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Biodiversity

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The Biodiversity or biological diversity is, according to the International Convention on Biological Diversity , the term by referring to the wide variety of life on is Earth and the natural patterns that form, the result of billions of years of evolution by natural processes and also the growing influence of human activities. Biodiversity also includes the variety of ecosystems and the differences genetic within each species that allow the combination of multiple forms of life, and whose mutual interactions with the rest of the environment underlying the sustenance of life on the planet .

The term "biodiversity" is a carbon copy of the English "biodiversity". This term, in turn, is a contraction of the term "biological diversity" that was used for the first time in October 1986 as the title of a conference on the subject, the National Forum on Biodiversity , convened by Walter G. Rosen , a who he is credited with the idea of the word. 1

The Earth Summit held by the United Nations in Rio de Janeiro in 1992 recognized the global need to reconcile the future preservation of biodiversity to human progress based on criteria of sustainability or sustainability promulgated in the International Convention on Biological Diversity which was approved in Nairobi on May 22, 1992, date subsequently declared by the UN General Assembly as International Biodiversity Day . With the same intention, the year 2010 was declared International Year of Biodiversityby the 61st session of the United Nations General Assembly in 2006, coinciding with the date of the 2010 Biodiversity Target.

Origin and evolution of the term 

 
Heliamphora chimantensis , carnivorous plant found only in theGran Sabana , Venezuela .

 
Several species epiphytes in ajungle of Central America ( Costa Rica). The ecosystems of the tropics are home to most of the current global biodiversity.

According to the RAE , the term biodiversity defines "variety of animal and plant species in their environment" 3

However the concept, because of its intuitive nature, has presented some difficulties for its precise definition, as noted by Fermín Martin Piera 4 in arguing that abuse their use could "empty of content" because in his words, "usually happens in the history of thought that new paradigms coexist for a while with the old ideas "with other authors consider that the concept of biodiversity was already pointed out by the very theory of evolution .

In the early twentieth century , ecologists Jaccard and Gleason proposed in different publications the first statistical indices destined to compare internal diversity of ecosystems. In the mid- twentieth century , the growing scientific interest allowed the development of the concept to describe the complexity and organization, until in 1980,Thomas Lovejoy proposed the expression biological diversity . 5

Definition

If in the field of biology biodiversity refers to the number of populations of organisms and species, to ecologists the concept includes diversity of durable interactions between species and their immediate environment or biotope , the ecosystem in which organisms live. In each ecosystem, living organisms are part of a whole interacting with each other but also with the air, water, and soil around them .

Three levels are usually distinguished in biodiversity:

It should also include the internal diversity of ecosystems, which traditionally refers expression ecological diversity .

Biodiversity

Biodiversity intraspecific (within the same species), note the different types of corn and beans.

Biodiversity that is now on Earth is the result of four billion years of evolution . 6

Although the origin of life has not been precisely determined, the evidence suggests that may have arisen ago 3800 7 8 9 to 3235 million years 10 . Some more recent research has opened the possibility of even started 4100 million years ago 11 although not yet conclusive. Until about 600 million years ago, all life consisted of bacteria and microorganisms 12 .

The history of biodiversity during the Phanerozoic -last 540 million years begins with the rapid growth during the Cambrian explosion , a period during which first appeared the edges of multicellular organisms. [ Citation needed ] Over the next 400 million years global biodiversity showed a relative improvement, but was marked by occasional mass extinction events. [ citation needed ]

The apparent biodiversity records show fossils suggests that a few million recent years include the period with the greatest biodiversity of Earth history . However, not all scientists hold this view, since it is not easy to determine if the abundant fossil record is due to an explosion of biodiversity, or - just to higher availability and preservation of recent geologic strata. [ citation needed ]

Some, like Alroy and other 13 think that improving sampling modern biodiversity is not much different from that of 300 million years ago. Estimates of the current macroscopic species vary from 2 to 100 million, an estimable logical value in 10 million species, approximately.

Most biologists agree however that the period since the appearance of man is part of a new mass extinction, the extinction event Holocene , especially caused by the impact that humans have on ecosystem development. It is estimated that the species extinguished by action of human activity is still lower than those observed during mass extinctions of previous eras geological. [ Citation needed ] However, many believe that the current rate of extinction is sufficient to create a great extinction mass in the space of less than 100 years. [ citation needed ] Those who disagree with this hypothesis argue that the current extinction rate can be maintained for several thousand years before biodiversity loss exceeds 20% in extinctions mass of the past. [ citation needed ]

New species - an average of three regularly discover birds per year [ citation needed ] estimated that 40% of: and many already discovered have not yet been classified fishfreshwater South America remain unclassified. [ Citation needed ]

Importance of biodiversity

The essential and fundamental value of biodiversity is that it is the result of a natural historical process of great antiquity. For this reason alone, biodiversity has the inalienable right to continue its existence. The man and his culture as product and part of this diversity, must ensure protect and respect.

Besides biodiversity is guarantor of wellness and balance in the biosphere . The various elements that compose the biodiversity conform true functional units, which provide and ensure many basic "services" for our survival.

Finally from our humanity, diversity also represents a natural capital . 14 The use and benefit of biodiversity has contributed in many ways to the development of human culture, and represents a potential source provide for future needs.

Considering the biological diversity from the point of view of their potential and present uses and benefits, arguments can be grouped into three main categories.

The ecological aspect

It refers to the role of biological diversity from the point of systemic and functional ( ecosystem ). Being indispensable to our own survival, many of these functions are usually called "services":

The elements that constitute the biological diversity of an area are the natural regulators of the flows of energy and matter . Play an important role in the regulation and stabilization of land and function areas coastlines . For example, on the mountain slopes, species diversity in the topsoil conforms true tissues that protect underlying inert layers of the mechanical action of the elements such as wind and water runoff. Biodiversity plays a decisive role in processes atmospheric and climate . Many exchanges and effects of land masses and oceans with the atmosphere are produced by living things (effect albedo , evapotranspiration, carbon cycle , etc.).

Biotic diversity of a natural system is one of the determining factors in recovery processes and conversion of waste and nutrient factors. In addition some ecosystems have organisms or communities able to degrade toxins , or fixing and stabilizing hazardous compounds naturally.

Even with the development of agriculture and the domestication of animals, biodiversity it is essential to maintain proper functioning of agro - ecosystems. 15 The trophodynamics regulation of biological populations is only possible respecting the delicate networks established in nature. The imbalance in these relations has already shown to have significant negative consequences. This is even more evident with marine resources, where most food sources consumed in the world are captured directly in the middle. The response to disturbances (natural or anthropogenic) occurs systemically, by way of response that tend to return to the initial equilibrium. However, human activities have increased dramatically in terms of intensity, inevitably affecting the biological diversity of some ecosystems and violating in many cases this responsiveness with catastrophic results.

Research suggests that a more diverse ecosystem can better withstand environmental stress and therefore more productive. It is likely that loss of a species decreases the system's ability to keep or recover from damage or disturbance. Just as a species with high genetic diversity, an ecosystem with high biodiversity can have a greater opportunity to adapt to environmental change. In other words: the more species comprising an ecosystem, the more likely that the ecosystem is stable. The mechanisms that underlie these effects are complex and hotly contested. However, in recent years, it has made ​​it clear that there really effects ecological biodiversity.

A high availability of resources in the environment favors greater biomass , but also the ecological dominance and frequently relatively poor ecosystems in nutrients present a greater diversity, which is systematically true in aquatic ecosystems. Greater biodiversity allows an ecosystem better withstand major environmental changes, making it less vulnerable, more resilient because the state of the system depends on the interrelationships between species and the disappearance of any of them is less crucial for the overall stability in less diverse and more marked by the dominance ecosystems.

The economic aspect

For all humans, biodiversity is the first resource for everyday life. An important aspect is the diversity of the crop which is also called agrobiodiversity.

Most people see biodiversity as a reservoir useful for the manufacture of food, pharmaceutical and cosmetic resources. This concept of biological resources explains most fears of resources disappearance.However, it is also the origin of new conflicts dealing with rules of division and appropriation of natural resources.

Some of the important economic items that biodiversity provides to humanity are:

Ecologists and environmentalists were the first to insist on the economic aspect of the protection of biodiversity.

The estimate of the value of biodiversity is a necessary precondition to any discussion on the distribution of wealth. This value can be discriminated between use value (direct such as tourism or indirect such as pollination) and intrinsic value.

If biological resources represent an ecological interest for the community, their economic value is also increasing. New products are developed due to biotechnology and new markets. For society, biodiversity is also a field of activity and profit. An arrangement requires appropriate management to determine how these resources will be used.

Most species have yet to be evaluated by the current and future economic importance. However, we must be aware that we still have much to learn to value, not only economically, even if no more than the value of ecosystems and the value or price we can not even imagine.

It is generally considered that the demographic and economic expansion of the human species is launching a mass extinction of incomparably greater than any previous extinction dimensions. The specific causes are indiscriminate disappearance of ecosystems , by cutting down forests , degradation of soil , the pollution environment, the hunting and fishing excessive, ... etc .. The scientific community judges, generally, that such extinction threatens the ability of the biosphere to sustain human life through various natural services and renewable resources .

Therefore understanding of cultural biodiversity in their relationship with ecosystems is key, as long as no natural resources of its cultural, historical and geographical context dissociate.

The scientific aspect

Biodiversity is important because each species can give scientists a clue to the evolution of life. In addition, biodiversity helps science to understand how the life process and the role that each species has on ecosystems work.

The biodiversity assessment

Parameters

Diversity is a phenomenological property that is intended to express the variety of different elements. As fundamental quality of our perception, we feel the need to quantify it . The development of a measure that would express in a clear and comparable way the biological diversity presents challenges and constraints. It is not just about measuring a variation of one or more common, but to quantify and weigh how many elements or groups of elements exist different elements. Existing diversity measures therefore are only semi - quantitative or quantitative models of a qualitative reality with very clear limits to its application and scope. The development of a logical and coherent for modeling biodiversity and level mathematical concept specific gene has been quite unexplored and presents a synthetic and robust body. The modeling of diversity at the ecosystem level is more recent, and has benefited from technological advances (such as GIS ). 16 measures simplest diversity consist of mathematical indices that express the amount of information and degree of organization Of the same. Basically the metric expressions of diversity into account three aspects:

Each of these indices of diversity is one dimensional and limited reading. Comparisons and assessments of biodiversity are necessarily incomplete in these terms. Are used for their practical and synthetic character, but insufficient against multi - scale and multi - dimensional alternative analytical models that best meet the specific needs of conservation and management. Thus, the two - dimensional modeling (wealth and relative abundance) can be considered the "classic" standard of measurement and expression of diversity. According to the spatial scale at which biodiversity is measured, there is talk of diversity alpha (spot diversity, represented by α), beta (diversity between habitats, represented by β) and gamma (diversity at the regional scale, represented by γ ). These terms were coined by Robert Whittaker in 1960 and generally enjoy wide acceptance.

Dynamic

Biodiversity is not static: it is a system evolving in both species, as well as each individual organism. A current species may have started doing 1-4000000 years, and 99% of all species that have ever existed on Earth are extinct.

Biodiversity is not distributed evenly on earth. It is richer in the tropics, and as one approaches the polar regions larger populations and fewer species are found. Flora and fauna vary depending on climate, altitude, soil and the presence of other species.

Spatial units and biodiversity

The distribution of current biodiversity is the result of evolutionary, biogeographic and ecological processes over time since the appearance of life on earth. Its existence, conservation and evolution depends on the environmental factors that make it possible. Each species has specific environmental requirements without which it is not possible to survive. Although orographic and oceanographic, altitudinal and latitudinal changes allow to define landscape units quite closely, the specific component of the species is the one that finally allows to identify relatively homogenous areas regarding the characteristics presented or offered for biological populations.

These units of Biosphere , can be identified as biodiversity units according to different endpoints: for example, the number of endemic species, species richness, ecosystem or phylogenetic. Although it is common to argue that this or that country has certain levels of biodiversity, spatial units of biological diversity are by definition independent of geopolitical boundaries or barriers.

Two of the existing spatial units of the biosphere, where the factor precedes biodiversity importance are Global 200 ecoregions 17 identified by the WWF and biodiversity hotspots or hotspots of Conservation International . 18

Global 200 identifies the most important ecoregions of the planet , both marine and inland freshwater and terrestrial - bodies of water according to species richness, number of endemic species and conservation status. 19

The term "biodiversity hotspot" was coined by Norman Myers in 1998 and identifies important terrestrial biogeographic regions according to the number of endemism and degree of threat to biodiversity. 20 In its latest revision Conservation International proposes 34 hotspots .

Threats

During the twentieth century it has been observed increasingly accelerated erosion of biodiversity. Estimates of extinction ratios are varied between very few and up to 200 species extinct per day, but all scientists acknowledge that the proportion of species loss is greater than at any time in human history.

In the plant kingdom it is estimated to be threatened about 12.5% ​​of known species. All agree that the losses are due to human activity, including the direct destruction of plants and their habitat.

There is also growing concern about the human introduction of exotic species in certain habitats, disrupting the food chain 21 .

Aimed at developing human activities that may affect biodiversity

Examples of development activities that can have the most significant negative consequences for biodiversity are:

Sociocultural aspects

To these can be added with sense cultural biodiversity . Work on biological biodiversity are incorporating the study the promotion and protection of cultural biodiversity, besides the specific biodiversity, ecosystems and genetic.

Eugenio Reyes Naranjo 22 defines the Cultural Biodiversity like diversity of knowledge that human beings have developed through history in its relation to biodiversity.

This includes beliefs, myths , legends dreams, language , scientific knowledge, psychological attitudes in the broadest possible sense, handlings exploitation, enjoyment and understanding of natural environment.

It is about understanding biological evolution taking into account all aspects of human intervention.