Page 104 - 《广西植物》2024年第10期
P. 104
1 9 0 6 广 西 植 物 44 卷
Abstract: To promote the restoration and reconstruction of ecosystem in the water ̄land ecotoneꎬ based on typical sample
investigationꎬ the variation patterns of vegetation species composition and diversityꎬ and soil nutrients under different
vegetation types were studied using Pearson correlation coefficient method and redundancy analysis method. The results
were as follows: (1) There were significant differences in plant community structure and species diversity of different
vegetation types (gravel zoneꎬ grass zoneꎬ shrub ̄grass zoneꎬ tree zone). As the submersed duration decreasedꎬ the
water ̄land ecotone gradually evolved from scattered herbaceous plant communities to grassꎬ shrubꎬ and tree plant
communitiesꎬ and the α diversity of vegetation species (Shannon ̄Wiener indexꎬ Pielou index and Simpson index ) and
vegetation coverage showed a gradually increasing trendꎬ which were lowest value on the gravel zone and the highest on
the tree zone. (2) There were significant differences in soil nutrient content among different vegetation types. With the
decrease of submersed durationꎬ soil organic matter content gradually increasedꎬ while soil water contentꎬ available
nitrogenꎬ available phosphorusꎬ and available potassium showed a trend of first increasing and then decreasingꎬ the
maximum values of these nutrients mostly occurred in shrub ̄grass zone or tree zoneꎬ followed by grass zoneꎬ and gravel
zone was the lowest. (3) Correlation and redundancy analysis showed that soil available nitrogenꎬ available potassiumꎬ
available phosphorus and organic matter were significantly positively correlated with various indicators of vegetation
species α diversityꎬ among which soil available nitrogen and available potassium had the strongest correlation with
vegetation species diversity. In conclusionꎬ different vegetation types in the Li River water ̄land ecotone have
heterogeneous patterns of vegetation species composition and diversity as well as soil nutrients. Moderate submergence is
beneficial for vegetation community aggregation and promoting soil nutrient accumulation. Herbaceous plants have
stronger adaptability to moderate submergence environments. During the ecological restoration process of the Li River
water ̄land ecotoneꎬ it is necessary to design restoration plans for different vegetation types and fully consider the
relationship between vegetation species diversity and soil available nutrients.
Key words: vegetation typeꎬ plant species diversityꎬ soil nutrientꎬ water ̄land ecotoneꎬ the Li River
水陆交错带ꎬ又被称为河岸带或河岸缓冲区ꎬ 律ꎬ将为退化水陆交错带植被修复和生态系统重
位于河道最低水位处ꎬ直至河水影响完全消失的 建提供科学依据( Capon & Pettitꎬ 2018ꎻ 郭 二 辉
区域(Naiman & Decampsꎬ 1997)ꎮ 作为水域和陆 等ꎬ2021)ꎮ
域两生态系统之间的过渡带ꎬ水陆交错带独特的 受水文变化( 洪水动态) 的影响ꎬ水陆交错带
环境因子(季节性洪水淹没、边缘效应等)、植物群 横向上呈现出连续变化的水淹环境梯度ꎮ 这一梯
落特征和生态过程ꎬ使其在调蓄洪水、减缓水土流 度从近河床的低处开始ꎬ那里的砾石滩因长时间
失、净化污染、生物多样性维护等方面具有重要作 水淹冲蚀而形成ꎻ随着向高处的延伸ꎬ河岸林仅在
用(Yi et al.ꎬ 2020ꎻ Zheng et al.ꎬ 2021)ꎮ 我国南 洪水泛滥期遭受水淹ꎻ重要的是ꎬ这种水淹环境梯
方地区受季节性降雨等影响ꎬ河道水位变化很大ꎬ 度在水淹时间(频率)、群落物种组成、土壤养分含
水陆交错带植被经常受到洪涝或干旱胁迫ꎬ尤其 量等方面存在显著差异(Naiman et al.ꎬ 2005)ꎮ 对
是近年来全球极端气候事件( 如极端干旱、洪涝) 漓江水陆交错带、三江平原湿地、三峡消落区等多
愈发频繁ꎮ 这些胁迫严重影响了水陆交错带植物 项研究均发现ꎬ水陆交错带植物的物种与覆盖度
个体生存及群落特征ꎬ致使植被破坏及土壤养分 等均与水陆交错带高程或淹没梯度密切相关ꎬ不
流失ꎬ最终导致水陆交错带生态系统退化( 方修琦 同植物对水淹的耐受程度和适应性有明显不同ꎬ
等ꎬ2007)ꎮ 大量研究证实ꎬ水文特征的变化是影 这导致了水陆交错带形成异质性的植被分配格
响水陆交错带植被格局和群落演替的重要因素ꎬ 局ꎬ而适度淹没有助于植物群落的聚集( Shan et
也是制约水陆交错带土壤养分迁移和循环的关键 al.ꎬ 2019ꎻChen et al.ꎬ 2020)ꎮ 对瑞典的 10 条河
因子(黄凯等ꎬ2007ꎻ McDaniel et al.ꎬ 2013ꎻ Gill et 流进行流量控制研究ꎬ得出流量及水位的变化会
al.ꎬ 2018ꎻ Yang et al.ꎬ 2018)ꎬ准确理解和把握水 导致草本和木本植物的相对丰度发生改变ꎬ进而
陆交错带植物群落结构组成及其土壤养分变异规 影响植物群落的物种组成和多样性( Bejarano et