STORAGE AND DECOMPOSITION OF PARTICULATE ORGANIC-MATTER ALONG THE LONGITUDINAL GRADIENT OF AN AGRICULTURALLY-IMPACTED STREAM
STORAGE AND DECOMPOSITION OF PARTICULATE ORGANIC-MATTER ALONG THE LONGITUDINAL GRADIENT OF AN AGRICULTURALLY-IMPACTED STREAM
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DOI：
10.1007/bf00007508
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发表时间：
1993-06-28
期刊：
影响因子：
2.6
通讯作者：
BRUSVEN, MA
中科院分区：
文献类型：
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作者：
DELONG, MD;BRUSVEN, MA
一个农业影响流在北方爱达荷州进行了为期两年的研究，以确定季节性和纵向模式的存储和分解的颗粒有机物。生物量的底栖有机物（BOM）是大大低于在文献中报道的可比，未受干扰的流值。粗、细和总的底栖颗粒有机物与有关河流大小的参数无关（例如，流序），但与采样地点和凋落物量相关。BOM与网站和凋落物的关联表明，颗粒有机物的存储是当地的特点，而不是流的大小的函数。储存有机物的低生物量是对顶极植被消失导致的陆地来源有机物输入量低的反应。桤木、赤杨属物种的叶包季节性投放30和60 d。虽然有显着差异的月份，没有显着差异的网站之间的叶包暴露30天。叶包暴露60天的网站和月份之间观察到显着差异，但是，网站之间的差异仅占5%的方差。沿着梯度的拉普瓦伊溪的有机物分解的差异的情况下，尽管流域的异质性和有机物的可用性，可能是在响应存储的底栖有机物的整体生物量低。这项研究表明，农业活动可以通过减少有机物质的可用性，可以大大影响instantaneous异养过程，并可以塑造流经农业流域的溪流的群落结构和生态系统动态。
An agriculturally-impacted stream in northern Idaho was examined over a two-year period to determine seasonal and longitudinal patterns of the storage and decomposition of particulate organic matter. Biomass of benthic organic matter (BOM) was considerably less than values reported in the literature for comparable, undisturbed streams. Coarse, fine, and total benthic particulate organic matter were not correlated with parameters pertaining to stream size (e.g., stream order), but were correlated with sample site and amount of litterfall. The association of BOM with site and litterfall suggests that storage of particulate organic matter is a function of local characteristics rather than stream size. Low biomass of stored organic matter is a response to the low input of terrestrially-derived organic matter resulting from removal of climax vegetation.Leaf packs of alder, Alnus sp., were placed in the stream seasonally for 30 and 60 d. While there were significant differences for months, there was no significant difference among sites for leaf packs exposed for 30 d. Significant differences were observed among both sites and months for leaf packs exposed for 60 d; however, differences among sites accounted for only 5% of the variance. The absence of differences in decomposition of organic matter along the gradient of Lapwai Creek, despite heterogeneity of the drainage basin and availability of organic matter, may be in response to the overall low biomass of stored benthic organic matter. This study demonstrates that agricultural activity can substantially influence instream heterotrophic processes through reduced availability of organic matter and can shape community structure and ecosystem dynamics of streams flowing through agricultural drainage basins.