Effects of nutrient enrichment on the colonization and decomposition of plant detritus by the microbiota of an arctic lake

Publisher Website
Google Scholar
Abstract
The effects of nitrogen and phosphorus enrichment on the colonization and decomposition of plant litter (Carex) by the microbiota of Toolik Lake, Alaska, were studied in microcosms. Added phosphorus resulted in a fourfold (p ≤ 0.01) increase in the levels of ATP associated with the microbiota on fresh litter, while nitrogen-plus-phosphorus enrichments resulted in a twofold increase in the ATP associated with the microbiota of fresh (p ≤ 0.01) or partially degraded (p ≤ 0.05) litter compared with controls. Neither nitrogen nor phosphorus enrichments, alone or together, significantly altered the observed weight loss of either fresh or partially degraded litter, although additional phosphorus was immobilized by the litter microbiota when available. Subsequent experiments demonstrated that the increase in ATP resulting from nutrient enrichment occurred when the microcosms were incubated in daylight but not in the dark, suggesting that nutrient enrichment primarily stimulated the photosynthetic component of the detrital community.