Summary
Published in Forest Ecology and Management 259: 867-874
Ecophysiology of black walnut (Juglans nigra L.) along a vertical canopy gradient was studied in a mixed species plantation for the first (2007) and second (2008) growing seasons after thinning to understand response mechanisms to increased resource availability. Parameters were affected by the thinning treatment in 2008 only. Thinned trees showed increased light-saturated maximum photosynthesis (Amax) from 2007 to 2008 compared to non-thinned trees. This response was likely due to increased light levels near thinned trees (vs. changes in water or nutrient status), because thinning did not affect midday leaf water potential (Ymd), average daily soil water content (SWC), or leaf nitrogen content per unit area (Na). Plantation thinning did not increase relative diameter growth during the experimental period. This may be due to low thinning intensity and mortality prior to thinning that reduced competition from firsttier neighbors. Certain leaf traits such as leaf mass per unit area (LMA) and Na increased from the bottom to the upper canopy position, but did not influence thinning responses. Distribution patterns of photosynthetic parameters through the vertical canopy gradient were less defined than leaf structural traits such as LMA and Na. Findings reflect black walnut’s large variability in response to thinning.
Sector(s):
Forests
Categorie(s):
Scientific Article
Theme(s):
Forestry Research, Forests, Silviculture
Author(s)
GAUTHIER, Martin-Michel and Douglass F. JACOBS
Year of publication :
2010
How to get the publication :
ISSN
0378-1127
Keywords :
éclaircie, écophysiologie, noyer noir, sylviculture, sylviculture des forêts naturelles feuillues, sylviculture et rendement des forêts naturelles - peuplements feuillus, Juglans nigra, article scientifique de recherche forestière, silviculture and yield of natural forests - hardwood stands, black walnut, ecophysiology, light-response curves, silviculture, thinning
