安徽省生态功能区划研究

生态功能区划是依据区域生态系统类型、生态系统受胁迫过程与效应、生态环境敏感性、生态服务功能重要性等特征的空间分异性而进行的地理空间分区 ,其目的是明确区域或国家生态安全重要地区 ,分析区域可能的生态环境问题与生态环境脆弱区 ,为产业布局、生态环境保护与建设规划提供科学依据 ,为实施区域生态环境分区管理提供基础和前提。在对区域生态环境特征分析的基础上 ,依据建立的生态功能区划原则、方法和指标体系 ,以安徽省域尺度生态系统为对象 ,在生态系统受胁迫过程与效应、生态环境敏感性和生态系统服务功能等指标评价的基础上 ,以中国生态环境区划方案为背景 ,综合了自然因素与人类活动对安徽省生态系统叠加影响 ,形成了安徽省生态功能区划方案 ,将安徽省分为 5个生态区、16个生态亚区、4 7个生态功能区 ,为生态保护与建设的重点、目标、措施的确定以及区域产业结构与布局的调整提供了重要依据     

辽宁省生态功能分区研究

分析了辽宁省生态环境基本特征,根据生态功能分区的原则与方法,应用遥感、地理信息系统和综合分析等手段对辽宁省在生态区、生态亚区和生态功能区3个级别上进行生态分区,划分为4个生态区、21个生态亚区和52个生态功能区。并用3级命名法对这些分区进行命名,绘制了辽宁省生态功能分区图。为辽宁省合理利用自然资源、科学布局工农业生产、实施可持续发展战略提供理论依据。     

低速磷胁迫对云南地方稻种核心种质抽穗期的影响

以云南16个地州和5个稻作区为单位,在低速磷胁迫和适速磷两种条件下,对545份云南稻种核心种质的抽穗期研究结果表明:不同稻种抽穗期受低速磷胁迫的影响差异较大,大部分稻种在低速磷胁迫下其抽穗期比适速磷条件下的延迟,但延迟天数明显低于不同稻种基因型差异;不同稻作区、地州的稻种抽穗期差异较大,这主要是与其生长的生态环境长期适应的结果.除了滇西北高寒粳稻区外,其他四个稻作区的核心种质在两种条件下的抽穗期有极显著差异,而各地州的核心种质在低速磷胁迫下的抽穗期存在显著差异的只有5个地州,即昭通、思茅、临沧、保山和西双版纳,其余地州间的差异不明显.     

中国西北干旱区生态区划

从国内外生态区划、生态土地分类和生态 生产范式的研究和发展入手, 从生态利用的角度出发, 在西北干旱区生态区域分异规律的基础上, 结合当地的社会经济发展特点, 全面完成了西北干旱区的生态区划方案。本着既尊重自然规律又符合可持续发展的生态 生产范式的原则, 在西北干旱区的生态区划过程中, 主要考虑以下几个方面:气候与巨地形系统、地貌与基质、植被与土壤以及土地利用与产业发展方向;区划方法是以经验判别和地理信息系统 (GIS) 相结合进行的, 过去发表的多种尺度的图件和区划方案均作为分区过程的辅助材料和新区划方案的校正材料;根据气候、巨地形系统、地貌、基质、植被、土壤以及土地利用和产业 发展方向等特征, 该生态区划的 3级分区指标如下:一级分区, 主要依据气候和巨地形系统, 并充分考虑该高级分区在生态环境建设和产业结构调整中的作用;二级分区, 主要根据次级地形和地貌系统以及大尺度植被类型;三级分区, 主要依据基质和土壤的差异所造成的局域植被类型的差异, 以及其生态 生产范式和将来的发展方向。根据以上区划的原则和指标体系, 西北干旱区的生态区划采用 3级区划制:生态域 (Ecodomain) 、生态区 (Ecoregion) 、生态小区 (Ecodistrict), 最后将西北干旱区划分为 3个生态域、2 3个生态区和 80个生态小区, 并利用GIS绘制了 1∶10 0万比例尺的西北干旱区生态区划图。西北干旱区生态区划的目的不仅在于发展独特的干旱区生态区划/生态分类的方法和理论体系, 建立生态区划的方案和生态 生产范式, 更重要的是要运用这些方法、规律和范式来指导当地的生态环境建设和产业结构调整, 促进当地的土地资源合理配置, 实现西北干旱区的可持续发展。     

干旱胁迫对油松和侧柏水分运输安全性和有效性的影响

通过采用改良的冲洗法测定5年生苗木油松(Pinus tabulaeformis)和侧柏(Platycladus orientalis)在不同干旱胁迫时期的水力结构参数,结果表明随着干旱胁迫增加,不同分枝级和茎段所在区域的导水率损失(PLC)增加,比导率(Ks)减少。油松和侧柏在0级,1级和2级分枝级的发生栓塞的水势阈值分别为-0.55、-0.49、-0.43和-0.90、-0.78、-0.74MPa。随着相对分枝级的增加,油松和侧柏的水势阈值增大,栓塞脆弱性变大。非限速区PLC大而Ks小,限速区PLC小而Ks大。油松和侧柏相对分枝级和茎段所在区域的栓塞脆弱性大小为2级1级0级,限速区非限速区,且油松大于侧柏。油松和侧柏在不同干旱胁迫,不同相对分枝级,不同茎段所在区域采取不同的方式来适应由水势降低而引起的栓塞变化。其采取的生态策略包括:保持较高的水分安全性;减轻安全性而对有效性的折衷;同时降低有效性和安全性但不终止任何生产力或树高的组织生长所需水的限制。     

胡麻种质萌发期抗旱性综合评价

为研究不同类型胡麻种质萌发期抗旱性表现,以筛选抗旱品种,为抗旱育种提供科技支撑。本研究采用不同浓度的PEG-6000高渗溶液模拟干旱胁迫的方法,对定亚17、陇亚8号和2011621080进行渗透胁迫试验,筛选适宜浓度的PEG-6000溶液。对161份不同类型的胡麻种质在萌发期进行渗透胁迫试验,考查与抗旱性相关的5个性状,并运用单项抗旱系数、综合抗旱系数、隶属函数和灰色关联度相结合的方法对种质资源的抗旱性进行综合评价。结果表明,不同浓度PEG-6000胁迫对胡麻种质的萌发均有影响,当PEG-6000的浓度在18%时,各种指标的抑制作用均显著加强,因此本研究选用18%的PEG-6000浓度模拟干旱胁迫试验;PEG-6000胁迫降低了161份胡麻种质资源的相对发芽率,抑制了幼芽的生长,种质间表现出较大差异。根据抗旱性量度值将供试种质划为5级,其中1级抗旱型2份、2级15份、3级28份、4级82份、5级34份;供试种质的抗旱性强弱与地理来源息息相关。试验结果说明选择多个性状,综合评价胡麻萌发期抗旱性是可行且准确的。     

microRNA在植物逆境胁迫应答中的作用

逆境胁迫严重影响着全世界范围内的作物产量。为减少逆境胁迫损伤,植物在长期的进化过程中形成了多级别（转录、转录后和翻译、翻译后）的基因表达调控应答机制。最近研究发现,内源microRNA（miRNA）在植物逆境胁迫应答中具有重要的调节作用。在逆境胁迫发生时,一些miRNA会表达上调,而另一些miRNA会表达下调;miRNA正是通过下调胁迫应答过程的负调节子靶基因和上调胁迫应答过程中的正调节子靶基因,来执行生理调控功能。通过综述miRNA在植物逆境应答中的作用,以期全面的了解逆境胁迫调控网络。     

中国环境管理分区:方法与方案

我国生态环境可持续性及其影响因素的区域差异显著,各地区环境管理面临的主要挑战和需要优先解决的生态环境问题不同。进行环境管理分区,根据各地区生态环境特征及其影响因素的差异性,制定有针对性的环境管理政策,将有效促进我国区域生态环境的整体优化。采取定性和定量分析相结合的方法进行我国环境管理分区。首先,在我国3大自然区的基础上,根据我国的自然地理格局和已有的相关区划成果,把我国划分为4个环境管理大区,包括:南部季风区、北部季风区、西北干旱区和青藏高寒区。其次,通过建立的包含13个指标的环境管理分区指标体系,采用一维化欧式距离法分析各环境管理大区下相邻省级行政区环境特征的相似性,把环境特征相似性大的相邻地区划分到同一分区,得到以省级行政区为基本单元的我国环境管理分区方案。然后,结合地区间历史渊源和区域未来发展趋势分析,对基于相似性分析的初步分区方案进行调整,把我国划分为8个以省级行政区为基本单元环境管理区。最后,根据相关调整原则和方法,对以省级行政区为基本单元的分区方案的边界线进行调整,得到以地级行政区为基本单元的分区方案,把我国划分为东北地区、华北平原区、华北山地与高原区、东南沿海地区、长江流域中游地区、西南地区、西北干旱区和青藏高寒区8个环境管理区。     

不同密度条件下芨芨草空间格局对环境胁迫的响应

基于小尺度上植物间相互作用与空间格局的高度相关性,选用可避免环境异质性影响的K2点格局函数,研究了沙枣-芨芨草群落中63个芨芨草样方(3密度条件×3生境条件×7重复)中芨芨草种群在小尺度下(0—0.5 m)的空间格局,探讨了在3种密度条件(高、中、低)及3种生境条件下(冠盖区、过渡区、空旷区),芨芨草种群空间格局对土壤理化性质胁迫(盐分、有机质及容重)程度的响应。研究结果表明,就土壤盐分,养分含量及土壤容重而言,土壤理化性质胁迫程度沿冠盖区、过渡区和空旷区增加的趋势。相应地,芨芨草种群呈聚集分布的样方比例在沿冠盖区(6/21)较低,而在过渡区(11/21)和空旷区(11/21)较高。然而,在不同密度条件下,芨芨草种群空间格局对土壤性质胁迫的响应不同。在低密度条件下,芨芨草种群在冠盖区多数为聚集分布(4/7),在过渡区和空旷区全部为聚集分布;中密度条件下,芨芨草聚集分布样方比例沿冠盖区-过渡区-空旷区梯度增加(分别为2/7,3/7,4/7),但低于同等胁迫条件下低密度样方中聚集分布数量;高密度条件下,在各胁迫条件下,除了一个过渡区高密度样方,其余芨芨草种群均为随机分布。总体上,随着环境胁迫增强,在中低密度下,芨芨草种群趋向于聚集分布;但在高密度下,芨芨草种群均以随机分布为主。此外,芨芨草种群空间格局随密度变化趋势比随土壤理化性质胁迫梯度变化趋势更加明显,可能表明相对于土壤理化性质胁迫程度,芨芨草种群密度对其空间格局影响更大。因此,在考虑芨芨草种群空间格局对环境胁迫的响应时,应当考虑种群密度因素。     

Environmental variability and the evolution of the glucocorticoid receptor (Nr3c1) in African starlings

One of the primary ways that organisms cope with environmental change is through regulation of the hypothalamo–pituitary–adrenal (HPA) axis, the neuroendocrine system that controls reactions to stress. Variation in genes regulating the HPA axis – particularly the glucocorticoid receptor – may facilitate adaptation to changing climatic conditions by altering expression. Here we examine signatures of selection on the glucocorticoid receptor gene (Nr3c1) in African starlings that inhabit a range of environments, including those with variable climatic conditions. To investigate potential adaptive mechanisms underlying the vertebrate stress response, we sequence the Nr3c1 gene in 27 species of African starlings. Although we find some evidence of positive selection, substitution rate is negatively correlated with variance in precipitation. This suggests climatic cycling in sub‐Saharan Africa may have resulted in lower substitution rates to maintain a successful coping strategy. When environmental conditions fluctuate rapidly, variation in the strength of purifying selection can explain evolutionary rate variation.     

Community theory: Testing environmental stress models

Intensifying climate change and an increasing need for understanding its impacts on ecological communities places new emphasis on testing environmental stress models (ESMs). Using a prior literature search plus references from a more recent search, I evaluated empirical support for ESMs, focusing on whether consumer pressure on prey decreased (consumer stress model; CSM) or increased (prey stress model; PSM) with increasing environmental stress. Applying the criterion that testing ESMs requires conducting research at multiple sites along environmental stress gradients, the analysis found that CSMs were most frequent, with ‘No Effect’ and PSMs occurring at low but similar frequencies. This result contrasts to a prior survey in which ‘No Effect’ studies were most frequent, thus suggesting that consumers are generally more suppressed by stress than prey. Thus, increased climate change-induced environmental stress seems likely to reduce, not increase impacts of consumers on prey more often than the reverse     

淡水螯虾生理生态学与环境毒理学研究进展

综述了我国2种主养的淡水螯虾(克氏原螯虾和红螯螯虾)在生理生态学与环境毒理学方面的研究进展。总结了淡水螯虾的环境条件(盐度、温度和pH)适应范围、毒性污染物(氨氮、亚硝酸盐、重金属和农药等)的半致死浓度和安全浓度,以及环境胁迫和毒性污染物暴露对淡水螯虾生长、组织结构、生理代谢和免疫功能等的影响,为淡水螯虾养殖的水环境监测与调控提供参考依据。     

环境胁迫下植物的化感作用及其诱导机制

植物化感作用是生态学研究中一个十分活跃的领域,对植物为什么和在什么条件下释放化感物质这一重要问题有不同的认识。在对环境胁迫下植物化感作用的变化及环境胁迫因子对化感物质听诱导机制等方面进行了评述后,指出植物化感化质的产生和释放是植物在环境胁迫的选择压力下形成的,植物化感作用是植物在进化过程中产生的一种对环境的适应性机制。     

环境胁迫下HOG-MAPK途径对真菌毒素形成的调控机制北大核心CSCD

真菌为了适应在生长侵染食品、饲料等农产品的过程中所面临的各种环境胁迫的考验,包括热胁迫、氧化胁迫、渗透压胁迫、紫外胁迫等,进化出一套高渗透性甘油促分裂原活化蛋白激酶(high osmolarity glycerol mitogen-activated protein kinase,HOG-MAPK)途径。该途径对真菌的生长发育、真菌毒素的产生和致病性都具有重要影响。HOG-MAPK途径共有两个分支,其中SLN1分支相比另一分支(SHO1分支)具有较为敏感的渗透压胁迫感应能力,能在高渗压和高盐浓度下进行渗透压胁迫反应。SHO1分支参与多种信号感应传导,比如氧化胁迫、热胁迫等。本文综述了真菌HOG-MAPK途径中关键基因sln1、sho1、ste11、ssk2、pbs2和hog1在应对渗透压胁迫、氧化胁迫等不同环境胁迫时所发挥的功能,说明HOG-MAPK途径可以响应多种环境信号,并参与调控黄曲霉、赭曲霉等致病真菌的生长和黄曲霉毒素(aflatoxin)、赭曲霉毒素(ochratoxin)等真菌毒素的产生。在不同环境胁迫下,HOG-MAPK途径对真菌毒素调控机制的研究可为食品和饲料等农产品真菌毒素的防控提供理论基础和指导方向。     

Patterns of variation in desiccation resistance in a set of recombinant inbred lines in Drosophila melanogaster

Desiccation, resulting from extremely dry environmental conditions, is a serious obstacle to the survival of organisms. Water is vital for the maintenance of intracellular structure and prevents the irreversible formation of aggregates, an occurrence leading to loss of cellular function. To characterize genetic variation in desiccation stress resistance (DSR) in Drosophila melanogaster Meigen, an intercontinental set of recombinant inbred lines (RIL) is used. Flies are exposed to a low humidity environment (<10% relative humidity) at a constant temperature of 25 °C. Desiccation stress resistance is higher in RIL derived from a backcross to the parental stock sensitive to heat stress (from Denmark) than in RIL derived from the reciprocal backcross to the heat‐stress resistant stock (from Australia). Composite interval mapping reveals significant quantitative trail loci (QTL) for DSR in the set of RIL. Both major and minor effects QTL are detected, suggesting a complex genetic architecture. When compared with a previous investigation performed on the same set of RIL, the present study indicates that not all traits of resistance to environmental stressors are affected in the same direction by segregating co‐localized QTL.     

Simultaneous exposure to a pulsed and a prolonged anthropogenic stressor can alter consumer multifunctionality

Ecosystems face multiple anthropogenic threats globally, and the effects of these environmental stressors range from individual‐level organismal responses to altered system functioning. Understanding the combined effects of stressors on process rates mediated by individuals in ecosystems would greatly improve our ability to predict organismal multifunctionality (e.g. multiple consumer‐mediated functions). We conducted a laboratory experiment to test direct and indirect, as well as immediate and delayed effects of a heat wave (pulsed stress) and micropollutants (MPs) (prolonged stress) on individual consumers (the great pond snail Lymnaea stagnalis) and their multifunctionality (i.e. consumption of basal resources, growth, reproduction, nutrient excretion and organic‐matter cycling). We found that stressful conditions increased the process rates of multiple functions mediated by individual consumers. Specifically, the artificial heat wave increased process rates in the majority of the quantified functions (either directly or indirectly), whereas exposure to MPs increased consumption of basal resources which led to increases in the release of nutrients and fine particulate organic matter. Moreover, snails exposed to a heat wave showed decreased reproduction and nutrient excretion after the heat‐wave, indicating the potential for ecologically relevant delayed effects. Our study indicates that the immediate and delayed effects of stressors on individual organisms may directly and indirectly impact multiple ecosystem functions. In particular, delayed effects of environmental stress on individual consumers may cumulatively impede recovery due to decreased functioning following a perturbation. Reconciling these results with studies incorporating responses at higher levels of biological complexity will enhance our ability to forecast how individual responses upscale to ecosystem multifunctionality.     

mRNA选择性剪切在植物发育中的作用

mRNA选择性剪切（altemativesplicing）是生物体基因转录调控的基本方式之一,随着新一代测序技术的广泛应用,越来越多的基因的选择性剪切现象被揭示。在植物发育的不同阶段及其应对外界逆境胁迫的过程中,许多基因发生了选择性剪切,产生植物各个发育阶段所需的特定蛋白质来完成不同的发育过程和形成不同应答因子以适应外界环境的变化。本文从种子发育、器官形态发育、开花时间、生物钟调控、环境胁迫等方面综述选择性剪切在植物发育中的研究进展。     

FLUCTUATING ASYMMETRY IN A SALIX HYBRID SYSTEM: THE IMPORTANCE OF GENETIC VERSUS ENVIRONMENTAL CAUSES

To examine the effects of hybridization and environmental stress on developmental instability, we examined fluctuating asymmetry (FA), the variance in random deviations from perfect symmetry in bilaterally symmetrical traits, for leaf symmetry in a Salix hybrid system. An abiotic environmental stress (water stress), an interspecific biotic stress (pathogen attack), and an intraspecific biotic stress (competition) were examined to determine which factors increase developmental instability. None of these three environmental stressors significantly increased FA. However, genetic stress through hybridization was detected; hybrid plants showed significantly higher levels of FA than parental species. In contrast to hybridization providing greater developmental stability through heterozygosity, these results suggest that complex, nonadditive interactions provided developmental stability and that developmental instability increased when coadapted gene complexes were disrupted through hybridization. In addition, plant biomass was significantly, negatively correlated with FA, suggesting that those individuals that were more able to buffer themselves against the disruptive effects of environmental stress may have a selective advantage over those that are less able to buffer themselves against these disruptive effects.