Talk:Biodiversity

From Wikipedia, the free encyclopedia

Charles Darwin This article is part of WikiProject Evolutionary biology, an attempt at building a useful set of articles on evolutionary biology and its associated subfields such as population genetics, quantitative genetics, molecular evolution, phylogenetics, evolutionary developmental biology. It is distinct from the WikiProject Tree of Life in that it attempts to cover patterns, process and theory rather than systematics and taxonomy. If you would like to participate, there are some suggestions on this page (see also Wikipedia:Contributing FAQ for more information) or visit WikiProject Evolutionary biology.
Biodiversity is included in the 2006 Wikipedia CD Selection, or is a candidate for inclusion in the next version. Please maintain high quality standards and, if possible, stick to GFDL-compatible images.


This environment-related article is part of a WikiProject to improve Wikipedia's coverage of the environment.
The aim is to write neutral and well-referenced articles on environment-related topics, as well as to ensure that environment articles are properly categorized.
See WikiProject Environment and Wikipedia:Contributing FAQ.
B This article has been rated as B-Class on the assessment scale.



This article is part of Wikipedia:WikiProject Ecoregions

Have not found the english sentence for

Edward O. Wilson wrote in 1992, that :la biodiversité est l'une des plus grandes richesses de la planète, et pourtant la moins reconnue comme telle

will see later user:anthere


the senntence above literaly translates from french to english is: "The biodiversity is the one of the bigger wealths of the planet, and nevertheless the less recognized as such." Your Welcome

XanaBlade 15:31, 13 November 2006 (UTC)

The article credits E.O. Wilson with coining the term biodiversity in 1986, but it was my understanding that the term was coined by Thomas Lovejoy in 1980. Comments? --Jose Ramos 19:37, 14 Sep 2003 (UTC)


I may have misunderstood one of Wilson comment. I don't remember exactly the source I used. So I looked at what I had currently at home.

The first two ones do not mention Wilson, just states the 1992 Rio conference was the moment the term really got famous. These are rather master student books.

Another one, more oriented toward patents, and more professional, mentions that "the word appeared in the middle of 80ies, at the favor of the National Forum on Biodiversity of Washington (Wilson, 1988)". It does not mention Lovejoy and rather explicitely indicate Wilson name.

Another one, rather dealing with economics as related to biodiversity, says the expression "diversité biologique = biological diversity" appeared at the beginning of the 80ies. The term "biodiversity" itself was invented during a scientific meeting in 1986, with a word game on National Forum on BioDiversity. (les Enjeux de la Biodiversité. Catherine Aubertin and Franck-Dominique Vivien, Ed Economica 1998)

Finally, I have an interview of Wilson (La Recherche 333, august 2000) himself, where he says he is wrongly credited the word biodiversity, but was just the first one to edit a book under that name. He says the word biodiversity first appeared in a report of the 1986 forum mentionned above, forum following an article Wilson had written on the topic, but where he didnot mentionned the word biodiversity. He further adds that the word biodiversity was mentionned by the forum staff, as more "commercial" than the expression "biological diversity". Wilson also says he first refused, because he found the word too american, too "flashy", but in front of their insistance, he agreed.

Since this last passage is an interview of Wilson himself, I tend to believe that version. If only to use as a citation :-)

From what I read, I would tend to imagine that the word "biological diversity" could have been coined by Lovejoy (but I insist I have no reference of that), then the word biodiversity itself by the forum staff, and the credit got to Wilson.

Comment ?

Anthère

Ok, biodiversity is a short form for biological diversity. But is it really fair to say it comes from biology, rather than the extremely well-known prefix bio-?

you are absolutely right. That is certainly more accurate. I entirely agree for a change on this poin :-) fr0069
I'm not sure that I understand this comment. There seems to be no doubt that people were talking about "biological diversity" for some time before we heard the term "biodiveristy", and I can well believe that it was a simple contraction, as happens very often in our language. It is not very easy to say "biological diversity", and it is the "-ological" bit that tangles the tongue, so getting rid of it makes sense, since it eases discussion (especially after a couple of beers). My guess therefore is that the neologism was created by contraction, not by starting from scratch and adding bio- to diversity. But is the origin of this word really all that important? User:Kalense
From what I understood, it was really coined, not spontaneously appeared. The origin of the word, I do not think is important, and I did not make the difference when I wrote most of this... however, since someone came and protested, I guess it became important :-) Would you like to improve my rather bad article (I was very newbie when I wrote it, and it would really need improvement; plus it is not in good english.) SweetLittleFluffyThing

I have to admit that when I first read this article a few years ago, I was so upset with it that I could not decide what to do - and in the end did nothing. I found that so much of what it said was only half-true, naive, imprecise or just generally made me feel uncomfortable. Unfortunately it would have needed completely re-writing, and I couldn't see that that would be socially acceptable. In particular, I'm very unhappy about the definition of biodiversity. I can perhaps understand why we do not use the CBD definition, but we should at least cite it. My own definition of biodiversity is "A characteristic or property of geographical areas or volumes, habitats, ecosystems or complexes of ecosystems, evaluated at a given time by considering the variety and dependencies within and between species or other taxonomic groups, and differences in the ecological systems of which they are a part. Variety may be evaluated, for example, by the quality, range and extent of differences between organisms, or by the relative abundance of the variants weighted by their taxonomic separation. Humans and human cultures are part of and interact strongly with other organisms, and are therefore part of biodiversity." Kalense

Besides being overly wordy and putting most readers to sleep the first part of the above quote is fine, and elements of it could be added to the intro; however the last sentence is incredibly human-centric, a characteristic that retards many of wikipedia's biology articles already. Anlace 16:53, 26 January 2007 (UTC)

Contents

[edit] Stability-Diversity

Should we really be stating the idea that stability increases with diversity as a fact? Guettarda 20:42, 11 Apr 2005 (UTC)

That's how its understood among ecologists. Check this out.
Actually that link oversimplifies things. While there appears to be a relationship between diversity and stability, it remains a hot topic in ecology. From your link: Although it is a key question, the relationship between diversity and stability is still being resolved. Guettarda 16:08, 29 Apr 2005 (UTC)

In line with this discussion the following line needs to be re-worked for NPOV. "Because an ecosystem decreases in stability as its species are made extinct, these studies warn that the global ecosystem is destined for collapse if it is further reduced in complexity." As much as I think this is the case and want this message broadcast around the world, I'm not sure it's been settled. I'm also not sure it can be settled, but that is a different argument.

Actually, much of the threats to biodiversity section is on the preachy side. I'm too tired to tackle it tonight, so if anyone is feeling ambitious, have at it. Jmeppley 05:18, 25 September 2005 (UTC)

[edit] Principles

I made this change thinking the first few lines should be for the layperson not out of any deep understanding of biology.KAM 17:41, 28 Apr 2005 (UTC)

As one approaches polar regions one finds larger and larger populations of fewer and fewer species. . Does the article explain why this is so somewhere?KAM 14:21, 29 Apr 2005 (UTC)

http://www.livescience.com/animalworld/060501_tropics_evo.html KAM 18:46, 2 May 2006 (UTC)

[edit] Conferences

COP8 (Eight Meeting of the Conference of the Parties to the Convention on Biological Diversity) 20 - 31 March / Curitiba - Brazil

[edit] need sub article called Threats to biodiversity

too much material in this subsection and it doesnt even begin to cover the subject Anlace 19:51, 27 June 2006 (UTC)

[edit] Article Clean Up

This article is filled with statements such as "Mr. Maxwell Smells", "What'chu lookin' at", etc. Someone please clean this up.

[edit] Information moved from main article

Additional additions for biodiversity

he variety of all living things; a contraction of biological diversity. Biodiversity can be measured on many biological levels ranging from genetic diversity within a species to the variety of ecosystems on Earth, but the term most commonly refers to the number of different species in a defined area. Global biodiversity Recent estimates of the total number of species range from 7 to 20 million, of which only about 1.75 million species have been scientifically described. The best-studied groups include plants and vertebrates (phylum Chordata), whereas poorly described groups include fungi, nematodes, and arthropods (see table). Species that live in the ocean and in soils remain poorly known. For most groups of species, there is a gradient of increasing diversity from the Poles to the Equator, and the vast majority of species are concentrated in the tropical and subtropical regions. Numbers of extant species for selected taxonomic groups Kingdom Phylum Number of species described Estimated number of species Percent described Protista 100,000 250,000 40.0 Fungi Eumycota 80,000 1,500,000 5.3 Plantae Bryophyta 14,000 30,000 46.7

 Tracheophyta 250,000 500,000 50.0

Animalia Nematoda 20,000 1,000,000 2.0

 Arthropoda 1,250,000 20,000,000 5.0 
 Mollusca 100,000 200,000 50.0 
 Chordata 40,000 50,000 80.0
  • With permission modified from G. K. Meffe, and C. R. Carroll, Principles of Conservation Biology, 1997.

Human activities, such as direct harvesting of species, introduction of alien species, habitat destruction, and various forms of habitat degradation (including environmental pollution), have caused dramatic losses of biodiversity. The sixth major extinction event in geologic history is well under way. Indeed, current extinction rates are estimated to be 100-1000 times higher than prehuman extinction rates. This rapid loss of species has spurred a great deal of scientific interest in the topic of biodiversity. Currently, many biologists are working to catalog and describe extant species before they are lost. In addition, much research is focused on understanding the importance of biodiversity, particularly whether high levels of biodiversity are essential for proper functioning of ecosystems. Importance Ethical and esthetic arguments have been offered regarding the value of biodiversity and why it is necessary to guard against its reduction. Scientists, however, focus on issues such as the biological or ecological functions of biodiversity that can be addressed with experiments rather than debates about values. Certainly, some measure of biodiversity is responsible for providing essential functions and services that directly improve human life. For example, many medicines, clothing fibers, and industrial products and the vast majority of foods are derived from naturally occurring species. In addition, species are the key working parts of natural ecosystems. They are responsible for maintenance of the gaseous composition of the atmosphere, regulation of the global climate, generation and maintenance of soils, recycling of nutrients and waste products, and biological control of pest species. Ecosystems surely would not function if all species were lost, although it is unclear just how many species are necessary for an ecosystem to function properly. Thus, the current extinction crisis has provoked many scientists to ask how many species can be lost from an ecosystem before the system is negatively affected. Ecosystem function Since species are the key working parts of ecosystems, biodiversity must be related to ecosystem function. Studies have assessed this relationship in ecosystem functions such as biogeochemical processes; the flow of nutrients, water, and atmospheric gases; and the processing of energy. Evidence of the importance of biodiversity for ecosystem function is derived from comparing ecosystems that differ in the number of species present. More recently, ecologists have undertaken manipulative experiments in which the number of species has been directly varied. Two notable experimental efforts include manipulations of plant diversity in a Minnesota grassland and manipulations of species and functional diversity in microbial communities. In general, these studies have demonstrated that various measures of ecosystem function such as production of biomass and nutrient uptake increase as the number of species present increases. However, some studies report no effect or even negative relationships between biodiversity and ecosystem processes. Although some evidence supports the hypothesis that biodiversity increases or improves the overall functioning of ecosystems, the underlying mechanisms remain unclear. For example, a positive relationship between species diversity and productivity could result because including more species to increases the chance of encompassing particularly productive or fast-growing species. Alternatively, a diverse group of species may use the available resources more efficiently, since each species has slightly different requirements, resulting in higher overall growth. It is unclear whether the number of species or the number of different functional types of species is driving these effects. This distinction is important because if the number of species matters most, every species that is added to an ecosystem should cause an improvement in ecosystem function (illus. a). In contrast, if the diversity of functional types is more important than the number of species per se, there will be initial increases in ecosystem function as species number rises, but these effects should level off once all of the functional types are represented (illus. b). Indeed, a nonlinear or satiating effect of species number on ecosystem processes is frequently observed (illus. b), suggesting that ecosystem function may be relatively unaffected by initial losses of species but may become severely impaired after some critical number of species is lost. Fig. Ecosystem function (a) as a positive, linear function of biodiversity and (b) as a nonlinear, satiating function of biodiversity.

Ecosystem stability A second purported benefit of biodiversity is that more diverse ecosystems may be more stable or more predictable through time when compared to species-poor ecosystems. Stability can be defined at the community level as fewer invasions and fewer extinctions, meaning that a more stable community will contain a more stable composition of species. However, stability can also be defined at the population level as reduced fluctuations in population size, meaning that a more stable population will contain a more constant number of individuals. The idea that biodiversity confers stability upon ecosystems has a long and controversial history. Early ecologists used several lines of reasoning to argue that diverse ecosystems are more stable than those with fewer species. First, attempts to create simple, low-diversity ecosystems in the laboratory tended to fail, with most or all of the species declining to extinction. Second, unpredictable or strongly cyclical population dynamics are often observed in animals that live at high latitudes, and high-latitude ecosystems generally include relatively few species. Finally, islands, which generally have fewer species than mainlands, tend to be more easily invaded by introduced species. In 1955, an additional argument was proposed in favor of a positive relationship between biodiversity and ecosystem stability. With more species in an ecosystem, there are more paths through which energy and nutrients can flow; therefore, in diverse ecosystems each species should be less affected by changes in the abundance of other species, leading to higher overall stability. Thus, the general consensus among early ecologists was that more diverse ecosystems should be more stable. See also: Ecosystem; Population ecology In 1973, mathematical models of many species interacting simultaneously were used to explore the relationship between biodiversity and population stability. The major outcome was that higher species diversity led to less stable population sizes of individual species. However, the apparent conflict between these modeling results and the intuitions of earlier ecologists remained unresolved for many years. Recent studies in which the number of species has been experimentally manipulated have helped to resolve this long-standing controversy. For example, manipulations of plant diversity were used to examine not only the productivity of a grassland ecosystem but also the stability of ecosystem productivity over time. This and other studies have shown that although the abundance of individual species fluctuates more dramatically in high-diversity ecosystems, the total abundance or productivity of all species combined is actually more stable. High biodiversity decreased the stability of each species' population, lending support to mathematical modeling results, whereas the positive relationship between biodiversity and the stability of overall ecosystem productivity supports the proposals of the earlier ecologists. Although the relationship between biodiversity and ecosystem stability is fairly clear, the mechanisms generating this pattern are not. In particular, diverse groups of species may be more stable because complementary species compensate for changes in one another's abundance. Alternatively, variation in aggregate measures such as total productivity may increase with richness due to averaging of random fluctuations in the growth of each species. Based on simple probability theory, it is expected that the more independently varying species added together, the more stable the sum of their abundances. The strength of this averaging effect depends on correlations among the species' fluctuations, but a positive relationship between biodiversity and the stability of aggregate measures of ecosystem function should usually be expected, simply due to averaging. Clearly, biodiversity is (at least sometimes) related to both the overall rates and the stability of ecosystem functions. However, documenting a relationship between biodiversity and some measure of ecosystem function or stability does not reveal its underlying cause. Current ecological research continues to explore the mechanisms by which species diversity and functional diversity contribute to ecosystem function. Species importance Some species clearly play very important roles in ecosystems. In some cases, the addition or deletion of a single species can lead to dramatic changes in ecosystem functions such as productivity or nutrient uptake. For example, the introduction of a nitrogen-fixing tree species to Hawaii resulted in substantially altered productivity and nutrient dynamics in submontane forest ecosystems. Species that exert such strong control over ecosystems are termed keystone species. It is not at all clear that most species in an ecosystem have such important effects. In other words, it may be possible to lose a number of species from an ecosystem and yet observe little overall impact on ecosystem function. This could be the case if several species that perform approximately the same function are present in the original ecosystem. The situation where multiple species play a similar role has been termed species redundancy. If species redundancy is a common phenomenon, ecosystem function should be largely independent of species diversity as long as major functional types are represented. Thus, when one species is lost from an ecosystem, some other species with a similar function may become abundant and compensate for the lost species, leaving the ecosystem as a whole relatively unaffected. Indeed, ecosystem processes often do remain stable despite large fluctuations in the abundance of the various species involved. In addition, the relationship between ecosystem function and biodiversity is often observed to be nonlinear (illus. b), suggesting that, at least initially, the loss of species would have little overall effect. The term species redundancy may seem to imply that all species are not necessary for an ecosystem to function properly. However, species redundancy may be an essential feature for the long-term health of ecosystems. Just as engineers include multiple structures with redundant functions to increase overall reliability of the final structure, ecosystems with sets of functionally redundant species may have a built-in safety net that is lacking in species-poor ecosystems. Rare species (those that occur in low abundance) may also appear to contribute relatively little to overall ecosystem functioning. However, during dramatic environmental changes, such as acidification of a lake, rare species can become very abundant, thereby compensating for reductions in other species. Even species that appear relatively unimportant because they are rare and functionally redundant with others may in fact be important in stabilizing ecosystem function during periods of rare but intense stress. The overwhelming variety of life has captivated the human imagination for centuries, so it is surprising how much scientific uncertainty currently surrounds the role of biodiversity. Ignorance probably reflects the fact that biodiversity has been taken for granted; only over the last few decades, as biodiversity's staggering decline became more apparent, did ecologists start investigating what exactly is being lost. Most experiments provide compelling evidence that at some point the erosion of biodiversity will impair ecosystem function and stability. However, these same experiments also show that a great deal of biodiversity can typically be lost with minimal effects. The value of biodiversity may well be revealed only on huge time scales that incorporate extremely infrequent but dramatic environmental challenges. If this is the case, standard short-term experiments will be unable to document the value of many species. Clearly, any failure of short-duration, small-scale experiments to identify a function for total biodiversity or for every species should not be used as a disingenuous argument to excuse human-caused extinctions. See also: Extinction (biology)

[edit] In the beginning

"to indicate the degree to which the aggregate of historical species are viable versus extinct." Can someone please explain the meaning of the sentence above? is there something wrong in it? --Alnokta 13:14, 17 December 2006 (UTC)

[edit] In definitions it says

The 1992 United Nations Earth Summit in Rio de Janeiro defined "biodiversity" 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 is, in fact, the closest thing to a single legally accepted definition of biodiversity, since it is the definition adopted by the United Nations Convention on Biological Diversity. The parties to this convention include all the countries on Earth, with the exception of Andorra, Brunei Darussalam, the Holy See, Iraq, Somalia, and the United States of America.

However, I am sure the USA did sign it. They didn't sign it at the convention, but the next year.

However, don't quote me on that.

From http://www.biodiv.org/convention/default.shtml it says "Signed by 150 government leaders at the 1992 Rio Earth Summit", which I guess means more signed later. Which includes the US I am sure. —The preceding unsigned comment was added by AFA (talk • contribs) 15:08, 20 March 2007 (UTC).

Retrieved from "http://en.wikipedia.org../../../b/i/o/Talk%7EBiodiversity_5700.html"