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Nitrogen and Phosphorus Runoff Losses from a Nutrient‐Poor Tropical Moist Forest
Author(s) -
Lewis William M.
Publication year - 1986
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1938683
Subject(s) - nutrient , phosphorus , environmental science , surface runoff , ecosystem , watershed , biomass (ecology) , nitrogen , ecology , hydrology (agriculture) , biology , chemistry , geology , geotechnical engineering , organic chemistry , machine learning , computer science
The Caura River of Venezuela drains 47 500 km 2 of undisturbed tropical moist forest overlying the Guyana Shield within the Orinoco River watershed. Discharge measurements and water samples were taken of the Caura biweekly for 2 yr. Samples were analyzed for total nitrogen, total phosphorus, and various species of these two elements. Losses of nitrogen (9.98 kg°ha — 1 °yr — 1 ) and of phosphorus (0.46 kg°ha — 1 °yr — 1 ) were unexpectedly high. Concentrations of total N and total P showed only minor seasonal variations, despite major seasonal changes in discharge. The data are consistent with the hypothesis that mature forested ecosystems have high yields of critical nutrients because they are not accumulating biomass. The data also show, however, that this mature ecosystem strongly buffers seasonal variations in nutrient loss.