مجله بوم شناسی کاربردی
پیاپی 14 (زمستان 1394)

Evaluation of habitat sustainability indexes is essential in wildlife management and conservation of rare species. Suitable habitats are required in wildlife managements and conservation also, they increase reproduction and survival rate of species. In this study in order to mapping habitat sustainability and recognizing habitat requirements of Iranian Cheetah (Acinonyx jubatus venaticus), field data from Dare Anjir wildlife refuge were collected since autumn 2009 until summer 2011. Ecological Niche Factor Analysis approach has been used to develop habitat suitability model. In this method primary maps of habitat variables including elevation, slope, aspect, vegetation cover, distance from water sources and environmental monitoring stations have been produced by Idrisi and Biomapper software and imported in Biomapper. The output scores obtained from the analysis showed that Iranian cheetah tends to mountain areas where has more topographical features for camouflage in order to hunting, and northern aspects which have more humidity, denser vegetation cover and more preys . Our result showed that the Iranian cheetah has medium niche width and prefer marginal habitats.

Baghe-shadi in Yazd province is one the forests which is reported to be an area with high rate fire occurrence. The aim of this study was to model and map the fire risk area using geographic information system and remote sensing. In this study Analytical Hierarchy Process (AHP) with human related factors (distance from road, distance from settlements, and distance from vegetation), climatic related factors (air temperature and rainfall), and physiographic related factors (elevation, slope, aspect) were selected. Vegetation cover was estimated using Landsat OLI Normalized Difference Vegetation Index (NDVI). Weights were determined from specialists through questionnaire. Weight of each factor, elevation, slope and aspect, temperature, precipitation, distance from roads, distance from settlements and vegetation cover was achieved through multiple criteria decision making model, then areas with five susceptible classes were determined using GIS. Results showed that vegetation related factor and human related factor with weights of 0.569 and 0.204 are the most important factors respectively. In order to assess the accuracy of developed model, fire susceptibility map of was compared with the previously fired area. Result of comparison showed very high and high risk areas are corresponding to the controls area. Receiver operating charasteristic (ROC) test confirmed the high level (0.88) of accuracy of presented model.

The effects of plant density and water stress on yield of Medicago sativa and Bromus tomentellus was studied. A greenhouse experiment was conducted at Isfahan University of Technology in 2013. The experiment included 18 treatments, three crop compositions (M.sativa, B. tomentellus or mixture of the two), two plant density levels, three watering regimes and four replicates, arranged in a completely randomized block design. Results showed that total yield of M. sativa mono-cropping was higher than mixed cropping and it was higher than B. tomentellus mono-cropping. Land Equivalent Ratio (LER) values were less than 1 for all mixed cropping treatments, indicated the interspecific competition in mixed cropping. The biomass production per plant decreased with increasing density, competition for resource utilization and water stress. Compare of above-ground and below-ground dry matter showed that M. sativa appeared to be more constrained by intraspecific than by interspecific competition, Conversely, B. tomentellus was more suppressed by interspecific competition exerted by M. sativa than by intraspecific competition. Relative competition intensity (RCI) values were positive for B. tomentellus and negative for M.sativa, implying that competitive ability of M.sativa was higher than B. tomentellus in mixed cropping .

Forest trees demonstrate different distribution patterns, depend on their living condition (Such as pest infestations). Forest density and epidemic pest concentration are hypothetically among the most influential factors. The current study was carried out on distribution pattern of the orchard ermine (Yponomeuta padella) infested hawthorn trees (Crataegus monogyna) in Bazoft river watershed in Central Zagros. Nine sites were selected with different infections. The site selection was based on pollution and position (North or South) it. Pollution, density of trees and coordinates (X , Y) were recorded for each tree. Eberhart and Ripley’s K functions were used to elucidate the infested and non-infested tree distribution. The results showed a clumped distribution of the trees in sound sites and in infested sites with high hawthorn density. Trees in low-dense infested sites had a tendency toward more random and even uniform population distribution.

To investigate the effects of plot size, shape and number on accuracy and precision of the estimates, forage production data of 5 regions of northern pastures of the country, collected separately by 640 one-square meter plots, were simulated using R software in a 640 m2 macro- plot with dimensions 20×32 m. The adequate sample size of different plot sizes of 1×1, 1×2, 2×2, 2×4, 4×4 and 4x8 m were obtained by the sketch method which were 60, 50, 40 ,30, 5, and 5, respectively. When the plot was sampled in different levels and shape based on the adequate plot numbers, almost all of them showed a mean equal to the actual mean. However, the highest precision was obtained using a 1x1 plot with the lowest SE. Comparison of plots with the same size and different shapes revealed that long-length rectangle plots show the highest precision. It is obvious that in actual situation of non-simulated studies with unknown parameters, the sampling guidelines of this paper will be helpful for proper and accurate estimation of the parameters.

The knowledge of rangeland vegetation types and factors influencing on their establishment and stability is essential for sustainable management and regeneration of rangeland areas. With this aim, Gonbad watershed, due to different vegetation types, environmental conditions and grazing managements was studied. The watershed was stratified to homogenous units based on morphology of vegetation types and environmental factors. Land properties, total canopy and canopy of the main five vegetation forms (annual grasses, perennial grasses, annual forbs, perennial forbs, and shrubs) were determined in 3 to 4 plots (1 x 1 m2) in each unit; plant and surface soil were sampled. Using TWINSPAN method, Silen sp., Centaura virgate, Astragalus verus and Cousinia bijarensis were identified as indicator species. DCA analysis subdivided the watershed into six ecological groups based on indicator plant species, production of perennial grasses and environmental factors, such as percent of sand and clay, and slope aspect. Based on the analysis of indicator species Asteragalus gossypinus (p= 0.001), Taeniatherum crinitum (p= 0.002) and Heteranthelium piliferum (p= 0.007) classified the vegetation cover into three main groups. Silen sp., Astragalus gossypinus, Centaurea virgat, Artemisa siberi, and Festuca ovina represent mountainous steppe and semi-steppe ecological environments. These deep rooting species are resistant to dry conditions. Therefore, ecological

Winter dens are one of the important components of brown bear's (Ursus arctos syriacus) habitat, affecting their reproduction and survival. Therefore identification of factors affecting the habitat selection and suitable denning areas in the conservation of our largest carnivore is necessary. We used Geographically Weighted Logistic Regression (GWLR) and Generalized Linear Model (GLM) for modeling suitability of denning habitat in Kouhkhom region in Fars province. In the present research, 20 dens (presence locations) and 20 caves where signs of bear were not found (absence locations) were used as dependent variables and six environmental factors were used for each location as independent variables. The results of GLM showed that variables of distance to settlements, altitude, and distance to water were the most important parameters affecting suitability of the brown bear's denning habitat. The results of GWLR showed the significant local variations in the relationship between occurrence of brown bear dens and the variable of distance to settlements. Based on the results of both models, suitable habitats for denning of the species are impassable areas in the mountains and inaccessible for humans.