Epsilon Archive for Student Projects

Abstract

Temperate deciduous forests are dynamic ecosystems where changes in light and soil conditions may affect the diversity and abundance of species on the herbaceous vegetation layer. In the national park Dalby Söderskog, located in southern Sweden, the tree canopies have opened due to tree diseases such as ash dieback and Dutch elm disease. At the same time, the arrival of wild boars has influenced soil conditions.
This study investigates the impact of changes in canopy cover and soil disturbance on the diversity and abundance of the forest herbaceous layer in Dalby Söderskog National Park between 2010 and 2019. It was hypothesized that (1) more open tree canopies are expected to increase both abundance and species diversity of the ground vegetation, and that (2) increased wild boar rooting leads to decreased cover and species diversity.
Based on vegetation surveys in 74 permanent sample plots, species richness and percentage ground cover of spring ephemerals, summer herbs, and woody species in the ground vegetation layer were related to wild boar rooting intensity, soil pH, soil moisture, and canopy cover using simple and multiple linear regression analyses.
The results revealed that reducing canopy cover and increasing soil pH were associated with higher herbaceous cover and species richness in the summer herb ground layer group. The wild boar rooting activity had a negative impact on spring ephemerals, while the woody species showed weak or no significant responses in relation to the environmental variables tested.
These results indicate that soil disturbance was the primary factor influencing the spring ephemeral vegetation, while changes in summer herbs were strongly correlated with changes in light availability. In combination, these factors have caused considerable shifts in the diversity and abundance of the ground vegetation in Dalby Söderskog between 2010 and 2019. These outcomes help understand the responses of the forest floor vegetation to disturbances and may inform biodiversity conservation strategies in temperate broadleaved forests.