CpDNA haplotype variation reveals strong human influence on oak stands of the Veluwe forest in the Netherlands

We examined chloroplast DNA (cpDNA) variation in 78 oak stands of an important forest complex (the Veluwe) in The Netherlands. Based on historical maps and information oak stands were classified as planted or autochthonous. A genetic study by means of cpDNA haplotype characterisation was carried out to describe (i) genetic diversity within and among stands; (ii) to investigate whether the stands originated from the same haplotypes; (iii) to relate haplotype distribution to the status of the stands. The planted stands were all polytypic, comprising a mixture of the four haplotypes that are common for The Netherlands. In addition, a fifth, non-autochtonous haplotype was detected in these stands. Of the putative autochthonous oak stands ca. 50% were monotypic and in all stands only the four autochthonous haplotypes were detected. These stands also showed lower intra-population diversity (h(S) = 0.259) than the planted stands (h(S) = 0.610). Moreover, a significant positive correlation between genetic differentiation and geographic distance was observed among the autochthonous stands, while this spatial genetic structure was absent among the planted stands. This study indicates substantial human influence on the distribution of genetic diversity in oak stands across the Veluwe. The occurrence of a non-autochthonous haplotype in 25% of the planted stands suggests long-distance seed transfer. In the remaining 75% of the planted stands long-distance seed transfer cannot be proven. However, the high genetic diversity and lack of spatial genetic structure in the planted stands suggests the use of mixtures of (local) seed material of various origins. (c) 2006 Elsevier B.V. All rights reserved.