Application of a {sup 15}N tracer to simulate and track the fate of atmospherically-deposited N in the coastal forests of the Waquoit Bay watershed, Cape Cod, MA
- Boston Univ., MA (United States)
Past studies of nutrient cycling in upland forests have generally found that atmospheric N inputs are efficiently sequestered in forest biomass and soil organic matter, thereby preventing the movement of this N into streams and ground water. However, coastal forests surrounding Waquoit Bay, Cape Cod retain only 40 - 62% of atmospherically-deposited N in vegetation and soils. We hypothesized that retention of N in coastal ecosystems developed on sandy, porous substrates is more dependent on soil texture and porosity than successional age or soil C:N ratios. In order to follow the movement of atmospheric N deposition into the various components of the forest ecosystem and its travel through the vadose zone to ground water we established several sites in the Waquoit Bay watershed along a gradient of soil texture and associated vegetation ranging from coarse sands to loams. We applied {sup 15}N as K{sup 15}NO{sub 3} in solution during the spring and the fall, at near background levels of N deposition for the site, to replicated 2 m{sup 2} plots overlying a series of depth stratified zero-tension lysimeters. Loss of the applied {sup 15}N to lower level lysimeters was higher in the sandy sites than in the loamy sites most likely due to higher rates of percolation. Incorporation of {sup 15}N into the microbial biomass peaked after 48 hours and then declined, while incorporation into organic soil continued to increase up to 1 month after both the fall and spring applications. These results indicate that microbial immobilization functions as an initial barrier to N loss and that incorporation into soil organic matter is an important pool for long term storage.
- OSTI ID:
- 107138
- Report Number(s):
- CONF-9507129-; ISSN 0012-9623; TRN: 95:006512-0054
- Journal Information:
- Bulletin of the Ecological Society of America, Vol. 76, Issue 3; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Sep 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Biogeochemistry of aluminum in McDonalds Branch Watershed, New Jersey Pine Barrens
Biogeochemistry of lead in McDonalds Branch Watershed, New Jersey Pine Barrens