Gap dynamics of natural Populus euphratica floodplain forests affected by hydrological alteration along the Tarim River: Implications for restoration of the riparian forests

Abstract

Abstract Due to climate change and excessive human activities, runoff dynamics of the Tarim River in northwest China become more pronounced. Understanding the effects of hydrological alteration on the life strategy and dynamics of the Populus euphratica riparian forests is becoming increasingly important. Forest gaps led by such disturbances change the structure and function of the desert riparian forest ecosystems. However, there is a lack of research on the gap formation and dynamics of this special forest type, for which the main driving force of the gap disturbance has always been unknown. In this study, we investigated several parameters of P. euphratica forest gap, such as gap size, gap age, gap fraction, and gap makers to quantify the gap disturbance regimes in the natural floodplain forests along the Tarim River in arid northwest China. In the middle reaches of the Tarim River, a total number of 263 gap makers and 60 gaps in six 50\u202fm\u202f×\u202f50\u202fm plots with a total area of 1.5\u202fhm2 were investigated. The result showed that gap fraction was