Showing 3 results for Species Diversity
Mehdi Heydari, Ali Mahdavi,
Volume 1, Issue 1 (9-2014)
Abstract
Despite the implementation of watershed management projects over a wide area has long history in Iran, but the quantitative assessment of these projects have been neglected. In this study, the effects of watershed management project of Kalan-e-Eyvan in Ilam province from ecological point of view (the relation of vegetation composition with physicochemical soil properties) were investigated. In doing so, four status of watersheds were assessed, namely, status A (implemented area after 5 years in 2010), status B (the witness area without implementation of plan in 2005), status C (the witness area without implementation of plan in 2010) and status D (the area A before implementation of the project in 2005). The results showed that plant species in four statuses were classified into two groups based upon Canonical Correspondence Analysis (CCA) and the species in A, B and C statuses were mostly perennial classified as climax stage species. The results showed a floristic similarity between planed and control areas after 5 yearsturned out. There werea clear differences regarding to vegetation composition, nutrient and saturation percentage (SP) between the area after and before plan implementation. The results of one-way ANOVA indicated significant differences regarding to diversity and richness between four statuses. The results of Duncan-Test showed that the implementation of watershed management project has caused increasing in diversity and richness in planned areas in comparison with non-planned watershed management ones.
Shaieste Gholami, Ehsan Sayad, Hanie Shahghobadi,
Volume 1, Issue 2 (3-2015)
Abstract
One of the main factors affecting sustainable management in the forest ecosystem is the biodiversity conservation. For achieving this purpose, we need to estimate and determine the biodiversity. The efficiency of sampling depends to some extent on plot size in a study. Therefore, a study was conducted in the Zagros forest (Baniloan, Javanrood, Kermanshah) to assess the effect of plot size on the abundance and diversity of tree species. We measured the diversity indices e.g. (Shannon H), richness (Minhinick) and evenness (Sheldon) in our data. These indices were analyzed at 270 sampling points along 3 parallel transects which ran perpendicular to the slope. The distances between transects was 500 m. Each transect comprised 30 sampling points with 3 different sizes of plots (10m×10m-20m×20m and 30m×30m plots). Abundance and diversity of tree species, richness and evenness analyzed by ANOVA and Duncan. The results showed that abundance and diversity increased significantly by increasing the size of the plots. The maximum diversity was seen in 900m2 plot size. At 400 m2 plot, richness was higher than two other plot size. But evenness was not significantly affected by plot size.
Mehdi Heydari, Ali Mahdavi,
Volume 2, Issue 1 (9-2015)
Abstract
In this study, the impact of land use change of forest areas to forest parks on species diversity indices in Chaghasabz Park (Ilam city) has been investigated. For this purpose, three regions in 30-hectare areas were considered, including the area, without, medium and intensive recreation. The field data were obtained using 20 sample plots with each plot covering an area of 400 m2 in a systematic random design (150 m×100 m) in each region. In order to record the herbaceous species, cover percentage for each herbaceous species was recorded in four micro-plots (1.5 m× 1.5 m) that were defined with Domin criterion. In order to evaluate plant diversity, biodiversity indices e.g. Shannon and Simpson and Maguran richness indices were computed. Also, for studying the comparison between the averages of plant diversity indices, Dunken analysis was used. The results showed that in areas without, average and intensive recreation, there were 29, 45 and 21 species respectively. Therophytes were dominant vegetative forms in all three areas. Asperula odorata, Centaurea irritans Wagentz. Marrabium vulgare L., Phlomis olivieri Benth. and Picnomon acarna (L.) Cass were not observed in intensive recreation region. The least shannon and Simpson diversity and richness indices were observed in intensive recreation region, but on the contrary, evenness index was substantial in intensive recreation. We concluded that intense increase of recreation in forest region might cause a loss species diversity.
