Understorey foraging and habitat selection by sheep in mixed Atlantic woodland

Abstract

Abstract. The main objectives of this study were to investigate sheep foraging behaviour in mixed Atlantic woodland and to assess its impact on the forest understorey. We established 89 plots along four forest types: Fagus woodland, Quercus woodland, riparian gallery forest and conifer plantations. The presence of plant species in the forest understorey and their foraging damage was surveyed bimonthly from July 1996 to June 1997. In addition, we estimated the selection of woodland types by sheep through the pellet‐group count technique. The intensity of foraging by sheep was negligible for most of the plant species, however several species showed substantial damage in some woodland types. Among the species that were abundant and widespread in the entire study area, Rubus ulmifolius, graminoids and Ilex aquifolium were consumed most. Sheep selected only larch plantations, where grasses and Rubus were very abundant. This grazing behaviour reduced browsing damage of the understorey of woodland stands with higher conservation value, such as Quercus and Fagus woodlands.

Effects of livestock exclusion on tree regeneration in church forests of Ethiopia

“…Three main components of structural change have been identified in a grazed forest: browsing on seedlings which limits stem density; browsing on leading shoots which limits height growth; and browsing on side shoots and climbers which reduces foliage density (Gill and Beardall, 2001;McEvoy et al, 2006). There is, however, great variability in the effects of grazing on plant population dynamics, depending on factors such as the susceptibility of the woody species involved (Garin et al, 2000;Motta, 2003;Sun et al, 1997;Teich et al, 2005). According to Miller et al (2006), protection given to the relatively palatable seedlings by neighboring tall, unpalatable thistles is consistent with two ecological hypotheses: the associational plant refuge hypothesis (Pfister and Hay, 1988) and apparency theory (Feeny, 1976).…”

Do domestic herbivores retard Polylepis australis Bitt. woodland recovery in the mountains of Córdoba, Argentina?

“…In these cases, the complete exclusion of large herbivores will often secure rapid growth of juvenile trees previously affected by browsing, but it could also result in losses of biodiversity (Mitchell and Kirby, 1990), increased fire hazard due to fuel accumulation (Belsky and Blumenthal, 1997) and reduced seedling establishment due to competition (Romagosa and Robison, 2003). Consequently, the control of grazing rather than its complete removal is now generally considered as a more desirable management option (Garin et al, 2000). Therefore, it is necessary to understand the interactions between herbivores and vegetation, both if the management objective is to maintain woodlands, or to maintain grasslands (Hunter, 1990;Garin et al, 2000;Weisberg and Bugmann, 2003).…”

“…There is, however, great variability in the effects of browsing on plant population dynamics, depending on factors such as the susceptibility of the woody species involved (e.g. Sun et al, 1997;Garin et al, 2000;Motta, 2003), the herbivore behaviour, which in turn might be influenced by habitat characteristics or the presence of predators (Garin et al, 2000;Palmer and Truscott, 2003;White et al, 2003;Pietrzykowski et al, 2003) and mortality due to factors other than browsing (Senn and Sutter, 2003;Palmer and Truscott, 2003).…”

“…Consequently, the control of grazing rather than its complete removal is now generally considered as a more desirable management option (Garin et al, 2000). Therefore, it is necessary to understand the interactions between herbivores and vegetation, both if the management objective is to maintain woodlands, or to maintain grasslands (Hunter, 1990;Garin et al, 2000;Weisberg and Bugmann, 2003).…”

Relationships between the species composition of forest field‐layer vegetation and environmental drivers, assessed using a national scale survey

“…2002) and direct management, including coppicing (Mason & MacDonald 2002) and grazing by wild ungulates or livestock (Mcinnes et al . 1992;Garin et al . 2000;Kirby & Thomas 2000), important at the local scale.…”