We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Response of canopy nitrogen uptake to a rapid decrease in bulk nitrate deposition in two eastern Canadian boreal forests.
- Authors
Houle, D.; Marty, C.; Duchesne, L.
- Abstract
A few studies have reported a recent and rapid decline in NO deposition in eastern North America. Whether this trend can be observed at remote boreal sites with low rates of N deposition and how it could impact canopy uptake (CU) of N remain unknown. Here we report trends between 1997/1999 and 2012 for precipitation, throughfall N deposition as well as inorganic N CU for two boreal forest sites of Quebec, Canada, with contrasted N deposition rates and tree species composition. NO bulk deposition declined by approximately 50 % at both sites over the studied period while no change was observed for NH. As a result, the contribution of NH to inorganic N deposition changed from ~33 % to more than 50 % during the study period. On average, 52-59 % of N deposition was intercepted by the canopy, the retention being higher for NH (60-67 %) than for NO (45-54 %). The decrease in NO bulk deposition and the increase in the NH:NO ratio had important impacts on N-canopy interactions. The contribution of NH CU to that of total inorganic N CU increased at both sites but the trend was significant only at Tirasse (lowest N deposition). At this site, absolute NO CU significantly decreased (as did total N CU) during the study period, a consequence of the strong relationship ( r = 0.88) between NO bulk deposition and NO CU. Our data suggest that N interactions with forest canopies may change rapidly with changes in N deposition as well as with tree species composition.
- Subjects
EASTERN Canada; PLANT canopies; ATMOSPHERIC nitrogen; NITROGEN content of plants; TAIGA ecology
- Publication
Oecologia, 2015, Vol 177, Issue 1, p29
- ISSN
0029-8549
- Publication type
Article
- DOI
10.1007/s00442-014-3118-0