Chen Xi, Zhou Xiumei, Jin Songheng, Bai Shangbin
Jiyang College, Zhejiang A&F University, Zhuji 311800, China.
Plants (Basel). 2025 Jun 2;14(11):1698. doi: 10.3390/plants14111698.
In subtropical regions of China, the expansion of Moso bamboo has become increasingly prominent, resulting in massive mortality of original trees in adjacent forest stands. Significant changes have also occurred in the population characteristics and spatial distribution patterns of these native tree species. This study aims to examine the impacts of Moso bamboo () expansion on the successional dynamics of coniferous and broad-leaved mixed forests. Three sample plots were successively set up in the transition zone from bamboo to conifer and broad-leaved forest, including conifer and broad-leaved mixed forest (CF), transition forest (TF), and Moso bamboo forest (MF); a total of 72 10 m × 10 m quadrats (24 per forest type) were included. The species composition, diameter class structure and distribution pattern of living stems and snags (dead standing stems) were studied. The results showed that during the late expansion phase of bamboo, the density of living stems and snags separately increased by 2234 stems·ha and 433 stems·ha, basal area increments of 23.45 m·ha and 7.81 m·ha. The individuals with large diameter in living stems and snags gradually decreased, and the distribution range of the diameter steps mainly narrowed to 10-15 cm. On the scale of 0-10 m, the spatial pattern of standing stems changed from random and weak aggregation distribution to strong aggregation distribution and then to weak aggregation and random distribution in the three stands, while the overall distribution of snags in the three stands was random. The spatial correlation between living stems and snags evolved from uncorrelated in CF, to significant positive correlation in TF, and then to positive correlation and uncorrelation in MF. These results indicated that the bamboo expansion accelerated the mortality rate of the original tree species, leading to the diversity of tree species decreased, the composition of diameter classes was simplified, the degree of stem aggregation increased, and intra- and inter-species competition became the main reasons for tree death.
在中国亚热带地区，毛竹扩张现象日益突出，导致邻近林分中原生树木大量死亡。这些本土树种的种群特征和空间分布格局也发生了显著变化。本研究旨在探讨毛竹扩张对针叶阔叶混交林演替动态的影响。在从竹林到针叶阔叶林的过渡带依次设置了三个样地，包括针叶阔叶混交林（CF）、过渡林（TF）和毛竹林（MF）；共设置了72个10米×10米的样方（每种林型24个）。研究了活立木和枯立木（死亡立木）的物种组成、径级结构和分布格局。结果表明，在竹子扩张后期，活立木和枯立木的密度分别增加了2234株·公顷和433株·公顷，胸高断面积增量分别为23.45平方米·公顷和7.81平方米·公顷。活立木和枯立木中大树径个体逐渐减少，径级分布范围主要缩小至10 - 15厘米。在0 - 10米尺度上，三个林分中活立木的空间格局从随机和弱聚集分布转变为强聚集分布，然后再转变为弱聚集和随机分布，而三个林分中枯立木的总体分布是随机的。活立木和枯立木之间的空间相关性从CF中的不相关，到TF中的显著正相关，再到MF中的正相关和不相关。这些结果表明，竹子扩张加速了原生树种的死亡率，导致树种多样性降低，径级组成简化，树干聚集程度增加，种内和种间竞争成为树木死亡的主要原因。
