基于不确定性的旱作作物种植结构优化

针对灌区规划问题,将模糊概念引入多目标线性优化模型。以甘肃民勤县为例,针对小麦、玉米、棉花、黑红瓜子、食葵、西甜瓜、白瓜子、辣椒几种作物,采用模糊多目标线性优化模型,从经济效益以及需水量两个角度对作物种植结构进行优化。结果显示,在语气算子不同的情况下优化结果也不同,如果要增加该地区的经济收益,就要将粮食作物的比重减少,而增加经济作物的种植比重。若要使需水量减少,则要增加棉花等需水量较小的作物的种植比重。并由此看出模糊优化方法在处理相关问题时的优越性。     

荒漠草原灌区多目标管理问题的目标规划模型研究

本文用目标规划模型研究了科学利用水资源、保证生态良性发展;用优化的地下水开采量确定可灌面积,制定经济用水灌溉制度,确定优化饲草料种植模式;充分利用当地生产资料、稳步发展经济、获得期望的社会效益及经济效益等多目标管理问题。 为确定现实目标的右端项,本文又采用了确定灌溉制度的随机离散动态规划模型和确定地下水优化开采量的响应函数矩阵嵌入耦合的地下水管理模型。     

塔南绿洲优化防护模式风洞实验研究初探

利用大气边界层风洞对不同结构防护林的防风效应进行了初步研究，并依据风洞模拟结果提出了一个优化目标参数，给出了林网优化防护模式的相对最优模型。     

灌区广义水资源不确定性多目标优化配置

针对农业水资源配置系统的复杂性和不确定性,构建模糊可信性随机多目标农业水资源优化配置模型,以农业灌溉净经济效益最大和绿水利用占比最大为目标,对丰水年、平水年和枯水年下不同分区各生育阶段的水稻灌溉水量进行优化配置。将模型应用于湖北省漳河灌区,目标权重组合分别为（0.5, 0.5）、（0.75, 0.25）和（0.25, 0.75）,可信性水平取0.5、0.6、0.7、0.8、0.9和1.0,得到不同情景下农业水资源配置方案。结果表明：多目标规划模型能够很好统筹社会经济发展目标与资源节约目标,优化方案的绿水利用占比在0.835以上,经济效益最高达14.153亿元;更高的可信性水平对应更低的系统效益与更高的绿水利用占比,丰富的优化方案能够帮助决策者权衡系统收益与违规风险;当水资源短缺时,应该优先保证抽穗期和孕穗期的作物需水,使因缺水造成的水稻减产损失最小化。总的来说,优化模型所得到的水资源配置方案能够为漳河灌区水资源管理者提供理论指导,同时为类似地区的农业水资源优化配置提供参考。     

基于需求导向的城市水资源优化配置模型

对城市水资源利用的相关驱动因素进行剖析,分析水资源需求量与其相关驱动因素之间的逻辑互动关系。一方面,根据城市水资源利用的演变发展趋势,将生长曲线模型与自回归聚合滑动平均模型相结合,初步预测城市未来水资源需求量;另一方面,结合城市社会经济发展规划,修正未来水资源需求量的初步预测结果,综合预测城市水资源需求量;在此基础上,综合考虑城市水资源利用的经济效益、社会效益与生态环境效益,根据城市水资源需求与供水情况,建立非线性多目标优化模型,实现城市水资源优化配置。并结合案例分析,进一步验证城市水资源需求预测及其优化配置模型的有效性。     

基于VB的旱作作物种植结构决策支持系统开发

以Jensen水分生产函数为基础,运用多目标规划的方法,建立了旱作条件下小麦、玉米、大豆、马铃薯、高粱等作物种植结构优化系统,并编制了可视化应用程序。输入多年降雨资料、日照时数、每日最高最低温度、每日风速等基本气象资料以及相关的土壤、作物参数,就可优化出研究地区主要作物种植比例和结构,操作简单,具有实用性。以山西晋中地区为例进行应用,系统根据多年的降雨资料预测出不同水文年型下每种作物的单产,在此基础上对种植结构进行了优化,并与实际结果比较证明其可靠性,从而对作物种植结构进行优化和指导,使粮食产量、经济效益、水分利用达到协调统一。     

环境信用评级结果对企业经济效益的影响及作用机制——基于内蒙古自治区298份企业的调查数据

环境信用评级结果能否提升企业经济效益、其影响经济效益的作用路径是什么，对这些问题的研究有助于企业认可、参与和践行环境信用评级及公开制度。基于内蒙古自治区4个城市298份企业问卷调查数据，采用多元有序Logistic模型和中介效应模型实证分析了环境信用评级结果改进对企业经济效益的影响及作用机理。结果显示：1)环境信用评级结果改善对企业经济效益现状及其变化情况均具有显著正向影响，同时经济效益提升受到企业自身及管理者特征的综合影响。2)环境信用评级结果改善有助于企业获取政府政策支持、增加外部投资、促进市场销售增长、提高社会声誉、推进技术创新及优化管理体制，进而实现经济效益的持续增长。3)市场销售增长及投资者投资激励变量的中介效应最大，而企业管理优化变量的中介效应最小，表明企业外部因素的中介效应较大，而内部因素的中介效应偏小。研究结论有助于理解环境信用评级结果与企业经济效益之间的内在关联，可为完善企业环境信用评级及公开制度、实现经济效益与环境效益的协调发展提供政策启示。     

闽西稻瘿蚊标葱田间优化管理决策的研究

本文运用优化埋论和多目标决策方法，通过对闽西地区稻瘿蚊标葱田间药剂防治实例的决策分析，提出防治成本低、天敌存活多、防治效果高和保产效果好的综合决策矩阵，为控制稻瘿蚊标葱田间优化管理提供了科学依据。２ａ经１万多ｈｍ^２应用，取得了较好的社会效益和经济效益，共挽回粮食损失１６４５０ｔ。     

渠道衬砌部位的优化

在当前灌区更新改造时，经常由于资金不足，只能分期安排渠道衬砌，为了解先衬些渠道后衬哪些渠道这一课题，我们从衬砌后水量损失最小这一目标出发，建立了优化模型，又从计算中分析总结出一个简单方便的寻优办法。同时，通过一个灌区的具体计算，证明该“优化”具有较好的经济效益和社会效益。     

宝鸡峡灌区多水库优化调度研究

针对宝鸡峡灌区缺水现状,从充分利用水资源的角度出发,对宝鸡峡林家村枢纽工程和4个灌区水库、魏家堡渠首进行优化调度研究,通过优化配水,充分发挥蓄水工程的调蓄功能,使水资源的利用量最大。基于大系统分解协调技术中的目标规划法,用模拟技术生成子系统非劣解集,提出目标规划模拟方法,建立以供水量最大为目标的多水库供水系统目标规划模型,进行了灌区多水库优化调度计算,对结果进行了分析。     

大兴安岭林区多年冻土退化的驱动力分析

大兴安岭是中国东北最大的原始林区 ,也是中国唯一的寒温带针叶林区。长期以来 ,人们忽略了引起大兴安岭森林环境恶化的多年冻土退化问题。本文从气候变暖和人类活动两方面分析引起大兴安岭多年冻土退化的驱动力因素 ,揭示大兴安岭多年冻土退化的主要原因。     

白音锡勒草原沙地云杉林的性质、可能成因及自然更新能力的初步研究

本文对内蒙古白音锡勒草原沙地白杆 (Picea meyeri)种群的大树和幼树及伴生植物进行了初步研究 ,认为沙地白杆林是在近极限生境条件下 ,由适应性不同的植物种依生境异质性组合而成的疏林群落。是第三纪云杉属植物广布分布区的残存片段 ,也是白杆现代分布区的北界。白杆种群现有大树 3 3 0株 ,幼树 1 62 9株。大树的死亡率随胸围增大而增高 ;幼树则每增加一个龄级死亡 48.7%。该种群具有自然更新的能力。由于生境相对严酷 ,种群较小 ,局部灭绝的危险尚不能排除。     

Seeds in a rainforest soil and their relation to shifting cultivation in the Ivory Coast

In the Taï region of the Ivory Coast, mature forest is felled and burned and a crop of rice is grown; forest is then allowed to regenerate for 20 or more years before being cropped again. The top 10 cm of soil beneath a 21-year-old forest prior to felling contained 2000 viable seeds m^?2 of mainly woody species of previous successional stages no longer represented in the vegetation. Seedling emergence was greater in full sunlight than under leaf canopy, especially for herbaceous species of open habitats. Burning destroyed almost half of the seeds, but overall germination of those that survived was advanced by about 2 weeks. Germination of some common pioneer species was enhanced by the fire. Provided that burning took place and the rice was planted immediately, vegetation arising from the seed bank did not present a problem. The density never exceeded 70 seedlings m^?2 and little or no weeding was required. Species present at densities greater than 1 seedling 10 m^?2 were all recorded in the seed bank.     

小陇山国家级自然保护区油松群落生态位研究

文中采用样方调查法,对研究区内油松群落中主要种群的Shannon-Weinner多样性指标及Lev-ins生态位宽度、生态位重叠值和生态位相似比例等进行了分析。结果表明:1)油松群落中油松的生态位宽度最大为0.9827,槲树的生态位宽度最小为0.1582;2)优势种油松与其他物种的生态位重叠值在0.06～0.1之间,反之在0.01～0.05之间,说明油松群落的生态位重叠值不大,群落中因利用相同的资源位而产生的种间竞争并不激烈,是一个稳定的森林群落;3)生态位相似比例大于0.5的有9对,占20%,其物种间生态位相似比例值一般较低,反映其主要物种利用资源的相似程度较小。但是生态位宽度较大的物种之间的生态位相似性比例仍较高,如油松与甘肃山楂、锐齿栎的生态位相似性比例分别为0.5209、0.5320。     

Influences of Post-fires on Subsequent Population of Japanese Pine Sawyer Beetles,Monochamus alternatus Hope (Coleoptera: Cerambycidae) in Masson Pine Forests

[Objective] Both fire and insect outbreaks are considered as important natural disturbance factors in manyforest ecosystems, yet few studies have addressed the effects of fires on subsequent insect outbreaks. [Method] In this paper, tree mortality, larval density and vertical distribution were measured through field investigation and sampling method to evaluate the short-term response of Japanese pine sawyer beetle, Monochamus alternatus Hope to Masson pine, Pinus massoniana Lamb. in the second year after the fire in Jiangxi Province, China. [Results] compared with unburned Masson pine forest, burned Masson pine forest suffered from higher tree mortality and more pine trees were attacked by M. alternatus. Burned Masson pine tended to harbor much higher larval density further up along the trunk than unburned pine trees, and most individuals distributed in the middle section and middle-lower section of the trunk. [Significance] The results confirmed that Masson pine forest after being damaged by non-lethal fires were more susceptible to attacks by Japanese pine sawyer beetles, displaying higher population density and higher vertical distribution position. The study will provide an important guideline for the managers of Masson pine forests suffering from fires and pest invaded areas.     

球孢白僵菌自然流行病与马尾松毛虫种群的相互关系

2006年4月下旬发现皖东明光县紫阳林场马尾松毛虫种群中暴发球孢白僵菌自然流行病。根据踏查确定了流行中心区,其僵虫密度远高于周围未流行区域;但中心区僵虫密度不同,最低不到1头／m^2,最高达39头／m^2,形成许多小型流行中心。据此断定,高密度的越冬马尾松毛虫种群呈聚集分布,有利于发病和流行中心的形成。根据僵虫虫龄结构,4～5龄幼虫占僵虫总数93．4％,3龄居中,6龄最少;根据僵虫分布部位,69．8％幼虫死于林冠下,30．2％死于树皮裂缝。由此推断,流行病始于越冬期,而流行高峰始于4月中旬之前。流行区松毛虫的体长和对照区无显著差异,但雌雄比远高于对照区,而产卵量则显著低于对照区。     

几种无公害技术对褐梗天牛的防治效果

褐梗天牛Arhopalus rusticus（L.）是松柏类等林木的重要害虫,近年来在山东泰安、威海等地发生严重。本文利用引诱剂诱杀、饵木诱杀和释放管氏肿腿蜂Sclerodermus guani Xiao et Wu与花绒寄甲Dastarcus helophoroides Fairmaire等无公害技术对褐梗天牛进行了室内外防治研究。Ⅱ号引诱剂诱捕效果最好,30 d平均诱捕量为69头。饵木诱杀每个样木平均诱捕量为63头。管氏肿腿蜂防治褐梗天牛幼虫的室内效果最高达71.00%,不同蜂虫比之间的防治效果差异不显著;林间释放管氏肿腿蜂对直径为10～15 cm被害木中的天牛幼虫的寄生率最高,为8.43%。利用花绒寄甲防治效果较好,室内当花绒寄甲成虫和天牛幼虫量为5:1时的寄生率最高,为80.02%;林间每株树释放20头花绒寄甲成虫的寄生率最高,达58.80%。结果表明,这几种防治技术都对褐梗天牛有良好的防治效果,可在防治中综合应用。     

The relationship between soil,climate and forest development in the mid-mountain zone of the Sangong River watershed in the northern Tianshan Mountains,China

The mountainous forests in arid regions, being sensitive to climate change, are one of the key research topics related to the mechanism of interaction between climate and the terrestrial ecosystem. In this study, the spatial distribution of a mid-mountain forest and its environmental factors were investigated by using a combination of remote sensing technology, field survey, climate indices and soil nutrient analysis in the Sangong River watershed of the northern Tianshan Mountains. The forest(Picea schrenkiana) was distributed between 1,510 and 2,720 m asl. Tree height and diameter at breast height(DBH) exhibited a bi-modal pattern with increasing elevation, and rested at 2,450 and 2,250 m asl, respectively. The two maxima of DBH appeared at 2,000 and 2,550 m asl, and the taller trees were observed at 2,100 and 2,600 m asl. For the annual mean temperature, the difference was approximately 5.8°C between the lowest and the highest limits of the forest, and the average decreasing rates per hundred meters were 0.49°C and 0.55°C with increasing altitude between 1,500 and 2,000 m asl and above 2,000 m asl, respectively. The annual precipitation in the forest zone first increased and then decreased with the increase of altitude, and the maximum value was at 2,000 m asl. For per hundred meters, the annual precipitation increased with the rate of 31 mm between 1,500 and 2,000 m asl and decreased by 7.8 mm above 2,000 m asl. The SOM, TN and TP were high between 2,000 and 2,700 m asl and low at the lower and upper forest limits. The minimum Ca CO3 concentration, p H value and EC coincided with the maximum precipitation belt at 2,000 m asl. The SOM, TN and TP were high in the topsoil(0–10 cm) and differed significantly from the values observed in the deep soil layers(10 cm). The soil nutrients exhibited spatial heterogeneity and higher aggregation in the topsoil. In conclusion, soil and climate are closely related to each other, working synergistically to determine the development and spatial distribution of the mid-mountain forest in the study area. The order of the importance of environmental factors to forest development in this study is as follows: soil nutrientsprecipitationelevationtemperature.     

Oasis cold island effect and its influence on air temperature: a case study of Tarim Basin,Northwest China

Oasis effect can improve the regional climate and habitability of an arid region. In this study, we explored the cold island effects of oases distributed along the edge of Tarim Basin by analyzing the oasis cold island effect(OCIE) intensity, spatial-temporal variation of OCIE, factors influencing the OCIE and impacts of OCIE on air temperature using geographical statistics and GIS methods based on the MODIS land surface temperature, land use/cover change(LUCC) and observed air temperature data. Results showed that all the oases in the Tarim Basin exhibited cold island effects, with the OCIE intensity highest in summer(-9.08°C), followed by autumn(-4.24°C) and spring(-3.85°C). The total area of oasis cold island(OCI) and the comprehensive OCIE index showed the same seasonal change trend as the OCIE intensity. However, the changing trends in areas of OCI with strong, medium and weak OCIEs were inconsistent across different seasons. Farmland and water areas were found to be the key contributors that affected the OCIE, and the area and aggregation metrics of these two land use/cover types directly contributed to the OCIE. By contrast, natural vegetation, such as forest and grassland, almost had no contribution to the OCIE. Simulation of observed air temperature data showed that if farmland is replaced by forest or grassland in the oasis, the mean, maximum and minimum air temperatures will increase significantly. This heating effect will be higher in summer(reaching 1.14°C to 2.08°C) and lower in spring and autumn. Moreover, the heating effect of farmland being replaced by forest will be higher than that of farmland being replaced by grassland. These results can provide a basis for understanding the cold island effect of oases in arid regions.     

Modelling the escape of Chondrostereum purpureum spores from a larch forest with biological control of Prunus serotina

Chondrostereum purpureum is being developed as a microbial herbicide to controlPrunus serotina in coniferous forests. After biological control, the fungus produces basidiospores that may reach and infect non-target plants. As part of a risk analysis, spore escape from a forest was quantified. For this purpose, a stratified model was developed for a forest of 250 m with 250 m. A turbulent diffusion equation was used to describe spore fluxes for each layer.In a simple calculation procedure, the spore fluxes for the different layers were calculated simultaneously. The downwind escape fraction was found to vary from 0.19 to 0.45, and the upward escapte fraction from 0.07 to 0.23. These escape fractions increased with increasing wind speed.Number of spores released from basidiocarps, and escape fractions could be used as inputs for a Gaussian plume model to calculate spore immission into orchards.