir David King, former chief scientific adviser
to the UK government, told a parliamentary
inquiry: "It is self-evident that the massive
growth in the human population through the
20th century has had more impact on biodiversity
than any other single factor." At least until
the middle of the 21st century, worldwide
losses of pristine biodiverse land will probably
depend much on the worldwide human birth rate.
Biologists such as Paul R. Ehrlich and Stuart
Pimm have noted that human population growth
and overconsumption are the main drivers of
species extinction.According to a 2014 study
by the World Wildlife Fund, the global human
population already exceeds planet's biocapacity
– it would take the equivalent of 1.5 Earths
of biocapacity to meet our current demands.
The report further points that if everyone
on the planet had the Footprint of the average
resident of Qatar, we would need 4.8 Earths
and if we lived the lifestyle of a typical
resident of the US, we would need 3.9 Earths.
== The Holocene extinction ==
Rates of decline in biodiversity in this sixth
mass extinction match or exceed rates of loss
in the five previous mass extinction events
in the fossil record. Loss of biodiversity
results in the loss of natural capital that
supplies ecosystem goods and services. From
the perspective of the method known as Natural
Economy the economic value of 17 ecosystem
services for Earth's biosphere (calculated
in 1997) has an estimated value of US$33 trillion
(3.3x1013) per year.
== Conservation ==
Conservation biology matured in the mid-20th
century as ecologists, naturalists and other
scientists began to research and address issues
pertaining to global biodiversity declines.The
conservation ethic advocates management of
natural resources for the purpose of sustaining
biodiversity in species, ecosystems, the evolutionary
process and human culture and society.Conservation
biology is reforming around strategic plans
to protect biodiversity. Preserving global
biodiversity is a priority in strategic conservation
plans that are designed to engage public policy
and concerns affecting local, regional and
global scales of communities, ecosystems and
cultures. Action plans identify ways of sustaining
human well-being, employing natural capital,
market capital and ecosystem services.In the
EU Directive 1999/22/EC zoos are described
as having a role in the preservation of the
biodiversity of wildlife animals by conducting
research or participation in breeding programs.
=== Protection and restoration techniques
===
Removal of exotic species will allow the species
that they have negatively impacted to recover
their ecological niches. Exotic species that
have become pests can be identified taxonomically
(e.g., with Digital Automated Identification
SYstem (DAISY), using the barcode of life).
Removal is practical only given large groups
of individuals due to the economic cost.
As sustainable populations of the remaining
native species in an area become assured,
"missing" species that are candidates for
reintroduction can be identified using databases
such as the Encyclopedia of Life and the Global
Biodiversity Information Facility.
Biodiversity banking places a monetary value
on biodiversity. One example is the Australian
Native Vegetation Management Framework.
Gene banks are collections of specimens and
genetic material. Some banks intend to reintroduce
banked species to the ecosystem (e.g., via
tree nurseries).
Reduction and better targeting of pesticides
allows more species to survive in agricultural
and urbanized areas.
Location-specific approaches may be less useful
for protecting migratory species. One approach
is to create wildlife corridors that correspond
to the animals' movements. National and other
boundaries can complicate corridor creation.
== Protected areas ==
Protected areas are meant for affording protection
to wild animals and their habitat which also
includes forest reserves and biosphere reserves.
Protected areas have been set up all over
the world with the specific aim of protecting
and conserving plants and animals. Some scientists
have called on the global community to designate
as protected areas 30 percent of the planet
by 2030, and 50 percent by 2050, in order
to mitigate biodiversity loss from anthropogenic
causes.
=== National parks ===
National park and nature reserve is the area
selected by governments or private organizations
for special protection against damage or degradation
with the objective of biodiversity and landscape
conservation. National parks are usually owned
and managed by national or state governments.
A limit is placed on the number of visitors
permitted to enter certain fragile areas.
Designated trails or roads are created. The
visitors are allowed to enter only for study,
cultural and recreation purposes. Forestry
operations, grazing of animals and hunting
of animals are regulated. Exploitation of
habitat or wildlife is banned.
=== Wildlife sanctuary ===
Wildlife sanctuaries aim only at conservation
of species and have the following features:
The boundaries of the sanctuaries are not
limited by state legislation.
The killing, hunting or capturing of any species
is prohibited except by or under the control
of the highest authority in the department
which is responsible for the management of
the sanctuary.
Private ownership may be allowed.
Forestry and other usages can also be permitted.
=== Forest reserves ===
The forests play a vital role in harbouring
more than 45,000 floral and 81,000 faunal
species of which 5150 floral and 1837 faunal
species are endemic. Plant and animal species
confined to a specific geographical area are
called endemic species. In reserved forests,
rights to activities like hunting and grazing
are sometimes given to communities living
on the fringes of the forest, who sustain
their livelihood partially or wholly from
forest resources or products. The unclassed
forests covers 6.4 percent of the total forest
area and they are marked by the following
characteristics:
They are large inaccessible forests.
Many of these are unoccupied.
They are ecologically and economically less
important.
==== Steps to conserve the forest cover ====
An extensive reforestation/afforestation programme
should be followed.
Alternative environment-friendly sources of
fuel energy such as biogas other than wood
should be used.
Loss of biodiversity due to forest fire is
a major problem, immediate steps to prevent
forest fire need to be taken.
Overgrazing by cattle can damage a forest
seriously. Therefore, certain steps should
be taken to prevent overgrazing by cattle.
Hunting and poaching should be banned.
=== Zoological parks ===
In zoological parks or zoos, live animals
are kept for public recreation, education
and conservation purposes. Modern zoos offer
veterinary facilities, provide opportunities
for threatened species to breed in captivity
and usually build environments that simulate
the native habitats of the animals in their
care. Zoos play a major role in creating awareness
about the need to conserve nature.
=== Botanical gardens ===
In botanical gardens, plants are grown and
displayed primarily for scientific and educational
purposes. They consist of a collection of
living plants, grown outdoors or under glass
in greenhouses and conservatories. In addition,
a botanical garden may include a collection
of dried plants or herbarium and such facilities
as lecture rooms, laboratories, libraries,
museums and experimental or research plantings.
== Resource allocation ==
Focusing on limited areas of higher potential
biodiversity promises greater immediate return
on investment than spreading resources evenly
or focusing on areas of little diversity but
greater interest in biodiversity.A second
strategy focuses on areas that retain most
of their original diversity, which typically
require little or no restoration. These are
typically non-urbanized, non-agricultural
areas. Tropical areas often fit both criteria,
given their natively high diversity and relative
lack of development.
== Legal status ==
=== 
International ===
United Nations Convention on Biological Diversity
(1992) and Cartagena Protocol on Biosafety;
Convention on International Trade in Endangered
Species (CITES);
Ramsar Convention (Wetlands);
Bonn Convention on Migratory Species;
World Heritage Convention (indirectly by protecting
biodiversity habitats)
Regional Conventions such as the Apia Convention
Bilateral agreements such as the Japan-Australia
Migratory Bird Agreement.Global agreements
such as the Convention on Biological Diversity,
give "sovereign national rights over biological
resources" (not property). The agreements
commit countries to "conserve biodiversity",
"develop resources for sustainability" and
"share the benefits" resulting from their
use. Biodiverse countries that allow bioprospecting
or collection of natural products, expect
a share of the benefits rather than allowing
the individual or institution that discovers/exploits
the resource to capture them privately. Bioprospecting
can become a type of biopiracy when such principles
are not respected.Sovereignty principles can
rely upon what is better known as Access and
Benefit Sharing Agreements (ABAs). The Convention
on Biodiversity implies informed consent between
the source country and the collector, to establish
which resource will be used and for what and
to settle on a fair agreement on benefit sharing.
=== National level laws ===
Biodiversity is taken into account in some
political and judicial decisions:
The relationship between law and ecosystems
is very ancient and has consequences for biodiversity.
It is related to private and public property
rights. It can define protection for threatened
ecosystems, but also some rights and duties
(for example, fishing and hunting rights).
Law regarding species is more recent. It defines
species that must be protected because they
may be threatened by extinction. The U.S.
Endangered Species Act is an example of an
attempt to address the "law and species" issue.
Laws regarding gene pools are only about a
century old. Domestication and plant breeding
methods are not new, but advances in genetic
engineering have led to tighter laws covering
distribution of genetically modified organisms,
gene patents and process patents. Governments
struggle to decide whether to focus on for
example, genes, genomes, or organisms and
species.Uniform approval for use of biodiversity
as a legal standard has not been achieved,
however. Bosselman argues that biodiversity
should not be used as a legal standard, claiming
that the remaining areas of scientific uncertainty
cause unacceptable administrative waste and
increase litigation without promoting preservation
goals.India passed the Biological Diversity
Act in 2002 for the conservation of biological
diversity in India. The Act also provides
mechanisms for equitable sharing of benefits
from the use of traditional biological resources
and knowledge.
== Analytical limits ==
=== 
Taxonomic and size relationships ===
Less than 1% of all species that have been
described have been studied beyond simply
noting their existence. The vast majority
of Earth's species are microbial. Contemporary
biodiversity physics is "firmly fixated on
the visible [macroscopic] world". For example,
microbial life is metabolically and environmentally
more diverse than multicellular life (see
e.g., extremophile). "On the tree of life,
based on analyses of small-subunit ribosomal
RNA, visible life consists of barely noticeable
twigs. The inverse relationship of size and
population recurs higher on the evolutionary
ladder—to a first approximation, all multicellular
species on Earth are insects". Insect extinction
rates are high—supporting the Holocene extinction
hypothesis.
== Diversity study (botany) ==
The number of morphological attributes that
can be scored for diversity study is generally
limited and prone to environmental influences;
thereby reducing the fine resolution required
to ascertain the phylogenetic relationships.
DNA based markers- microsatellites otherwise
known as simple sequence repeats (SSR) were
therefore used for the diversity studies of
certain species and their wild relatives.
In the case of cowpea, a study conducted to
assess the level of genetic diversity in cowpea
germplasm and related wide species, where
the relatedness among various taxa were compared,
primers useful for classification of taxa
identified, and the origin and phylogeny of
cultivated cowpea classified show that SSR
markers are useful in validating with species
classification and revealing the center of
diversity.
== See also ==
Biodiversity portal
Australian Grains Genebank
Defaunation
Deforestation and climate change
Ecological indicator
Index of biodiversity articles
International Day for Biological Diversity
Megadiverse countries
World Scientists' Warning to Humanity
Zero-Force Evolutionary Law
