Effect of harvest gap formation and thinning on soil nitrogen cycling at the boreal-temperate interface

The main goal of this study was to investigate the soil nitrogen dynamics in response to two partial harvesting treatments, used alone or in combination: commercial thinning creating tree size canopy gaps and harvest gaps creating 0.05 ha gaps. In a 30-year-old stand, both treatments, alone or in combination, were compared on replicated 0.75 ha plots. The most noticeable changes following treatments were observed in gaps while commercial thinning did not significantly influence any of the parameters assessed. In gaps, increases in N mineralization rates and mineral N concentrations and proportions (NO3- and NH4+) relative to DON were observed. Our results suggest that these changes are caused by the increase in soil temperature and water content. In these forests, the response threshold of the N cycling regarding the size of the intervention would therefore be located between the removal of a very small group of trees (2-3 stems, 6-9 m2) and a gap of 500 m2. Other studies conducted in different climate and forest types have showed that this threshold could be of equivalent or of a smaller size. These findings will contribute to optimizing our management strategies regarding partial cuts or small-scale clearcuts.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author