【作者】 胡淑萍；

【导师】 周心澄； 余新晓；

【作者基本信息】 北京林业大学 ， 工程绿化， 2008， 博士

【摘要】 水资源紧缺,水土流失严重,风沙危害频繁是北京市生态环境恶化的集中表现,是困扰首都生态建设的重要问题。北京山区作为北京市重要的生态屏障,在保持水土、涵养水源、防风固沙、美化环境等方面发挥着重要作用,但由于防护林体系空间布局与结构配置不尽合理,生态功能发挥不够充分,加之防护林建设规模与生态耗水、生态用水定量不协调,水土资源利用效率不合理等问题,严重阻碍北京山区防护林体系生态功能的发挥。为优化防护林体系配置,提高防护林体系生态功能的发挥,本研究结合“十一五”国家科技支撑“防护林体系空间配置和结构优化技术研究”,在小流域尺度上,从防护林体系结构布局、结构配置与水土资源利用关系着手,对北京山区典型流域防护林体系的对位配置、防护林体系与水土资源的关系进行深入研究,提出了典型流域防护林体系的对位配置模式。主要研究成果如下:(1)从北京山区森林资源现状着手,以乡镇或林场为研究单元,分析每个研究单元的森林资源特征,采用因子分析和系统聚类分析的方法将北京山区防护林体系划分为五个类型,针对每个类型的地形地貌特征、森林资源特点、区域发展目标等特点,提出每个防护林体系类型的适宜林种。(2)在综合考虑典型流域主导生态方向的基础上,收集土地利用状况和降雨、水质等资料,探讨了典型流域适宜森林覆盖率的计算方法,认为适宜森林覆盖率的确定应综合考虑最大限度拦蓄特大暴雨、减轻土壤侵蚀和净化水质3个方面。研究结果表明:土门西沟流域的适宜森林覆盖率为54.94%,潮关西沟流域的适宜森林覆盖率为55.36%,半城子水库流域的适宜森林覆盖率为58.61%。这一结果为小流域尺度防护林建设提够了一定价值的参考依据。(3)在研究典型流域森林植被特征的基础上,以“近自然林业”为理论基础,采用系统动力学模型人工神经网络对典型流域进行植被类型的配置,配置结果为:土门西沟流域针叶林13.40%,阔叶林30.24%,混交林34.99%,灌木林21.37%;潮关西沟流域针叶林3.66%,阔叶林19.36%,混交林52.45%,灌木林22.65%;半城子水库流域针叶林22.71%,阔叶林8.72%,混交林37.78%,灌木林29.24%。(4)选择北京山区的主栽优势树种——油松、侧柏、刺槐、栎类、荆条、绣线菊、北鹅耳枥,研究坡度、坡向、坡位、海拔、土壤类型、土壤质地等立地因子对其高生长和径生长的影响,为优势树种的立地选择和防护林体系建设提供参考。在分析主栽树种的林冠截留能力、枯枝落叶层的持水能力、土壤层贮水能力的基础上,采用坐标综合评定法对主要优势树种的水源涵养功能进行评定,结果表明混交林水源涵养功能最好。(5)论文基于地理信息系统(GIS)、遥感(RS)、景观分析软件FRAGSTATS进行综合分析,研究半城子水库流域1990-2005年森林植被格局的动态变化特征和驱动力,在此基础上构建SWAT模型空间数据库和属性数据库,根据典型流域DEM和水系分布图将整个流域分成23个子流域,结合1990-2006年水文实测资料进行模型参数的敏感度分析以及参数的校准和验证,研究表明:不同典型年的径流特征显示降雨和土地利用变化对径流产生了较大的影响。年内降雨较多的月份,产生的径流也较大,反之年内降雨量较少的月份,产生的径流量也较小。防护林体系对位配置的结果表明,各植被类型的产流量大小为阔叶林122.26mm,针叶林185.34mm,灌木林340.18mm,混交林255.33mm。与2005年相比,流域内植被的生态用水减少,径流量增加49.01万m3。为森林植被变化的水文响应研究提供了有效的途径。更多还原

【Abstract】 Less water resource, serious soil erosion and strong sandstorm are concentrated experience of worsens ecological environment of Beijing, and puzzled ecological construction of capital. Beijing mountain area is an important ecological barrier of Beijing city, which plays influential role on maintain soil and water, conserve water resource, protection sandstorm and improvement environment. But unreasonable spatial allocation and structure, weakened ecological function, incompatible protection forest systems’scale with ecological water use and quota of ecological water use serious hindered ecological function of protection forest system in Beijing mountain area. In order to optimize structure and enhance function of protection forest system, the research start with structure pattern, structure allocation and relation of water and soil, pare allocated protection forest system, analysis relation of water and soil resource with protection forest system, proposed para allocation patterns of protection forest system in typical watershed. The main research results are as follows:(1) Start from forest resource situation of Beijing mountain area, take the villages and towns or the farm as research unit, divided protection forest system of Beijing mountain area into five types by using factorial analysis and cluster analysis method, propose suitable forest type of each protection forest system.(2) Concerning of main ecological oriental of typical watershed, collected land use, rainfall, water quality data. Discussed computational method of suitable forest coverage in typical watershed, and thought retain maximum rainfall, reduce soil erosion and purify water should be concerned. The result shows: suitable forest coverage rate of Tumen West watershed is 54.94%, suitable forest coverage rate of Chaoguan West watershed is 55.36%, suitable forest coverage rate of Banchengzi reservoir watershed is 58.61%. The result offers reference on protection forest system construction in small watershed.(3) As a foundation of research on forest characteristics, take“near natural forestry” as rationale, used systems dynamics model artificial neural network to allocate forest type, the disposition results show: coniferous forest 13.40%, foliage forest 30.24%, mixed forest 34.99%, scrub forest 21.37% in Tumen west watershed; coniferous forest 3.66%, foliage forest 19.36%, mixed forest 52.45%, scrub forest 22.65% in Chaoguan west watershed; coniferous forest 22.71% hm2, foliage forest 8.72%, mixed forest 37.78%, scrub forest 29.24% in Banchengzi reservoir watershed.(4) Choose dominant species Pinus tabulaeformis, Platycladus orientalis, Robinia pseudoacacia, Quercus, Vitex negundo, Spiraea, Carpinus turczaninowii Hance as object in Beijing mountain area, research influence of slope, elevation, soil type, soil texture on their high growth and diameter growth, provided reference for site selection and protection forest system’s construction. Analyzed interception capacity of forest crown, litter and soil, and the conclusion indicated the strongest is mixed forest.(5) Used GIS, RS and FRAGSTATS to research landscape patterns and driving of Banchengzi reservoir watershed from 1990 to 2005, and construct spatial data and attribute data in SWAT. According to DEM, Banchengzi reservoir watershed is divided into 23 sub basins, and calibrated parameter with hydrology data from 1990 to 2006, the model shows: rainfall characteristic and land use characteristic strong influenced runoff. With plenty rainfall, the runoff is bigger; with less rainfall, runoff is small. Disposition result of protection forest system shows: runoff of foliage forest, coniferous forest, scrub forest and mixed forest are 122.26mm, 185.34mm, 340.18mm and 255.33mm. Ecological water use of forest is reduces, the amount of runoff increases 490,100m3. The results provided effective method to research the relation of landscape and hydrology response.更多还原