Grazing and Biodiversity – The Positive Side
Restoration of abandoned and shrub-encroached alpine grasslands has become an important issue to preserve agro-pastoral activities and biodiversity. In our work, strategic placement of mineral mix supplements (MMS) attracted cattle on shrub-encroached and traditionally underused grasslands, resulting in a decrease in shrub cover and an increase in forage quality through the combined effect of trampling, grazing, and fertilization. Strategic placement of MMS may be a sustainable management practice to be considered for restoration of alpine grasslands within agri-environmental schemes.
Vegetation responses to differing sheep grazing regimes in an open communal experimental design were assessed over 3 years in grasslands of south-eastern Australia. Manipulation of season and duration of grazing exclusion led to few major changes in the cover of perennial grasses or forbs, although seasonal variation was considerable. This work highlights the need for a mosaic of flexible grazing regimes across the landscape to benefit native plant diversity.
Enclosures are areas protected from livestock grazing during the rainy season and are widely used by pastoralists in East Africa. The direction of vegetation change following the removal of grazing livestock has been a controversial issue, and we compared vegetation changes inside and outside a set of enclosures established in the rangelands of eastern Ethiopia. The establishment of enclosures led to positive vegetation changes in terms of diverse desirable species and increased herbage mass.
Since human demand is driving the development and expansion of livestock farming, the impact of this land-use on natural biodiversity is a topic of increasing interest. This study investigated the impacts of sheep farming on the small-mammal community in a savanna ecosystem in South Africa, finding grass height to be the primary determinant of differences in small-mammal community structure among grazing treatments. Although the results demonstrate an overarching adverse relationship between sheep and small mammals, the latter may persist in isolated long-grass patches within heavily grazed pastures subjected to rotational grazing.
Livestock grazing is one of the primary uses of sagebrush rangelands in western North America; therefore, it is important to understand how grazing might affect habitat for native wildlife. The effects of cattle grazing on components of habitat for an uncommon animal that inhabitants sagebrush rangelands, the pygmy rabbit, which has been petitioned for endangered or threatened status in the USA, was studied and it was found that grazing influenced some, but not all aspects of the habitat of pygmy rabbits. Understanding how cattle grazing influences habitat for pygmy rabbits and other sagebrush-dependent wildlife can guide conservation and management strategies for these species on sagebrush rangelands managed under multiple-use policies.
Banning of grazing is a widely used means of restoring degraded rangeland in China. However, little is known about the time required to restore degraded alpine meadows through the use of a grazing ban. An experiment compared continued grazing with a ban of grazing for different numbers of years. The results showed that a grazing ban can increase herbage mass and plant diversity but it is suggested that some grazing after a grazing ban may be necessary according to the dynamics of ecosystem responses with time.
We focussed on rangeland cover change associated with livestock grazing in the Altun National Nature Reserve. There was a positive correlation between the change in area of sparse rangeland and the amount of livestock grazing. The change in non-rangeland was significantly negatively correlated with the amount of livestock grazing in the grazed area. Appropriate livestock grazing may be essential for promoting the resilience of the predominant ecosystems and key habitats of wildlife.
Despite the increasing number of horses grazing in northern Spanish mountains, little is known about their effects on predominant plant communities such as heathlands. We studied vegetation dynamics under horse grazing at three different heathland types during three years, and found that gorse dominance was reduced whereas the cover of typical heather species and some herbaceous plants increased. Floristic diversity increased compared with non-grazed heathlands, so horse grazing could be beneficial for the restoration of these rangelands.