Environmental Issues

It has become evident in the world that biodiversity is fast declining.  It has been documented that about one third of the world plant and animal species in most countries are faced with the risk of extinction. This is considered a monumental problem as it poses a risk to the continued existence of world biodiversity (Colyvan 147). Owing to the risk faced, scientists have gone back to the debate of ecological diversity and stability. The current research and debate on the future of ecosystem viewed in lenses declining biodiversity is supported by the fear of unknown. The biodiversity-stability debate looks into the future of the world ecosystem based on theoretical bases. What will happen to the stability of the world ecosystem with the declining biodiversity

The world flora and fauna is disappearing at an alarming rate.  It is considered that the extinction of the world flora and fauna is faster than the mass extinction events. Ecological findings also evidence that species invasion has been happening at an alarming rate thanks to the increased globalization (Lodge 135). These two events are putting the ecosystem at a greater stress which has made it important for scientific world to understand the relations existing between change in ecological biodiversity and the stability.   The issue at hand at hand is the continued deconstruction of earth in assumption that the ecosystem has developed its own ability to cope with species assault and extinction.

The old debate shows that in a way, diversity and stability are correlated. Increased biodiversity is correlated with ecosystem stability.  Although it does not infer that diversity is the main driver of ecosystem stability, there is sustainable evidence which shows that diversity is a passive recipient of the different ecological mechanisms which drives stability in the ecosystem (Yodzis 675).

One of such mechanism has proposed that in an ecosystem, there are weakly interacting species which tend to stabilize communist dynamism and enhance increase stability (Odum 324). This means that the existence of more of such species will end up creating a more stable ecosystem.  This has been further supported by empirical description of interaction distribution theory.  If this theory is assumed to be true, it is therefore evident that decrease in biodiversity  is accompanied by increase in average interaction strengths between species in an ecosystem and therefore in the long run will create a decreased stability in the ecosystem (Cooper 530).

Earlier studies in diversity-stability debates showed that there was a positive interaction between the two aspects.  One of the strong proponents Charles Elton argued that simple communities tend to be upset faster compared to richer communities.  This implied that simple communities were prone to destructive oscillations in their population and were also more vulnerable to species invasion (Castle 155).  This presumption was supported by works of other ecologists who supported the argument that simplified terrestrial communities were prone to violet population fluctuations compared to diverse terrestrial communities. For example they showed that species invasion mostly occurred on lands which have been cultivated since they have been left with simplified ecosystems (McArthur 534).  They also showed that attacks of phytophagous insects were more common in boreal forests while less attacks were experienced in diverse tropical forests.  These and other observations led to conclusion that the presence of a diverse ecosystem with predators and parasites was important to prevent explosive growths in such ecosystems.

However, studies carried out consecutively in 1970s using mathematics linear models showed the opposite.  Through use of statistical universe which had randomly constructed community which had been assigned interaction strengths showed that diverse made the ecosystem weak and less stable. However, opponents argued that these studies used weak model to study the diversity-stability relations and hence there is need to carry out more research to authenticate the reliability of this model (May 18).

A long term study that was carried out by David Tilman in 1982 looked closely into this relationship. The study was aimed at delineating experimentally the existing relationship in plant communities.  It was carried out in four grassland fields located in Cedar Creek in Minnesota and was further divided into 200 experimental plots. The study collected information on richness, community biomass, and population biomass over a long period of time.  The study showed that diversity in the ecosystem was   positively correlated to stability in the plant community (Riciardi 123).  This means that biodiversity is related to decreased coefficient of variability in the community biomass.  Biodiversity-stability relationship among these primary producers can be supported by averaging effect and covariance effect hypothesis. Both hypothesis argue that diversity tend to increase stability since diverse communities respond differently to variable background process.  The sum in differential population responses over a long time brings about stable community dynamics (Elliot 35).
Research findings shows that biodiversity leads to ecological stability. A model diverse ecosystem is in a better position to withstand the effects of population fluctuations. A diverse community also withstands the invasion of species. In long term, withstanding population fluctuation and species invasion creates stability in the ecosystem.