Works of young research scientists in New Uzbekistan

MATERIALS AND METHODS.

The variety of problems studied in Ecology requires the use of type-specific methods. In ecology, the following methods are used, namely: field, laboratory, experimental and mathematical modules.

3. 
   Results and Discussion.
   

Biodiversity includes three hierarchical levels: Genetic, species and ecosystem diversity
Genetic diversity Genetic diversity refers to the variation in the genetic composition of individuals within or among species. The genetic diversity enables the population to adapt to its environment and respond to natural selection. The amount of genetic variation is the basis of speciation. Genetic diversity occurs at several levels of organization such as among higher taxonomic categories such as kingdoms phyla and families, among species and among populations. Most genetic
diversity one can see between organisms of two kingdoms (such as plants versus animals),between phyla (such as arthropods versus chordates), between classes (such as birds versus reptiles) and so on.
Species diversity According to biological species concept, species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups. Simply, species diversity refers to the variety of species within a region i.e. species richness. However, in the broad sense, species diversity includes species richness, species evenness as well as taxonomic (or phylogenetic) diversity. Taxonomic or phylogenetic diversity describes the genetic relationship between different groups of species. A more taxonomically diverse community is therefore considered richer compared to the less taxonomically diverse community.
Species richness and evenness
The simplest measure of species diversity is species richness, i.e. the number of species present in per unit area. Species richness is only one aspect of diversity. Not all species exist in equal numbers: some are rare, some are common but not numerous, and others are very abundant. Imagine two forests, both of which contain a total of 100 individuals belonging to 5 different species. In one forest, there are 20 individuals of each species. In the other, one species has 60 individuals, while each of the other four species has 10 individuals. These two samples differ in a property called evenness. The first, in which the species are represented by the same number of individuals, is more even, and thus, has high overall species diversity. Thus, the species diversity of a community depends on both its richness as well as evenness:
higher species numbers, with the individuals more evenly distributed among them, contribute to higher community diversity.