There has been increased emphasis on the results of the way plant interact with each other. This emphasis is due to ecologists and environmental biologists. With the increased environmental changes in the environment due to climatic and man made consequences, ecobiologists have been at pains to investigate and come up with relevant conclusions as to the complete impact of these changes. Ecologists have been forced to predict and come up with hypothesis on the responses that occur on natural systems. The interaction on these natural systems is not as simple as seen as seen through the eyes of any layman. These interactions are complex hence making the investigations on the matter seem like looking for a target in the dark, hoping to hit the bulls eye. Without any clear interpretation and understanding on the field of plant interaction, forecasting on plant community reaction to rising deposition in nitrogen levels and composition of plant species becomes more and more difficult. This does not eliminate the fact that there are increases in diversity to the rising carbon dioxide in the atmosphere. (Tillman 1999)
The author is an ecologist whose main area of interest is in the field of biodiversity and composition of the ecosystem. His other areas of expertise include the areas of plant stability and ecological productivity. The author pursued his PhD studies in University of Michigan in 1976. The author has published over one hundred and sixty papers. His works on the consequences of changes in Biodiversity is a result of his long exploration on how to match the human requirements be it through food resources, energy or any other services in the ecosystem. The author has on the importance of grasslands as a source of biofuels.
In his article The Ecological Consequences of Changes IN Biodiversity: A Search for General Principles. David focuses on results of an experiment that lasted 20 years. He also formulates theories and comes up with models to try and forecast on diversity versus stability in plant community and other variances. Mans ruthless supremacy over his environment has led to a reduction in the variety of species in the habitat all around the world (Tillman 1999). As of today animals and plants alike are becoming extinct due to environmental threats. The full impact of the consequences remains to be fully evaluated as only hypothesis have been drawn out.
The author uses field experiments that were carried over a long period of time. Data collected from 200 plots in grassland fields in Minnesota. The on the number of unlike species in an area and biomass that has been formed in each community. Quantitative observations in combination with theories based on mechanistics were used as evidence to test the hypothesis. These that the impact on the processes driving the ecosystem are closely linked to the biodiversity. The author used 245 plots that measured 9 meters by 9 meters that contained up to 16 plant species that were randomly chosen.
Composition of Plants versus Variety
Differing traits in the ecological processes and species are attributed to composition matters. These trait are manifested in the form of presence of nitrogen fixation have impacted greatly on ecological processes. The composition of species is said to be a great determinant of ecological stability and other trait that may be present in the ecosystem. The composition that was present in each plot was subjected to experimental analysis; the findings showed that on average, the species were equal in their chances of being present in any plot. What this means is that there was no bias as to the composition of species that could be found in any plot. Hence to have any control in the composition of the species, there was need to manage the differences in diversity. Techniques of multiple regressions are used to control the compositional aspects. Climate factors, soil type, affect the composition of species and not the latitudinal gradients.
Diversity and Stability Factors
The author disapproves a past hypothesis which showed that diversity had a part to play in the stability factor in any ecological system. This hypothesis was that an increase in diversity was proportional to the stability. It went ahead to show that communities that are highly diverse were less likely to be invaded by exotic species. This differed in the whereby the level of diversity was inversely proportional to multi species stability. Stability is the opposition to disturbance and constancy. The author bases his argument on temporal stability, as the mean overflow may show some difference. Diversity increase leads to more coverage present in ant given habitat (Tillman 1999).