Effects of livestock grazing on pollination on a steppe in eastern Mongolia
Effects of livestock grazing on pollination on a steppe in eastern Mongolia
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DOI：
10.1016/j.biocon.2008.07.004
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发表时间：
2008-09
影响因子：
5.9
通讯作者：
Yu Yoshiharaa;Buyanaa Chimeddorjb;Bayarbaatar Buuveibaatarc;Badamjavin Lhagvasurenc;Seiki Takatsukid
中科院分区：
文献类型：
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作者：
Yu Yoshiharaa;Buyanaa Chimeddorjb;Bayarbaatar Buuveibaatarc;Badamjavin Lhagvasurenc;Seiki Takatsukid
蒙古草原因过度放牧而普遍退化，引起全球关注。本研究的目的是揭示放牧对授粉的影响，作为蒙古草原生物多样性相互作用的一个例子。在蒙古国东部草原上，根据放牧强度设置了3个样地。在每个样地，我们记录了昆虫授粉植物的数量，并观察了传粉者在6月和8月的觅食行为。昆虫传粉物种丰富度较高，且在轻度放牧样地中最为丰富，与不同传粉者形成复杂的关系。但在重度放牧区，访花频率和授粉指数较高。所有授粉性能最差的中间放牧地块。这些结果表明，在绵羊和山羊的forb-biased觅食减少了花的昆虫授粉物种的多样性，从而减少了传粉媒介在中间放牧地块。在严重放牧的地块中，只有有限的杂草物种可以在重度放牧下生存，这种简单的植被与传粉者形成了不平衡但牢固的联系。迁移模拟结果表明，对于某些物种的灭绝，互网络更加脆弱。
Widespread degradation of Mongolian grasslands by overgrazing is of global concern. The objective of this study was to reveal the effects of grazing on pollination as an example of interaction biodiversity in Mongolian grasslands. We established three plots according to grazing intensity on the eastern steppe of Mongolia. In each plot, we recorded the numbers of insect-pollinated plants and observed the foraging behavior of pollinators in June and August. The richness of insect-pollinated species was high and these species were most abundant in lightly grazed plots, and formed complex relations with diverse pollinators. But, frequency of flower visitation and pollination index were greater in heavily grazed plots. All pollination properties were poorest in intermediately grazed plots. These results suggest that the forb-biased foraging of sheep and goats reduces the floral diversity of insect-pollinated species, and consequently reduces pollinators in the intermediately grazed plots. In the heavily grazed plots, only limited ruderal species could survive under heavy cattle grazing, and such simple vegetation formed unbalanced but strong bonds with pollinators. Removal simulation showed that the mutual network was more fragile with respect to the extinction of certain species.