Diversity of patch structure in Central European forests: are tree diameter distributions in near-natural multilayered Abies-Fagus stands heterogeneous?

作者：Podlaski Rafal^*

来源：Ecological Research, 2010, 25(3): 599-608.

DOI：10.1007/s11284-010-0690-6

• Diameter structure
• Multilayered stands
• Structural heterogeneity
• Environmental modeling
• Two-component mixture models
• Abies alba-Fagus sylvatica

Near-natural multilayered Abies alba Mill.-Fagus sylvatica L. forests form structural mosaics and consist of patches in different developmental stages and phases. Knowledge of the diversity of patch structure and adequate methods to describe the diameter structure is essential for modeling forest dynamics. The hypotheses tested in the study are that near-natural multilayered stands are structurally heterogeneous (i.e., tree diameter (DBH) distributions of these stands are heterogeneous) and, that in these forests the finite-mixture models are suitable for modeling the empirical DBH distributions. Diversity of patch structure was studied based on data collected from 33 sample plots. In multilayered stands, four groups of empirical DBH distributions were distinguished using hierarchical cluster analysis (HCA) and correspondence analysis (CA). Stands investigated are structurally heterogeneous; 27% multilayered stands showed the slightly rotated sigmoid (SRS) type of empirical DBH distribution, 34% the distinctly rotated sigmoid (DRS) type, 18% the bimodal M-shaped (BMS) type, and 21% the unimodal highly skewed (UHS) type. The gamma distribution, the two-component mixture gamma model, and the two-component mixture Weibull model were more flexible for the SRS type of DBH distributions. The average p-values (Chi-square test) for these theoretical distributions were 0.4712, 0.4718, and 0.4660, respectively. The two-component mixture gamma model and the two-component mixture Weibull model were a good choice for modeling the DRS, BMS, and UHS types of DBH distributions. The average p-values (Chi-square test) for these models ranged from 0.2684 to 0.4854. In near-natural multilayered Abies-Fagus forest patches of different DBH distributions occur together. The empirical DBH distributions in these stands are characterized by irregular and complicated shapes and therefore are best approximated by finite-mixture models.

• 出版日期2010-5