مجله بوم شناسی کاربردی
پیاپی 45 (پاییز 1402)

Specialized species living in high mountain areas face more threats compared to species living in low altitudes, primarily due to habitat destruction or fragmentation and climate change.The Caspian snowcock is a  species with a specialized ecological niche and serves as an indicator of mountain ecosystems. Despite the high sensitivity of this species to habitat changes and its role as an umbrella or flagship species in mountainous areas, there is a scarcity of data on the ecology of this species. In the current study, we predicted the geographical range of this bird using 262 presence localities and 10 environmental and anthropogenic variables within an ensemble framework, resulting from five modeling algorithms. Based on the ensemble model, about 96527.4 km2 (5.8%) of the country was identified as a suitable habitat for the Caspian snowcock. Potential habitats of the species appeared to be strongly influenced by topographical roughness (30.02), average annual temperature (29.61), altitude (18.57), and isothermality (14.14). About 16.04% and 23.13% of the predicted suitable range overlapped with no-hunting  and protected areas. It is suggested that effective conservation measures should be taken by focusing on the possible threats caused by human activities, including the development of tourism infrastructure, road networks, overgrazing, and poaching.

Evaluation, identification, and conservation of native ecotypes of medicinal plants as human heritage are essential. Therefore, collecting and evaluating native ecotypes, as well as introducing adaptive ecotypes, are important for farmers. In order to evaluate the agricultural characteristics of 49 ecotypes of the dragon's head collected from different regions of the country, a randomized complete block design with three replications was applied at the research farm of the Faculty of Agriculture at Tabriz University. The tallest plant was associated with the ecotype number 6 (Kolvanagh 5), with an average of 41.13 cm. The ecotype number 23 exhibited the highest number of leaves on the main stem, with an average of 30.14 leaves. The highest chlorophyll index was associated with ecotype number 49 (Nazirlo and Darwish Bakal villages), averaging 36.04. The highest leaf area index was associated with ecotype No. 20, averaging 2.89 cm2. The highest seed yield of a single plant was associated with ecotype number 25 (the local population of Taze Kand 1 Haris village), averaging 1.05 g. The findings indicate that ecotypes No. 7 (Kolvanagh 6) and 14 (Tabriz 3), which exhibited the highest biological performance, could be used for fodder production.

The present study was conducted to investigate NPP changes and its relationship with drought. The monthly time series of NPP for the country's rangelands was prepared from the sum of net photosynthesis production (PSN) of the eight-day MODIS sensor (MOD17A2H) with a spatial scale of 500 m for 2000 to 2022.The monthly rainfall data of 165 synoptic stations were obtained from the National Meteorological Organization to calculate the Standard Precipitation Index (SPI) and monitor droughts in this period. Box plots of precipitation and NPP were prepared and showed that the highest values of NPP with an average of more than 50 gC.m-2month-1 occur during spring and early summer in humid areas. Results showed that NPP is increasing in Iran's rangeland ecosystems, and on average, the NPP of all rangeland ecosystems in the country is about 112.6 ± 13 gC.m-2.year-1  ,in other words, about 76 million tons of carbon per year. It is absorbed by the plants in the rangeland ecosystems of the country. The trend of changes in the monthly series of NPP was not significant due to the influence of seasonal characteristics, but the annual changes of NPP showed a significant trend of increase in all regions.

Wetlands, as fragile water sources, are constantly affected by climate change and human activities. Recently, human intervention and the reduction of surface water in the catchment area of Lake Urmia have altered the microflora and physicochemical parameters of the wetlands, which need to be investigated. Results showed that phytoplankton populations of Darga-Sangi wetland consisted of Chlorophyta (2 classes, 10 families, and 22 genera), Cyanobacteriata (1 classes, 3 families, and 4 genera), Streptophyta (1 classes, 2 families, and 2 genera), Ochrophyta (2 classes, 2 families, and 2 genera), and Basillariophyta (4 orders, 6 families, and 10 genera ). In addition, pH value, Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) were investigated. The highest amount of BOD5 of Darga-Sangi wetland was estimated to be between 78 and 98 mg/l, while the highest amount of COD was 159 and 198 mg/l during the summer season. The results indicate that the high influx of organic and mineral substances into the wetland has affected its enrichment which resulted in blooming of microalgae and hence, rising ecological concerns. The bacterial load in this wetland puts it in an unfavorable condition, which can be dangerous for native and migratory organisms.

Leaf litter decomposition plays a key role in the nutrient cycle of forest ecosystems. However, there is not a comprehensive understanding of the non-additive decomposition effects in leaf litter mixing experiments. In this study, the dynamics of nutrients and the rate of decomposition of Iranian oak (Quercus brantii), tree of heaven (Celtis caucasica), and wild pistachio (Pistacia atlantica) were investigated in both pure and mixed stands. For this purpose, 81 single- and double-litter bags were placed in the study area and incubated for 180 days. According to the results, at the end of the incubation period, the decomposition of oak litters in combination with tree of heaven, tree of heaven in combination with wild pistachio, and wild pistachio in combination with oak showed positive results. Based on the results, the nitrogen concentration in oak mixed with tree of heaven was higher than in its pure state. But the concentration of phosphorus in its pure and combined states did not show any significant differences. In general, the findings showed the positive non-additive effects of litter on its decomposition rate. Regarding the dynamics of nutrients, these effects were considered positive only for nitrogen.

This research was conducted to investigate the energy balance and global warming potential of almond production through by traditional and mechanized cultivation in Lenjan county, Isfahan province. Information related to the consumption of inputs and outputs was collected using 175 and 177 questionnaires in traditional and mechanized cultivation, respectively. Equivalent energy of inputs and outputs, as well as global warming potential, were calculated using coefficients of equivalent inputs. The results showed that the total energy consumption in traditional and mechanized cultivation is 14108.53 and 13767.39 MJ ha -1, energy efficiency is 0.19 and 0.24, and energy efficiency is 0.10 and 0.12 kg/MJ, respectively. Statistically, a significant difference was observed between the energy intensity index and energy consumption in both methods (P≤ 0.05). However no significant difference was observed between the energy intensity index in these two methods. Based on the economic analysis, the profit-to-cost ratio in traditional and mechanized cultivation was 3.27 and 4.2, respectively. The global warming potential from traditional and mechanized cultivation was 533.23 and 672.3 kg equivalent of carbon dioxide per hectare. The highest levels of environmental pollution in traditional and mechanized farming were associated with diesel fuel, accounting for 64.46% and 83.83%, respectively.