ROA: Associated and Abiotically Released DOM: Significanceto Stream Detritivores

异地输入到林地溪流的有机物构成了不同种类有害食肉动物在整个生命周期或其生命周期的不同阶段的主要能量来源。然而，这一说法仅指摄取碎屑的能力，对碎屑中的哪些成分被同化仍知之甚少。已知相关微生物生物量只占被检查的有害食肉动物饮食需求的12%-45%。由于有害食肉动物缺乏降解主要植物结构成分的酶，因此有人认为碎屑中的其他成分也被有害食肉动物利用。据认为，有害动物的主要膳食需求是由溶解有机物(DOM)提供的，DOM与粗颗粒有机物(CPOM)有关和/或从粗颗粒有机物(CPOM)中释放出来。这种DOM的主要来源是：1)从摄入的碎屑基质中释放出来；2)从细胞外微生物产物中释放出来；或3)由与其消化道相关的微生物转化。据推测，有害食肉动物已经进化出各种摄食和消化策略，以最大限度地利用这些资源。这些是1)与中肠相关的物理化学性质，以释放和消化这些化合物；2)后肠道微生物的新陈代谢和有害动物对这些代谢物的同化。研究将包括：1)表征与CPOM有关和/或从CPOM中非生物释放的DOM的时间、质量和数量性质；以及2)确定这些摄取的化合物的相对同化和去向。这些研究的意义不仅适用于有害的营养和生长的基本原理，也适用于对生态系统中碳的吸收、保持和周转的理解。

Allochthonous inputs of organic matter to woodland streams comprise the principal energy source for diverse groups of detritivores during all, or for various stages of their life cycle. However, this statement only refers to the ability to ingest detritus and it remains poorly understood what components of detritus are assimilated. Associated microbial biomass is known to only contribute 12-45% of the dietary needs of the detritivores examined. Since detritivores lack the enzymes to degrade major plant structural components, it is suggested that other components of detritus are exploited by detritivores. It is proposed that the major dietary requirements of detritivores are provided by dissolved organic matter (DOM) which is associated with and/or released from coarse particulate organic matter (CPOM). The major source of this DOM is derived from organics which are: 1) released from the matrix of ingested detritus; 2) released from extracellular microbial products; or 3) transformed by microorganisms associated with their alimentary tract. It is hypothesized that detritivores have evolved a variety of feeding and digestive strategies to maximize the utilization of these resources. These are 1) physico-chemical properties associated with their midgut to release and digest these compounds; and 2) metabolism by hindgut micro-organisms and assimilation of these metabolites by detritivores. Studies will include: 1) characterization of the temporal qualitative and quantitative nature of DOM which is associated with and/or abiotically released from CPOM; and 2) determining the relative assimilation and fate of these ingested compounds. The significance of these studies not only applies to the basic principles of detritivore nutrition and growth, but to an understanding of carbon sorption, retention and turnover in lotic systems.