Estimating the ecotourism carrying capacity (ETCC) in protected areas (PAs) is essential for minimizing the negative impacts of ecotourism and sustainable environmental management. PAs are one of the prominent ecotourism locations and many of these areas have been created to protect biodiversity and improve human wellbeing. This study has identified and prioritized negative impacts of ecotourism in Lar national park, the Jajrud protected area with the sustainable use of natural resources, and Tangeh Vashi national natural monument. For this purpose, physical carrying capacity (PCC), real carrying capacity (RCC), and effective carrying capacity (ECC) were estimated using the ETCC model. The results indicated that due to these areas’ ecological sensitivity, the most negative impacts of ecotourism are related to the environmental-physical dimensions. In contrast, the lowest impacts have been observed in the economic-institutional dimensions. Moreover, the results revealed that the highest PCC is related to Lar national park, and the lowest PCC is associated with Tangeh Vashi natural monument. There are more tourists in the Jajrud protected area with the sustainable use of natural resources than other areas in RCC and ECC due to low levels of restrictions and legal instructions. In contrast, in Lar national park and Tangeh Vashi natural monument, due to the short duration of ecotourism in these areas (from June to October), high level of restrictions, and ecological sensitivity, the number of tourists is less than the RCC and ECC. As these areas have a limited ability to attract visitors and ecotourism, the protection of these areas requires the implementation of sustainable management to control the negative impacts of ecotourism and estimate the number of visitors.

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.

The integration and connection of habitats in protected areas (PAs) are essential for the survival of plant and animal species and attaining sustainable development. Investigating the integrity of PAs can be useful in developing connections among patches and decreasing the fragmentation of a habitat. The current study has analyzed spatial and temporal changes to habitat to quantify fragmentation and structural destruction in PAs in Tehran Province, Iran. To achieve this purpose, the trends in land use/land cover (LULC) changes and the quantitative metrics of the landscape ecology approach have been examined. The results revealed that in Lar National Park, low-density pasture has the top increasing trend with 4.2% from 1989 to 2019; in Jajrud PA, built-up has the top increasing trend with 1.5% during the studied years; and among the land uses in TangehVashi Natural Monument, bare land has the top increasing trend with 0.6% from 1989 to 2019. According to the findings, habitat fragmentation and patch numbers have expanded in the studied areas due to the development of economic and physical activities. The results also indicate that the current trend of habitat fragmentation in PAs will have the highest negative impacts, especially in decreasing habitat integrity, changing the structure of patterns and spatial elements, and increasing the edge effect of patches.

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.

Ecotourism in protected areas facilitates responsible travel to natural places that conserve the environment, deliver economic benefits to local communities, and offer interpretation and education to visitors. Proper planning and sufficient monitoring of ecotourism sustainability indicators is needed to manage visitor activities in protected areas. Therefore, identifying the major impacts and mitigating them in the early stages of ecotourism development could contribute significantly to the achievement of sustainable development. There is a current gap between the situation in the field and academic contributions to this problem in protected areas of Iran. In the present study, we evaluated ecotourism sustainability levels in four different types of protected areas in Iran, including Lar National Park, Jajrud Protected Area with Sustainable Use of Natural Resource Areas, Tangeh Vashi National Natural Monument, and Kavdeh Wildlife Refuge. We developed a comprehensive list of ecotourism sustainability indicators, including 38 indicators in the environmental–physical dimension, 42 indicators in the demographic–social dimension, and 30 indicators in the economic–institutional dimension. Harnessing local community expertise, we adopted a Delphi approach to determine sustainability levels and factors impacting sustainability. Ecotourism in Lar National Park was most sustainable because of the high levels of restrictions protecting the area and the difficulty in access. Conversely, ecotourism sustainability was lowest at Tangeh Vashi National Natural Monument, which allowed for an uncontrolled influx of visitors. We discuss further factors that impact sustainability, such as population growth, expanding urbanization, an increase in physical and economic activities, and extended annual periods of ecotourism activities. Although the presented ecotourism sustainability indicators are specific to Iran, this study can also be seen to provide a template to plan for sustainable ecotourism in other countries. Altogether, our results suggest conducting a type-by-type analysis of the particular circumstances of various protected areas.

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.