A Study on the Evaluation of Forest Ecosystem Quality and Its Influencing Factors in Guangxi

The forests of Guangxi represent a significant collective forest area and a vital ecological security barrier in southern China.It is the first modern forestry industry demonstration zone jointly built by the central and local governments.Evaluating and monitoring forest ecosystem quality can provide theoretical support for the high-quality development of forests and the realization of ecological civilization value.Based on monitoring data from 147 forest plots in Guangxi in 2022,eight evaluation indicators were selected across three dimensions of forest productivity,forest structure and ecological stress of forest ecosystem.The analytic hierarchy process was used to assign weights to the indicators,and a weighted summation method was applied to calculate the quality index scores for each forest ecosystem sample plot.The random forest model was used to analyze the influencing factors.The results showed that:①The comprehensive index of forest ecosystem quality in Guangxi in 2022 was 70.99,which falls into the "good" category.All 147 plots were rated as either good or excellent in ecological quality,with the overall forest ecosystem quality showing a gradual decline from the southeast to the northwest.②Among different forest types,coniferous and broad-leaved mixed forests had the highest ecosystem quality index (72.03),followed by evergreen and deciduous broad-leaved mixed forests (71.62),evergreen broad-leaved forests (70.86),subtropical coniferous forests (70.60),bamboo forests (70.25) and artificial forests (68.55).Mountain shrublands had the lowest ecosystem quality index (65.73).③Precipitation had the strongest influence on the forest ecosystem quality index in Guangxi (0.263),followed by resident population (0.157, soil clay content (0.148) and soil organic carbon storage (0.103).The influences of temperature,topographic factors (slope aspect,altitude and slope gradient) and soil pH were all below 0.1.The evaluation index system and research conclusions of forest ecosystem quality proposed in this paper can provide an important theoretical reference for the monitoring and evaluation of regional forest ecosystem quality.