thumbnail

Nutrient availability and phytoplankton nutrient limitation across a gradient of atmospheric nitrogen deposition

Ecology

By:
, , , ,
DOI: 10.1890/08-1742.1

Links

Abstract

Atmospheric nitrogen (N) deposition to lakes and watersheds has been increasing steadily due to various anthropogenic activities. Because such anthropogenic N is widely distributed, even lakes relatively removed from direct human disturbance are potentially impacted. However, the effects of increased atmospheric N deposition on lakes are not well documented, We examined phytoplankton biomass, the absolute and relative abundance of limiting nutrients (N and phosphorus [P]), and phytoplankton nutrient limitation in alpine lakes of the Rocky Mountains of Colorado (USA) receiving elevated (>6 kg N??ha-1??yr-1) or low (<2 kg N??ha-1??yr-1) levels of atmospheric N deposition. Highdeposition lakes had higher NO3-N and total N concentrations and higher total N : total P ratios. Concentrations of chlorophyll and seston carbon (C) were 2-2.5 times higher in highdeposition relative to low-deposition lakes, while high-deposition lakes also had higher seston C:N and C:P (but not N:P) ratios. Short-term enrichment bioassays indicated a qualitative shift in the nature of phytoplankton nutrient limitation due to N deposition, as highdeposition lakes had an increased frequency of primary P limitation and a decreased frequency and magnitude of response to N and to combined N and P enrichment. Thus elevated atmospheric N deposition appears to have shifted nutrient supply from a relatively balanced but predominantly N-deficient regime to a more consistently P-limited regime in Colorado alpine lakes. This adds to accumulating evidence that sustained N deposition may have important effects on lake phytoplankton communities and plankton-based food webs by shifting the quantitative and qualitative nature of nutrient limitation. ?? 2009 by the Ecological Society of America.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Nutrient availability and phytoplankton nutrient limitation across a gradient of atmospheric nitrogen deposition
Series title:
Ecology
DOI:
10.1890/08-1742.1
Volume
90
Issue:
11
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Ecology
First page:
3062
Last page:
3073
Number of Pages:
12