Subalpine ecosystems are highly fragile as compared to biological andenvironmental factors. Landslide is one of the ruinous upshots of this ecosystem. One of theimpressionable areas in the cause of natural factor is Masoleh watershed in western AlborzMt, (Iran). In order to landslide hazard zonation, landslide index and frequency ratio methodbased on twelve causative factors such as slope, slope aspect, land use, lithology, distancefrom faults, distance from road, distance from stream, rainfall, range condition, StreamPower Index (SPI), Component Topographic Index (CTI) and elevation Receiver OperatorCharacteristic (ROC) curve analysis method was also used to evaluate the model. Theresults showed that geological, physiographical and grassland conditions have an importantrole in landslide area. Overgrazing, grazing in forth of season, early grazing, late termegression, and excess livestock are considered as direct affecting factors on vegetation, sothat they have simultaneous role to make the landslide risk. The verification results via ROCcurve showed that the landslide index model (85%) performed slightly better than thefrequency ratio model (82%). It was concluded that managers and protectors of thisecosystem can inhibit and conserve the landslide by decreasing the amount of livestock, andshort-term exclosure on critical area, and biomechanical dams in landslide-occurred area. تفاصيل المقالة

Recent attitude of vegetation assessors is using of new ecologic approaches to evaluate and analyse the complex rangeland ecosystems. Plant diversity is the most important indices to assess the ecological changes of rangelands. In order to survey of plant indices of rangelands, two exclosure areas (long-term and mid-term) and a grazing area in rangelands of Javaherdeh (Ramsar, Iran) were selected. Quadrate size and number were respectively obtained by minimal area and statistical formula methods. The diversity, richness, and evenness indices in each quadrate were calculated. For comparing of these indices, one way ANOVA and Duncan test method were used. Results showed that the higher values of diversity and richness indices were obtained in the long term exclosure and the lower values of evenness index were obtained in the grazed area. The SHE analysis clarifies that the highest species richness and diversity was obtained in lower plots number in the long-term exclosure areas and reversely it needs more plots for assessment of grazed area. Along with time elapsing, the long-term exclosure and grazing area had higher and lower evenness, respectively. The mid-term exclosure, however, needs also long time to reach the maximum species richness and diversity. Hence, in order to achieve the ecologic management of the rangeland ecosystems, knowing of bio-indicators and their components analysis (SHE) can draw future trend of the ecosystem and bring out data to program it. تفاصيل المقالة