稀有种和常见种对鳌江口红树林大型底栖动物群落多样性的贡献

Contributions of rare and common species to the species diversity of the mangrove macrobenthic community in Aojiang Estuary

为了探究群落中稀有种和常见种对物种多样性的贡献,本实验以鳌江口红树林大型底栖动物为研究对象,结合地理范围指数(gri)、生境特异性指数(hsi)和种群规模指数(psi)识别群落稀有种;根据稀有度大小对物种进行排序,形成稀有种-常见种和常见种-稀有种2个物种序列。在此基础上,通过逐一添加物种,比较物种多样性(α多样性和β多样性)的变化,确定稀有种和常见种对物种多样性的相对贡献。结果显示,α多样性在稀有种-常见种物种序列中,随着物种加入Shannon-Wiener多样性指数和丰富度指数呈现先上升后下降的趋势,而均匀度指数仅在2020年先上升后下降,其余均呈下降趋势;在常见种-稀有种物种序列中,随着物种的加入Shannon-Wiener多样性指数和丰富度指数呈上升趋势,而均匀度指数呈下降趋势。β多样性在稀有种-常见种物种序列中,随着物种的加入群落异质性(βSOR)和嵌套组分(βNES)呈上升趋势,周转组分(βSIM)呈下降趋势;在常见种-稀有种物种序列,随着物种的加入βSOR、βSIM和βNES均呈上升趋势。综上,稀有种对群落α多样性贡献更大,并影响群落β多样性的周转组分,而常见种对嵌套组分影响更大。因此,对不同类型物种应采取不同的生态保护策略,研究结果为鳌江口红树林生态保护提供理论支持,以期更好地保护该区域红树林生态系统。

Species diversity is closely related to the composition of rare and common species in the community.However,their contribution to community species diversity remains controversial,studying the relationship between rare species and species diversity is helpful to better understand the mechanism of community construction.We calculated theα-diversity andβ-diversity of the community,combined with geographic range(gri),habitat specificity index(hsi)and population size index(psi)recognition community rare species to investigate the effects of rare and common species onα-diversity andβ-diversity of macrobenthos community,and to reveal the basic process of community construction,mangrove macrobenthos in Aojiang Estuary were as the research object in this experiment.Meanwhile,the species were sorted according to their rarity,forming two species sequences of rare species-common species and common species-rare species.On this basis,the relative contributions of rare and common species to species diversity were determined by comparing the changes in species diversity(α-diversity andβ-diversity)by adding species one by one.The results showed that a total of 47 species of macrobenthos were identified in the mangroves of Aojiang Estuary from 2017 to 2020.Theαdiversity of mangroves in spring and autumn was higher than that in summer and winter.Theβdiversity was similar in four seasons,mainly dominated by nested components.Theα-diversity increased first and then decreased with the addition of species to Shannon-Wiener diversity index and richness index in rare species-common species sequence,while evenness index only increased first and then decreased in 2020,and the rest showed a downward trend.Shannon-Wiener diversity index and richness index showed an increasing trend,while evenness index showed a decreasing trend with the addition of species in the common-rare species sequence.β-diversity increased with the addition of species to community heterogeneity(β_(SOR))and nested component(β_(NES)),while turnover component(β_(SIM))decreased in the rare species to common species sequence.In the sequence of common species and rare species,β_(SOR),β_(SIM),andβ_(NES) increased with the addition of species.In conclusion,rarity index could accurately and effectively identify rare species in the community,the rare species contributed more to communityαdiversity and affected the turnover component of communityβdiversity,while the common species had a greater impact on the nested component.Therefore,different ecological conservation strategies should be adopted for different species,these results of this study provide theoretical support for mangrove ecological protection in Aojiang Estuary to better protect the mangrove ecosystem in this region.