【作者】 郝亦荣；

【导师】 马履一； 孙向阳；

【作者基本信息】 北京林业大学 ， 森林培育， 2005， 硕士

【摘要】 生态垫是来自马来西亚的一种新型可降解覆盖产品,首次在我国北方风沙源治理造林工程中应用。本文研究了在沙地造林初期覆盖生态垫对林地土壤、林木生长等方面的作用机理及作用效果。主要从土壤物理化学性质、林木生长及林木光合生理生态等方面进行系统研究,对比分析生态垫覆盖与对照的差异。 研究结果表明,在生态垫覆盖林地的两个生长季内,表层0～20cm的土壤含水率、土壤温度受覆盖影响最明显。在土壤含水率日变化中,覆盖提高了土壤含水率18.2%～41.7%(相对百分比);在整个生长季,生态垫对初春和雨季的土壤含水率影响最显著,增加了初春土壤含水率45%、增加了雨季土壤含水率24%;在不同铺设方式对比中带状铺设方式改善0-20cm和20-40cm土层的土壤含水率最明显。 覆盖降低了夏季土壤表层温度7.3℃～7.6℃(相对百分比22.0%～35.6%),缩小了高温季节土壤表层温度日较差10.3℃(相对百分比64.8%)。覆盖下土壤孔隙度降低2.58%,利于表土层保水性能的增加;由于覆盖对土壤水热条件的改善,促进了土壤微生物活动、增加了土壤养分、提高了午间土壤呼吸2.5%;覆盖能够明显抑制造林初期林地杂草的生长,减少了杂草的盖度、高度、生物量等,其中杂草种类降低了40%,生物量降低99%。 覆盖促进了林木根系的生长,提高不同土层油松根系密度0.12～4.43g/1000cm~3,但与对照相比仍未达显著差异。覆盖下栾树、青杨、小花香槐、油松、侧柏胸(地)径年生长量高出对照3.6%～59.1%,其中油松试验地覆盖样树的地径生长量高出对照59.1%;对油松林木成活率调查结果表明,覆盖下油松成活率为88.43%,高出对照5.1%;覆盖生态垫在一定程度上促进了林木的生长,但由于种植时间短、苗木规格大,与对照相比差异还不明显。覆盖提高了林木叶片养分含量,增加了杨树和栾树的叶面积指数,覆盖提高了油松、栾树光合日变化中光合速率极(Pn)大值30%、28.65%,增加了油松、栾树日平均光合速率17.5%～23%:在相同光饱和点下覆盖提高了油松、栾树的光合速率10.6%～44.3%、13.05%～76.56%,有利于促进树木积累更多的有机物质。在一定程度上,覆盖提高了油松、栾树日变化中正午时蒸腾速率(Tr)与气孔导度(Cond),利于叶片在高温环境下的适应能力,但水分利用效率(WUE)受覆盖影响不大。更多还原

【Abstract】 Eco-mat is a new type of mulching materials coming from Malaysia and used in sandstorm areas in Beijing for the first time. The main purpose of this paper is to research the effects of Eco-mat mulching sands on soil and the tree growth. Comparing the differences on the physical & chemical properties of soil and the tree growth and photosynthetic parameters, the results were as following:After the floor of the plantation was covered with Eco-mat for two growth seasons, there are significant differences 0~20cm soil moisture and soil temperature. With mulching Eco-mat the soil moisture in the layer of 0~10cm was increased by 18.2%-41.7% and the soil moisture enhanced by 45% in Spring and 24% in Summer. Mulching with belting way has shown the great effect on soil moisture in the layer of 0~10cm and 20~40cm. And the surface soil temperature was reduced by 7.3℃~7.6℃ (relatively ratio 22.0%~35.6% ) in Summer and the daily range of soil temperature was lessened by 10.3℃ (relatively ratio 64.8 % ) ,and the bulk density of the surface soil was increased by 0.059g/cm3. Due to the moisture and temperature of soil were improved, the soil microbe number and the soil nutrients were increased in some degree and the soil respiration rate was 2.5% higher than CK at noon. Meanwhile mulching Eco-mat can control weed growth and reduce the height biomass abundant of weed. The weed species and the weed biomass were decreased by 40% and 99% respectively compared with the CK.Mulched with Eco-mat, the root density was increased by 0.12-4.43 g/1000cm3 in different soil layers, and the annual growth of the treated tree diameter was3. 6%~59. 1% higher than CK about Koelreuteria panicuiata , Populus cathayana , Pinus tabulaeformis, C.sinensis, Piatycladus orientalis. Compared with CK the survival rate was increased by 5.1%, and both the leaf nutrient and the LAI was increased. To Platycladus orientalis Koelreuteria panicuiata ,the daily maximum photosynthetic rate and the Pn in the photosynthesis-saturated point were increased by 30% 28.65 % and 10.6 %~44.3% 13.05%-76.56% respectively compared with the CK; the Tr and Cond were increased to some extent, while the light compensation points and the water-consumption efficiencies of the trees between the treated and CK were not different from each other remarkably.更多还原