生物多样性 ›› 2024, Vol. 32 ›› Issue (12): 24239.  DOI: 10.17520/biods.2024239  cstr: 32101.14.biods.2024239

• 研究报告 • 上一篇    下一篇

秦岭山地木本植物群落结构及多样性的海拔梯度格局

吴芳芳, 刘娜, 何春梅, 原作强, 郝占庆, 尹秋龙*()   

  1. 西北工业大学生态环境学院, 陕西省秦岭生态智能化监测与保护重点实验室, 西安 710129
  • 收稿日期:2024-06-17 接受日期:2024-10-13 出版日期:2024-12-20 发布日期:2024-12-28
  • 通讯作者: E-mail: yinql@nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(32230067);国家自然科学基金(32001171);中央高校基本科研业务费专项资金(5000220151)

Elevational gradient pattern of woody plant community structure and diversity in the Qinling Mountains

Fangfang Wu, Na Liu, Chunmei He, Zuoqiang Yuan, Zhanqing Hao, Qiulong Yin*()   

  1. School of Ecology and Environment/Shaanxi Key Laboratory of Qinling Ecological Intelligent Monitoring and Protection, Northwestern Polytechnical University, Xi’an 710129, China
  • Received:2024-06-17 Accepted:2024-10-13 Online:2024-12-20 Published:2024-12-28
  • Contact: E-mail: yinql@nwpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(32230067);National Natural Science Foundation of China(32001171);Fundamental Research Funds for the Central Universities(5000220151)

摘要: 研究植物群落结构及多样性格局有利于揭示生物多样性维持机制。秦岭处于南北气候分界线和动植物区系的交汇过渡带, 区系成分丰富且起源古老, 植被类型多样, 群落结构复杂, 是研究过渡区植物群落结构及多样性分布格局的重要平台。参照美国史密森热带研究院热带森林研究中心的样地建设标准, 我们以秦岭皇冠25 ha大样地为核心, 在秦岭南坡中段海拔800-2,600 m地段设置10个1 ha (100 m × 100 m)的长期定位监测样地并进行群落调查, 对胸径(diameter at breast height, DBH) ≥ 1 cm的木本植物物种组成、区系特征、径级结构、优势种空间分布和物种多样性的海拔梯度格局进行初步研究。结果表明: (1)共调查到种子植物208种, 分属50科109属。温带区系成分的属占总属数的69.7%, 温带区系特征明显。随海拔上升, 植物群落稀有种、偶见种及科、属、种组成呈现先上升后下降的单峰格局。群落优势种沿海拔梯度具有明显的更替现象, 中海拔呈现阔叶栎林与针叶杉林过渡性质。(2)所有样地内木本植物径级分布总体呈倒“J”型。分海拔来看, 除了海拔1,600 m、2,000 m木本植物径级分布呈现双峰型, 其余海拔均呈现倒“J”型, 群落结构总体较为稳定。优势种在不同海拔空间点格局表现为1-10 m尺度内聚集分布, 随着尺度的增加, 逐渐转变为随机分布和均匀分布。随着海拔的升高, 去除生境异质性后, 聚集分布的尺度范围缩小, 随机分布的尺度范围增大。(3)随海拔上升, 物种丰富度呈显著的单峰分布格局, 峰值出现在海拔1,200-1,400 m之间。Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数沿海拔梯度的变化呈显著的双峰格局, 两个峰值均出现在海拔1,000-1,200 m和海拔2,000-2,200 m。β多样性(Bray-Curtis相异指数和Jaccard相异指数)随海拔的升高呈现单峰趋势。本文为亚热带-暖温带过渡区森林长期监测和基础数据库建设奠定了基础, 同时为该过渡区生物多样性保护和森林可持续经营提供了理论支持。

关键词: 秦岭, 群落结构, 空间分布, 物种多样性, 海拔

Abstract

Aims: Plant community structure and diversity patterns research is valuable for revealing the mechanism of biodiversity maintenance. The Qinling Mountains are in the transition zone at the north-south climate dividing line where the flora and fauna meet. This region is an important platform for studying the plant community structure and diversity distribution pattern in the transition zone.

Methods: According to standards of Center for Tropical Forest Science (CTFS), the Smithson Institute for Tropical Research, we establish ten 1 ha (100 m × 100 m) long-term positional monitoring plots from 800 m to 2,600 m in the middle part of the southern slope of the Qinling Mountains. We conduct community surveys using our plots with the Qinling Huangguan forest plot as the core. Initially, we analyze the elevation gradient pattern of the species composition, systematic characters, diameter class structure, spatial distribution of dominant species, and species diversity of woody plants with diameter at breast height (DBH) ≥ 1 cm.

Results: (1) We investigate a total of 208 seed plant species belonging to 50 families and 109 genera. The genera in the temperate zone account for 69.7% of the total number of genera, and the temperate zone is obvious. With increasing elevation, rare and occasional species and the composition of families, genera and species of the plant community show a unimodal pattern of increasing first and then decreasing. The dominant species of the community has obvious turnover along the elevational gradient, and the middle elevation shows the transitional nature of broad-leaved oak and coniferous fir forests. (2) The overall structure of DBH size class of all woody plant individuals generally shows an inverse “J” type. In terms of elevation, except for the bimodal distribution of woody plants at 1,600 m and 2,000 m, the rest of the elevation showed an inverted “J” shape, and the community structure is generally more stable. The spatial point pattern of dominant species at different elevations shows an aggregated distribution within the 1-10 m scale, which gradually changes to random and uniform distribution as the scale increased. With increasing elevation and removal of habitat heterogeneity, the scale range of aggregated distributions decreases and the scale range of random distributions increases. (3) In increasing elevation species richness shows a significant unimodal distribution pattern with the peak occurring between 1,200 m and 1,400 m. Changes in Shannon-Wiener diversity index, Simpson dominance index, Pielou evenness index along the elevational gradient shows a significant bimodal pattern, with both peaks occurring in 1,000-1,200 m, and 2,000-2,200 m. β diversity (Bray-Curtis index and Jaccard index) shows a unimodal trend along the elevational gradient.

Conclusion: Our study forms the foundation for the construction of long-term monitoring and a basic database of forests in the subtropical-warm temperate transition zone. This research provides a theoretical basis for the conservation of biodiversity in this transition zone and for sustainable forest management.

Key words: Qinling Mountains, community structure, spatial distribution, species diversity, elevation