Analyzing size-symmetric vs. size-asymmetric and intra- vs. inter-specific competition in beech (Fagus sylvatica L.) mixed stands

摘要: In mixed stands, inter-specific competition can be lower than intra-specific when niche complementarity and/or facilitation between species prevail. These positive interactions take place at belowground aboveground levels. Belowground tends to size symmetric while the is usually for light and almost always size-asymmetric. Interactions forest tree explored analyzing growth level by comparing intra competition. At same time, possible causes of inferred relating with mode competition, i.e. size-symmetric or The aim this paper further our understanding detect reduction in stands beech (Fagus sylvatica L.) other species: pine–beech, oak–beech fir–beech. To test whether better explained size-asymmetric five different structures where included basal area models fitted using data from Spanish National Forest Inventory Pyrenees. considered either size-symmetry only (Reineke’s stand density index, SDI), size-asymmetry (SDI large trees SDI small trees), both combined. order assess influence admixture, these indices were introduced two ways, one which was consider that all compete a similar way, split into intra- components. results showed pine–beech mixtures, there slightly negative effect on pine benefitted admixture Scots pine; being greater as proportion larger classes increases. also positively influenced presence oaks trees. oak, however, decreased increased, although promoted oak growth. Finally, fir–beech neither fir nor species. indicate stronger highlighting importance Positive involved asymmetry size-growth relationships.