沿海沙地丛生竹在空间结构差异下的防风效能分析

发布时间：2018-08-01 14:54

【摘要】：以沿海沙地引种成功的绿竹、麻竹、大头典竹、黄金间碧竹和花吊丝竹等5种丛生竹林为研究对象,从林分特性、林分空间结构、竹木混交方式等方面,利用层次分析法(AHP)对沿海沙地丛生竹防护林的防风效能进行综合分析评价,以期为沿海沙地防护竹林科学经营和培育提供理论基础和参考依据。主要研究结果如下:1、疏透度是衡量林分结构的重要指标。疏透结构下绿竹防护林防风效能最佳,林带后平均防风效能为45.86%,比麻竹、大头典竹、黄金间碧竹和花吊丝竹分别高10.91%、4.84%、12.73%和4.26%。通风结构下以大头典竹、麻竹和绿竹防护林的林带后平均防风效能较好,均超过26%。紧密结构下以绿竹和花吊丝竹防护林的林带后平均防风效能最好,分别为37.68%和27.63%。2、沿海沙地5种丛生竹防护林的林带后平均防风效能随林分密度增大而增强。2年生的5种丛生竹林地在林分密度为800株· hm-2时,林带后平均防风效能为24.82%,以黄金间碧竹防护林最佳为29.1%;在林分密度为1500株·hm-2时,5种丛生竹林的林带后平均防风效能为54.40%,其中麻竹防护林的防风效能最好为60.4%;在林分密度为2100株·hm-2时,麻竹防护林的防风效能最佳为63.4%。受林分疏透度影响,防风效能随着林分密度的增大先增强而后开始缓慢下降。3、沿海沙地5种丛生竹林的防风效能随风速的增大先是增强而后略有减弱。5种丛生竹林的林带后风速变化曲线趋势较为一致,风速在林带后1H-3H距离内风速逐渐下降,至3H处达到最低,比林前对照风速降低52.8%-69.1%。随着林带后距离的增加,林带防风效能逐渐减弱,风速逐渐上升。5种丛生竹林在4组对照风速下的林带后平均防风效能由高到低依次为麻竹54.29%绿竹48.39%大头典竹44.27%花吊丝竹33.54%黄金间碧竹30.79%。4、林带宽度和带间距离从空间配置上对丛生竹林防风效能产生影响。防风效能随着林带宽度的增加而增加,最低风速出现在林带后3H-4H距离处。累积防风效益随带间距离的增大而降低。5、在林带后不同距离处防风效能随高度和风速增大而降低,不同疏透结构林带后三个垂直高度上的平均防风效能大小为:疏透结构39.3%紧密结构39.0%通风结构32.6%。6、竹木混交林比竹子纯林及木麻黄纯林拥有更好的防风效能。株间混交比例为2:1时林带防风效能大小依次为:麻竹53.70%绿竹48.21%大头典竹42.86%花吊丝竹41.18%黄金间碧竹38.46%;行带状混交比例为5:3时林带防风效能大小依次为:麻竹64.50%绿竹62.70%花吊丝竹56.30%大头典竹55.20%黄金间碧竹52.00%;块状混交模式下,块状边长为10-15m时林带防风效能的大小依次为:麻竹55.41%绿竹45.31%花吊丝竹44.00%大头典竹42.37%黄金间碧竹40.58%。7、利用层次分析法(AHP)对东山沿海沙地5种竹木混交模式综合防风效能建立评价模型,评价所得5种混交方式综合值大小依次为:株间混交41.14%块状混交36.82%行间混交19.25%带状混交18.88%星状混交12.36%。
[Abstract]:In this paper, five kinds of clumped bamboo forests, such as green bamboo, hemp bamboo, big head bamboo, yellow bamboo and flower bamboo, which were successfully introduced into coastal sandy land, were studied in terms of stand characteristics, stand spatial structure, mixed way of bamboo and wood, and so on. In order to provide theoretical basis and reference basis for scientific management and cultivation of bamboo forest protection in coastal sandy land, the wind-proof effectiveness of bamboo shelterbelt in coastal sandy land was comprehensively analyzed and evaluated by using AHP (Analytic hierarchy process) (AHP). The main results are as follows: 1. Thinness is an important index to measure stand structure. The windbreak efficiency of green bamboo protective forest under thinning and permeating structure was the best. The average windbreak efficiency behind the forest belt was 45.86, which was 10.914.84% and 4.26% higher than that of Phyllostachys officinalis, Typhostachys davidii, Cymbidium sinensis and Phyllostachys formosana, respectively, and was 12.73% and 4.26%, respectively. Under the ventilation structure, the average windbreak efficiency of the shelterbelt of bamboo, hemp and green bamboo was better than 26. Under the tight structure, the average windbreak efficiency of the protective forest with green bamboo and flower hanging silk bamboo was the best. The average windbreak efficiency of 5 kinds of shelterbelts in coastal sandy land was increased with the increase of stand density, respectively, and the mean windbreak efficiency of 5 types of bamboo forest with 2 years old was increased with stand density of 800 hm-2. The average windbreak efficiency behind the forest belt is 24.82, and the best is 29.1 for the golden bamboo protection forest, and 54.40 for the forest belt with the stand density of 1500 hm-2, and the best is 60.4 for the bamboo shelterbelt; the best for the bamboo shelterbelt is 60.4 in the forest. When the partial density was 2100 strains of hm-2, The best wind-proof effect of bamboo shelterbelt is 63.4%. Affected by stand thinning permeability, With the increase of stand density, the windbreak efficiency first increased and then decreased slowly. 3. The windbreak efficiency of 5 kinds of clumped bamboo forests in coastal sandy land increased first with the increase of wind speed, then slightly weakened the wind speed change of 5 species of bamboo forest after the forest belt. The trend of the curve is more consistent. The wind speed decreased gradually within the 1H-3H distance after the forest belt and reached the lowest at 3H, which was 52.8- 69.1 lower than that of the control. With the increase of the distance behind the forest belt, the wind-proof effect of the forest belt decreases gradually. Wind speed gradually increased. 5 species of cluster bamboo forest under the four control wind speed, the average windbreak efficiency was 54.29%, 48.39%, 44.27%, 33.54%, 30.79.4, the width of the forest belt and the distance between the bands from the air space, 44.29%, 48.39%, 44.27%, and the width of the forest belt and the distance between the bands from the air. The wind-proof effect of cluster bamboo forest was influenced by the arrangement of bamboo forest. The windbreak efficiency increased with the increase of forest belt width, and the lowest wind speed appeared at the 3H-4H distance behind the forest belt. The cumulative windbreak benefit decreased with the increase of the distance between the two zones, and decreased with the increase of height and wind speed at different distances behind the forest belt. The average wind-proof efficiency of the three vertical height of different thinning structures was 39.3% tight structure 39.0% ventilation structure 32.6.6. the bamboo and wood mixed forest had better wind protection efficiency than pure bamboo forest and Casuarina equisetifolia pure forest. When the ratio of mixed plants is 2:1, the wind-proof efficiency of forest belt is 53.70%, 48.21%, 42.86%, 41.18%, 38.46% and 38.46%, respectively, and the wind-proof efficiency of forest belt is 64.50%, when the ratio of intercropping is 5:3. 62.70%, 56.30%, 55.20%, 52.00%, 52.00%, 52.00%, 52.00%, 52.00%, 52.00%, 52.00%, 52.00%, 52.00%. When the block length is 10-15m, the wind-proof efficiency of the forest belt is 55.41%, 45.31%, 44.00%, 42.37%, 42.37%, respectively. The comprehensive wind control effect of bamboo and wood mixed model of 5 kinds of bamboo and wood mixed in Dongshan coastal sandy land is analyzed by using analytic hierarchy process (AHP) (AHP). The ability to build evaluation models, The comprehensive values of the five mixed ways were as follows: 41.14% interplant mixed with 36.82% interrow mixed and 19.25% banded mixed with 18.88% star-like mixed 12.3636.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S795

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