مجله بوم شناسی کاربردی
پیاپی 47 (بهار 1403)

Most of the world's aquatic ecosystems are experiencing a substantial decline in their ecological services. This research was conducted to investigate the ecological condition of the Tajen estuary using the Nygaard-Palmer index at six stations during both cold and warm seasons. The results led to the identification of 32 genera belonging to 27 orders and 8 classes of phytoplankton. The identified phytoplanktons were classified into five orders: Ochrophyta, Chlorophyta, Cyanophyta, Euglenophyta, and Pyrrophyta. The highest species richness was observed in Bacillariophyceae. Thirteen genera that are tolerant to pollution were identified, and the results indicated that the ecological condition of the Tajen estuary is undesirable, with a status index calculated as very polluted, exceeding 20 in both warm and cold seasons. Field investigations also revealed that the Tajen estuary is affected by various environmental hazards at both local and catchment scales. These hazards have created unfavorable conditions and pressure on this habitat, resulting in a shift towards more pollution-tolerant species within the estuary. Overall, this index can be recommended for the biological and ecological assessment of other estuaries in the southern Caspian Sea basin. To reduce uncertainty, other suitable complementary indices may also be employed.

Pardisan Nature Park, the last remaining natural habitat in Tehran and home to 443 indigenous plant species, requires sustainable management due to its unique ecological characteristics. Estimating the ecological footprint is an effective method for assessing the ecological status of areas to ensure their optimal use. This study has calculated the quantitative ecological footprint of Pardisan Park using the component method. The ecological footprint was calculated for five consumption activities: electricity, water, gas, waste, and food. The biological capacity of different land types; along with ecological deficit and intensity indices were calculated.The results indicate that the ecological footprints for electricity, water, gas, waste, food, and the total are 121970.15, 86.72, 0.00, 2585.88, 0.00 and 124642.75, respectively. The biological capacity is measured at 438.47 hectares. The difference between the biological capacity and the total ecological footprint suggests an ecological deficit in the consumption sector. The ecological pressure index footprint intensity in the water, waste, and gas sectors is rated at level one (good), while electricity and food are rated at level four (very poor). Hence, park management has demonstrated efficiency in the consumption of water, gas, and waste, but has shown weaknesses in the consumption of electricity and food.

Globally, bird populations are experiencing a significant decline due to disruptions caused by human activities. The Chahakhoor International Wetland, as one of the important bird areas, is located in Chaharmahal and Bakhtiari Province. In this study, we evaluated the habitat quality of Chahakhoor over an 11-year period using the InVEST model. Land use and land cover maps for 2013, obtained from the Forests and Ranges Organization, and for 2024 were prepared using Landsat 9 image classification, employing a supervised method and the random forest algorithm. The results showed that habitat quality for waterbirds in this wetland declined by approximately 20% from 2013 to 2024. Additionally, changes in land use and land cover indicated reductions in water resources, dense vegetation, and average pasture land, while areas allocated for villages, cities, roads, and agriculture increased. Overall, our findings suggest that the decline in the abundance of many surveyed waterbird species in Chahakhoor Wetland is likely associated with the decline in the habitat quality over the 11-year period. This highlights the urgent need for conservation initiatives aimed at restoring and protecting this wetland, which supports bird populations.

Zoning of protected areas is an effective solution for reducing conflicts between various objectives, such as prioritizing conservation while also addressing secondary goals like rehabilitation, tourism, and multiple-use zones. Achieving these objectives is not feasible without zoning. This study aimed to allocate areas for conservation, rehabilitation, tourism, and multiple-use zones within the Abbasabad Wildlife Sanctuary, considering the interactions among different zones to optimize the arrangement of incompatible areas through multi-criteria evaluation method. Fuzzy models were used to standardize criteria, and Best-worst Weighting Model (BWM) was used to determine their weights. Suitability maps for each land use were prepared separately using the Ordered Weighted Average (OWA) method, while the zoning map for optimal land allocation was created using the multi objective land allocation (MOLA). The results indicated that the final suitability of the designated zones ranged from zero (the lowest suitability) to one (the highest suitability). The suitability scores for conservation, rehabilitation, tourism, and multiple zones were 0.82, 0.98, 0.82, and 0.84, respectively. The findings of this research can be used as a model for planning and prioritizing land use in protected areas.

Pollution caused by traffic is the result of incomplete combustion, wear of pads, and erosion of road surfaces. The purpose of this research was to determine the concentration of nickel and chromium in soil along the road of Shadmehr-Gonabad, in Khorasan Razavi, to evaluate the soil quality and effect of traffic on the concentration of elements. The results showed that the highest concentration of chromium and nickel in Faiz Abad station was 212.75 and 194 mg/kg in autumn and 143.25 and 159.25 mg/kg in winter, respectively. According to the results of the Potential Ecological Risk Index and the Risk Index, the biological toxicity of the elements was in the low-risk class. ANOVA and Pearson's analysis tests indicated the correlation between chromium and nickel with the distance from the road inversely and significantly (p< 0.05). The results of counting the cars using video showed that the number of passing cars at Shadmehr police station was more than the other stations. The average concentration of chromium (74.41 mg/kg) and nickel (73.79 mg/kg) were higher than the global soil average and the average soil of Khorasan Razavi. This research showed that high pollution is due to the simultaneous effect of traffic and geological origin.