HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Chappell, H.N. Articles by Vesterdal, L. Search for Related Content PubMed Articles by Chappell, H.N. Articles by Vesterdal, L. Agricola Articles by Chappell, H.N. Articles by Vesterdal, L.

DIVISION S-7-FOREST & RANGE SOILS

Long-Term Effects of Nitrogen Fertilization on Nitrogen Availability in Coastal Douglas-Fir Forest Floors

H.N. Chappell^,a, C.E. Prescott^b and L. Vesterdal^c

^a College of Forest Resources, Univ. of Washington, Seattle, WA 98195 USA
^b Faculty of Forestry, Univ. of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
^c Dep. of Forest Ecology, Danish Forest and Landscape Research Institute, Hørsholm Kongevej 11, DK-2970 Hørsholm, Denmark

cpres{at}interchange.ubc.ca

It has been suggested that a long-term increase in N availability could be achieved by repeated N fertilization of forests, and that the increase in N availability would be greatest at initially N-rich sites. The aim of this study was to determine if N availability was elevated 8 to 12 yr after repeated N fertilization, and if the effects of N fertilization were related to the soil N capital. Rates of N cycling in control and fertilized plots of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] were compared by measuring net N mineralization rates in forest floors and by estimating rates of N turnover from the litterfall/forest floor ratio. Litterfall N contents, litter N concentrations, and rates of N turnover increased along the gradient in soil N capital in both control and fertilized stands. Fertilization did not affect litterfall N content, but C/N ratios of litter and forest floors were significantly lower in fertilized stands along the gradient. Turnover rates of N in the forest floors were not higher in fertilized plots than in control plots, nor were rates of net N mineralization affected by fertilization. Net nitrification rates were higher in some of the plots that received 1120 kg N ha^-1 than in control plots. We conclude that N fertilization did not result in a sustained increase in N cycling and N availability analogous to a higher site N capital, and that the effect of N fertilization was not related to the initial soil N capital of these sites.

This article has been cited by other articles:

				T. R. Fox Nitrogen Mineralization Following Fertilization of Douglas-fir Forests with Urea in Western Washington Soil Sci. Soc. Am. J., September 1, 2004; 68(5): 1720 - 1728. [Abstract] [Full Text] [PDF]

				L. Breuer, R. Kiese, and K. Butterbach-Bahl Temperature and Moisture Effects on Nitrification Rates in Tropical Rain-Forest Soils Soil Sci. Soc. Am. J., May 1, 2002; 66(3): 834 - 844. [Abstract] [Full Text] [PDF]