Positive and negative effects of livestock grazing on plant diversity of Mongolian nomadic pasturelands along a slope with soil moisture gradient

Abstract

To examine different effects of herbivorous large mammals’ grazing pressure on plant diversity along a slope in a Mongolian nomadic pasture, we compared species richness, Simpson’s index of diversity, and the total plant coverage of plants between protected pasture from livestock grazing and grazed pasture on the near ridge, upper slope, lower slope, foot slope and valley bottom. The species richness and Simpson’s index of diversity decreased and the total coverage increased downwardly with increase in pasture soil moisture along the slope. The species richness of the protected pasture decreased, changed little, and increased on the near ridge and the upper slope, the lower slope and the foot slope, and the valley bottom, respectively. Simpson’s index of diversity of the protected pasture decreased compared with the grazed pasture only on the valley bottom. The total coverage became lower in the grazed pasture. As the reason for our results, we discuss positive and negative effects of livestock grazing on the species diversity of plants. The positive effect is shown on the valley bottom, where soil moisture and plant growth becomes high with the total coverage over 100%, due to relaxing indirectly the competitive exclusion among plants due to the grazing of dominant plants. The negative effect is obtained on the near ridge and the upper slope, where the soil moisture and the plant growth are low, because of elimination of some plants from the pasture by direct grazing damage.

Topography‐ and management‐mediated resource gradients maintain rare and common plant diversity around paddy terraces

“…Suzuki, R. G. Ohara, and A. Ushimaru, unpublished data). Changes in plant diversity and composition along resource and/or aboveground biomass gradients generated by topography and management practices (mowing and grazing) were also observed in Mediterranean and Mongolian seminatural grasslands (Tzialla et al 2006, Sasaki et al 2008, Fujita et al 2009). To better generalize our findings, other types of seminatural grasslands should be examined in terms of the distribution of both rare and common species along topography-and management-mediated resource gradients.…”

Effects of Different Grazing Systems on Aboveground Biomass and Plant Species Dominance in Typical Chinese and Mongolian Steppes

“…After discussion and approval by the village committee, collective pastures are typically leased to herder households for 50 years [16]. In Mongolia, nomadic grazing (i.e., two, three, or four-season rotational grazing) is carried out by the herders according to the specifics of the pasture and seasonal changes [17].…”

“…After discussion and approval by the village committee, collective pastures are typically leased to herder households for 50 years [16]. In Mongolia, nomadic grazing (i.e., two, three, or four-season rotational grazing) is carried out by the herders according to the specifics of the pasture and seasonal changes [17]. Field sampling was performed from late July to mid-August 2016 in two cross-border, neighboring soums (one on each side of the China-Mongolia border), with identical, natural, and typical steppe conditions.…”

Functional traits but not environmental gradients explain seed weight in Mongolian plant species

“…Livestock (Fujita et al . ) and wild animals (Hülber et al . ) are highly selective in the utilisation of (potential) fodder plants in cold environments.…”