Epsilon Archive for Student Projects

Abstract

In temperate Europe, the regrowth of open and semi-open habitats poses a threat to biodiversity, including the survival of light-demanding woody species. This study examines whether large herbivores and fire, individually and in combination, can reduce the survival of ten temperate woody species and thus create and maintain openness in the landscape. Additionally, it investigates whether woody species respond differently to large herbivores and fire regarding survival. Here, the survival rate of 4,800 planted saplings is evaluated in a full-factorial experiment. This study shows that the survival of nearly all tested trees and shrubs was significantly reduced by both large herbivores and fire, individually and in combination. The results indicate that large herbivores and fire not only may create and maintain openness but are also able to shape divergent woody species assemblages in temperate European ecosystems. Species with a significantly higher survival rate in the large herbivore treatment compared to the fire treatment are Picea abies, Carpinus betulus, Fagus sylvatica and Prunus spinosa. In contrast, Betula pendula, Quercus robur, Tilia cordata, Corylus avellana and Viburnum opulus have a significantly higher survival rate in the fire treatment. Hence, the survival rates between the two treatments significantly differed for all species except Pinus sylvestris. The results may also be compared to recent palaeoecological studies, which indicate that Quercus robur and Corylus avellana were also prevalent in the presumably large herbivore-driven last interglacial. This anomaly can be explained by the difference between planting saplings in the experiment and the natural recruitment process of these species in landscapes shaped by large herbivores. Consequently, the aforementioned species can also be a part of woody species assemblages in large herbivore dominated ecosystems. In conclusion, this study provides experimental understanding of how large herbivores and fire shape semi-open wood-pasture conditions, resulting in different woody species assemblages.