The dendroclimatic and dendrohydrologic potential of riparian plane trees (Platanus orientalis) along the Zayandeh-Rud River, Iran

Abstract

Platanus orientalis is a key riparian species in central Iran with the potential to serve as a climate and streamflow proxy within this region. However, there are limited studies concerning its dendrochronological potential and climate-growth relationships. Therefore, this study investigates the dendroclimatic potential of P. orientalis along the riparian ecosystem of the Zayandeh-Rud River in central Iran. A total of 50 trees were sampled and analyzed at two distinct basin sites, representing varying elevations, climate characteristics, and water availability. Our findings reveal that the tree-ring width index (TRWI) at the lower basin site, which is characterized by higher temperatures, and lower precipitation, is positively affected by streamflow in May and July. This relationship is highly dependent on the amount of precipitation in the upper and lower basin sites. Moreover, analyses reveal a significant negative relationship between TRWI and temperature during the growing season at the lower basin site. In contrast, trees at the upper basin site, characterized by higher precipitation, show weaker climate-growth relationships. These findings imply that P. orientalis tree-rings could provide insight into long-term climatic patterns within riparian ecosystems in central Iran.