森林⁃草原生态系统交错带植物与微生物多样性研究进展

Research progress in plant and soil microbial diversity in forest⁃grassland ecotone

森林⁃草原生态系统交错带是森林和草原两种地带性植物群落之间的交接地带,景观类型多样,环境异质性强,边缘效应明显,对全球气候变化敏感,是生物多样性保护的重要地带。林草交错带特殊的生境导致地上与地下生物多样性及其生态关联比森林、草原、农田等生态系统复杂。本文综合评述了地形、生态系统养分内循环、全球变化以及人类活动干扰等因素对林草交错带植物多样性的影响,分析了土地利用类型、氮沉降和大气CO_(2)浓度升高、植物凋落物、土壤有机质及土层深度等对土壤微生物多样性的影响。今后,应当加强局域尺度控制实验与跨环境梯度调查相结合的研究手段,以揭示林草交错带生物多样性形成的地理格局与生态学机制。具体包括林草交错带复合系统物种多样性对土壤酸化、火灾、凋落物组成、围封和放牧及多因子交互作用的响应规律,以及地上⁃地下生物多样性的生态关联、退化生境修复与植被恢复等方面的研究,为林草交错带土地利用和生物多样性保护提供科学依据和数据参考。

Forest⁃grassland ecotone is a cline of plant communities between forest and grassland.This ecotone is characterized by diverse landscape types,strong environmental heterogeneity,and evident edge effects.Forestgrassland ecotone is sensitive to global climate change,and serves as critical zones of biodiversity conservation.Because of its special habitat,above⁃and belowground biodiversity and ecological linkages of the forest⁃grassland ecotone is far more complicated than other ecosystems,such as forests,grasslands and farmlands.Here,we reviewed the effects of topographic factors,nutrient cycling of ecosystems,global changes,and anthropogenic disturbances on plant diversity in forest⁃grassland ecotone.We also discussed the effects of land use types,nitrogen deposition,atmospheric CO_(2) enrichment,litterfall,soil organic matter content,and soil depth on soil microbial diversi⁃ty.Future studies should focus on research approaches that combine manipulative experiments of local scale with observations crossing environmental gradients,so as to reveal the geographical pattern and ecological mechanism of biodiversity formation in forest⁃grassland ecotone.Specifically,this includes how biodiversity responds to soil acidification,fire,litter composition,enclosure and grazing,and interactions of multi⁃factors as well as ecological linkages between aboveand belowground biodiversity and degraded habitat restoration and vegetation recovery.This would provide theoretical guidance and data reference for land use and biodiversity conservation in the forest⁃grassland ecotone.