Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài:"Variability and heterogeneity of humus forms at stand level: Comparison between pure beech and mixed beech-hornbeam forest" | Ann. For. Sci. 63 2006 177-188 INRA EDP Sciences 2006 DOI forest 2005110 177 Original article Variability and heterogeneity of humus forms at stand level Comparison between pure beech and mixed beech-hornbeam forest Michael Aubert Pierre Margerie Aude Ernoult Thibaud Decaens Fabrice Bureau Groupe de recherche ECODIV UPRES-EA 1293 Faculté des Sciences et des Techniques Université de Rouen 76821 Mont-Saint-Aignan Cedex France Received 17 January 2005 accepted 24 August 2005 Abstract - We investigate the influence of tree canopy composition on humus form variability and heterogeneity by comparing a pure beech stand and a mixed beech-hornbeam one 70 beech and 30 hornbeam . Macro-morphological humus form descriptors were recorded using a spatially explicit sample design at stand level. Leaf litter composition and light intensity accounting for stand management as well as bulk density for harvesting practices soil compaction were also recorded. A multiple correspondence analysis MCA and geostatistics were used to assess humus form variability and heterogeneity as well as the spatial correlation between stand characteristics and humus forms. Humus form variability and activity were greater under the mixed stand than under the pure one. Geostatistics revealed that humus form patchiness was greater under the mixed stand than under the pure one and the improvement in decomposition processes seemed to be confined to spatial distribution of hornbeam litterfall. From a practical viewpoint these results could provide ideas on the way of mixing tree species at stand level. We assume that with a given percentage of mull-forming tree species a dispersed tree mixture provides a more extensive improvement than a clumped mixture. humus form pure stand mixed stand geostatistics spatial pattern heterogeneity Fagus sylvatica Carpinus betulus Résumé - Variabilité et hétérogénéité des formes d humus à l echelle du peuplement comparaison entre peuplement pur de hêtre et forêt .
