Introduction: Tourism plays a pivotal role in the economic revitalization and diversification of communities. However, it can simultaneously induce significant transformations in the social, economic, and ecological dimensions of the host regions. The impacts of this industry on society may be physical, economic, social, or cultural in nature. There exists a reciprocal relationship between protected area management and the tourism industry—each depending on the other for its sustainability. Although this interrelationship is often complex and occasionally conflicting, tourism—if effectively managed—serves as a crucial mechanism for the preservation, development, and diversification of protected areas. Within the framework of sustainable management of protected regions, and with the dual objective of optimizing tourist use while safeguarding environmental and security values, estimating tourist numbers is of paramount importance. Accordingly, the present study adopts a sustainable tourism development perspective and employs a quantitative model to assess the tourism carrying capacity of the Palang Darreh Protected Area, located in Qom Province, Iran. Palang Darreh, as the sole protected area in the province, features pristine landscapes, diverse vegetation, and a variety of animal species. Situated approximately fifty kilometers southwest of Qom, it functions as a key ecotourism destination in the region.
Materials and Methods: To evaluate the tourism carrying capacity, expert consultations were conducted to identify the key indicators influencing capacity estimation, including the number of frost days, storm days, and hours of extreme heat, rainy days, breeding season restrictions, and human resource availability. The study area encompassed several ecological and recreational zones, such as wildlife viewing sites, birdwatching locations, mountaineering areas, and water resources. Then in each region separately, the physical carrying capacity, which is the maximum number of visitors who can be physically present at a site at a given time; the real carrying capacity, which is the number of visitors a site can accommodate after adjusting for limiting environmental or situational factors, and the effective carrying capacity, which means the number of visitors a site can sustainably support given the management’s operational capabilities, were calculated.
Results: The estimated effective carrying capacities for wildlife viewing and birdwatching sites—located in the eastern and western sections—were 998 and 499 visitors per day, respectively. For mountaineering sites, Aleh Mountain and Sakht Hesr accommodated an estimated 12,355 and 18,112 visitors per day. Regarding the region’s water resources, the capacities of Kosh-e-Taghcheh Spring, Dega aqueduct, and Khajeh Hassan aqueduct were estimated at 125, 250, and 375 visitors per day, respectively, demonstrating high tourism potential. Among the evaluated sites, mountaineering areas exhibited the highest physical, real, and effective carrying capacities, while the springs and aqueducts had the lowest. Specifically, Sakht-e-Hesar Mountain had the greatest capacity across all indices, whereas the Taqcheh Spring exhibited the smallest capacity values.
Discussion: The findings indicate that the Palang Darreh region possesses substantial effective tourism carrying capacity. In light of emerging challenges faced by Iran’s ecotourism sector, it is evident that this region requires the enhancement of its infrastructure and service facilities to both accommodate increasing tourist demand and mitigate potential negative environmental impacts—particularly those related to the harvesting of medicinal plants. Regional management strategies should prioritize two main objectives: (1) ensuring the protection of the area’s ecological and conservation values, and (2) maximizing visitor satisfaction through sustainable tourism planning and management.