DIVERSITY AND RICHNESS

Biodiversity is an expression of the presence of a wide variety of forms of expression, the number and nature of communion yangterlihat at different levels of living beings, namely tingkatekosistem, type and genetics. In assessing the potential of biodiversity, which is more often the center of attention is the diversity of species, because it is most easily observed, while the genetic diversity that is the preparation of these species are generally more difficult to identify. Biodiversity is the number of species present in an area.

In another sense; biodiversity refers to diversity of all kinds of plants, animals and micro-organisms (microorganisms), as well as ecosystems and ecological processes in which they are a part (Act No. 5 of 1994 on Ratification UNCBD). Genetic diversity (in kind) cover the entire genetic information as a carrier of offspring traits of all living beings.

Diversity of species related to the diversity of organisms or species that have a specific genetic expression. Meanwhile, ecosystem diversity refers to the diversity of habitats, where the different types of living beings carry out their lives and

interact with other abiotic and biotic factors. Biodiversity is more than just the number of species of flora and fauna.

Diversity Index is a depiction mathematically to make it easier to analyze information on the number of individudan species of organisms as well as some of the many number jenisyang located within an area (Odum, 1971) According to Desmukh (1992) suggested that species diversity as the number of species and number of individuals in the community. So diversity is pointing to the number of types and amounts.

Diversity index can be used to express the abundance of species in a community relations. Diversity consists of two components namely:

1. The total number of species.

2. The similarity (How abundance of data spread across many species).

Example ; in a community composed of 10 species, if 90% is one species and 10% are 9 types of spread, called low similarity. Conversely, if each species amount to 10%, the maximum similarity. A few years later appeared on the classification of the index and the wealth index similarity index. After it merged into a Diversity Index with a variable that characterize the community structure:

1) The number of species

2) The relative abundance of species (similarity)

3) The homogeneity and the size of the area of sample

diversity / Diversity Index

Richness species and its similarity to a single value is described by the index Deversitas. Diversity index may result from a combination of species richness and similarity .There same diversity index values obtained from the community with a wealth of high similarity is low and if a same community obtained from communities with high wealth and low similarity. If hanyamemberikan value diversity index, it is impossible to say what relative importance of species richness and similarity. Diversity presented by Hill (1973 b) more easily ecologically.

A. Understanding the diversity of species

Diversity of species is also called the heterogeneity of types, is a unique characteristic to describe the community structure in the organization's life. A community is said to have high species diversity, if the abundance of each kind of high and low species diversity conversely if only tar-be some kind of abundance.

B. Species diversity index

species diversity index (H ') describes the state of a population of organisms mathematically, to make it easier to analyze the information the number of individuals of each species in a community. Among these species diversity index is the diversity index Shannon - Wiener.

There are two general diversity index,

1. ekuitabilitas index: the index homogeneity / equalization

2. Dominance index: the index most widely / general

To get an idea of the relationship between physical and chemical factors and community structure of macrozoobenthos done using regression analysis. More detailed analysis can be done with the "principle components analysis". From these figures are expected to be disclosed types of macrozoobenthos alleged can be used as an indicator of water quality as well as any chemical physics factor that primarily affect the existence of macrozoobenthos in the waters.

C.     species richness

It is the size of manybit of diversity in an animal species are present in a place of life in a certain time. It - it is influenced by several factors, including:

1. Power reproduction

2. Availability of food

3. Adaptability

4. Number of predator

D.    Application diversity and richness of the type of

information about the kind of - kind of a community of organisms not describe diversity. If it is not provided with information about the amount of each individual constituent populations or species of organisms.

For example, suppose we examine the protozoan animal communities in the two pools, and in water samples taken each - each found four different types of organisms such as Amoeba, Paramecium, Stentor, and Euglena. Suppose the sample derived from an individual that a number of the four types of organisms are the same, while the number of individuals among the four species in a pond two are not the same, we can not say that the protozoan community diversity in the pool was the same.

Thus the composition or characteristics of the community is determined by the type of organism and the ratio of the number of individuals of each species with the number of individuals of all kinds.

,    Dominance Index

DominanceIndex is used to obtain information about the types of fish that dominate in a community in each habitat index Dominance proposed by Simpson that (Ludwig and Reynolds, 1988):

C = Σ()²

With C = Index dominance Simpson

S = Number of types (species)

ni = the total number of individual types of larvae i

N = total number of individuals in total n

Pi = ni / N = as a proportion of all i

dominance index value close to one (1) if the community is dominated by a certain type or species dominance and if the index is close to zero (0) then no species or species that dominate Odum (1971). Many say the least species are present in a water sample will affect the dominance index, although this value depends on the number of individuals of each species (Kaswadji, 1976).

The influence of environment on the quality of fish abundance is always different depending on the type of fish, because each species of fish have different adaptation and tolerance to habitat. The index is used to obtain more detailed information about fish communities (Anwar, 2011).

D.    Diversity Index

DiversityIndex is used to determine the biodiversity of organisms studied. In principle, the higher the index value, meaning it is increasingly diverse community waters and not dominated by one or more of the taxon there. Generally, this type of calculation for plankton diversity index Simpson formula used, and for benthos is Shannon & Wiener.Berdasarkan formula calculation results aquatic biota diversity index, it is known generally about the biological status of water quality. Criteria for plankton, when the Simpson diversity index is less than 0.6, indicating that there has been a perturbation (disruption) of the water quality of the life of plankton (Odum, 1975). The main factors affecting the number of organisms, the species diversity and dominance among others, the destruction of natural habitats such as land conversion, pecemaran and organic chemistry, as well as climate change (Widodo, 1997).

Richness index

of species richness index (S), which is the total number of species in a community. S depending on the sample size (and the time required to achieve it), is defined as a comparative index (Yap, 1979). Therefore, it is proposed to calculate the index number of species richness which depends on the sample size. This is because the relationship between the S and the total number of individuals observed, n, which increases with increasing sample size.

1. Margalef Index (1958)

2. Menhirick Index (1964)