【作者】 彭贤锋；

【导师】 赵廷宁；

【作者基本信息】 北京林业大学 ， 工程绿化， 2013， 硕士

【摘要】 汶川地震诱发的次生地质灾害破坏森林形成了大量的裸地,在植被恢复重建中具有诸多不利因素。土壤种子库是植被恢复的基础,为了解次生地质灾害土壤种子库特征及其植被恢复特点,在汶川地震重灾区四川省北川县采用野外取样和在当地自然环境下萌发相结合的办法,研究了5种不同灾害类型(包括滑坡、崩塌、泥石流、落石及堰塞湖)以及作为对比参照的5类(7种)未受损的当地主要林型(针叶林、阔叶林、针阔混交林、灌草林、竹林)的土壤种子库及其地上植被特征。主要结论如下：(1)损毁林地和未受损林地存在大规模的持久种子库,损毁地种子库密度介于30133.33±6776.03～93383.33±26499.81粒·m-2,未受损林地种子库密度介于40250.00±3224.86～93900.00±9104.84粒·m-2。(2)损毁林地种子库含有42个物种,独有物种4种；未受损林地含57个物种,独有物种19种。损毁地种子库植物主要由菊科(Asteraceae)、唇形科(Lamiaceae)、禾本科(Poaceae)组成,所占比例分别为26.19%、11.90%、7.14%,草本植物占90.48%,灌木占9.52%,没有乔木种。未受损林草本占91.23%,灌木占7.02%,乔木占1.75%。(3)损毁地和未受损地持久种子库密度垂直变化均不明显,O～5cm、5～10cm层都含有大量种子。(4)损毁林地和未受损林地地上植物优势种都属菊科(Asteraceae)、蔷薇科(Rosaceae)、禾本科(Poaceae)、豆科(Fabaceae)4科植物,但二者种类组成差别明显。损毁地均形成草本层,草本层盖度介于36.42%～86.25%,并且生长了较少量的灌木和乔木。(5)所有样地土壤种子库与地上植被的相似度很低,表明持久种子库对地上植被的更新直接贡献较小(6)各类损毁地的堆积体皆具有自我更新恢复的能力,但是种子库缺少乔木种。针对这些研究结果提出了一些关于灾害损毁地植被恢复的建议：对于人为活动较少区域的植被恢复宜采取自然恢复的措施。由于乔木种缺失,对于居民点、道路、景区等较迫切需要恢复的区域考虑引入乔木。在选择物种时,尽力选择北川县乡土树种,根据需要选择经济树种或者景观树种。损毁地自身的保水保土能力较差,采取简单的坡下拦挡、蓄水、排水等水土保持措施将能更好的促进植被群落的建立与恢复。更多还原

【Abstract】 Secondary geological disasters induced by the earthquake destruction of forests formed a lot of bare ground, causing many unfavorable factors in vegetation rehabilitation. Soil seed bank is the basis of vegetation restoration. In order to understand the soil seed bank characteristics and vegetation recovery features of secondary geological disasters, studied soil seed bank and aboveground vegetation characteristics of five different disaster types (including landslides, avalanches, debris flow, rockfall and barrier lake) and five categories(7species) undamaged local forest types(including coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrub and grass forest, bamboo forest), combining field sampling with germination in the local natural environment, in Beichuan County, Sichuan which is the Wenchuan quake-hit. The main conclusions are as follows.(1)There was a large-scale persistent seed bank in damaged woodland and undamaged woodland. The seed bank density of damaged woodland was between30133.33±6776.03-93383.33±26499.81seeds·m-2. The seed bank density of undamaged woodland was40250.00±3224.86～93900.00±9104.84seeds·m-2(2)The damaged woodland contained42species,4unique species, undamaged woodland containing57species,19kinds of unique species. The plants of damaged woodland were mainly composed by Asteraceae, Labiatae, Gramineae, and the proportion was26.19%,11.90%,7.14%. The herbaceous plants and shrubs in seed banks of damaged woodland accounted for90.48%and9.52%, and there is no tree species in it. The herbaceous plants, shrubs and trees accounted for91.23%,7.02%,1.75%.(3)Density vertical change of damage and undamaged persistent seed bank was not obvious.0to5 cm,5to10cm layer both contained a large number of seeds.(4)Aboveground dominant species in both damaged woodland and undamaged woodland belonged to Asteraceae, Rosaceae, Poaceae, Fabaceae4families, but both species composition were significantly different. Damaged woodland formed herb layer, and the herb layer cover ranged from36.42%to86.25%. A small amount of shrubs and trees have been grown.(5)The similarity of all samples between soil seed bank and aboveground vegetation was very low, indicating that the persistent seed bank contributing less to the update on the ground vegetation.(6)A11kinds of accumulation bodies in damaged woodland had self-renewal ability to recover, but were lack of trees species in seed banks.These findings put forward some proposals about recovery of damaged woodland. Natural recovery should take measures to those areas with less human activities. Due to the lack of tree species, considered the introduction of trees in the regional where was urgent need to restore such as settlements, roads, scenic spots. Try to select Beichuan County native trees in the choice of species, and select economic tree species or landscape tree species when needed. Damaged woodland itself was less able to soil and water conservation. To take simple soil and water measures conservation such as retaining wall, water storage, drainage will be better able to promote the establishment and recovery of vegetation communities.更多还原