Question

QUESTION 4 Describe the concept of an ecological niche as a "multidimensional hypervolume."Be specific about factors involved in identifying a niche. TTT Arial 3 (12pt) · T EE.. Words:

Answer 1

Species have limited abilities to tolerate extremes of environmental conditions. In other words, for all environmental factors there are upper and lower bounds of intensity that organisms can endure. For example, a particular species of plant or animal might be able to survive over an extended period of time within a zone of temperature bounded by certain high and low extremes. Extended exposures to hotter or colder temperatures cannot be tolerated, and the species will not occur in such environments. The boundaries of temperature tolerance can be represented as a component of the niche of the species in a single dimension-that of environmental temperature.

There are similar boundaries of tolerance for other environmental factors including climatic, chemical, and habitat variables, each of which can be similarly represented as a component of the larger niche in a single dimension. Conceptually, the niche of the species can be viewed as a multidimensional composite in which all of the boundaries of tolerance of diverse environmental influences are assembled into a single, multivariate factor. This is known as the fundamental niche, or the multidimensional zone (also known as a hypervolume) of environmental tolerance, in which an individual can potentially survive or in which a species can maintain viable populations.

However, in natural ecosystems species are rarely faced with habitat opportunities that are only defined by the boundaries of their tolerance of diverse environmental factors. The actual utilization of the fundamental niche is also significantly influenced by ecological interactions of various sorts. For example, other species may have similar tolerances of environmental factors. These species will seek to utilize some portion of the environmental opportunities that are available, resulting in the ecological interaction known as competition. Competition exerts a very important influence on the ability of species to optimally exploit their fundamental niche and on the structure of ecological communities. If species have very similar fundamental niches, then competition between them will be intense. In extreme cases this can cause one species to be eliminated from the community through a process known as competitive exclusion. More often, however, species are displaced by competition to particular zones within their fundamental niche.