Dispersal of vascular plants by four species of wild mammals in a deciduous forest in NE Germany
Heinken, Thilo; Hanspach, Heike; Raudnitschka, Dorit; Schaumann, Friederike
The dispersal of vascular plant diaspores by common wild herbivorous and omnivorous mammals with a large home range was investigated in a 6.5-km2-forest area in NE Germany dominated by mesophilous deciduous forests. Endozoochory was studied by collecting faeces from roe deer, hare, wild boar and martens throughout one vegetation period. Epizoochory was investigated by brushing out the diaspores from the coats and hooves of shot roe deer and wild boar. The results were compared with the forest vegetation of the study area. The content of viable seeds was considerable in the faeces of herbivores (mainly weeds), low in the faeces of wild boar, and high in the scats of martens (mostly fleshy fruits). Whilst wild boar transported large amounts of various diaspores in the coat, the significance of roe deer for epizoochory was low. Altogether, 80 vascular plant species were dispersed; 38 species internally, and 55 externally. The open landscape was the most important source of dispersed seeds, and only a small proportion of the seeds came from the forest. Thus, most plants growing in the study forest received no effective dispersal by the four species of mammals, although most forest species were very abundant in the herb layer of the study area. We conclude that wild mammals are more effective in dispersal of ruderal and grassland species in central Europe. As epi- and endozoochory by large mammals are important mechanisms for long-distance dispersal of plants, we hypothesise that many herbaceous plants of mesophilous deciduous forests only have low dispersal potentials.