Temporal and spatial variability in insect grazing of the canopies of five Australian rainforest tree species.
Temporal and spatial variability in insect grazing of the canopies of five Australian rainforest tree species.
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澳大利亚五种雨林树种树冠昆虫吃草的时间和空间变化。
DOI：
10.1111/j.1442-9993.1985.tb00859.x
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发表时间：
1985
期刊：
影响因子：
1.5
通讯作者：
M. Lowman
中科院分区：
文献类型：
--
作者：
M. Lowman
在澳大利亚5种雨林树种的树冠上，对带有永久标记的重复枝条的叶片进行了为期两年的每月食草情况测量。昆虫啃食活动的变异性在以下几个因素方面很明显：
1. 叶龄——嫩叶比老叶组织更受青睐；
2. 高度——靠近地面的叶片被啃食得更严重；
3. 光照——阴生叶比阳生叶更受喜爱；
4. 时间——春季和夏季啃食严重，秋季和冬季几乎可以忽略不计，但两年间累计情况相似；
5. 空间——在小空间尺度上，如在单个叶片和枝条之间，啃食情况差异极大，但在较大尺度上，当数百片叶子汇集在一起时，在单个树冠之间以及不同地理位置的地点之间情况相似；
6. 树木丰度——在某一树种常见的地点，啃食情况比该树种稀少的地点更严重；
7. 寄主树种。
长期观察得出的食草情况估计值更高且更准确，因为可以对完全被吃掉的叶片损失进行量化，而这一情况在离散采样的田间方法中未被考虑到，在该方法中只是采集叶片并测量缺失的面积。从植物 - 昆虫物候、植物防御、树种演替状况以及昆虫行为等方面对食草情况的变异性进行了讨论。
Herbivory was measured monthly for 2 years on leaves of permanently marked replicate branches in the canopies of five Australian rainforest tree species. Variability in insect grazing activities was evident with respect to several factors:
1
leafage — young leaves were preferred over older leaf tissue:
2
height — leaves closer to ground level were more heavily grazed:
3
light — shade leaves were preferred to sun leaves:
4
time — grazing was intense during spring and summer months, and almost negligible during autumn and winter, but was cumulatively similar between the 2 years:
5
space — grazing was extremely variable on small spatial scales such as between individual leaves and branches, but similar where hundreds of leaves were pooled on larger scales between individual canopies and among geographically different sites:
6
tree abundance — grazing was heavier at sites where a tree species was common than where it was rare:
7
host tree species.
Long term observations resulted in higher but more accurate estimates of herbivory since it was possible to quantify losses of leaves totally eaten, an event not accounted for infield methods of discrete sampling whereby leaves are merely harvested and measured for area missing. Variability in herbivory is discussed in terms of plant-insect phenologies, plant defences, successional status of tree species, and insect behaviour.