The effect of plant spatial pattern within a patch on foraging selectivity of grazing sheep
The effect of plant spatial pattern within a patch on foraging selectivity of grazing sheep
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DOI：
10.1007/s10980-012-9744-1
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发表时间：
2012-05
影响因子：
5.2
通讯作者：
Yue Huang;Ling Wang;Deli Wang;Yexing Li;D. Alves
中科院分区：
文献类型：
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作者：
Yue Huang;Ling Wang;Deli Wang;Yexing Li;D. Alves
植物空间格局一直被认为是影响天然草地食草动物饲料选择的重要因素之一。以往的研究都强调食物资源空间分布格局对整个植物群落的影响。我们的目的是探讨斑块内食物空间格局的变化是否会影响斑块内和斑块间绵羊的饲料选择。采用三种适口性和丰度不同的本土植物，在不同的处理条件下，人工制造出三种不同质量的斑块。我们分别比较了高、中、低质量斑块内聚集模式和随机分散模式对绵羊饲料选择的影响。斑块内植物空间格局对斑块本身牧草选择的影响很大程度上取决于斑块质量。在高质量斑块中，食物资源的随机分散显著降低了绵羊对斑块内美味植物的消耗。这种效应在低质量的贴片中被逆转，而在中等质量的贴片中不显著。优质斑块内植物空间格局的变化对其他斑块的牧草选择影响较大。而中低质量斑块内植物空间格局的变化只对高质量斑块的绵羊觅食响应有显著影响。因此，我们得出结论，高质量的资源站点是最具影响力和最易受影响的觅食区域。我们的研究结果强调了在考虑放牧草地保护和管理时，优质资源站点的重要性。
Plant spatial pattern has been considered as one of the most important factors influencing forage selection of herbivores in natural grasslands. Previous work has emphasized the effects of spatial distribution patterns of food resource at the scale of whole plant communities. Our objective was to explore whether changes in spatial patterns of food within a patchy site affected forage selection of sheep within and among patches. We conducted a manipulative experiment using three native plant species of different palatability and abundance to artificially create three different quality patches in each treatment. We compared the effects of aggregated and randomly dispersed patterns, within high, medium, and low quality patches respectively, on sheep forage selection. Effects of plant spatial patterns within a patch on sheep forage selection of the patch itself strongly depended on the patch quality. For high quality patches, random dispersion of food resources significantly decreased sheep consumption of the palatable plant within the patch. This effect was reversed in low quality patches, and was not significant in medium quality patches. Changes in plant spatial patterns within high quality patches greatly influenced sheep forage selection of other patches. However, changes in plant spatial patterns within medium or low quality patches significantly influenced foraging responses of sheep only for high quality patches. We therefore conclude that high quality resource sites are the most influential and susceptible foraging areas. Our results highlight the importance of high quality resource sites when considering grazing grassland conservation and management.