Qiu Jing, Han An-Xia, He Chun-Mei, Yin Qiu-Long, Jia Shi-Hong, Luo Ying, Li Chen-Lu, Hao Zhan-Qing
School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710129, China.
Ying Yong Sheng Tai Xue Bao. 2022 Aug;33(8):2035-2042. doi: 10.13287/j.1001-9332.202208.002.
To explore the spatial distribution and intraspecific correlation of var. , a domi-nant tree species in a 25 hm plot of warm temperate deciduous broadleaved forest in Qinling Mountains, the pair-correlation function () was used to study the spatial pattern and intraspecific association. The results showed that the diameter class structure of . var. was bimodal, with a large proportion of young trees (1 cm≤DBH＜5 cm), indicating an increase population structure with good capability of regeneration. The abundance of middle trees (15 cm≤DBH＜25 cm) was slightly more than that of big trees (25 cm≤DBH＜35 cm) and old trees (DBH≥35 cm), but far less than that of young trees and small trees. The spatial distribution of . var. was obviously altitude dependent, which mainly distributed in the middle and high altitude areas. Results of complete spatial randomness (CSR) model analysis showed that young trees, small trees, adult trees, big trees, and old trees were aggregated in the large scale (＜60 m). Heterogeneous Poisson (HP) model was used to eliminate habitat heterogeneity. The results of HP model showed that the individual aggregation degree of each diameter class decreased, indicating that the distribution was affected by habitat heterogeneity. At the small scale (＜40 m), spatial correlation was positively correlated between individuals with small diameter gap, whereas the spatial correlation was negative correlation and no correlation between individuals with large diameter gap. At large scale (>40 m), the spatial correlation was positively correlated between large-diameter individuals, but negatively correlated and unrelated between saplings and other diameter individuals. Our results indicated that biological cha-racteristics of . var. and habitat heterogeneity were important drivers for the formation of population spatial pattern.
为探究秦岭暖温带落叶阔叶林25公顷样地内优势树种某变种的空间分布及种内相关性，采用对偶相关函数（ ）研究其空间格局和种内关联。结果表明，该变种的径级结构呈双峰型，幼树（1厘米≤胸径＜5厘米）比例较大，表明种群结构呈增长型，具有良好的更新能力。中树（15厘米≤胸径＜25厘米）的数量略多于大树（25厘米≤胸径＜35厘米）和老树（胸径≥35厘米），但远少于幼树和小树。该变种的空间分布明显依赖海拔，主要分布在中高海拔地区。完全空间随机（CSR）模型分析结果表明，幼树、小树、成年树、大树和老树在大尺度（＜60米）上呈聚集分布。采用非均匀泊松（HP）模型消除生境异质性。HP模型结果表明，各径级个体的聚集程度降低，表明分布受生境异质性影响。在小尺度（＜40米）下，小径差个体间的空间相关性为正相关，而大径差个体间的空间相关性为负相关且无相关性。在大尺度（＞40米）下，大径级个体间的空间相关性为正相关，但幼树与其他径级个体间的空间相关性为负相关且无相关性。我们的结果表明，该变种的生物学特性和生境异质性是种群空间格局形成的重要驱动因素。
