Retention of dead leaves by grasses as a defense against herbivores. A test on the palatable grass Paspalum dilatatum
Retention of dead leaves by grasses as a defense against herbivores. A test on the palatable grass Paspalum dilatatum
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草保留枯叶以防御食草动物。
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Oesterheld
中科院分区：
文献类型：
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作者：
A. Mingo;M. Oesterheld
绝大多数草种在衰老时保留它们的叶子，导致死亡生物量的积累，这可能限制植物的生产力。在这项研究中，我们测试的假设，枯叶保留草作为防御大型食草动物。在洪水大草原的天然草地上，进行了以落叶清除和放牧为主因子的析因试验。从可口的草雀稗中除去枯叶，并在没有或存在大型食草动物的情况下测量生长。在没有食草动物的情况下，去除枯叶促进植物生长。在有食草动物的情况下，清除枯叶增加了牛的消费，特别是在最大的植物中。结果，在食草动物的存在下，去除枯叶的植物比完整的植物生长得更少。结果表明，在没有食草动物的情况下，保留枯叶对草种来说是昂贵的，但是，正如我们的假设所提出的那样，这种成本可以通过相应减少放牧消耗来补偿。
The vast majority of grass species retain their leaves as they become senescent, inducing an accumulation of dead biomass that may limit plant productivity. In this research, we tested the hypothesis that dead leaf retention by grasses act as a defense against large herbivores. In a natural grassland of the Flooding Pampa, we carried out a factorial experiment with dead-leaf removal and grazing as main factors. Dead leaves were removed from the palatable grass Paspalum dilatatum, and growth was measured either in the absence or in the presence of large grazers. In the absence of grazers, dead-leaf removal promoted plant growth. In the presence of grazers, dead-leaf removal increased consumption by cattle, particularly among the largest plants. As a result, in the presence of grazers, plants with dead leaves removed grew less than intact plants. The results indicate that retaining dead leaves is costly for grass species in the absence of grazers, but, as proposed by our hypothesis, that cost is compensated by a corresponding reduction of grazing consumption.