Technical development of revegetation works on hill slopes used of the wood waste

利用木屑，来自砍伐树木的不可用部分，最近进行了广泛的基础材料，在植被工程中，通过在山坡上进行水播，目的是合理处置木质废物。然而，它对植被发育的影响仍然没有得到明确的解释。为了评价木屑坡面喷洒的效果，对播种后的植被演替、立地条件和基质的化学性质进行了研究，结果表明，播种后的豆科植物在初期由于与牧草共生而生长不良，但在播种后半年由于木屑中氮含量较低而生长良好。生物量产量比喷人工土壤的坡地高2倍以上。然而，豆科植物的过度生长，不仅由于其密集的生长，而且由于其显著的化感作用，延缓了后继植被的演替。豆科植物本身的密度也随着内共生作用而逐渐降低，而替代豆科植物的三叶草由于高度相对较低，对地表干燥敏感，虽然不能覆盖整个喷洒区域，但生长迅速。与豆科植物一样，三叶草的快速生长延缓了植被的演替，而坡脚裸露的斑块则为植物的入侵提供了更多的机会;喷屑的分解几乎不随时间的推移和坡向的不同而进行，这影响了表层土壤的湿度，而与植物覆盖度有关。根据我们在斜坡上的观察，木屑足以取代喷播的基础材料。为在山坡地建立多样性植被群落，选择抗旱能力强的先锋植物是必要的。

Use of wood chips, derived from the unavailable parts of felled trees, is recently carried out extensively as the base material in revegetation works by hydroseeding on hill slopes with the objective of sensible disposal on woody waste. However, its influence on the development of vegetation has still not been clearly explained. In order to evaluate the effects of wood chips sprayed on slopes, the succession of vegetation after seeding, the site conditions and the chemical properties of base materials were examined.The seeded legumes vegetated undesirably in the initial stage owing to the concurrence with pastures, but showed from a half year after seeding an outstanding growth on account of lower contents of nitrogen in chips. Their biomass yield, compared with those on slopes sprayed with artificial soil, was two or more times higher. However, the luxuriance of legumes has leaded to delay the succession of following vegetation, not only by their dense growth but also by their remarkable allelopathy. The density of legumes itself decreased gradually by the internal concurrence.The clovers used in place of legume have grown rapidly, even though they did not cover the whole sprayed area due to their sensitivity to surface dryness caused by their relatively shorter height. As same as legumes, the rapid growth of clovers delayed the succession of the vegetation ; however, the bare patches on splayed slope can provide more opportunities for the plants invasion.The decomposition of sprayed chips hardly progressed with the passage of time and the deference of the slope direction which affects the humidity of surface soil, but had a relationship with plant coverage. From our observation on the slopes, wood chips would be useful enough as a replacement of the base material for hydroseeding. For the establishment of diverse vegetation community on hill slopes, the choice of pioneer plants with the high resistance capacity against dryness is necessary in the splaying.