Urban parks affect soil macroinvertebrate communities: The case of Tehran, Iran

Land use change represents a significant environmental transformation on a global scale, profoundly impacting natural ecosystems. The conversion of rangelands into urban parks can adversely affect soil characteristics and biodiversity. This transformation may lead to alterations in soil properties and invertebrate communities, subsequently influencing ecosystem functioning and resilience. This study aims to investigate the diversity of soil macroinvertebrates and examine the impacts of land use changes on their communities. Therefore, sampling was conducted at three locations in Tehran (Chitgar, Lavizan, and Darakeh), where rangelands surround by urban parks. Two sites were selected within each region, and 72 quadrats surveyed the study area. In total, 1517 samples were collected and classified into 267 morphological operational taxonomic units (MorphOTUs). Our findings indicate that the total abundance of macroinvertebrates is higher in rangeland habitats, with a count of 872, compared to 645 in urban parks. Additionally, rangelands demonstrate a greater diversity of MorphOTUs than urban parks. Specifically, Chitgar, Lavizan, and Darakeh reported 162, 141, and 190 MorphOTUs, respectively, while urban parks reported 152, 122, and 118. Univariate and multivariate statistical analyses were employed on abundance, diversity, and macroinvertebrate communities to examine the impacts of changing rangelands to urban parks. Our research indicates that land use change from rangelands to urban parks can significantly (p-value < 0.05) affect the abundance and community composition of macroinvertebrates, as these groups are sensitive to land use changes. Beta diversity analysis indicated turnover happened between them (Chitgar = 0.986; Lavizan = 0.983; Darakeh = 0.983). The SIMPER analysis showed that several MorphOTUs have contributed to this dissimilarity in every location. Furthermore, the Shannon-Wiener diversity index values for Araneae, Hemiptera, and Orthoptera were slightly higher in the rangeland than in the urban park. Our results also exhibited a diverse range of species in urban parks highlighting their important role in supporting biodiversity. Given that these parks have been established for many years, they have had ample opportunity to recover and enhance their ecological value. This study emphasizes that attention to soil organisms is essential for addressing conservation issues. Therefore, studying macroinvertebrate groups as biological indicators can assist in monitoring the effects of land use changes and will contribute to ecosystem management.