Detrital Energy and the Decomposition of Organic Matter

Benthic Fluxes of Fluorescent Dissolved Organic Material, Salt, and Heat Measured by Multiple-Sensor Aquatic Eddy Covariance

“…Benthic cycling of DOC is a complicated interplay of abiotic and biotic processes, including diffusion between water column and sediment porewaters, groundwater input, sedimentation or sediment resuspension, adsorption or desorption, leachate from terrestrial detritus, exudates from primary producers like algae and macrophytes, and processing and consumption by heterotrophic bacteria for respiration and growth [13,15,50]. In streams and other freshwater systems, detritus-based pathways are particularly important to organic matter cycling, as organic carbon originating from allochthonous and autochthonous sources is processed along multiple pathways, transformed between particulate and dissolved fractions, and ultimately buried in sediments, transported downstream, or respired to CO 2 [50]. Thus, the sediment can be both a source and a sink of DOC.…”

“…DOC addition experiments in streams, involving in situ steady state or pulsed additions of a chosen form of DOC (often simple compounds or leachates), have been used to quantify sediment uptake in terms of uptake velocities [57]. In general, DOC uptake rates are highly variable and appear to depend on many factors, including the amount of exchange with, and size of, the hyporheic zone, nutrient availability, the rate of microbial activity (itself a function of various environmental conditions), and, to a large degree, the bioavailability of the DOC, which can vary significantly among systems [50,52,55,57,58].…”

No effects of macroconsumer exclusion on macroinvertebrate functional composition in Brazilian karst streams along a gradient of riparian forest loss

“…The absence of inputs of wood from the riparian forest can also alter habitat complexity and retention of organic matter that provides food for different detritivores (Baker et al, 2016;Sitati et al, 2021). These changes in riparian cover can often affect the abundance of functional feeding groups (FFG) of the benthic invertebrates by decreasing the allochthonous organic matter inputs (e.g., leaves, fruits, woody materials, and terrestrial insects) that constitute important food resources and substrates for specific benthic invertebrates (Allan et al, 2021;Sánchez-Hernández, 2023;Webster et al, 1983). Overall, the loss of key macroconsumers can substantially affect benthic communities and stream ecosystems (Dangles & Guérold, 2001;Hildrew & Giller, 2023;Marshall et al, 2012) as well as influence the effectiveness of biotic indices for water-quality analyses (Brasil et al, 2020).…”