مجله بوم شناسی کاربردی
پیاپی 37 (پاییز 1400)

The aim of the study was to determine the most important environmental factors (topography, climate, and soil) affecting changes in production and canopy cover of plant variations and to prepare prediction maps, based on the most important factor, in semi-steppe rangelands of Hir-Baghrou, Ardabil province, Iran. First, by detecting the vegetation types and different classes of environmental factors, the production and canopy cover were estimated in 1-m2 plots at full flower stage of dominant species. Then, to determine the most important environmental factors, affecting the production and canopy cover changes, the principal component analysis (PCA) was used. For modeling, first, the correlation between the most effective environmental factors was obtained from the PCA. Then, the highly correlated factors were eliminated and the quadratic polynomial models were obtained. Finally, the obtained models were simulated in GIS. The results of the PCA showed that the first six components with 71.65% had the greatest effect on the production and canopy cover changes. Based on the root mean squared error (RMSE), simulating maps of production (RMSE=0.76) and canopy cover (RMSE=0.48) by effective factor (annual precipitation) showed the highest accuracy. The results of this study can be used to manage the rangelands of Ardabil province to create a balance between supply and demand of production and also to balance carbon.

This study focused on vegetation classification of Darabkola forest in the middle part of Hyrcanian forests in north of Iran. For this purpose, 139 releves were sampled using systematic- selective method in 400 m grid dimensions by the consideration of indicator stands concept. Based on modified TWINSPAN method and Braun-Blanquet phytosociological method, five associations (Parrotio persicae-Carpinetum betuli, Zelkovo carpinifoliae-Quercetum, Solano kieseritzkii-Fagetum orientalis, Aceri velutini-Parrotietum persicae and  Euphorbio amygdaloidae-Fagetum orientale) and four sub-associations (Zelkovo carpinifoliae-Quercetum castaneifoliae subasso a typical subasso Quercetosum, Zelkovo carpinifoliae-Quercetum castaneifoliae subasso Fagetosum orientale, Aceri velutini-Parrotietum persicae subasso Carpinetusum betuli and Aceri velutini-Parrotietum persicae subasso Pteroetosum fraxinifoliae) were distinguished. Demonstration of plant communities along the first two axes of detrended correspondence analysis (DCA) showed that these associations had almost distinct pattern. Also, results of multiple regression of topographic factors with the two first ordination axes of DCA indicated that elevation was the most important topographic factor in distribution of the associations in the Darabkola forests. In addition, the results of this study can lead to the more efficient management and better protection of Darbakla forest.

The purpose of this study was to investigate the level of environmental responsibility and environmental participation among the residents of rural areas in Bandar Abbas county, which was conducted by survey and field methods. Sample size was determined based on the Cochran’s formula and the required data were collected through questionnaires. A total of 366 questionnaires were completed in a stratified-random manner. The research questionnaire was designed in two parts: environmental participation and environmental responsibility, using the 5-points Likert scale. The reliability of the questionnaires, calculated by test-retest and Cronbach's alpha coefficient for the participation and environmental responsibility questionnaires, were 0.79 and 0.86 respectively. Results showed that economic, social and cultural participations with the score of 14.37, 13.70 and 12.96 respectively, have the highest scores in rural communities. Among the dimensions of responsibility, human rights responsibility with an average of 19.43 was the highest score among the residents of rural areas, followed by legal responsibility (18.6), intellectual and internal (17.37) and operational (16.85) responsibility. Comparison of participation and responsibility in rural areas of Bandar Abbas showed that there is no significant difference between different rural areas (P ˃ 0.05). The rural residents are active and involved in environmental protection, showing people's attention to the natural environment of the region.

The prevalence of the Pest des petits ruminants (PPR) over the past ten years in Iran has resulted in devastating effects on the wild goat (Capra aegagrus) and mouflon (Ovis gmelini) populations, as well as small domestic ruminants. The aim of this study was to identify areas with high risk of PPR outbreak, determine the environmental and landscape factors affecting the spread of the disease, and identify the transmission corridors of the disease through the wild hosts of PPR virus in Markazi province. The risk of occurrence of PPR was mapped once in livestock and wildlife separately and also jointly for both groups using maximum entropy model. An electrical circuit model was used to identify migration corridors and evaluate the transmission of disease through the wild hosts of the PPR virus. The model performance index was calculated 0.727 for livestock, 0.997 for wild ruminants, and 0.849 for both groups. The results showed that precipitation of the wettest month was the most important variable affecting the prevalence of PPR. Potential migration corridors of wild sheep matched the areas where the risk of PPR occurrence was high. The results of the present study can be operative in developing effective methods to prevent the spread of this fatal disease in the country's wildlife.

Prioritization and selection of sample areas from the whole nature is necessary to protect biodiversity. The main purpose of this study was to evaluate the development of a network of conservation areas in Markazi province using landscape metrics. For this purpose, we used MaxEnt, Marxan, Fragstat softwares and eight conservation criteria. Results were compared by using simulated sorting, greedy, best and max rarity algorithms and different landscape metrics. Maximum entropy method was used to model the wildlife habitats. The results of different protection scenarios showed that a 30% conservation target with a Boundary Length Modifier (BLM)of 30 is the most appropriate option. The simulated sorting algorithm provided  more acceptable results in all cases. Overlaping  the selected protection areas with the map of protected areas in Markazi province showed that only two protection criteria, out of the 8 selected criteria, are successful in providing the 30% protection target, which is not efficient in terms of achieving protection goals. In most scenarios, the overlap of the selected protection networks with the existing protected areas are less than 31.45%.Results of landscape metrics showed that the distance between conservation areas varies. The diversity and abundance  of the conservation areas are low. . Therefore, the conservation areas in Markazi province are among the vulnerable ecosystems with high fragility.

Although one of the most important factors affecting the decline and drying of Zagros forests is the occurrence of climate change, especially during the last two decades, the degradation and decline of Zagros forests can intensify the trend of climate change in this ecosystem. In order to detect the occurrence of climate change in the Zagros oak (Quecus brantii) forests of Chaharmahal and Bakhtiari province, daily data of minimum temperature, maximum temperature and precipitation parameters were used. Data were analyzed for quality and homogeneity and prepared to enter into the climate model that reveals the occurrence of climate change. Warm temperature indicators for climate change detection were calculated, using ClimPACT software in R 2.10 programming environment for the  period of 1992-1999. Trend change, trend slope error and significance of changes were extracted at p = 0.05. The results showed that at all monitoring sites, hot temperature indices, including 2TX2TN SU35, SU30, SU25, TN90p, TX90p, TX50p, WSDI6, WSDI2, had a significantly increasing trend. Changes in the slope of the trend of these indicators coincided with the beginning of the decline phenomenon and have been more intense in the last two decades. Due to the increasing trend of temperature, this increasing trend of indicators will continue in the coming years and the forests of the region will face more drought stress. Awareness of the severity of the changes that have occurred and their continuation in the future can help managers and planners of the Zagros forest ecosystem in operational solutions in adapting to climate change to preserve and rehabilitate forests.