Land-use history affects understorey plant species distributions in a large temperate-forest complex, Denmark

Abstract

In Europe, forests have been strongly influenced by human land-use for millennia. Here, we studied the importance of anthropogenic historical factors as determinants of understorey species distributions in a 967 ha Danish forest complex using 156 randomly placed 100-m 2 plots, 15 environmental, 9 spatial, and 5 historical variables, and principal components analysis (PCA), redundancy analysis (RDA) as well as indicator species analysis. The historical variables were status as ancient (1805 AD) high forest, reclaimed bogs, B100 m from Bronze Age burial mounds, or former conifer plantation, and stand age. The PCA results showed that the main gradients in species composition were strongly related to the explanatory variables. Forward variable selection and variation partitioning using RDA showed that although modern environment was the dominant driver of species composition, anthropogenic historical factors were also important. The pure historical variation fraction constituted 13% of the variation explained. The RDA results showed that ancient-forest status and, secondarily, reclaimed bog status were the only significant historical variables. Many typical forest interior species, with poor dispersal and a strong literature record as ancientforest species, were still concentrated in areas that were high forest in 1805. Among the younger forests, there were clear floristic differences between those on reclaimed bogs and those not. Apparently remnant populations of wet-soil plants were still present in the reclaimed bog areas. Our results emphasize the importance of historical factors for understanding modern vegetation patterns in forested landscapes.

Of niche differentiation, dispersal ability and historical legacies: what drives woody community assembly in recent Mediterranean forests?

“…To sum up, our study shows a weak colonization credit in Mediterranean forests except for vertebrate‐dispersed woody species. Our study also shows contrasting woody species assembly in pre‐existing and recent Mediterranean forests, as also found in other forests (Hermy et al , Svenning et al ). Niche differentiation seems to play a key role in the Mediterranean woody community assembly.…”

“…These results are quite surprising, as vertebrate‐dispersed species are presumed to achieve longer dispersal distances than non‐vertebrate‐dispersed ones (Tiffney and Mazer ). A number of previous studies have pointed out that species with good dispersal abilities are overrepresented in isolated patches (Kolb and Diekmann , Tremlovà and Münzbergovà ), particularly in recent forests (Flinn and Vellend , Svenning et al ). In the Mediterranean forests, Montoya et al () found that fragmented patches are mostly dominated by long‐distance vertebrate‐dispersed species.…”

Understorey plant species show long‐range spatial patterns in forest patches according to distance‐to‐edge

“…; Svenning et al. ). The traits associated with core and peripheral species could also be explained by the remnant effect of former agricultural land use.…”

Hydrological and environmental variables outperform spatial factors in structuring species, trait composition, and beta diversity of pelagic algae

“…(ii) Principal coordinates of neighborhood matrix (PCNM) analysis based on the geographical distance was used to compute spatial variables (i.e., historic factors) representing geographical positions through the pcnm function in R package vegan (version 2.4‐2). The generated eigenvectors were considered as spatial variables (i.e., PCNMs), which could reflect unmeasured broadscale variation in the modern environment or historic factors, for example, natural dispersal‐generated patterns demonstrating internal local‐scale dispersal dynamics or regional‐scale migration history (Svenning, Baktoft, & Balslev, ). PCNMs with large eigenvalues and small code represent broadscale spatial pattern, while the smaller eigenvalues with large code represent fine‐scale patterns.…”