铜胁迫对抗虫转基因水稻根际土壤微生物的影响

根际土壤微生物群落是联系土壤环境与作物生长的重要纽带,也是转基因作物环境安全评价的主要指标,而Cu胁迫对转基因水稻根际土壤微生物的影响目前尚不清楚。本研究基于盆栽试验,采用高通量测序等技术研究Cu胁迫(Cu含量100 mg/kg)对抗虫转基因水稻华恢1号(HH)及其亲本非转基因水稻明恢63(MH)农艺性状及成熟期根际土壤微生物的影响,并以不施加Cu胁迫处理为对照。结果显示:Cu胁迫显著降低了水稻株高、生物量及产量;Cu胁迫改变了水稻根际土壤总氮、铵态氮含量及氧化还原电位值,而种植转基因水稻仅降低了根际土壤氧化还原电位值;Cu胁迫没有影响水稻根际土壤细菌丰度,但降低了细菌群落Alpha-多样性,改变了水稻根际土壤细菌群落组成和群落结构;相同Cu含量胁迫下,HH和MH水稻生长指标及根际土壤细菌群落结构及组成差异较小。上述研究表明,Cu胁迫抑制了水稻农艺性状及根际土壤细菌群落,但种植抗虫转基因水稻没有影响水稻植株及根际土壤细菌群落对Cu胁迫的抗性。     

转基因作物对土壤生物学特性的影响

随着转基因作物的大力推广,其对农田生态系统的潜在风险备受关注。本文综述了转基因作物在土壤生态系统释放可能引起的生态风险及其对土壤部分生物学特性的影响,涉及土壤生物多样性、土壤动物、土壤微生物及土壤酶活性。最后,提出了今后相关研究中应该注意的几个问题。     

转Chi＋Glu双价基因棉对土壤微生物群落功能多样性的影响

为研究转Chi＋Glu双价基因棉对土壤微生物群落功能多样性的影响,揭示其对土壤生态系统的安全性,在大田试验条件下,利用Biolog代谢指纹方法分析了种植转Chi＋Glu双价基因棉、转Bt基因棉和常规棉不同生育期土壤微生物群落功能多样性。结果表明,两个转基因棉花土壤微生物数量差异不显著,而转基因棉花土壤细菌和放线菌数量在花期和铃期显著高于常规棉花（P〈0.05）,真菌数量在花期和铃期却显著低于常规棉花（P〈0.05）。与非转基因棉花相比,转基因棉花土壤微生物群落碳源利用能力在花期和铃期显著增加,转基因棉花土壤微生物群落的Shannon指数和McIntosh指数在花期、铃期和吐絮期显著高于常规棉花,Simpson指数在花期和铃期则显著低于常规棉花。主成分分析结果显示,花期转基因棉花和常规棉花对31种碳源的利用差异较大。转基因棉花在苗期和蕾期对羧酸类、氨基酸类和多胺类,花期和铃期对糖类、羧酸类和双亲化合物类的利用分别较常规棉高;吐絮期转基因和常规棉花对所有碳源的利用均较低,其中转基因棉花对糖类和羧酸类的利用高于常规棉花。研究结果显示,种植转Chi＋Glu双价基因棉花在花期和铃期对土壤微生物群落影响显著,其与转Bt基因棉花无明显差异。     

影响土壤微生物活性与群落结构因素研究进展

土壤微生物在陆地生态系统中具有重要作用,是整个陆地生态系统物质循环、能量流动的推动者,与陆地生态系统地稳定性密切相关。本文就影响土壤微生物活性与群落结构因素研究进展作了综述,主要内容有:土壤理化性状对土壤微生物群落结构的影响;土壤微生物之间的相互作用,土壤动物多样性,植物多样性对土壤微生物群落结构的影响;不同的经营管理措施对土壤微生物群落结构的影响。并对今后的发展趋势作了探讨,提出深入研究土壤微生物群落结构与其在陆地生态系统中的功能关系,合理调控土壤微生物群落结构,维护整个陆地生态系统稳定的研究方向。     

土壤微生物多样性与地上植被类型关系的研究进展

土壤微生物是生态系统中重要的组成成分,土壤微生物多样性代表着微生物群落的稳定性,对植物的生长发育和群落结构的演替具有重要作用。同时地上植被也影响土壤微生物多样性,地上植被和地下微生物间具协同作用和正负反馈效应的互作机制。探讨植被和土壤微生物多样性之间的互作关系,为植物保护和生态系统的可持续发展研究提供参考。     

土壤微生物多样性与地上植被类型关系的研究进展

土壤微生物是生态系统中重要的组成成分,土壤微生物多样性代表着微生物群落的稳定性,对植物的生长发育和群落结构的演替具有重要作用。同时地上植被也影响土壤微生物多样性,地上植被和地下微生物间具协同作用和正负反馈效应的互作机制。探讨植被和土壤微生物多样性之间的互作关系,为植物保护和生态系统的可持续发展研究提供参考。     

土壤微生物多样性与地上植被类型关系的研究进展

土壤微生物是生态系统中重要的组成成分,土壤微生物多样性代表着微生物群落的稳定性,对植物的生长发育和群落结构的演替具有重要作用.同时地上植被也影响土壤微生物多样性,地上植被和地下微生物间具协同作用和正负反馈效应的互作机制.探讨植被和土壤微生物多样性之间的互作关系,为植物保护和生态系统的可持续发展研究提供参考.     

农田管理措施对土壤有机碳周转及微生物的影响

农田管理措施对农田生态系统碳循环影响显著,进而制约土壤肥力、农业生产及粮食安全,影响气候变化和环境健康。本文综述了不同农田管理措施(施肥方式、种植制度、耕作模式)对农田土壤有机碳、含碳温室气体排放和土壤微生物的影响。发现有机肥与无机肥配施情景下土壤有机碳增速最快,且施肥量与土壤碳库存在阈值效应;有机肥的施用增加了土壤中CO2排放通量,磷、钾两种肥料的施用与施用氮肥相比更能降低农田土壤排放温室气体产生的全球增温潜势;提高有机肥和磷肥的施用比例有利于土壤中微生物丰富度的提高和微生物量碳的积累。种植结构和种植密度均会影响农田土壤的碳储量,种植结构对农田生态系统温室气体排放影响显著,轮作和间作的种植模式与传统单一作物种植相比可有效减少农田含碳温室气体的排放,同时,轮作与连作相比更有利于土壤微生物多样性的增加。保护性耕作措施有利于农田土壤固碳效率的提高,可降低农田温室气体的排放,且对微生物活性、多样性、群落结构以及碳源利用情况均有积极影响。最后总结了国际主流碳模型在农田生态系统的应用概况,并提出了未来发展展望。     

我国转基因水稻的环境生物安全评价及其关键问题分析

转基因水稻的商品化种植可能带来潜在的环境生物安全问题,例如：转基因对非靶标生物的影响,外源转基因逃逸及其可能带来的生态后果,转基因植物对生物多样性的影响,以及转基因对土壤微生物群落的影响等。对于转基因水稻的大规模种植进行科学的环境安全评价,有利于其可持续生产和安全利用。从我国的水稻生态系统和水稻种植方式的实际情况出发,结合我国可能进行商品化种植的转基因水稻种类,作者对转基因水稻品种的环境释放和商品化种植可能导致的潜在环境生物安全问题进行了科学和理性的分析。根据风险评价的原则（风险% = 危害性 × 发生概率）,本文特别对抗病、虫和抗除草剂转基因水稻的商品化种植可能带来的直接和间接影响进行了分析和讨论,希望能为转基因水稻商品化种植的决策提供参考,并为转基因水稻的环境安全性评价提供科学依据。     

转Bt基因作物对丛枝菌根真菌的影响研究进展

在过去的十年里，世界范围内转基因作物尤其是抗虫性转Bt基因作物的品种和种植面积迅速增加。同时，转Bt基因作物的环境安全性评价问题成为人们关注和研究的热点。丛枝菌根真菌（AMF）是生态系统中普遍存在的土壤微生物，能与绝大多数植物种类形成共生关系，在农业生态系统中起重要作用。转Bt基因作物环境释放后，其与AMF问的共生关系是否受所转入Bt基因的影响，以及影响机制需要及时研究。为此，综述了转Bt基因作物与AMF共生特征方面的研究进展，并根据Bt毒素发生的空间和时间规律提出了危害机制以及转Bt基因植物的规模化种植将降低农田系统中的AMF的生物多样性的观点。     

气候变化对中国农业生产的影响

未来气候变化下中国农业的稳定事关中国的长远持续发展,国内外气候变化研究界和农业气象研究界对气候变化对中国农业生产的影响的评估未有一致的认识。本文从农业科学角度讨论了气候变化对中国农业生产涉及的气象资源、土地资源、农业生物环境和生态系统的影响,并从作物生长和经济产量形成的角度讨论和分析了气候变化对中国种植业、养殖业不同产业行业的影响,气候变化中一些趋势性变化因不同作物和不同区域而异,例如温度和CO2浓度变化对农业生产的影响因不同作物和不同时相而异,反之,极端性气候／天气事件对农业不同行业的生产都显得危害很大,而气候变化中区域性干旱将成为我国未来农业生产愈来愈严重的挑战。气候变化对中国农业生产的影响甚为复杂,一些气候变化因子的实际影响还存在很大不确定性。当前,定量评价气候变化对中国农业生产的影响还存在困难。     

Two-year field study shows little evidence that PPO-transgenic rice affects the structure of soil microbial communities

There is global concern about the environmental consequences associated with transgenic crops. Their effects on the soil ecosystem are of special interest when assessing ecological safety and integrity. Although many efforts have been made to develop crops genetically modified to have resistance to protoporphyrin oxidase (PPO)-inhibiting herbicides, little is known about their influence on soil microbial communities. We conducted a 2-year field study and an analysis via terminal restriction fragment length polymorphism (T-RFLP) to assess the impacts of PPO-transgenic rice on bacterial and fungal communities. In the first year we sampled the rhizosphere and surrounding bulk soil, while in the second year we sampled rhizosphere soil only. No differences were observed in the diversity indices and community composition of microbial communities between transgenic rice and its parental non-transgenic counterpart (cultivar Dongjin). Instead, community variation was strongly dependent on growth stage and year. Therefore, we observed no adverse effects by these crops of modified rice on the microbial community composition in paddy soils.     

植物篱技术发展回顾和贵州省的研究进展

通过国际国内植物篱技术发展的回顾,认为通过研究,已初步形成了一种新型的、可供推广应用的坡耕地治理技术。植物篱技术的优点在于能有效的控制坡地的水土流失,增加作物的产量,增加经济收益,促进畜牧业的发展,在逐步形成梯地的过程中,投资较省、地力得到提高。但在该技术的推广应用上,因受地域条件差异的影响和农民对经济效益的追求使成篱作物较难选择,形成的植物篱容易破坏。我们采用农民参与选择成篱作物的方法,实践证明在一定范围内,农民能选择出风险小、经济效益较高,适合当地条件的,受群众欢迎的新型植物篱模式,能促进植物篱技术发展,明显地提高了植物篱技术推广的成功率。     

Impact of enhanced ultraviolet-B irradiance on cotton growth, development, yield, and qualities under field conditions

The stratospheric ozone depletion and enhanced solar ultraviolet-B (UV-B) irradiance may have adverse impacts on the productivity of agricultural crops. The effect of UV-B enhancements on agricultural crops includes reduction in yield, alteration in species competition, decrease in photosynthetic activity, susceptibility to disease, and changes in structure and pigmentation. Many studies have examined the influence of supplemental UV-B irradiance on different crops, but the effect of UV-B irradiance on cotton (Gossypium hirsutum L.) crops has received little attention. Cotton is one of the most versatile of all the crops. It is a major fiber crop of the world and a major source of trade and economy in many countries. In this study, we provide quantitative examination of the effects of elevated UV-B irradiance on cotton plant (Sukang 103). The tested cotton crop was grown under natural and four regimes of supplemental UV-B irradiance in the field. With UV-B irradiance increased 9.5% throughout the growing season, the negative impacts on cotton growth included reductions in height of 14%, in leaf area of 29%, and in total biomass of 34%. Fiber quality was reduced and economic yield dropped 72%; an economic coefficient was reduced 58%. A brief discussion is included on how the impacts on cotton contrast with impacts that have been observed in other studies on other plants, including trees.     

Integrated model systems for national assessments of the effects of climate change: Applications in New Zealand and Bangladesh

To examine the sensitivity of environmental systems to climatic variability and change, integrated model systems for climate impact assessment are being developed for New Zealand (CLIMPACTS) and Bangladesh (BDCLIM). Features common to both model systems include a global climate model, regional modules for generating climate scenarios, and models for biophysical impact analyses. For CLIMPACTS, modified ecosystem models for horticultural crops, arable crops, and pasture production are being incorporated. For BDCLIM, the emphasis is on analysis ofpossible changes in agroclimatic zones and hydrology, including the risks of floods and droughts. The initial emphasis of both systems is on nationwide spatial analyses, using simplified models as much as possible. The development of integrated model systems supports the needs of the respective countries in assessing scientific uncertainties, evaluating vulnerabilities, and identifying adaptation options as a basis for international reporting requirements under the U.N. Framework Convention on Climate Change and for policy and planning at national and regional levels. The major advantage of such integrated model systems is that they can readily be updated as the science of climate change advances, thus providing an evolving tool for future reassessments of climate impacts.     

基于低碳经济的山东省德州市农田生态系统碳汇估算

依据2001-2010年农作物产量、耕地面积及农业投入等数据,对山东省德州市农田生态系统的碳汇进行了估算,并分析了其变化情况.结果表明,德州市2001-2010年农田生态系统的碳吸收总量呈增加的趋势,且2004年以来增加的趋势较明显;小麦、玉米作为主要的粮食作物,碳吸收量明显高于其他农作物,棉花作为主要经济作物,吸收量不高;2001-2010年,由于德州市发展生态、高效、优质农作物,碳排放呈现先增后减的变化;不同县市由于农业发展方向和发展特色的差异,具有不同的碳排放;在这3种途径的碳排放过程中,化肥施用过程中碳排放所占的比例较大,且呈减少的趋势;2001-2010年德州市碳吸收量为6.35×107t,碳排放总量为4.53×106 t,碳吸收量远远大于碳排放量,说明德州市农田生态系统具有较强的碳汇功能.     

Assessment of the economic costs of damage caused by air-pollution

Cost-benefit analysis is one of the fundamental tools for the development of economic instruments for pollution control. The costs of various abatement measures are reasonably well characterised. However, assessment of the economic costs of pollutant impacts is less well developed. This paper reports on two studies carried out for DGXII of the European Commission, the ExternE-Project and the Green Accounting Research Project. Both studies have been performed by international, multi-disciplinary research teams.Analysis of the effects of emissions of PM₁₀, SO₂, NO_x and VOCs (as ozone precursors) has included assessment of human health, materials, crops and other terrestrial ecosystems, and freshwater fisheries. The analysis follows the impact pathway approach, linking dose-response functions, valuation data and other models. It differs significantly to earlier top-down approaches that made only very limited use of the wealth of scientific data available. Most success has been achieved in analysis of impacts on human health, building materials and crops. Significant uncertainties exist for these receptors, though these have been identified and are now being addressed. Assessment of impacts on other receptors, perhaps most notably forests, is more limited. The methodology is particularly applicable for analysis of impacts on receptors for which the critical loads approach is not appropriate.     

Ants as indicators of soil-based ecosystem services in agroecosystems of the Colombian Llanos

Ants represent a widespread and functionally diverse taxonomic group that are both sensitive to land management and serve as important regulators of key soil processes. Building upon this idea, we sought to understand the impacts of agricultural management on ant communities in the Orinoco River Basin of eastern Colombia and to identify species that could be used as indicators of soil-based ecosystem services. Ants were collected and identified from the soil and litter layer within 75 fields (nine TSBF sub-samples along a transect in each field) divided among five common agricultural land uses in the region: 1) annual crops (maize, soy and rice), 2) rubber plantations, 3) oil palm plantations, 4) improved pastures (based on Brachiaria spp.), and 5) semi-natural savannas. As expected, land management was found to greatly influence ant communities. Improved pastures showed the highest species richness (6.9 species per transect) and semi-natural savanna the greatest abundance of ants (145 individuals per transect). Within each of these fields a suite of soil and agroecosystem characteristics were measured and combined into synthetic indicators of five soil-based ecosystem services: 1) nutrient provision, 2) water storage and regulation, 3) maintenance of soil structure, 4) climate regulation services and 5) soil biodiversity and biological activity. Ant species were then associated with these synthetic indicators using the IndVal method to identify indicator species for each of the five consolidated ecosystem services measured. In total, 14 indicator species were identified and found to be significantly associated with either the high or low provision of each of the five services. The development of such bioindicators offers a rapid and relatively inexpensive tool to facilitate land management and policy decisions in this biologically diverse and rapidly changing region of Colombia.     

龙羊峡水库蓄水对水温的净影响

分析水库蓄水对水温的影响对于研究水库气候效应,探讨水库建设对水生生物和下游农作物灌溉的影响具有重要意义。本文建立了计算分层型水库对水温净影响的数学模型,并利用龙羊峡水库和下游河道实测水温和气温成果,在深入分析了龙羊峡水库水温类型和水温铅直分布规律的基础上,采用该模型计算了龙羊峡水库蓄水对坝前和下游河道水温的净影响。与传统的差值法相比,该模型引入了基于气温与水温相关关系的修正因子,扣除了自然因素引起的水温背景值的变化,可以获得更为准确的计算结果。