CPOM Flux

Introduction

Ecosystem subsidies, the movement of resources across ecosystem boundries (Polis 1997), are an important part of organic matter cycling in aquatic systems. The reciprical transfer of resources between aquatic and terrestrial systems is common (Nakano 2001), however the input of terrestrial organic matter to aquatic systems is an especially significant flux of material since, this subsidy has been shown to support metabolism and secondary production in a majority of lentic and lotic ecosystems(Marcarelli 2011). Organic matter subsidies from terrestrial to aquatic ecosystems are dominated by detrital plant material either as dissolved (DOC) or particulate (POC) organic carbon, and can substantially augment autochthonous organic matter production (Hodkinson 1975, GASITH 1976, (citation not found: wetzel_1984) WETZEL 1995, Webster 1997, Kobayashi 2011, Mehring 2014).

The direct input of DOC dominates terrestrial subsidies in most aquatic systems (Rich 1978, (citation not found: wetzel_1984) (citation not found: CITE) but POC inputs, mainly in the form of leaf litter, can substantially augment aquatic organic matter pools (Wetzel 1972, Hodkinson 1975, GASITH 1976, Rich 1978, (citation not found: Wallace_1999) Mehring 2014). During the process of leaf litter decomposition in aquatic systems, the leaf biomass supplies distinct subsidies to the aquatic ecosystem (Gessner 1999, Marcarelli 2011). Up to 30% of the initial mass of leaves can be leached as DOC (citation not found: CITE) Meyer 1998, Duan 2014), although large initial DOC fluxes from dried leaves in decomposition experiments may be an artifact of air drying the leaves (CITE). This supply of DOC is an important component of aquatic organic matter budgets (McDowell 1976, Karlsson 2007) and has been shown to alter the abundance (Bott 1984, Fey 2015) and function (MCCONNELL 1968, Lennon 2005) of aquatic microbial communities. Furthermore, DOC subsidies processed through the microbial loop support metazoan production (Hall 1998,