Impact of leaf removal on initial survival and growth of container-grown and bare-root seedlings of Hinoki cypress (Chamaecyparis obtusa).
Impact of leaf removal on initial survival and growth of container-grown and bare-root seedlings of Hinoki cypress (Chamaecyparis obtusa).
复制标题
叶子去除对扁柏（Chamaecyparis obtusa）容器种植和裸根幼苗初始存活和生长的影响。
DOI：
10.1016/j.foreco.2016.03.054
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发表时间：
2016
影响因子：
3.7
通讯作者：
KAJIMOTO Takuya
中科院分区：
文献类型：
--
作者：
YAMASHITA Naoko;OKUDA Shiro;SUWA Rempei;Thomas Ting Lei;TOBITA Hiroyuki;UTSUGI Hajime;KAJIMOTO Takuya
作为改善森林管理实践的一部分，我们测试的想法，部分落叶的容器生长和裸根扁柏（Chamaaparis obtusa）苗出植前可以减少移植休克和提高幼苗存活在移植后的第一个生长季节。对于容器生长的幼苗，脱叶幼苗的剩余叶片在前3周表现出比非脱叶对照高约1.5倍的光合能力（Amax）。对于脱叶裸根苗，在移栽后的前4周内，Amax是未脱叶对照的3.3-4.8倍。此后，两种类型的落叶苗的Amax开始缓慢下降。容器苗移栽后新长出的叶片的Amax显著高于现存叶片，而裸根苗则不显著。对于容器育苗，去叶和不去叶的植株都表现出较高的存活率（>90%），并且去叶水平之间没有显著差异。对于裸根苗，在生长季节结束时，未落叶的对照表现出最高的死亡率（30%），而落叶25%，50%，75%的幼苗都遭受很少的死亡率。在初始生长方面，在容器苗中脱叶和非脱叶对照之间没有显著差异，表明脱叶处理对降低其生长没有影响。相比之下，裸根幼苗表现出轻微但显着更大的高度生长在落叶植物，这表明非落叶幼苗遭受更大的移植冲击，减少叶片的数量可能有助于减少水分胁迫和死亡率。因此，我们发现，对于裸根苗，部分脱叶可以有效地减少移植冲击，从而提高存活率和生长性能;容器生长的幼苗缺乏脱叶反应，这表明脱叶对于提高其移植成功率是不必要的。
As a part of improving forest management practices, we tested the idea that partial defoliation of container-grown and bare-root Hinoki cypress (Chamaecyparis obtusa) seedlings prior to outplanting can reduce transplant shock and enhance seedling survival during their first growing season after transplanting. For container-grown seedlings, the remaining leaves of defoliated seedlings showed photosynthetic capacity (Amax) about 1.5 times higher than the non-defoliated control in the first 3 weeks. For defoliated bare-root seedlings, Amax ranged 3.3–4.8 times higher than non-defoliated control in the first 4 weeks after transplanting. Thereafter, Amax of defoliated seedlings of both types began to decrease slowly. Amax of newly emerged leaves after transplanting was significantly higher than that of existing leaves for container-grown seedlings but not bare-root seedlings. For container-grown seedlings, both defoliated and non-defoliated plants showed high survival rate (>90%) and there were no significant differences among levels of defoliation. For bare-root seedlings, non-defoliated control showed highest mortality (30%) by the end of the growing season but seedlings that were 25%, 50%, 75% defoliated all suffered little mortality. In terms of initial growth, there was no significant difference between defoliated and non-defoliated control in container seedlings suggesting that defoliation treatment had no effect on reducing their growth. In comparison, bare-root seedlings showed marginally but significantly greater height growth in defoliated plants, suggesting that non-defoliated seedlings suffered greater transplant shock and reducing the amount of leaves may contribute to minimize water stress and mortality. Therefore, we found that for bare-root seedlings, partial defoliation can effectively reduce transplant shock resulting in high survivorship and growth performance; the lack of defoliation response in container-grown seedlings would suggest that defoliation is unnecessary for improving their transplant success.