Quantitive Ecology

Biodiversity is defined as the diversity of beings and things that related to the environment such creatures. Diversity includes two levels:

1.    Genetic diversity, a diversity that is the best, because this diversity can continue and be lowered. Genetic diversity is associated with distinctive ecological and evolutionary processes.

2.    Diversity of species, including flora and fauna. Diverse types of behavior, life strategies, shape, chain food, space and also the dependence between the type of one another. The existence of high diversity will produce a steady environmental stability.

The 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.

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).

Species richness, evenenness, and diversity

a.       Species richness

of species richness is the number of species in the area in a community, each species does not seem to have the same number of individuals.

b.      Shareable individuals between species called fairness or equibility species. Equity to a maximum if all species have the same number of individuals.

c.       Species diversity is a combination of richness and evenness. Species diversity is species richness in species evenness, and there is a formula to express a single index number. Biologically, diversity is the heterogeneity of the population of a community.

B.  Some species diversity index

Diversity index 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. Based on the 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, pollution and organic chemistry, as well as climate change (Widodo, 1997).

1.       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), this is limited as a comparative index. 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 was observed, which increases with increasing sample size.

2.       Diversity index

Richness species and similarity within a single value is described with Deversitas index. Diversity index may result from a combination of species richness and similarity .There same diversity index values obtained from the community with a richness of high similarity is low and if a same community obtained from communities with high richness and low similarity. If the only value diversity index, it is impossible to say what relative importance of species richness and similarity. more easily ecologically

NA = S (Pi)1 / (1-A)

where Pi = the size of the individual (or biomass, etc.) that are owned by a single species. indicates that the sequence 0, 1, and 2 of the amount of diversity. Number of

Diversity:

Total 0: N0 = S where S is the number of total species

number 1: N1 = e H 'where H is the index Shanon

Number 2: N 2 = 1 /ë where ë is the index of Simpson.

This diversity in the number of units, the number of species counted was named by Hill

as the effective number of species present in the sample. The effective number of species

is a matter for the comparable abundance distributed among

species. More specifically, N0 is the number of all species in the sample (without

regard to their abundance), N2 is the number of species is most abundant and N1 is the number of species is abundant (always between N0 and N1 N2). In other words, the effective number of species is a count of the number of species in the sample where each species is affected by the richest. Example: the sample with 11 species and 100 individuals where abundance is dispersed as 90, 1, 1, 1,1, 1, 1, 1, 1, 1, 1. Only one species is very abundant, allegedly N2 close to 1 (N2 = 1 , 23). N0 = 11 and N1 = 1.74. So the unit Hill, s is a species whose numbers rose: 1) less than the width occupied by rare species (called N0, the lowest number, is the number of all species in the sample), 2). The lower value resulting from the N1 and N2, showed abundant and very abundant in the sample.

There are two indices are required to complete the diversity Hill:

1. Simpson index

l = S Pi2

Where: Pi is the abundance of each species proporsial with

Pi = ni, i = 1, 2, 3,. , , , 5 where ni is the number of individuals on that species,

N is the total number of known inidividu for all S species in the population index value is from 0-1 indicating the possibility that two individuals taken at random from a population of the same species. If the probability is high that the 2nd individual has the same species, the diversity of the community that the sample is low.

2. Shannon Index

This index is based on information theory and an average count

of uncertainty in predicting what species were selected randomly from the collection of species and individual S N will be held. This average rose with increasing number of species and individual distribution among species-species become equal / equitable. There are two things that are owned by Shanon index, namely;

1. H '= 0 if and only if there is one species in the sample.

2. H is the maximum only when all the species S is represented bynumber of

the same individuals, it is the abundance of equitable distribution perfectly.

3.       Similarity index

If theall species in a sample of the same abundance, it indicates that the maximum similarity index and will decline toward zero as the relative abundance of a species that is not the same. According Hurlbert (1971)

has an abundance of ownership if they can be represented more.

V '= D

_____

Dmax

where D is the diversity index, while dmin and Dmax arevalue

the minimum and maximumin a sequence that D can be obtained. For the

treatment of similarity index refers to the study of Alatalo (1981). Similarity index (E1). Generally similarity index used were:

E1 = H '= ln (N1)

__________

Ln (S) ln (N0)

This is almost the same as the formula J' by Pielou (1975, 1977), where H 'relatively quickly obtained the maximum value that H 'is obtained when all the species in the sample without error even with one individual per species (ie ln S).

C.  Equibility index and dominance

the 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.      Equibility index: the index homogeneity / equalization

2.      Dominance index: the index most widely / general

dominance index 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  i

N = total number of individuals in total n

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

Values dominance index 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). Comparison between diversity and maximum diversity expressed se-like uniformity of the population, which is symbolized by the letter E. The value of this E-sar Berki between 0 - 1. The smaller the value E, the smaller the uniformity of the population, meaning that the spread of the number of individuals of each species are not the same and there is a tendency of the species to dominate, and vice versa greater the value of E then there is no dominant species. To see the dominance of a species used dominance index (C).

Based on the value of diversity zoobentos index, which is calculated based on the formulation of Shannon-Wiener, may be determined some water quality. Wilhm (1975) states that the water is heavily polluted, the zoobentos species diversity index less than one. If the range between one and three, then the half-contaminated water. Clean water, large the zoobentos diversity index of three. Staub et al. in Wilhm (1975) stated that based on the diversity index zoobentos, water quality can be grouped into: heavily polluted (0 <H '<1), half polluted (1 <H' <2), lightly polluted (2 <H '<3) and polluted very light (3 <H <4.5). The range of values of H 'that come into one's vision-right part of the water quality assessment carried out in an integrated manner by a factor of chemical physics of water. Meanwhile, Lee et al. (1978) states that the value of the diversity index (H) in waters heavily polluted, less than one (H <1), polluted medium (1.0 to 1.5), lightly polluted (1.6 to 2.0), and H polluted not greater than two (H> 2.0).

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.

The higher the index of dominance then the diversity kind of a diminishing habitat and vice versa. Level or index of dominance and diversity of new habitats because they good enough dominance index level or less while high diversity index.

The level of diversity of the habitat shows fertility rates of these habitats.  The fertility of a habitat greatly affect the bio-diversity community

D.  Richness species

Richness much size a bit 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.      Reproduction

2.       Food

3.       Availability

4.       Adaptability

5.       The number of predators

Refrences:

Deshmukh, Lan, 1986. Ekologi dan Biologi Tropika. Blackwell Scientific Publications Limited, Oxford.

Erawati, Nety V., dan Sih Kahono (2010). “J. Entomol. Indon” Keanekaragaman Dan Kelimpahan Belalang Dan Kerabatnya (Orthoptera) Pada Ekosistem Pegunungan Di Taman Nasional Gunung Halimun-Salak. September 2010,  Vol. 7, No. 2. Hal: 100-115.

Indriyanto, 2010. Ekologi Hutan. Bumi Aksara, Jakarta.

Michael, P., 1999. Metode Ekologi Untuk Penyelidikan Ladang Dan Laboratorium. Universitas Indonesia Press, Jakarta.

Soegianto, A., 1994. Ekologi Kuantitatif:Metode Analisis Populasi dan Komunitas. Penerbit Usaha Nasional, Jakarta.