乐山绿心公园不同干扰强度对慈竹生物量碳的影响

Effects of Different Disturbance Intensities on Biomass Carbon of Bambusa emeiensis in Leshan Green Heart Park

摘要: 城市公园人为活动会改变竹林群落结构与碳汇功能，但目前城市绿地慈竹碳储量对人为干扰的响应特征及核心驱动因子尚不明确，相关实证研究较为薄弱。本文以乐山市绿心公园慈竹林为研究对象，依据样地与步道的距离差异，划分高强度干扰(0~10 m)、中度干扰(10~20 m)、低度干扰(>20 m)三类干扰梯度，野外测定坡度、郁闭度、慈竹胸径、株高、立竹密度等指标，结合生物量计量模型估算地上生物量碳储量。采用单因素方差分析、Pearson相关性分析及逐步回归分析，探究人为干扰强度与环境结构因子对慈竹林碳储量的影响规律。结果表明：(1) 慈竹生物量碳储量在不同干扰梯度下差异显著，整体表现为中度干扰(68.26 t/hm²) > 低度干扰(37.12 t/hm²) > 高度干扰(19.73 t/hm²)，其中中度干扰碳储量较高度、低度干扰分别显著提升245.97%、83.89%；(2) Pearson相关性分析表明，坡度、样地距步道距离与碳储量无显著相关，而郁闭度、立竹密度、平均胸径为核心影响因子，与碳储量呈极显著正相关，慈竹株高与碳储量呈显著正相关；(3) 逐步回归分析进一步筛选出立竹密度、平均胸径为碳储量的主导影响因子，二者可共同解释95.5%的碳储量变异，且立竹密度的影响强度更高。适度人为干扰可有效优化慈竹林群落结构，平衡种群种内竞争，改善植株生长条件，显著提升单位面积生物量碳储量。本研究明确了城市公园不同人为干扰梯度下慈竹林碳储量的差异化响应规律与核心驱动机制，可为乐山绿心公园竹林精细化管护与城市绿地碳汇提升提供数据支撑。

Abstract: Human activities in urban parks can alter the community structure and carbon sequestration capacity of bamboo forests. However, the response characteristics and core driving factors of Bambusa emeiensis carbon storage to anthropogenic disturbance in urban green spaces remain unclear, and relevant empirical research is insufficient. Taking the Bambusa emeiensis forests in Leshan Green Heart Park as the research object, three disturbance gradients were classified based on the distance between sample plots and trails: high-intensity disturbance (0~10 m), moderate-intensity disturbance (10~20 m), and low-intensity disturbance (>20 m). Field measurements were conducted on indicators including slope, canopy closure, DBH of Bambusa emeiensis, plant height and culm density, and the above-ground biomass carbon storage was estimated using a biomass measurement model. One-way analysis of variance, Pearson correlation analysis and stepwise regression analysis were adopted to explore the influence rules of anthropogenic disturbance intensity and environmental structural factors on carbon storage of Bambusa emeiensis forests. The results showed that: (1) The biomass carbon storage of Bambusa emeiensis differed significantly across disturbance gradients, ranking as moderate disturbance (68.26 t/hm²) > low disturbance (37.12 t/hm²) > high disturbance (19.73 t/hm²). Compared with high and low disturbance groups, the carbon storage under moderate disturbance increased significantly by 245.97% and 83.89%, respectively; (2) Pearson correlation analysis revealed that slope and the distance from plots to trails had no significant correlation with carbon storage. Canopy closure, culm density and average DBH acted as core influencing factors and exhibited extremely significant positive correlations with carbon storage, while the plant height of Bambusa emeiensis was significantly positively correlated with carbon storage; (3) Stepwise regression analysis further screened culm density and average DBH as the dominant factors affecting carbon storage, which jointly explained 95.5% of the variation in carbon storage, and culm density exerted a stronger influence. Moderate anthropogenic disturbance can effectively optimize the community structure of Bambusa emeiensis forests, balance intraspecific competition and improve plant growth conditions, thereby significantly increasing biomass carbon storage per unit area. This study clarifies the differential response patterns and core driving mechanisms of carbon storage in Bambusa emeiensis forests under different anthropogenic disturbance gradients in urban parks, and provides data support for refined management of bamboo forests and carbon sequestration improvement of urban green spaces in Leshan Green Heart Park.