Biodiversity

	Ecosystems Condition
	Land · Freshwater · Oceans and Seas · Biodiversity · Atmosphere

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Biodiversity

The term ‘biodiversity’ was coined as a contraction of "biological diversity" in 1985. It refers to the totality and variety of life on earth. The number of species of plants, animals, and microorganisms, the enormous diversity of genes in these species, the different ecosystems on the planet, such as deserts, rainforests and coral reefs are all part of a biologically diverse Earth; namely it is considered at three levels: ecosystems, species, and genes.

Definitions and Approaches

The variety of concepts and definitions that abound indicates the difficulties to assign a practical, working definition of biological diversity. In recent years, a number of concepts have been developed relating to indicators of or principles for biodiversity management, including ¨ecosystem integrity¨, ¨ecosystem health¨, ¨sustainability¨, and ¨resilience¨.

The convention on Biological Diversity defines the 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" (UNEP, 1994). So the term ´biodiversity` includes the variety of all life on earth, and also identifies “how the interaction of the different components of ecosystems reinforces the provision of essential ecosystem services on the one site, and social and recreational opportunities on the other, including being a source of inspiration and cultural identity” (Commonwealth of Australia, 1996).

The problem of defining biodiversity is that it is difficult to exclude anything from a concept that is taken so easily to mean "everything". Over the time, biodiversity has taken the meaning of “life” in regard to the principle of “conservation” and “preservation”. For instance, Sarkar (2005) interprets biodiversity across all biological levels, from genes to ecosystems, considering all biological entities, so that biodiversity absurdly "becomes all of biology". Also he believes in the importance of preservation’s biodiversity, because as well as process, it has “positive transformative value both directly and indirectly”. Callicott et al. (1999) examins "biodiversity" as one of the current non-descriptive (normative) concepts in conservation. According to him, biodiversity remains ill-defined, and distinctions can be made between "functional" and "compositional" perspectives in approaching biodiversity. "Functional" refers to a primarily concern with ecosystem and evolutionary processes, while "compositional" sees organisms as aggregated into populations, species, higher taxa, communities, and other categories. Norton (1994) argues that there will never be a single "objective scientific definition" of biodiversity, in the sense of a prescription for how to measure it. In fact, he claims that any increase in our understanding of biodiversity will make it less likely that there will be a single objective measure. This biodiversity pluralism is based on an argument that inevitably there are many different "theory bound" versions of biodiversity and many different ways to value it. This perspective is in accord with recognition of functional-compositional perspectives on biodiversity. Norton (1994; 2001) focuses on structure and process regarding ecological "health" or "integrity". It can be seen as going beyond a conventional elements-oriented perspective for biodiversity.Other researchers are to ”describe in ways appropriate given certain purposes" and the choice among these different biodiversity "models" will depend on what values are important to the decision-maker. This perspective is characterized as "post-positivist" because it recognizes biodiversity as inevitably value-laden. There is no one, correct, measure of biodiversity to be discovered but many, each having different values. Roebuck and Phifer (1999) argue that biodiversity conservation is rooted primarily in ethics and it is necessary accept values and advocacy. E. O. Wilson (1988) sees "biodiversity" as corresponding to a dramatic transformation for biologists from a "bits and pieces" approach to a much more holistic approach. Wilson describes this change in perspective as a realization that biological diversity is disappearing and, unlike other threatened things, is irreversible. Ehrenfeld (1988) reinforces the idea of the value of diversity in the aggregate. He claims that diversity now is recognised as endangered in its own right. Wrapped up in the term therefore is the idea of a "biodiversity crisis".

The importance of Biodiversity

Sometimes the definition of "biodiversity" explicitly reflects these links to an extinction crisis. It is seen by many as a symbol for our lack of knowledge about the components of life's variation, and their importance to humankind . The definition of biodiversity is wrapped up in the idea of strategies needed to preserve variation (Takacs, 1996) . These arguments suggest that core biodiversity values might be based more on what we do not know than what we do know. For Wilson (1988), biodiversity captures the idea of a "frontier of the future", presenting a prospect of largely unknown variety, with unanticipated uses. Anticipated future uses and values of the unknown are captured in the idea of "option values". A species, or other element of biodiversity, has option value when its continued existence retains the possibility of future uses and benefits. Option value corresponds not just to unknown future values of known species, but also to the unknown values of unknown species (or other components of variation). This concept is at the core of biodiversity because it links "variation" and "value".