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草业学报 ›› 2024, Vol. 33 ›› Issue (2): 28-38.DOI: 10.11686/cyxb2023133

• 研究论文 • 上一篇    下一篇

小生境尺度下喀斯特弃耕地植物多样性、生物量及其影响因素

雷颖(), 罗杰, 郭旭曼, 秘二停, 刘锦春()   

  1. 三峡库区生态环境教育部重点实验室,重庆市三峡库区植物生态与资源重点实验室,西南大学生命科学学院,重庆 400715
  • 收稿日期:2023-04-24 修回日期:2023-05-29 出版日期:2024-02-20 发布日期:2023-12-12
  • 通讯作者: 刘锦春
  • 作者简介:E-mail: jinchun@swu.edu.cn
    雷颖(1997-),女,畲族,江西鹰潭人,在读硕士。E-mail: 651738106@qq.com
  • 基金资助:
    重庆市自然科学基金(cstc2020jcyj-msxmX0244);国家自然科学基金项目(31500399)

Microhabitat plant diversity and biomass differences in abandoned karst farmland and their driving factors

Ying LEI(), Jie LUO, Xu-man GUO, Er-ting BI, Jin-chun LIU()   

  1. Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region,School of Life Sciences,Southwest University,Chongqing 400715,China
  • Received:2023-04-24 Revised:2023-05-29 Online:2024-02-20 Published:2023-12-12
  • Contact: Jin-chun LIU

摘要:

深入探讨小生境尺度下物种多样性及其影响因素,可以为弃耕地演替早期群落恢复提供理论依据。本研究以重庆喀斯特典型弃耕地(弃耕年限为4~6年)为研究对象,根据地下特征选出均质浅土、均质深土、异质梯型和异质漏斗型4种小生境并对其进行植物群落调查,分析不同小生境的土壤理化性质、生物量和物种多样性变化及其之间的关系。结果表明:1) 4种小生境中土壤含水量随着土壤深度的增加呈增加趋势,但总氮含量和碳氮比随着土壤深度的增加呈降低趋势;在2种异质生境中,土壤深度、土壤含水率的变异系数相差不大,均属于高等变异强度。2) 不同小生境之间的物种丰富度指数、香农-维纳指数和均匀度指数无显著差异。3) 各小生境的地上生物量之间无显著差异,异质性生境的地下生物量和总生物量均高于均质性生境。4) 不同小生境中仅异质漏斗型的生物量与多样性存在显著负相关关系(P<0.05)。资源异质性对喀斯特弃耕地演替早期群落生物量产生了积极影响,但物种多样性在该阶段受生境的影响不大。中等厚度土壤促进了植物的生长、有利于生产力的维持。因此在植被恢复的早期阶段,应充分利用各生境类型特点,维持植物的多样性及其生长。

关键词: 石漠化, 生境异质性, 资源有效性, 生物多样性

Abstract:

An in-depth investigation of changes in species diversity and biomass in different ecological niches of typical abandoned arable land in karst areas of Chongqing was conducted to provide a theoretical basis for community restoration in the early vegetation succession following farmland abandonment. The former farmland under study had been abandoned for four to six years. The vegetation biomass and species diversity together with changes in soil physicochemical properties, and their relationships were studied in four microhabitats: homogeneous shallow soil, homogeneous deep soil, heterogeneous trapezoid and heterogeneous funnel. It was found that: 1) Soil water content increased with soil depth, but total nitrogen and carbon nitrogen ratio decreased with soil depth. In the two heterogeneous habitats, the coefficients of variation for soil depth and soil water content differed little and indicated high intensity of variation. 2) The richness index, Shannon-Wiener index and Pielou index were not significantly different among the different microhabitats. 3) There were no significant differences between the aboveground biomass of the four microhabitats, while the below-ground biomass and total biomass of heterogeneous habitats were higher than those of homogeneous habitats. 4) There was a significant negative correlation (P<0.05) between the biomass and species diversity data for microhabitats with heterogeneous funnel. However, there was no significant relationship in other habitats. Resource heterogeneity had a positive effect on community biomass in the early succession stages after abandonment of karst farmland, but biodiversity was not greatly affected by habitat at this stage. Medium-thickness soil was found to promote plant growth and maintain productivity, while high-thickness soils counterintuitively had lower productivity due to lower nutrient content and poor permeability. Therefore, in the early stages of vegetation restoration, the characteristics of each habitat type should be fully understood in order to manage the recovery to maintain the diversity and growth of the vegetation.

Key words: rocky desertification, habitat heterogeneity, resource availability, biodiversity