陇东黄土高原典型站苹果生长对气候变化的响应

利用西峰、崆峒两地连续24a的苹果物候观测资料(1984-2007年)、产量资料(1986-2007年)和1961-2007年的气象观测资料,分析陇东黄土高原苹果生育进程等对气候变化的响应。结果显示,分析期内,随着气候变化,当地苹果的叶芽开放、开花等生育期提前,成熟期推迟,生长周期延长;生育期气象条件呈现出向暖干化发展的趋势,以花期变化最为明显;影响崆峒苹果产量的主要气象因子为4月份最低气温、1月上旬降水、6月上旬日照时数以及7-8月最低气温,在气候变化条件下,这些因子的变化各不相同,对苹果产量的影响有利有弊。未来在苹果生产中,应调整布局、加强田间管理以应对气候变化的影响。     

Spatial Hierarchical Modeling of Precipitation Extremes From a Regional Climate Model

The goal of this work is to characterize the extreme precipitation simulated by a regional climate model (RCM) over its spatial domain. For this purpose, we develop a Bayesian hierarchical model. Since extreme value analyses typically only use data considered to be extreme, the hierarchical approach is particularly useful as it sensibly pools the limited data from neighboring locations. We simultaneously model the data from both a control and future run of the RCM which allows for easy inference about projected change. Additionally, this hierarchical model is the first to spatially model the shape parameter which characterizes the nature of the distribution’s tail. Our hierarchical model shows that for the winter season, the RCM indicates a general increase in 100-year precipitation return levels for most of the study region. For the summer season, the RCM surprisingly indicates a significant decrease in the 100-year precipitation return level.     

Joint Modeling of Spatial Variability and Within-Row Interplot Competition to Increase the Efficiency of Plant Improvement

Trials in the early stages of selection are often subject to variation arising from spatial variability and interplot competition, which can seriously bias the assessment of varietal performance and reduce genetic progress. An approach to jointly model both sources of bias is presented. It models genotypic and residual competition and also global and extraneous spatial variation. Variety effects were considered random and residual maximum likelihood was used for parameter estimation. Competition at the residual level was examined using two special simultaneous autoregressive models. An equal-roots second-order autoregressive (EAR(2)) model is proposed for trials where competition is dominant. An equal-roots third-order autoregressive (EAR(3)) model allows for competition and spatial variability. These models are applied to two yield data sets from an Australian sugarcane selection program. One data set is in the paper and the other is in supplementary material available online. To determine the effect of simultaneously adjusting for spatial variability and interplot competition on selection, the percentages of superior varieties in common in the top 15% for the joint model and classical approaches were compared. Agreement between the two approaches was 45 and 84%. Hence, for some trials there are large differences in varieties advanced to the next stage of selection.     

利用作物模型研究气候变化对农业影响的发展过程

模型模拟是研究气候变化对农业生产影响的有效途径,得到了广泛关注和应用。本文着重介绍了利用作物模型研究气候变化对农业生产影响的发展过程,即从最初通过人为改变气候参数模拟气候变化对农业的可能影响,到与气候情景结合模拟未来气候变化对农业的可能影响及近年来与其它模型结合综合模拟未来气候变化对农业的影响,并通过对气候变化农业影响模型模拟研究中经验模型与机理模型、站点尺度与区域尺度、确定性气候情景与概率气候情景几个关键问题的评述,指出了存在的问题及未来发展趋势。     

生态经济型乔木树种集约栽培技术

在干旱少雨、水土流失严重的晋西黄土丘陵沟壑区，如何解决乔木树种生长中水分不足的问题，是实现乔木树种生态经济效果的关键。集约栽培技术正是针对这一现实，经过多年调查、试验后，提出的全方位、多措施克服水源不足，减少水分流散。充分利用自然降水的实用技术，主要包括秋季截干造林技术、药物浸蘸根技术、林地深松爆破技术、抑制土壤表面蒸发技术和林分复壮技术。     

中国冰川系统变化趋势预测研究

基于中国冰川编目资料，应用冰川系统、零平衡线、冰川径流变化与冰川面积之间的关系以及冰川对环境变化的适应功能等理论，按几种不同升温率的气候情景，对全国各大流域冰川径流、面积、储量及平衡线高度等变化趋势进行预测。结果表明：平均来讲，21世纪前50年如果中国西部山区，以增温率为每年0．02K及0．03K计算，到2030年，全国冰川径流将达到最高潮，2030年后全国冰川径流将普遍回落，但至2050年仍将高于20世纪末的水平。如上述升温趋势一直维持下去，本世纪中国冰川的面积和储量将持续减少，到2030年，将减少6%～9％；到2050年减少10%～15％；到本世纪末，全国冰川径流将回落到1980年的水平以下，全国冰川面积将减少23．2％～34％。     

Modeling Regional Carbon Dynamics and Soil Erosion in Disturbed and Rehabilitated Ecosystems as Affected by Land Use and Climate

The quantification of carbon (C) and nitrogen (N) cycling inecosystems is important for (a) understanding changes inecosystem structure and function with changes in land use, (b)determining the sustainability of ecosystems, and (c) balancingthe global C budget as it relates to global climate change.A meso-scale study was conducted to determine regional effectsof climate change on C and N cycling within disturbedecosystems. Objectives of the research were to quantify (a)sediment yield, (b) current C storage in vegetation and soils,and (c) soil C efflux from both abandoned and rehabilitatedcoal surface-mined lands in Ohio. A dynamic model was developedto simulate sediment yield, grassland production, and C and Ncycling on surface-mined lands. Evaluation of plant productionand soil erosion submodels with data sets from surface-minedlands in the mid-western U.S. resulted in r² values of 0.99 and0.97, respectively. Depending on the initial values of soil organic carbon (SOC),model simulations estimated that unvegetated surface-mined landsin Ohio yield approximately 441,325 Mg yr^-1 of sediment andemit between 2,000–20,000 Mg yr^-1 of C to the atmosphere fromdecomposition of SOC. While rehabilitated lands had a higher Cefflux rate than barren lands, a positive C sequestration rateof 18.4 Mg km^-2 yr ^-1 was estimated as a result oforganic matter additions. This sequestion rate increasedconsiderably under projected climate change scenarios, while itdecreased when simulated rehabilitated grasslands were harvestedfor hay. Changes in land use and cover can cause surface-minedlands to be either a net sink or source for C. Successful rehabilitation of mined lands can decrease erosion and promotesoil C sequestration, while at the same time providingadditional lands for the management of natural resources.     

Modeling Soil Organic Carbon Dynamics in Response to Climate Change in Mount Everest Region of Nepal

Eurasian Soil Science - This study provides an estimate of soil organic carbon (SOC) stock, projects future SOC stocks under different climate change scenarios, and considers impacts on topsoil SOC...     

中国果树气象灾害及其综合防御体系

在分析我国果树分布、灾害类型和特点的基础上，提出了一个综合防御气象灾害的体系，该上８个子体系组成，如能全面实施，可使果树受害减少到最低程度。     

浅谈园林树木养护管理

有关园林植物历来是重栽轻管,加强养护管理,是提高绿化质量与效果的重要措施。文章介绍了常规养护、特别养护、病虫害防治等方面的一些有效方法。     

罗定江流域水土保持林存在的问题与改造建议

经过十几年的整治 ,罗定江流域的水土流失得到了较好的控制 ,但还存在“上绿下赤”的现象 ,主要原因是现有水土保持林树种结构单一 ,大多数是以马尾松为主的针叶林 ,并且不注意人为促进水土流失区的生态修复。因此 ,必须对现有水土保持林进行改造 ,并采取封山育林、封山禁牧等方法促进水土流失区的生态修复     

南方水土保持林引种选择

水土保持林能有效的控制水土流失,在福建漳州通过林木引种选择适合该地区立地条件的树种,在此又介绍了8种引种比较成功的树种,利用它们的特性,探讨治理水土流失、生态重建的途径。     

南方水土保持林引种选择

水土保持林能有效的控制水土流失,在福建漳州通过林木引种选择适合该地区立地条件的树种,在此介绍了8种引种比较成功的树种,利用它们的特性,探讨治理水土流失、生态重建的途径。     

Ozone - a Risk Factor for Trees and Forests in Europe?

Tropospheric ozone (O₃) may adversely affect tree growth, with critical levels for O₃ being exceeded in many parts of Europe. However, unequivocal evidence for O₃-induced foliar injury on woody species under field conditions has only been found in a few places. Visible O₃ injury appears to occur mainly in the Mediterranean Basin, which is also the area where the least amount of information is available on O₃ exposure as well as the sensitivity of individual species. Overall, the quantitative risk assessment of O₃ impacts on mature trees and forests is vague at the European scale, as most knowledge is derived from controlled O₃ fumigations of young trees, grown in isolation in exposure chambers. Research suggests that risks exist, but these need to be validated for stand conditions. O₃-induced changes in resource allocation rather than productivity appear to be crucial as they affect competitiveness and predisposition to parasite attack and may eventually lead to the loss of genetic diversity. ‘Free-air’ O₃ fumigations in forest canopies may reveal processes that are susceptible to O₃ stress under field conditions and provide a scientific basis towards quantitative risk assessment and realistic definitions of critical levels for O₃ in forest ecosystems.     

四种城市绿化乔木树种污染物去除效果研究

污染水体土壤生物修复工程技术具有成本低、环境友好以及维护方便等优点,在世界各地人工湿地处理、河岸生态修复以及土地处理系统方面得到了十分广泛的应用,但以往的研究主要针对的是草本植物,对适合我国北方城市林业建设的乔木树种很少研究。因此,在分析已有成果的基础上,筛选了杨树、枫杨、水杉、柳树4种适宜北方城市森林建设的常见树种,于2008年7月到9月进行了室外盆栽污水灌溉试验。结果表明,4种乔木对污染物都表现出较好的去除能力。总体来看,对TN的去除能力,枫杨>杨树>水杉>柳树;对TP的去除能力,杨树>枫杨>水杉>柳树;对COD的去除能力,柳树>枫杨>水杉>杨树。     

普洱市古树调查与保护研究

为摸清和更好地保护云南省普洱市的古树,对普洱市内及周边地区的古树进行了实地调查,结果表明,普洱市现存古树138株,隶属于14科17属20种。其中包括侧柏（Platycladus orientalis）81株、红椿（Toona ciliata）11株、黄葛树（Ficusvirensvar．Sublanceolata）8株、高山榕（Ficus altissima）7株,糖胶树（Alstonia scholaris）4株等;有二级古树2株,三级古树110株,古树后备资源26株;全市古树的平均年龄为118年,树龄最大的为300年。在此基础上对古树生长状况、树龄与保护级别以及分布情况进行了分析,提出了保护管理措施与建议。     

几种果树开花结实动态的研究

作者在平邑县资邱乡东岭开发区对凯特杏、五月火油桃及苍方早生的开花结实作了动态调查研究，开花结实率受树种的生物学特性、异常气候、枝所处的位置等影响。确定了各树种开花结实的关键物候阶段和各阶段的转移比率。开发初期的优先顺序大多是下层、中层、上层；结实主要集中在上、中层，结实率分别为：4.3%、、7.7%、%5.5%。相应对各树种的竞争指数与开花结实的关系进行了探讨。这些规律为疏花疏果实践提供了基础性依据。     

浅析地埂林草建设技术

地埂林草建设是宁夏山区"三田"和生态建设的一项重要内容,根据小流域综合治理实践,就林草建设方法、配置模式、林草品种等进行了对比分析。试验结果表明,宜选择柠条、柽柳、杞柳作为地埂造林的主要树种,新疆杨作为地埂底部造林的主要树种;在光、热、水条件较好的地方,地埂造林可以考虑种植花椒等经济林木;牧草中紫花苜蓿的耗水量较低,可作为梯田地埂种草的主要草种。     

中国现代气候变化的规律及未来情景预测

20世纪50年代以来，由于受太阳周期活动、地球和天体运动、地壳运动、温室气体的温室效应、气溶胶的冷却效应、大气环流变化、海温变化、冬夏季风减弱和破坏森林等对气候变化的综合影响，我国年平均气温已升高0．68℃，北方最低气温升高0．24℃；全国年降水量减少了23．2mm，北方减幅大于南方。经模拟预测，从1987年开始的气候变暖将持续到2015年，2016年将转入低温期，2039年又将转入高温期；到2020年全国气温将升高1．68℃，西北地区升高2．2℃，南方年降水量增加28mm，北方没有变化；2030年海平面升高5．3～14．2cm，气候将更加干旱。