TY - JOUR

T1 - Horizontal, but not vertical canopy structure is related to stand functional diversity in a subtropical slope forest

AU - Lang, Anne C.

AU - Härdtle, Werner

AU - Bruelheide, Helge

AU - Kröber, Wenzel

AU - Schröter, Matthias

AU - von Wehrden, Henrik

AU - Oheimb, Goddert

PY - 2012/1

Y1 - 2012/1

N2 - The aim of this study was to analyse the relation of horizontal and vertical canopy structure to tree functional diversity of a highly diverse subtropical broad-leaved slope forest, stratified for different successional stages. This is of particular interest because many key ecosystem processes and functions are related to the arrangement of forest canopies. We assessed the effect of stand-related functional diversity (FD Q, measured as Rao's quadratic entropy of leaf traits), together with other environmental variables on horizontal [measured as relative crown projection areas (CPA r)] and vertical [relative crown overlap, coefficients of variation (CV) of crown positioning variables] structure of the upper canopy at the local neighbourhood level. The analyses with mixed effects models revealed a negative relation (p = 0.025; estimate -0.07) between FD Q and CPA r. No significant effect of FD Q on vertical canopy structure has been found (p > 0.05). The findings are discussed with regard to resource partitioning and niche differentiation of canopy and sub-canopy species. Successional stage positively impacted the CV of crown length (p = 0.019; estimate 0.03) but did not affect other response variables. The sloping terrain strongly influenced vertical canopy structure as revealed by the significant effect of slope inclination on CV of crown length (p = 0.004; estimate -0.05) and of slope aspect on CV of mean crown height (p = 0.036; estimate -0.03). The high complexity of vertical crown positioning depending on the heterogeneous sloping terrain of the study area may have obscured relations of FD Q to vertical canopy structure.

AB - The aim of this study was to analyse the relation of horizontal and vertical canopy structure to tree functional diversity of a highly diverse subtropical broad-leaved slope forest, stratified for different successional stages. This is of particular interest because many key ecosystem processes and functions are related to the arrangement of forest canopies. We assessed the effect of stand-related functional diversity (FD Q, measured as Rao's quadratic entropy of leaf traits), together with other environmental variables on horizontal [measured as relative crown projection areas (CPA r)] and vertical [relative crown overlap, coefficients of variation (CV) of crown positioning variables] structure of the upper canopy at the local neighbourhood level. The analyses with mixed effects models revealed a negative relation (p = 0.025; estimate -0.07) between FD Q and CPA r. No significant effect of FD Q on vertical canopy structure has been found (p > 0.05). The findings are discussed with regard to resource partitioning and niche differentiation of canopy and sub-canopy species. Successional stage positively impacted the CV of crown length (p = 0.019; estimate 0.03) but did not affect other response variables. The sloping terrain strongly influenced vertical canopy structure as revealed by the significant effect of slope inclination on CV of crown length (p = 0.004; estimate -0.05) and of slope aspect on CV of mean crown height (p = 0.036; estimate -0.03). The high complexity of vertical crown positioning depending on the heterogeneous sloping terrain of the study area may have obscured relations of FD Q to vertical canopy structure.

KW - Biology

KW - BEF-China

KW - Coefficient of variation

KW - Gutianshan National Nature Reserve

KW - Tree individual

KW - Ecosystems Research

KW - Niche differentiation

UR - http://www.scopus.com/inward/record.url?scp=84856136225&partnerID=8YFLogxK

U2 - 10.1007/s11284-011-0887-3

DO - 10.1007/s11284-011-0887-3

M3 - Journal articles

VL - 27

SP - 181

EP - 189

JO - Ecological Research

JF - Ecological Research

SN - 0912-3814

IS - 1

ER -