Effects of thinning on canopy transpiration of a dense Moso bamboo stand in Western Japan
Effects of thinning on canopy transpiration of a dense Moso bamboo stand in Western Japan
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DOI：
10.1080/13416979.2019.1647592
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发表时间：
2019-07
影响因子：
1.5
通讯作者：
Ryuji Ichihashi;H. Komatsu;T. Kume;Yoshinori Shinohara;K. Tsuruta;K. Otsuki
中科院分区：
文献类型：
--
作者：
Ryuji Ichihashi;H. Komatsu;T. Kume;Yoshinori Shinohara;K. Tsuruta;K. Otsuki
摘要 竹子往往会因人类活动而变得丰富，并可能影响包括植被水循环在内的生态系统动态。我们根据液流测量结果，研究了间伐对密集、未管理（即未间伐）毛竹林冠层蒸腾作用 (Ec) 的影响。我们在夏季无选择地间伐了研究地块中 45% 的秆（即第一次间伐）。在第二年春天，小区中产生了许多新的秆，并且相当数量的秆被间伐（即第二次间伐）。第一次间伐后，在给定的潜在蒸发量 (Ep) 下，平均树液通量 (Js) 立即增加约 60%；因此，间伐林的Ec达到间伐前的90%。第二年，第二次间伐后，在给定的 Ep 下，当年秆的 Js 一般为间伐前的 2 倍以上，而老秆的 Js 又下降到间伐前的水平。总体 Ec 是疏伐前条件的 78%。我们的结果表明，适度疏伐茂密的毛竹林可能不会对 Ec 产生重大影响；因此，当目的是控制竹林的水分流失时，需要进行密集间伐。间伐后竹林的用水相对不敏感是由于单个竹秆用水的动态变化造成的。这些过程可能与竹子的克隆性质有关，竹子的竹秆在结构和生理上是相互关联的。
ABSTRACT Bamboos tend to become abundant associated with human activities and possibly affect ecosystem dynamics including vegetation water cycles. We examined the effects of thinning on canopy transpiration (Ec) for a dense, unmanaged (i.e. unthinned) Moso bamboo stand based on sap flow measurements. We unselectively thinned 45% of the culms during summer in a study plot (i.e. the first thinning). During the next spring, many new culms were generated in the plot and a comparable number of culms were thinned (i.e. the second thinning). After the first thinning, mean stand sap flux (Js) increased immediately by approximately 60% at a given potential evaporation (Ep); therefore, the Ec of the thinned stand reached 90% that of the pre-thinning condition. During the next year, after the second thinning, the Js of the current year culms was generally more than twice that of the pre-thinning stand at a given Ep, whereas the Js of the older culms decreased again to the level of the pre-thinning condition. The overall Ec was 78% that of the pre-thinning condition. Our results suggest that moderate thinning of dense Moso bamboo stands may not have major effects on Ec; thus, intensive thinning is required when the aim is to control water loss from bamboo stands. The relative insensitivity of water use in bamboo stands after thinning resulted from dynamic changes in water use in the individual culms. These processes might be related to the clonal nature of bamboo where culms are structurally and physiologically interconnected.