复合农林生境游猎型蜘蛛时空动态规律研究

指出了蜘蛛是农区重要的天敌类群,研究了华北农区农林复合环境下的游猎型蜘蛛多样性以及其优势种在"农田—林带"环境中的分布动态,结果表明:研究区优势种游猎型蜘蛛为星豹蛛(Pardosa astrigera L. Koch)和白纹舞蛛(Alopecosa albostriata Grube);游猎型蜘蛛密度在农林生境中具有明显的"林带效应":在冬小麦—圆柏农林系统中,距林带40 m范围内蜘蛛密度变化与距林带距离呈显著的负相关(P=0.026,α=0.05);在玉米—圆柏农林系统中,距林带10 m范围内蜘蛛密度处于高位状态,在距林带10～40m范围内蜘蛛密度显著下降(P=0.039,α=0.05),与距林带距离呈负相关;农事活动中喷洒农药对蜘蛛种群具有极大的负面影响,农田蜘蛛密度在喷药次日急剧下降(P=0.001,α=0.05),之后缓慢增加,蜘蛛种群发生了从林带生境到农田生境不断的迁移过程(林带与农田生境内蜘蛛密度变化t-检验:P_{Sig.(2-tailed})=0.817,α=0.05;二者蜘蛛密度变化率的Pearson相关系数:-0.998,P_{Sig.(2-tailed})=0.853,α=0.05);林带生境对于维系农田天敌群落的延续以及生态链的稳定所表现出的积极作用展示了林业在绿色农业构建中的特殊地位。     

西双版纳林区十五种游猎型蜘蛛听毛比较

听毛是蜘蛛感受空气震动的重要感觉器官,其数量和分布在不同类群中相对稳定,其形态特征可作为一些类群的分类指标。利用体视显微镜和扫描电镜对管巢蛛科、狼蛛科、猫蛛科、跳蛛科和拟平腹蛛科共5科15种游猎型蜘蛛的听毛、听毛窝进行了观察和拍照,对听毛的形态、分布和数量以及听毛窝的形态等特征进行了比较和分析。结果表明:5科蜘蛛听毛在体视显微镜下形态多为丝状,纤细柔软,基部与体表几乎垂直着生;电镜下听毛及听毛窝形态可见明显差异;5科蜘蛛腿节均无听毛分布;听毛数量在各科间及种间均存在差异,狼蛛科和跳蛛科种间差异较小,管巢蛛科胫节种间差异较大,猫蛛科跗节种间差异较大。     

林带对瓢虫种群分布的影响研究

以冀中北部的廊坊市固安县为试验点,对瓢虫的生物生态学及生存对策进行研究,目的在于量化出防护林对农田系统的生态作用辐射范围及阈值。通过对天敌瓢虫生物学信息进行系统的研究,以量化的形式揭示出林带—天敌—害虫关系中天敌节肢动物对农田害虫的作用范围,结果表明,春末夏初及作物生长成熟期,龟纹瓢虫对比其他瓢虫具有绝对优势;大多数环境的龟纹瓢虫都占优势;在作物耕种前和生长早期,瓢虫种群基本集中在林带;不同的作物生境间,瓢虫存在一定的选择趋向性,对间作田的趋向性较农田单一作物斑块更为明显。     

农林复合生态系统建立技术的研究

阐述了在沿海防护林体系建设工程中建立农林复合生态系统的作用和意义,提出了海岸带建立农林复合生态系统的配套技术。     

农林复合生态系统机理研究文献综述

一、农林复合生态系统概述关于农林复合生态系统(Agroforestry)的定义,1978年国际农林复合生态系统研究委员会的第一任主席King在一篇有关Agroforestry的文章中,把其定义为:"在同一土地单元内将农作物生产与林业和畜牧业生产结合起来,使土地总生产力得以提高的持续性土地经营体系"(杨修、贾渝彬等1995-1996)。1982     

农林复合生态系统机理研究文献综述

一、农林复合生态系统概述关于农林复合生态系统（Agroforestry）的定义,1978年国际农林复合生态系统研究委员会的第一任主席King在一篇有关Agroforestry的文章中,把其定义为：＂在同一土地单元内将农作物生产与林业和畜牧业生产结合起来,使土地总生产力得以提高的持续性土地经营体系＂（杨修、贾渝彬等1995-1996）。     

农林复合生态系统节肢动物群落多样性研究

通过对枣-麦间作系统、枣-草间作系统和小麦单作系统进行调查,发现3种系统的植物群落多样性指数的关系为枣-草间作系统（2．5265）〉枣-麦间作系统（1．6615）〉小麦单作系统（0．1890）;相应的节肢动物群落也有相似的趋势,枣-草间作（3．0322）〉枣-麦间作（1.7708）〉小麦单作（0．1890）。还将3种样地的节肢动物群落划分为不同的功能集团分析了其多样性,发现3种样地功能集团之间的差异并不显著。     

农林复合生态系统中林木对农作物的影响

通过对农林复合生态系统饶阳试区中农作物（小麦、玉米）的调查，结果表明：由于系统中林木材有的防护作用，就总体而言，农作物的平均叶面积指数、个体高度以及分蘖数等生长指标均大于对照，其平均籽粒产量，秸杆产量，收获产量以及千粒重等产量指标也高于对照。就其林木的胁地（付作用）来看，在一定范围内，距林木越远，胁地越轻，其林木胁地的距离、程度受其方位、季节以及作物本身的影响。     

农林复合生态系统中林木对农作物的影响

通过对农林复合生态系统饶阳试区中农作物(小麦、玉米)的调查，结果表明：由于系统中林木特有的防护作用，就总体而言，农作物的平均叶面积指数、个体高度以及分蘖数等生长指标均大于对照．其平均籽粒产量，秸杆产量，收获产量以及千粒重等产量指标也高于对照。就其林木的胁地(付作用)来看，在一定范围内，距林木越远，胁地越轻．其林木胁地的距离、程度受其方位、季节以及作物本身的影响。     

宁波天童森林公园蜘蛛资源及区系的研究

对宁波天童森林公园内的蜘蛛资源、区系及蜘蛛在对害虫的生物防治中所起的作用进行了调查，发现区域内有蜘蛛194种，隶属于99属30科，其中，古北界的种类有7种，古北界和东洋界的种类有75种，东洋界的种类有112种，该地区蜘蛛以东洋界种类为主，蜘蛛对林区害虫的为害起到了一定的控制作用。     

Predicting equations of main factors affecting regional climate in the "Three-North" Protective Forest Area

lntroductionInordertosolvetheseriousecologicaIproblemwefacedandimprovethephenomenonoflanddesertifi-cationinthenorthareaofChina.ChinahasbeguntoconstructtheThree-NorthProtectiveForestSystemsince1978.Withthehardworkoftwentyyears,itistold"Thegreatestecologicalprojectoftheworld"and"ThegreengreatwaIl".AIthoughthecountryinvestedIotsofcapitaItobuiIdtheThree-Northshelter-forestsystemthroughmanywayssuchasThree-Northspecialinvestment,financeappropriatefunds,finan-cialloansandtakeoutfundsforbringup…     

人工林防火林带网络密度的研究

根据森林经济效益，建立精确计算防火林带网络最大允许密度的数学模型，以例说明在人工林防火林带网络密度的可行性评判应用，为防火林 带网络建设提供依据。     

Cocoa-based agroforestry system dynamics and trends in the Akongo subregion of central Cameroon

Cocoa is a major crop and income source for most farmers and rural households in the Centre, South and South-West regions of Cameroon, where cocoa is generally produced in agroforestry systems. In this country, cocoa-based agroforestry systems (CBAFS) are undergoing multiple changes alongside the rapid changes underway in the natural, economic and socio-political conditions. This study—carried out in the Akongo subregion in central Cameroon—was designed to gain insight into the CBAFS trends and dynamics in the light of those multiple changes. This semi-structured socioeconomic survey involved interviews and direct observations at plot, farm, household and village scales. Overall, forty cocoa growers from ten villages were interviewed and then fifteen cocoa plots were characterized on the basis of the survey findings. They revealed that cocoa was the major crop in this study area, with cocoa plantations occupying three quarters of the total farming area. Three types of CBAFS were identified, which differed according to their vegetation structure, management practices and age of the plantations. Dynamics affecting the structural characteristics and the spatial extension of these systems emerged and were intimately linked to the dynamics of the cocoa farmer population in relation to their context.

     

广西雅长林场防火林带树种选择与密度确定方法

营建生物防火林带是预防森林火灾蔓延、减少经济损失的有效方法，科学地选择防火树种和合理确定林带密度则是营建生物防火林带的关键。以广西国有雅长林场为研究对象，提出了基于理想点评价方法的防火树种选择和地理信息系统支持下的防火林带密度确定方法，结果表明：借助于现代决策方法与地理信息系统技术，可使防火树种的选择和林火阻隔网合理密度确定更为科学、客观、合理。     

Factors affecting the dynamics of tree diversity in agroforestry parklands of cereal and cotton farming systems in Burkina Faso

Despite their socio-economic and ecological role, many studies have shown that the parklands are degrading very rapidly. Therefore, there is a need to undertake restoration actions for both production and environmental services. To do so, there is a need to identify factors that are affecting the dynamics of parkland systems. The present study aimed at characterizing and quantifying tree diversity of parkland systems taking into consideration the household’s wealth status, land uses, market access and the type of farming system (cereal based on the “Plateau Central” and cotton based in “Boucle du Mouhoun”). Six villages (Kienfangué, Ipelcé, and Kuizili with easy access to the market and, Karang-Tanghin, Nionsna and Targho with poor access to the market) in the “Plateau Central” and six villages (Bondoukuy, Ouahabou and Yaho with easy access to the market and, Dora, Fakéna and Mamou with poor access to the market) in “Boucle du Mouhoun” were studied. In each village, the Participatory Analysis of Poverty and Livelihood Dynamics method was used by rural farmers to rank farmer households of their communities and that gave three groups of wealth status that are poor, fairly well-off and well-off. Five households representing each of the three wealth groups in each village, giving a total of 15 households per village, were randomly selected by wealth group. Tree/shrub inventories were conducted in all land use types (house fields, village fields and bush fields) of the 180 selected households for the 12 studied sites. The number of species in the different land use types ranged from 96 to 102, but the majority of species were represented by less than 10 individuals. This indicates the selection effect made by the farmers to the parklands. Land use and farming system showed a clear effect on tree diversity in parklands. The effect of accessibility to market was evident in some cases whereas wealth status did not show any effect. Despite the statistical significant effect of farming system and land use type, the ANOVA models accounted for relatively little variation, indicating that other factors may contribute to tree diversity in parkland systems. The most threatened species were Adansonia digitata, Afzelia africana, Bombax costatum, Celtis integrifolia, Ficus asperifolia, Ficus iteophylla, Lannea velutina, and Parkia biglobosa. These species were represented in the largest diameter class (≥80 cm) or showed very few individuals in the different diameter classes. Due to the increasing degradation of the parklands, a domestication and conservation strategy of key threatened species needs to be developed and implemented with the participation of local communities.     

Identifying factors affecting plantation performance in boreal forests of Ontario

Plantation data from northern Ontario were subjected to stepwise regression analysis to express survival and total height as functions of site factors, planting stock characteristics and age for each of black spruce (Picea mariana [Mill.] B.S.P.), white spruce (P. glauca [Moench] Voss) and jack pine (Pinus banksiana Lamb.).Total height and height increment were affected more significantly, but by fewer factors, than survival. Black spruce survival was the most heterogeneous variable, as six factors accounted for 55.6% of its variability. Between one and five qualitative site factors (represented by dummy variables) accounted for less than 23% and 30%, respectively, of the variability in survival rate and total height. Stock type, planting season, weed control and chemical site preparation showed low but significant correlations with the response variables. Quality index was significant in every case, while shoot:root ratio, root collar diameter and dry weight were significant in some cases. The single most significant variable was plantation age, accounting for up to 30% and 63%, respectively, of the variability in survival rate and total height.     

不同森林类型物种多样性及影响因子研究

采用丰富度指数、多样性指数、均匀度指数对雾灵山不同森林类型灌木层和草本层的物种多样性进行了研究,并在此基础上用逐步回归方法研究影响森林物种多样性的主要因子。结果表明,在不同森林类型中灌木层和草本层物种多样性由高到低依次为:针阔混交林>落叶阔叶林>针叶林;多数森林类型草本层丰富度指数和多样性指数均高于灌木层,而均匀度指数则相反。影响灌木层物种多样性的主要因子包括林龄、郁闭度和坡向,影响草本层物种多样性的主要因子包括林分公顷株数、郁闭度和土层厚度。     

冰雪冻灾后松墨天牛成虫种群数量动态研究

应用"蛀干类害虫引诱剂"开展松墨天牛成虫种群数量变化的研究,发现雨雪冰冻后松墨天牛成虫种群数量呈暴发式增长,且雌雄性比稳定,种群可能继续增长.在研究分析成虫羽化规律的基础上,提出了相应的防控建议.     

Nitrogen and fine root length dynamics in a tropical agroforestry system with periodically pruned Erythrina poeppigiana

The effect of pruning all branches (complete pruning) or retaining one branch (partial pruning) on the dynamics of nitrogen cycling in aboveground biomass, nitrogen supplying power of an amended Eutric Cambisol, and fine root length, was studied in an Erythrina poeppigiana (Walp.) O.F. Cook—tomato (Lycopersicon esculentum Mill.) alley cropping practice in Turrialba, Costa Rica during 1999–2000. Over the 1 year pruning cycle, in which trees were completely or partially pruned four times, respective aboveground biomass production was 4.4 Mg or 7 Mg ha⁻¹ (2-year-old trees) and 5.5 Mg or 9 Mg ha⁻¹ (8-year-old trees); N cycled in aboveground biomass was 123 kg or 187 kg ha⁻¹ (2-year-old trees) and 160 kg or 256 kg N ha⁻¹ (8-year-old trees); mean fine root length was 489 or 821 m (2-year-old-trees), 184 or 364 m per tree (8-year-old-trees). Pruning intensity did not significantly affect net N mineralisation and net nitrification rates during the tomato-cropping season. For the tomato crop, pre-plant mean net N mineralisation rate of 2.5 mg N kg⁻¹ soil day⁻¹ was significantly lower than 16.7 or 11.6 mg N kg⁻¹ soil day⁻¹ at the end of vegetative development and flowering, respectively. Mean net nitrification rates of 3.5, and 4.3 mg N kg⁻¹ soil day⁻¹, at pre-plant and end of vegetative development, respectively, were significantly higher than 0.3 mg N kg⁻¹ soil day⁻¹ at end of flowering. In humid tropical low-input agroforestry practices that depend on organic inputs from trees for crop nutrition, retention of a branch on the pruned tree stump appears to be a good alternative to removal of all branches for reducing N losses through higher N cycling in aboveground biomass, and for conserving fine root length for higher N uptake, although it might enhance competition for associated crops.