TY - JOUR
T1 - Comparison between the productivity of pure and mixed stands of Norway spruce and European beech along an ecological gradient
AU - Pretzsch, Hans
AU - Block, Joachim
AU - Dieler, Jochen
AU - Dong, Phan Hoang
AU - Kohnle, Ulrich
AU - Nagel, Jürgen
AU - Spellmann, Hermann
AU - Zingg, Andreas
PY - 2010
Y1 - 2010
N2 - Existing growth and yield plots of pure and mixed stands of Norway spruce (Picea abies (L.) H. Karst.) and European beech (Fagus sylvatica L.) were aggregated in order to unify the somewhat scattered sources of information currently available, as well as to develop a sound working hypothesis about mixing effects. The database contains information from 23 long-term plots, covering an ecological gradient from nutrient poor and dry to nutrient rich and moist sites throughout Central Europe. • An empirically formed interaction model showed, that depending on the site conditions, dry mass growth in mixed stands can range from - 46% to +138 % of the growth yielded by a scaled combination of pure stands at equal mixing proportions. • Drawing from the interaction model, overyielding of the mixed stands appears to be triggered by two separate mechanisms. On poor sites, where significant overyielding is commonly found, facilitation by beech offsets nutrient-related growth limitations in spruce. In contrast, overyielding of mixed stands occurs less frequently on rich sites, and appears to be based on an admixture effect, with spruce reducing the severe intra-specific competition common in pure beech stands. • It was concluded that silviculture can accelerate growth of spruce by beech admixtures on poor sites, while growth of beech can be promoted by admixture of spruce, particularly on excellent sites.
AB - Existing growth and yield plots of pure and mixed stands of Norway spruce (Picea abies (L.) H. Karst.) and European beech (Fagus sylvatica L.) were aggregated in order to unify the somewhat scattered sources of information currently available, as well as to develop a sound working hypothesis about mixing effects. The database contains information from 23 long-term plots, covering an ecological gradient from nutrient poor and dry to nutrient rich and moist sites throughout Central Europe. • An empirically formed interaction model showed, that depending on the site conditions, dry mass growth in mixed stands can range from - 46% to +138 % of the growth yielded by a scaled combination of pure stands at equal mixing proportions. • Drawing from the interaction model, overyielding of the mixed stands appears to be triggered by two separate mechanisms. On poor sites, where significant overyielding is commonly found, facilitation by beech offsets nutrient-related growth limitations in spruce. In contrast, overyielding of mixed stands occurs less frequently on rich sites, and appears to be based on an admixture effect, with spruce reducing the severe intra-specific competition common in pure beech stands. • It was concluded that silviculture can accelerate growth of spruce by beech admixtures on poor sites, while growth of beech can be promoted by admixture of spruce, particularly on excellent sites.
KW - Competitive reduction
KW - Facilitation
KW - Fagus sylvatica
KW - Long-term mixing experiments
KW - Mixing effect
KW - Overyielding
KW - Picea abies
KW - Underyielding
UR - http://www.scopus.com/inward/record.url?scp=77957803592&partnerID=8YFLogxK
U2 - 10.1051/forest/2010037
DO - 10.1051/forest/2010037
M3 - Article
AN - SCOPUS:77957803592
SN - 1286-4560
VL - 67
SP - 712
JO - Annals of Forest Science
JF - Annals of Forest Science
IS - 7
ER -