Modeling the Relationships between Benthos and Stream Environmental Variables

水底生物與河流環境因子相關模式之探討

Lilian D. Minja ； Shaw L. Yu ； Howard Epstein

《Journal of Ecotechnology》 2卷2期 (2006/12) Pp. 48-65

https://doi.org/10.29769/JE.200612.0008

摘要

本研究對水底大型無脊椎動物（Macroinvertebrates或MI）與河流環境因子間量化性之關係作一探討。因MI常用為河川生態狀況之重要指標，故此種量化性之關係，可用來做改善環境因子（如流量及水質參數）之根據。
本研究所用之數據為維吉尼亞州環境品質局於1994年至2001年所收集之資料，MI族群之分類指標為物種之數量及多樣性、數量最多之二個物種、最敏感物種之比例，以及最抗污染物種之比例。考慮之溪流環境因子共有20個，其中8個為物理及化學方面之因子，其他12個則與棲息地有關。
研究結果顯示在溪流中懸浮固體(TSS)濃度從9mg/l升高到17mg/l時，MI物種之數量及多樣性有顯著的減少，流量到85CFS以上時亦有相同之情形。在溶氧量增加時，最敏感物種之比例亦隨之增加，而最抗污物種及數量最多之二個物種之比例則相對減少。另外，所用之數據之pH值在6至9之間，對MI似無任何影響。在棲地因子方面，MI族群數量及多樣性，以及最敏感物種之比例，都與流量及河床介質有正面之相關關係，而最抗污物種比例則與河床介質呈負面之相關關係。

關鍵字

溪流環境 ； 水底生物 ； 大型無脊椎動物 ； 統計模式分析

並列摘要

This study investigated the quantitative relationships between benthic macroinvertebrates and stream environmental variables using generalized additive models. The benthic data used in the study were collected by the Virginia Department of Environmental Quality from 1994 through 2001. The benthic macroinvertebrate assemblages were represented by five benthic metrics namely taxonomic richness, proportion of the two most dominant taxa, proportion of sensitive taxa, proportion of tolerant taxon, and proportion of shredders. Twenty environmental variables, of which eight were physicochemical and twelve were habitat related, represented stream environmental conditions. The study findings suggest a sharp decline in taxonomic richness at total suspended solids concentration of 9 mg/L to 17 mg/L. At flow rates above 85 cfs, taxonomic richness decreases with increasing flow rate. As the dissolved oxygen concentration increases, the proportion of sensitive taxa also increases, while the proportion of tolerant taxon and the two most dominant taxa decreases. None of the physicochemical variables showed a significant effect on the proportion of shredders. Also, the variations of pH within the pH range observed in the case study streams (pH 6 to pH 10) had no significant effects on the responses of the benthic metrics. For the habitat variables, taxonomic richness and sensitive taxa positively correlated with channel flow status and substrate, respectively. Tolerant taxon negatively correlated with substrate.

並列關鍵字

Stream Environmental ； Benthos ； macroinvertebrate