Hassan Esmaeilzadeh

Balancing ecotourism development with water resource sustainability is an urgent challenge for semiarid cities experiencing escalating water stress. Tehran, a rapidly expanding Middle Eastern metropolis, has faced acute water scarcity in recent years, making water-entered planning critical for sustainable tourism. This study combines ecological capability evaluation (ECE), GIS-based multi-criteria analysis, and institutional review to delineate suitable zones for ecotourism. Twenty-three indicators across physical, ecohydrological, and socio-economic dimensions were weighted using the Analytic Hierarchy Process (AHP) and integrated through Weighted Linear Combination (WLC). Results showed a clear spatial polarization: northern highlands and river valleys, with higher precipitation and abundant surface water, were identified as the most suitable areas for both intensive and extensive ecotourism, while southern plains with chronic water scarcity and flood risk were classified as unsuitable. More than 60% of intensive ecotourism zones are located within 1 km of perennial rivers, underscoring the decisive role of surface water. Extensive ecotourism suitability was more strongly associated with upland regions combining groundwater accessibility and higher rainfall. This study shows that water is not merely a limiting resource but the strategic axis around which ecotourism planning in semiarid cities must be organized. The framework developed here provides a decision-support tool for Tehran and offers transferable guidance for semiarid metropolitan regions confronting water scarcity and uncoordinated land-use expansion.

Air quality concerns have become increasingly serious in metropolises such as Tehran (Iran) in recent years. This study aims to assess the contribution of urban trees in Tehran toward mitigating air pollution and to evaluate the economic value of this ecosystem service using the i-Tree Eco model. To accomplish this objective, we utilized Tehran's original land use map, identifying five distinct land use categories: commercial and industrial, parks and urban forests, residential areas, roads and transportation, and urban services. Field data necessary for this analysis were collected from 316 designated plots, each with a radius of 11.3 m, and subsequently analyzed using the i-Tree Eco model. The locations of these plots were determined using the stratified sampling method. The results illustrate that Tehran's urban trees removed 1286.4 tons of pollutants in 2020. Specifically, the annual rates of air pollution removal were found to be 134.8 tons for CO; 299.7 tons for NO2; 270.3 tons for O3; 0.7 tons for PM2.5; 489.4 tons for PM10 (particulate matter with a diameter size between 2.5 and 10 µm); and 91.5 tons for SO2, with an associated monetary value of US$1 536 619. However, despite this significant removal capacity, the impact remains relatively small compared with the total amount of pollution emitted in 2020, accounting for only 0.17%. This is attributed to the high emissions rate and low per capita green space in the city. These findings could serve as a foundation for future research and urban planning initiatives aimed at enhancing green spaces in urban areas, thereby promoting sustainable urban development. Integr Environ Assess Manag 2024;20:2142–2152. © 2024 SETAC Key Points Tehran's urban trees removed 1286 tons of pollutants in 2020, and yet their contribution toward improving air quality was relatively small, accounting for less than 1% of the overall pollution reduction and unable to offset local emissions due to dormancy in winter. Compared with other preferred approaches, such as replacing eroded diesel buses and trucks with newer models, urban trees showed the lowest cost-effectiveness in improving air quality but were insufficient on their own. Urban planners and managers must consider the combined impact of urban trees with other approaches to significantly mitigate air pollution and ensure city sustainability. Future research should investigate the role of shrubs alongside trees in reducing air pollution and quantify the combined air pollution removal by vegetation canopies to fully understand urban green infrastructure's effectiveness in mitigating air pollution.

Cities play a critical role in anthropogenic CO₂ emissions, which exacerbate climate change and impact urban populations. Urban green infrastructure, such as urban trees, provides essential ecosystem services, including reducing atmospheric CO₂ levels. However, there is a significant knowledge gap regarding the impact of urban trees on climate change in semiarid, polluted cities like Tehran, the capital and largest metropolis of the Middle East. This study assesses the carbon sequestration and storage potential of Tehran’s urban infrastructure using the i-Tree Eco model. A randomized cluster sampling method was employed, collecting data on species composition, diameter at breast height (DBH), and total tree height. The results indicate that Tehran’s urban trees sequester approximately 60,102 tons of carbon per year, equivalent to 220,393 tons of CO₂. The net carbon storage in urban trees is about 254,579 tons, equivalent to 933,455 tons of CO₂. Parks and urban green spaces demonstrate the highest rate of carbon sequestration per hectare, followed by urban services land use. Prioritizing the planting of species with high sequestration rates like Cupressus arizonica (Arizona cypress) and Cupressus sempervirens L. var. horizontalis (Mediterranean cypress) could enhance carbon sequestration efforts in Tehran. These data provide valuable insights into the carbon sequestration potential and environmental impact of different land use types, and may aid in the development of effective environmental policies and land management strategies in semiarid urban areas and other cities in similar settings.

Protected areas are prime areas for ecotourism development, attracting large numbers of visitors to an abundance of ecologically significant and often sensitive flora and fauna. The current study identified adverse impacts of ecotourism in four prominent tourist hotspots in Iran, namely Lar National Park, Jajrud Protected Area with Sustainable Use of Natural Resources, Tangeh Vashi National Natural Monument, and Kavdeh Wildlife Refuge. Impacts were compared against the IUCN guidelines according to the degree of ecological sensitivity and multiple managerial objectives. In addition, an analytic network process (ANP) was applied within a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis to identify optimal strategies for reducing threats and weaknesses and improving opportunities and strengths for sustainable ecotourism management. We found the greatest negative impacts of ecotourism in a Jajrud that was exposed to rapidly expanding urbanisation and the corresponding development of economic and physical activities. Conversely, the least negative impact occurred in a national park (Lar) that was managed based on conservation approaches, accounting for high ecological sensitivities, and adapting legal prohibitions. The SWOT-ANP analysis demonstrates that certain strategies can minimise impacts and should be adopted as conservation tools by protected area managers and land planners.

Land use/land cover (LULC) changes in response to natural factors and human activities constitute a pressing issue for the conservation of Protected Areas in urban–rural landscapes. The present study investigated LULC changes in the Jajrud Protected Area (JPA) and the Kavdeh Wildlife Refuge (KWR) in the Tehran province, Iran, between 1989 and 2019. To inform ecological conservation measures for the JPA and KWR, LULC changes were identified and monitored using Landsat imagery from between 1989 and 2019. In addition, the landscape ecological risk (ER) was evaluated by conducting a landscape pattern index analysis. Then, the importance of different indicators affected by ER in these two PAs was assessed using the Delphi method, and expert opinions were solicited through a questionnaire. As for LULC changes in the JPA, high-density pasture declined the most over 1989–2019, from 38.6% (29,241 ha) to 37.7% (28,540 ha). In contrast, built-up areas increased the most, from 10.4% (7895 ha) in 1989 to 11.9% (9048 ha) in 2019. Water bodies also increased, from 0.88% (676 ha) in 1989 to 0.94% (715 ha) in 2019. In the KWR, cropland and gardens increased the most, from 2.14% (1647 ha) in 1989 to 3.4% (2606 ha) in 2019. Built-up areas also increased, from 0.05% (45 ha) in 1989 to 0.09% (75 ha) in 2019. Water bodies increased from 0.69% (538 ha) in 1989 to 0.71% (552 ha) in 2019. Finally, high-density pasture decreased the most, from 29.4% (22,603 ha) in 1989 to 28.5% (21,955 ha) in 2019. At the same time, the high and very high ER classes increased, more so in the JPA compared to the KWR. Finally, considering both LULC and ER changes, the Delphi method demonstrated that the greatest impacts occurred in the JPA. Various illegal economic and physical activities have created LULC changes and caused extensive destruction of ecosystems, posing a high ER in the study areas. The intensity of ER differs between the two PAs because of the varying distance from the metropolis, varying degrees of human activities, LULC changes, along with differences in legal restrictions of use. Aligned with the management plans of these areas, our research shows that it is necessary to develop land only within the designated zones to minimize the amount of ER. Various models of LULC changes have been presented, and a comparison of these models relating to the methodology and model effectiveness can help increase their accuracy and power of interpretation.

This study examines the distribution of water resources in Protected Areas in Iran and their priority for conservation. The results show that most of the water resources are located in the north and northwest of Iran due to favorable climatic conditions, topography, ambient temperature, and annual rainfall levels. Conversely, the lowest amount of water resources are located in the center and southeast of the country. Water resources were prioritized based on expert ratings of indicators to determine their value for conservation. The wetland with the highest priority for conservation is the Anzali Wetland (Gilan province), which is an international Ramsar Wetland. Conversely, Namak Lake (Qom province) was deemed the least important due to its geographical location, biological sensitivity, and conservation status. Protected Areas were found to support more surface water resources and provide space for the largest percentage of water resources, demonstrating their great value for protecting water resources in Iran. However, the level of protection of these critical resources, although located in Protected Areas, was shown to be insufficient. Therefore, appropriate planning and integrated management approaches are urgently needed to protect water resources and aquatic habitats in Protected Areas in Iran to address the current water crisis.

Nature conservation efforts cannot succeed without stakeholder participation. The inherent complexity of nature-based ecotourism has made the development of sustainable ecotourism operations a challenge, so it is essential to increase community stakeholder participation. Hence, this study investigates local community participation in Lar National Park (LNP) and the Jajrud Protected Area with the Sustainable Use of Natural Resource Areas (JPA) in Iran and evaluates how this influences the sustainability of ecotourism. This study found that in LNP, sustainable ecotourism development involving local communities is increasing because of the high level of attachment and interest to this part of pristine nature. In the JPA, the relationship between local community participation and ecotourism sustainability is significant too. As a result, natural habitats have been degraded and sustainability has decreased. To conserve these critically endangered natural areas, managers and decision-makers must increase community participation and education to encourage local communities to engage more in developing sustainable ecotourism.