30 years of course particulate organic matter exports from tropical montane watersheds

Abstract. Leaf litter is an important energy source for aquatic food webs and biogeochemical cycles. As leaf litter from the watershed enters streams it slowly starts to break down and transform into course particulate organic matter (CPOM). While this has been extensively explored in temperate regions, many questions remain in the tropics about patterns, timing, and magnitudes of CPOM inputs. Here we present 30 years of continuous CPOM data collected in two streams of the Bisley Experimental Watersheds (BEW) in the Luquillo Experimental Forest in northeastern Puerto Rico. We report CPOM as litterflow, which is all the plant and organic material that flows and accumulates from multiple sources (i.e., canopy, riparian zone, and upstream) and is collected at a fixed location in each stream. In this long-term dataset, temporal patterns (peaks and seasonality) can be observed in relation to various hurricanes and drought periods that occurred in Puerto Rico. The BEW litterflow data provides a view into the inherent connection between terrestrial and aquatic ecosystems to better understand how organic material can move through the landscape to be exported in streams and transported downriver to sustain the food webs of receiving bodies of water.