Evaluation of Diversity and Functional Group as One of the Biodiversity Indices in Response to Elevation Gradients (Case Study: Cheshme Sarkho Rangelands, Ravar, Kerman)

Document Type : Research Paper


1 Department of Rangeland Management, Faulty of Natural Resources, Sari Agricultural sciences and natural Resources University, Sari, Iran

2 Natural Resources Administration of Kerman Province, Kerman, Iran

3 Natural Resources Administration of Alborz Province, Karaj, Iran


The diversity of living organisms in natural ecosystems is reduced as a result of human intervention, climate change, and the effects of living and non-living interfering factors. In the past, to investigate the relationship between the functioning of ecological systems and the variety of classical varieties of diversity, this issue was criticized because it was unable to communicate well between diversity and function, and variety and stability. For this reason, the researchers sought to use indicators that could solve the problem. They described the best way to solve the problem using plant characteristics and their involvement in diversity indices. Accordingly, they defined concepts such as groups and functional attributes. This will have an adverse effect on the ecosystem's functioning and services. In the last decade, significant advances have been made in the use of spatial distribution of plant species in order to understand ecological mechanisms, preserve biodiversity and predict the dynamics of plant masses and the functioning of plant communities. The emergence of any plant is influenced by environmental factors and inter-species relationships that one or more environmental factors have a great influence on the establishment of a species if one can determine these factors and its behavior with the environmental variables of the species. In addition, it is possible to achieve predictive models of species distribution. However, quantitative studies have been done on functional features at the community and location level. Considering that most of the research work carried out in the country concerned the study of plant communities, richness and species diversity, so far, there has been little research on the establishment of functional species groups and functional variations of plants. From there It is necessary to know the effect of environmental factors such as elevation gradient on functional characteristics that causes the destruction of habitats, biomes and consequently the reduction of species diversity and function, such studies in the country such as Ravar rangelands It seems necessary.
Materials and Methods
Sarcho Fountain with an area of 5098 hectares located in the northeastern part of Ravar and north of Kerman province. Its minimum and maximum altitudes are 1880 and 3040 meters above sea level. The average annual precipitation is 140 mm. sampling in a gradient elevation was carried out from 1880 m to 2980 m above sea level. 12 altitude points were taken at a distance of 100 meters for vector sampling. In each sampling point, 5 plots were positioned 10 meters along the horizontal transect and information of all species within the plots was recorded. The plot size was 1 m2 for herbaceous plants and 4 m2 for bush plants and 25 m2 for shrubs. In each plot, data such as species names, number of species, cover percentage, plant height were measured directly. The height of herbaceous and bush plants was measured using a crop rotation and shrubs using a meter. To illustrate the use of plant species in the community, two functional traits including plant height, vegetative form were directly measured and recorded in the plot, and four other traits including reproduction, longevity, the form of life and type Nitrogen fixation from the sources was collected. Then, the collected data were analyzed using FDiversity software, which was linked with R software (R Core Team., 2014), and the functional diversity and species diversity indices for each plot were calculated. In this study, eight functional variables were comprised of Rao, Cone polyhedron (Rao), Functional richness (FRic), Functional uniformity (FEve), Functional divergence (FDiv), Functional dispersion (FDis), Functional feature diversity (FAD1) And the Modified Functional Diversity Index (MFAD). Also, the varieties of Shannon-Weiner, Simpson, Ghana and species uniformity were also included. The effect of height on functional and species diversity was analyzed by ANOVA and the mean comparison tests in SPSS version 23 software. Nonlinear regressions were also used to study the relationship between variability and height indices. FDiversity software was used to determine the functional group along the gradient elevation. For this purpose, using functional traits and input method and Euclidean distance of dendrogram groups were extracted. Then height and frequency of species were compared between functional groups.
The results showed that the only indicators of richness, uniformity of function and species uniformity at different heights did not differ significantly, but the remaining indices were meaningful. It can be said that the height of these indices has an effect. Most indicators of functional diversity show a curved pattern. In the middle elevation, the greatest amount of these indicators is seen. Convergent multidimensional index with R2 = 0.078 and FAD1 with R2 = 0.88 have the highest R2 value. The dispersion index of the function and the divergence of function and the richness of function at all points of the altitude is interstitial and has not changed much. As the results show, there is no significant difference between the frequencies of the groups, but there is a significant difference between the heights of the species in different functional groups. According to Fig. 4, the height of the species of the functional group was the highest, so that the group was placed in a separate group alone and the height of the species of the other groups was in the same group, with the difference of group 2 had to mean.
Therefore, in the low and high ranges, the rate of functional dispersion decreased, due to the decrease in the frequency of species, but in the middle elevations, with increasing frequency of species, this index also increased. The functional uniformity index shows the uniformity of a vegetative feature in a sample or a community, which is conceptually similar to the Simpson Valley uniformity index but varies in terms of its function. Functional uniformity shows how varieties are uniform in their impact on system performance. Therefore, in the present study, uniformity in vegetation characteristics is the same in all altitudes, although the variability and variation of the plants vary greatly, but the plants that were present in the area did not have significantly different characteristics and did not change dramatically. Therefore, the height of the effect It has no meaning. Functional Diversity Index Function (FAD1). The number of combinations of total plant characteristics of a sample or community equal to or less than the number of species available. The FAD1 index, which is equivalent to species richness, has the lowest performance in elevations. This confirms that, in a situation where the richness of the function is reduced, additional use of food sources occurs and the function decreases. The FAD1 index is directly related to the number of species, in other words, increasing or decreasing the number of species. As a result, the MFAD was introduced to correct the above index. The FEve index showed a poor performance value because it is ecologically complex. This indicator may be further affected by other factors such as competition between plant species and land use. The uniformity of function changes from zero to non-uniformity to one for uniformity. Indicator value when relative frequency of species with uniformity is low. The results of the comparison of the height of six functional communities showed that the height of the second community is greater than other communities because it includes shrubs and vegetative forms. All species in the region are multiplied by seed except for the Iris Sisyrichium, which is propagated through the underground gut, which is located in a separate functional community. The results of this research can be used in executive projects because functional characteristics of the ecosystem's intensity and direction are very well illustrated by environmental factors and in understanding ecological processes such as the formation of sequence and sustainability of communities they help us. Also, functional plant features can be used as a management tool for assessing the effects of degradation on natural ecosystems.


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