Comprehensive Evaluation of Soil Quality under Different Vegetation Types in the Green Heart Area of the Changsha-Zhuzhou-Xiangtan City Cluster

• • Mixed forest soil exhibited the highest values for field water holding capacity, total porosity, saturated water content, total nitrogen, total carbon, available potassium, and available phosphorus, indicating superior soil physical and chemical properties compared to other vegetation types. • • Soil quality ranking: mixed forest > broad-leaved forest > shrub forest > economic forest > grassland > coniferous forest > abandoned cropland, with mixed forest significantly outperforming all others (p < 0.05). • • Compared to abandoned cropland, soil water content, total porosity, field water holding capacity, saturated water content, total carbon, total nitrogen, available potassium, and available phosphorus were significantly higher, while soil bulk density was significantly lower, demonstrating the positive impact of vegetation restoration on soil quality. • • Soil bulk density showed extremely significant negative correlations with soil water content, total porosity, and saturated water content (p < 0.01), and significant negative correlations with field water holding capacity, total carbon, and total nitrogen (p < 0.05), highlighting the critical role of soil compaction in nutrient and water retention.