Anderson J M
Department of Zoology, King's College, University of London, London, UK.
Animal Ecology Research Group, Department of Zoology, South Parks Road, Oxford.
Oecologia. 1973 Sep;12(3):251-274. doi: 10.1007/BF00347566.
Weight losses from sweet chestnut and beech leaves, attributable to biotic and abiotic breakdown processes, leaching and microbial decomposition have been studied using tethered leaves and litter bags. The experimental sites were two adjacent areas of deciduous woodland. In one area (the Castanea site) a mor-like moder humus form has developed under a stand dominated by coppiced chestnut, in the other a mull-like moder underlies a stand of coppiced beech (the Fagus site).Chestnut leaves in the Castanea site are primarily comminuted by abiotic processes (wind, rain, hygroscopic movements, etc.) and soil animals make a relatively small contribution to leaf litter breakdown. After 31 months in the field 36.03% of the initial weight of chestnut leaves remained in the fine mesh bags against 22.82% in the coarse mesh bags. Weight losses from the coarse and fine mesh bags containing beech litter were not significantly different after 31 months when a mean weight of 57.10% of the litter remained.In the Fagus site, leaf litter breakdown was mainly due to the feeding activities of earthworms. However, chestnut leaves were more readily selected than beech leaves. After 8 months in the field nearly 45% more chestnut leaf material had been lost from the coarse mesh bags than from the fine mesh bags. Weight losses from the coarse and fine mesh bags containing beech litter were not significantly different after 31 months, when a mean weight of 43.30% of the litter remained.The leaching and decomposition rates of either type of leaves were not significantly different in the two sites. Chestnut leaves in fine mesh bags lost weight at twice the rate of beech leaves under similar conditions during the first 20 months of the study; however, most of the weight losses from beech and up to 75% of the losses from chestnut were attributable to leaching rather than to microbial decomposition. The rates of weight losses from the chestnut litter in fine mesh bags declined over the last year of the study, but beech maintained approximately constant weight loss rates for 31 months in the field. This difference may be due to different rates at which similar proportions of water soluble materials were leached from the leaves.A major defect in the litterbag technique is demonstrated. The litter bags maintain the micro-environmental characteristics of the surface litter layers and do not follow the breakdown and decomposition pattern of the leaf litter year class from which the experimental material was drawn.
利用系留树叶和凋落物袋，研究了甜栗树叶和山毛榉树叶因生物和非生物分解过程、淋溶及微生物分解造成的重量损失。实验地点为两片相邻的落叶林地。在其中一片区域（栗树区域），在以萌生栗树为主的林分下形成了类粗腐殖质的半腐殖质形态；在另一片区域（山毛榉区域），萌生山毛榉林分下有类腐殖质的半腐殖质。栗树区域的栗树叶主要通过非生物过程（风、雨、吸湿运动等）被粉碎，土壤动物对树叶凋落物分解的贡献相对较小。在野外放置31个月后，细网袋中仍保留了初始重量36.03%的栗树叶，而粗网袋中这一比例为22.82%。装有山毛榉凋落物的粗网袋和细网袋在31个月后的重量损失没有显著差异，此时凋落物平均剩余重量为57.10%。在山毛榉区域，树叶凋落物分解主要归因于蚯蚓的取食活动。然而，栗树叶比山毛榉叶更容易被选中。在野外放置8个月后，粗网袋中栗树叶的损失量比细网袋中多近45%。装有山毛榉凋落物的粗网袋和细网袋在31个月后的重量损失没有显著差异，此时凋落物平均剩余重量为43.30%。两种树叶在两个地点的淋溶和分解速率没有显著差异。在研究的前20个月里，在类似条件下，细网袋中栗树叶的失重速度是山毛榉叶的两倍；然而，山毛榉叶的大部分重量损失以及栗树叶高达75%的重量损失归因于淋溶而非微生物分解。在研究的最后一年，细网袋中栗树凋落物的失重速率下降，但山毛榉叶在野外31个月内的失重速率大致保持不变。这种差异可能是由于从树叶中淋溶出相似比例水溶性物质的速率不同。研究证明了凋落物袋技术存在一个主要缺陷。凋落物袋保持了地表凋落物层的微环境特征，没有遵循取自实验材料的叶凋落物年份等级的分解和腐烂模式。
