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农田防护林
    BENEFIT AND ITS APPRAISING METHOD OF FARMLAND PROTECTION FOREST SYSTEM
    农田防护林体系的效益及评价方法
    Selecting Optimum Tree Species of Farmland Protection Forest in Linxia Beiyuan by Analytical Hierarchy Process
    运用层次分析法优选临夏北塬农田防护林树种
    An objective and complete evaluation of the multiple benefits of farmland protection forest and analysis of the producing mechanism of these benefits are very useful for the construction and development of farmland protection forest.
    对防护林体系综合效益进行客观全面的评价,分析其产生效益的机理,将有助于促进区域农田防护林体系的建设和发展。
    In this thesis the multiple benefits of the farmland protection forest in Jingtai electric-irrigated area are evaluated by using the principles and methods of economy, ecology and silvics.
    本文运用经济学、生态学、造林学等原理和方法,对景电灌区农田防护林体系综合效益进行评价分析,结果如下:
    The main results are showed as following:1 According to the data investigated in stand sample plot, the prediction model of real stand growth of farmland protection forest in Jingtai electric-irrigated area was established. Then according to the prediction model of real stand growth, the growth process table and the mean money income table of all age classes were obtained and the cutting cycle was defined as 18 year.
    1.根据林分样地调查数据,建立景电灌区农田防护林现实林分生长量预估模型,计算得到林分生长过程表和各龄级平均货币收入表,研究得到该区农田防护林林分轮伐期为18年。
    The total value on the economic benefits of farmland protection forest in this area is 28065666.1 Yuan/a obtained by adding up the values on the three benefits.
    以上三项合计,得到景电灌区农田防护林林分年平均经济效益为28065666.1元。
    4 Regional ecological benefit of the farmland protection forest in Jingtai electric-irrigated area was studied, adopting the method of gray associate analysis. The gray associate degrees between forest cover percentage and climatic phenomenon factors of region climate including annual average air temperature, annual maxim air temperature, annual minimum air temperature, annual precipitation, annual average wind velocity and freeze-free season are 0.5781, 0.5691, 0.6095, 0.5671, 0.5739, 0.5647, 0.5680 respectively.
    4.采用灰色关联度分析方法,对景电灌区农田防护林体系的区域生态效益进行研究,结果表明:区域气候指标年均气温、年最高气温、年最低气温、年降水量、年均风速、无霜期等因素与区域森林覆被率的关联度分别为0.5781、0.5691、0.6095、0.5671、0.5739、0.5647、0.568。
    The results showed that the effects of construction of farmland protection forest in Jingtai electric-irrigated area to the region climate of this area are not significant under the current size of farmland protection forest system.
    这说明景电灌区在目前的防护林体系建设规模下,农田防护林体系建设对区域气候的影响并不显著。
    In accordance with various functions of Harbin forest types, the expert system presented expectation value of every index in different trees as follows. Salix matsudana, Ulmus pumila, Quermus mongolica, Populus alba×P. beroliensis and Betula platyphlla are frontal 5 tree species with weight value 90.37, 90.12, 88.12, 87.55 and 86.2 respectively, were used for farmland protection forest;
    根据哈尔滨地区不同林种的功能要求,给出了不同指标的期望值,通过查询系统可以得到旱柳、榆树、蒙古栎、银中杨、白桦为符合农田防护林的前五位的树种,权重值分别为90.37、90.12、88.12、87.55、86.2;
    5)Low-waterlogging farmland protection forest ecosystem in Huai Bei areas evergreen andleaf-fall broadleaf forest ecosystem on the south slope of Funiu Mountains ,and evergreenleaf-fall broadleaf forest ecosystem in Tong Bai and Da Rie mountain regions were relative-ly stable type.
    5)淮北低洼易涝农田防护林森林生态系统、伏牛山南坡常绿、落叶阔叶林森林生态系统和大别、桐柏山地常绿、落叶阔叶林森林生态系统属较稳定类型。
    The windbreak effect of tree species is the key of playing a synthetically protection role of farmland protection forest.
    防护效果评价因子,尤其是树种的防风效果,是农田防护林能否得到充分发挥综合防护效益的关键,对优选分析评价具有重要影响;
 

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