The Development of Stand Growth Tables of Quercus mongolica Under Climate Change Scenarios

Numerous studies have demonstrated that climate exerts a substantial impact on forest growth. Traditional stand growth yield tables fail to take climatic factors into account, resulting in low accuracy and limited applicability. The study aimed to develop stand growth tables under climate change scenarios by incorporating the effects of climatic factors on stand growth, based on five successive permanent plot monitoring of natural Quercus mongolica broad-leaved mixed forests in Jilin Province from 1994 to 2014. First, the optimal growth models were selected from common theoretical growth equations to establish the site class curve. Then, growth equations for stand quadratic mean diameter at breast height (Dg), number of trees per hectare (N), and stand volume per hectare (V) were fitted separately. Climate-sensitive stand growth tables were compiled by site class using the simultaneous equations method, and stand growth dynamics were predicted under four climate scenarios (SSP126, SSP245, SSP370, SSP585) from 2011 to 2100. The results showed that model fitting identified the Logistic function as optimal for stand mean height and Dg, an exponential function for N, and the Richards function for V. Stand mean height was positively correlated with mean annual precipitation. Dg was positively correlated with mean temperature of the warmest month and mean annual precipitation. N was negatively correlated with mean temperature of the warmest month and showed no significant correlation with mean annual precipitation. V was negatively correlated with mean temperature of the warmest month and positively correlated with mean annual precipitation. The climate-sensitive stand growth tables improved long-term prediction accuracy compared with conventional static yield tables. This study provides dynamic and reliable technical support for the scientific management and ecological regulation of Quercus mongolica forests under climate change, and it also offers methodological references for compiling growth tables of other broad-leaved mixed forests.