Yu Wen, Yan Yan, Liu Xiao-Yun, Zhang Shuo-Xin
College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China.
Qinling National Forest Ecosystem Research Station, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2020 Jun;31(6):1923-1932. doi: 10.13287/j.1001-9332.202006.003.
Qinling Mountains are biodiversity hotspots in China, with rich vegetation resources and species diversity. To clarify the mechanism underlying biodiversity maintenance during vegetation restoration in this area, we established two permanent plots with each area of 100 m×150 m in the Q. aliena var. acuteserrata secondary forest (SF) and primary forest (PF) in the northern slope of Taibai Mountain in 2016, following the standardized protocols by CTFS (the Center for Tropical Forest Science). We analyzed community composition and structure with measuring all trees with DBH ≥ 1 cm. 2839 and 2840 trees were recorded in the SF and PF plots, respectively. Trees in those two plots belong to 29 families, 45 genera, 65 species and 21 families, 37 genera, 47 species, respectively. The proportions of occasional species and rare species were 38.4% and 24.6% in the SF plot, and 40.4% and 19.2% in the PF plot. Most of the trees were distributed in northern temperate zones, and the proportions of genera were 46.6% and 48.7% in the SF and PF plots, respectively. The diameter of Q. aliena var. acuteserrata in both plots followed a unimodal distribution (more young trees than old ones). The diameter distributions of companion species (e.g., Sorbus alnifolia, Acer davidii, Cornus kousa, and Staphylea holocarpa) were inverted "J" shapes, indicating that those populations could have complete life history. In the pair correlation function g(r) analyses, the aggregation of dominant species were the strongest at 0-2 m scale in the two plots when r=10 m. The degree of aggregation gradually weakened with increasing scale. The population distribution patterns of the dominant species were random or uniform when the scale increased to certain value. The average uniform angle index (W) were 0.56 and 0.58 in the SF and PF, respectively. Trees in the communities followed an aggregated distribution. The average W of the community and dominant species in the SF were smaller than that in the PF, indicating weaker species aggregation in the SF. The average dominance in the SF and PF was both 0.47, indicating that the stands were in a co-dominant state. The average mingling was 0.70 and 0.57 in the SF and PF, respectively, which belonged to high and moderate mingling. Species richness, community stability and spatial distribution patterns of forest community could be affected by human disturbance. The role of interspecific interaction, effects of habitat heterogeneity on species coexistence, and variation of community structure should be considered during vegetation restoration of disturbed forest community.
秦岭是中国的生物多样性热点地区，拥有丰富的植被资源和物种多样性。为阐明该地区植被恢复过程中生物多样性维持的潜在机制，我们于2016年在太白山北坡的锐齿栎次生林（SF）和原始林（PF）中，按照CTFS（热带森林科学中心）的标准化方案，建立了两个面积均为100 m×150 m的永久样地。我们通过测量所有胸径≥1 cm的树木来分析群落组成和结构。SF样地和PF样地分别记录到2839棵和2840棵树木。这两个样地中的树木分别属于29科、45属、65种和21科、37属、47种。偶见种和稀有种的比例在SF样地中分别为38.4%和24.6%，在PF样地中分别为40.4%和19.2%。大多数树木分布在北温带，属的比例在SF样地和PF样地中分别为46.6%和48.7%。两个样地中锐齿栎的直径呈单峰分布（幼树多于老树）。伴生种（如辽东楸子、青榨槭、四照花和膀胱果）的直径分布呈倒“J”形，表明这些种群可能具有完整的生活史。在对关联函数g(r)分析中，当r = 10 m时，两个样地中优势种在0 - 2 m尺度上的聚集最强。聚集程度随尺度增加而逐渐减弱。当尺度增加到一定值时，优势种的种群分布格局为随机或均匀分布。SF和PF样地的平均均匀角指数（W）分别为0.56和0.58。群落中的树木呈聚集分布。SF样地中群落和优势种的平均W值小于PF样地，表明SF样地中物种聚集较弱。SF和PF样地的平均优势度均为0.47，表明林分处于共优状态。SF和PF样地的平均混交度分别为0.70和0.57，分别属于高混交和中等混交。森林群落的物种丰富度、群落稳定性和空间分布格局可能受到人为干扰的影响。在受干扰森林群落的植被恢复过程中应考虑种间相互作用的作用、生境异质性对物种共存的影响以及群落结构的变化。
