Overview of design concepts of traditional Iranian architecture and its reflections in Iranian contemporary architecture

This article has attempted to investigate the patterns of traditional architecture in Iran's warm and dry climate and whether these patterns have been attended to in Iran's contemporary architecture or not. Since the two elements of culture and climate are much significant in Iran's traditional constructions, this article aimed at dealing with subjects such as the causes of the shapes of traditional buildings in Iran's warm and dry climate in constructions like houses, schools, mosques and bazaars, and why they were constructed in those shapes, and also considering their patterns in these places in the light of cultural and climatic aspects, and their cultural and climatic relationships and investigating cultural-climatic causes of the directions and situations designed for the spaces present in these buildings and finally it is intended to classify the conceptual patterns of the traditional architecture of Iran's warm and dry climate. The article is going to consider the amount of using these patterns in Iran's contemporary architecture. The study has been conducted using library and field method.

Report of the Study Group on “ Fisheries and Ecosystem Response to Recent Regime Shifts”

EXECUTIVE SUMMARY 1. DECADAL-SCALE CLIMATE EVENTS 1.1 Introduction 1.2 Basin-scale Patterns 1.3 Long Time Series in the North Pacific 1.4 Decadal Climate Variability in Ecological Regions of the North Pacific 1.5 Mechanisms 1.6 References 2. COHERENT REGIONAL RESPONSES 2.1 Introduction 2.2 Central North Pacific (CNP) 2.3 California Current System (CCS) 2.4 Gulf of Alaska (GOA) 2.5 Bering Sea and Aleutian Islands 2.6 Western North Pacific (WNP) 2.7 Coherence in Regional Responses to the 1998 Regime Shift 2.8 Climate Indicators for Detecting Regime Shifts 2.9 References 3. IMPLICATIONS FOR THE MANAGEMENT OF MARINE RESOURCES 3.1 Introduction 3.2 Response Time of Biota to Regime Shifts 3.3 Response Time of Management to Regime Shifts 3.4 Provision of Stock Assessment Advice 3.5 Decision Rules 3.6 References 4. SUGGESTED LITERATURE 4.1 Climate Regimes 4.2 Impacts on Lower Trophic Levels 4.3 Impacts on Fish and Higher Trophic Levels 4.4 Impacts on Ecosystems and Possible Mechanisms 4.5 Regimes and Fisheries Management APPENDIX 1: RECENT ECOSYSTEM CHANGES IN THE CENTRAL NORTH PACIFIC A1.1 Introduction A1.2 Physical Oceanography A1.3 Lower Trophic Levels A1.4 Invertebrates A1.5 Fishes A1.6 References APPENDIX 2: RECENT ECOSYSTEM CHANGES IN THE CALIFORNIA CURRENT SYSTEM A2.1 Introduction A2.2 Physical Oceanography A2.3 Lower Trophic Levels A2.4 Invertebrates A2.5 Fishes A2.6 References APPENDIX 3: RECENT ECOSYSTEM CHANGES IN THE GULF OF ALASKA A3.1 Introduction A3.2 Physical Oceanography A3.3 Lower Trophic Levels A3.4 Invertebrates A3.5 Fishes A3.6 Higher Trophic Levels A3.7 Coherence in Gulf of Alaska Fish A3.8 Combined Standardized Indices of Recruitment and Survival Rate A3.9 References APPENDIX 4: RECENT ECOSYSTEM CHANGES IN THE BERING SEA AND ALEUTIAN ISLANDS A4.1 Introduction A4.2 Bering Sea Environmental Variables and Physical Oceanography A4.3 Bering Sea Lower Trophic Levels A4.4 Bering Sea Invertebrates A4.5 Bering Sea Fishes A4.6 Bering Sea Higher Trophic Levels A4.7 Coherence in Bering Sea Fish Responses A4.8 Combined Standardized Indices of Bering Fish Recruitment and Survival Rate A4.9 Aleutian Islands A4.10 References APPENDIX 5: RECENT ECOSYSTEM CHANGES IN THE WESTERN NORTH PACIFIC A5.1 Introduction A5.2 Sea of Okhotsk A5.3 Tsushima Current Region and Kuroshio/Oyashio Current Region A5.4 Bohai Sea, Yellow Sea, and East China Sea A5.5 References (168 page document)

Meteorological signals in primary productivity at two mountain lakes

Fluctuations in primary productivity at two subalpine lakes reveal both meteorological and biological influences. At Castle Lake, California, large-scale climate events such as the El Niño/Southern Oscillation affect total annual production and, combined with human fishing activity, modify the seasonal pattern of productivity. At Lake Tahoe, California-Nevada, local spring weather conditions modulate annual production and its seasonality by determining the depth of mixing and resulting internal nutrient load. Climatic conditions also contribute to deviations from the long-term trend in productivity by increasing the incidence of forest fires and through anomalous external nutrient loads during precipitation extremes. A 3-year cycle in productivity of as yet unknown origin has also been detected at Lake Tahoe.

遮荫与外源脱落酸喷施对粗枝云杉(Picea asperata Mast.)不同种群抗旱性的影响

本研究通过粗枝云杉不同种群进行的温室半控制试验，采用植物生态学、生理学和生物化学的研究方法，系统地研究了粗枝云杉不同种群抗旱性的生长、形态、生理和生化机理，并结合有关研究进行综合分析，得出主要研究结论如下： 1.粗枝云杉对干旱胁迫的综合反应 粗枝云杉在干旱胁迫下的适应机制为：（1）相对生长速率及植株结构的调整：干旱胁迫下虽然植株相对生长速率显著降低，且有相对较多的生物量向根部分配，但并未发现细根/总根比增加。（2）粗枝云杉对干旱胁迫的光合作用表现为：干旱胁迫显著地降低了控制的理想条件下的气体交换，但干旱胁迫对PSII最大光化学效率（Fv/Fm）没有影响，表明干旱并未影响到光合机构。（3）干旱还影响了很多生理生化过程，包括渗透调解物质（游离脯氨酸）、膜脂过氧化产物、脱落酸（ABA）含量的增加，以及保护酶活性的升高。这些结果证明植物遭受干旱胁迫后发生了一系列的形态、生理和生化响应，这些变化能提高干旱时期植物的存活和生长能力。 2.粗枝云杉不同种群对干旱胁迫反应的种群差异 粗枝云杉三个种群－干旱种群（四川丹巴和甘肃迭部）和湿润种群（四川黑水）对干旱适应不同，这种不同应归因于它们采用的用水策略不同：在水分良好和干旱胁迫条件下，受试种群在相对生长速率和水分利用效率（WUE）方面都表现出显著的种群间差异。与湿润种群相比，干旱种群在两种水分条件下有更高的WUE。粗枝云杉不同种群的碳同位素组分（δ13C）只在干旱胁迫下有显著差异，并且这种差异在水分良好时比干旱胁迫条件下小，说明生理响应和干旱适应性之间的关系受植物内部抗旱机制和外部环境条件（如水分可利用性）或两者互作效应的影响。这些结果说明干旱种群和湿润种群所采用的用水策略不同。干旱种群有更强的抗旱能力，采用的是节水型的用水策略，而湿润种群抗旱能力较弱，采用的是耗水型的用水策略。 3. 遮荫对粗枝云杉不同种群抗旱性影响 干旱胁迫显著降低了全光条件下叶相对含水量（RWC）、相对生长速率、气体交换参数、PSII的有效量子产量（Y），提高了非光化学猝灭效率（qN）、水分利用效率、脯氨酸（PRO）积累、脱落酸（ABA）含量及保护酶活性。然而这种变化在遮荫条件下不明显。我们得出结论适度遮荫降低了干旱对植物的胁迫作用。另一方面，在干旱条件下，与湿润种群相比，干旱种群抗旱性更强，表现在干旱种群净光合速率与单位重量上叶氮含量（Nmass）降低较少。另外，干旱种群表现出更为敏感的气孔导度，更高的热耗散能力（qN）能力、用水效率、ABA积累、保护酶活性，以及更低的总用水量、相对生长速率。这一结果表明这两种群采用不同的生理策略对干旱和遮荫做出反应。许多生长和生理反应差异与这两个种群原产地气候条件相适应。 4. 外源脱落酸(ABA)喷施对粗枝云杉不同种群抗旱性影响 外源ABA喷施在干旱和水分良好条件下均不同程度地提高了根/茎比，表明根和茎对ABA敏感程度不同。实验结果还表明，外源ABA喷施对这两个种群在干旱胁迫期间影响不同。干旱胁迫期间，伴随着ABA喷施，湿润种群净光合速率(A)显著降低，而干旱种群净光合速率变化不明显。另一方面，外源ABA喷施显著提高了干旱条件下干旱种群的单位叶面积重（LMA）、根/茎比、细根/总根（Ft）比、水分利用效率（WUE）、ABA含量, 以及保护酶活性。然而，外源ABA喷施对湿润种群的上述测定指标没有显著影响。这一结果表明干旱种群对外源ABA喷施更为敏感, 反应在更大的气孔导度降低，更高的生物量可塑性，及更高的水分利用效率、ABA含量和保护酶活性。综上所述，我们得出结论，粗枝云杉对外源ABA敏感性因种群的不同而不同。该研究结果可为两个明显不同种群在适应分化方面提供强有力的证据。 Arid or semi-arid land covers more than half of China's land territory. In arid systems, severe shortages of soil water often coincide with periods of high temperatures and high solar radiation, producing multiple stresses on plant performance. Protection from high radiation loads in shaded microenvironments during drought may compensate for a loss of productivity due to reduced irradiance when water is available. Additionally, ABA, a well-known stress-inducible plant hormone, has long been studied as a potential mediator for induction of drought tolerance in plants. Picea asperata Mast., which is one of the most important tree species used for the production of pulp wood and timber, is a prime reforestation species in western China. In this experiment, different population of P. asperata were used as experiment material to study the adaptability to drought stress and population differences in adaptabiliy, and the effects of shade and exogenous abscisic acid (ABA) application on the drought tolerance. Our results cold provide a strong theoretical evidence and scientific direction for the afforestation, and rehabilitation of ecosystem in the arid and semi-arid area, and provide a strong evidence for adaptive differentiation of different populations, and so may be used as criteria for species selection and tree improvement. The results are as follows: 1. A large set of parallel response to drought stress Drought stress caused pronounced inhibition of the growth and increased relatively dry matter allocation into the root; drought stress also caused pronounced inhibition of photosynthesis, while drought showed no effects on the maximal quantum yield of PSII photochemistry (Fv/Fm) in dark-adapted leaves, indicating that drought had no effects on the primary photochemistry of PSII. However, in light-adapted leaves, drought reduced the quantum yield of PSII electron transport (Y) and increased the non-photochemical quenching (qN). Drought also affected many physiological and biochemical processes, including increases in superoxide dismutase (SOD), ascorbate peroxidase (APX) activities, malondialdehyde and ABA content. These results demonstrate that there are a large set of parallel changes in the morphological, physiological and biochemical responses when plants are exposed to drought stress; these changes may enhance the capability of plants to survive and grow during drought periods. 2. Difference in adaptation to drought stress between contrasting populations of Picea asperata There were significant population differences in growth, dry matter allocation and water use efficiency. Compared with the wet climate population (Heishui), the dry climate population (Dan ba and Jiebu) showed higher LMA, fine root/total root ratio and water use efficiency under drought-stressed treatments. The results suggested that there were different water-use strategies between the dry population and the wet population. The dry climate population with higher drought tolerance may employ a conservative water-use strategy, whereas the wet climate population with lower drought tolerance may employ a prodigal water-use strategy. These variations in drought responses may be used as criteria for species selection and tree improvement. 3. The effects of shade on the drought tolerance For both populations tested, drought resulted in lower needle relative water content (RWC), relative growth rate (RGR), gas exchange parameters and effective PSII quantum yield (Y), and higher non-photochemical quenching (qN), water use efficiency (WUE), proline (PRO) and abscisic acid (ABA) accumulation, superoxide dismutase (SOD), ascorbate peroxidase (APX) activities as well as malondialdehyde (MDA) levels and electrolyte leakage in sun plants, whereas these changes were not significant in shade plants. Our study results implied that shade, applied together with drought, ameliorated the detrimental effects of drought. On the other hand, compared with the wet climate population, the dry climate population was more tolerant to drought in the sun treatment, as indicated by less decreases in A and mass-based leaf nitrogen content (Nmass), more responsive stomata, greater capacity for non-radiative dissipation of excitation energy as heat (analysed by qN), and higher WUE，higher level of antioxidant enzyme activities，higher ABA accumulation as well as lower MDA content and electrolyte leakage. Many of the differences in growth and physiological responses reported here are consistent with the climatic differences between the locations of the populations of P. asperata. 4. The effects of exogenous abscisic acid (ABA) application on the drought tolerance For both populations tested, exogenous ABA application increased root/shoot ratio (Rs) under well-watered and drought-stressed conditions, indicating that there was differential sensitivity to ABA in the roots and shoots. However, it appeared that ABA application affected the two P. asperata populations very differently during drought. CO2 assimilation rate (A) was significantly decreased in the wet climate population, but only to a minor extent in the dry climate population following ABA application during soil drying. On the other hand, ABA application significantly decreased stomatal conductance (gs), transpiration rate (E) and malondialdehyde (MDA) content, and significantly increased leaf mass per area (LMA), Rs, fine root/total root ratio (Ft), water use efficiency (WUE), ABA contents, superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) activities under drought condition in the dry climate population, whereas ABA application did not significantly affect these parameters in the wet population plants. The results clearly demonstrated that the dry climate population was more responsive to ABA application than the wet climate population, as indicated by the strong stomata closure and by greater plasticity of LMA and biomass allocation, as well as by higher WUE, ABA content and anti-oxidative capacity to defense against oxidative stress, possibly predominantly by APX. We concluded that sensitivity to exogenous ABA application is population dependent in P. asperata. Our results provide strong evidence for adaptive differentiation between populations of P. asperata.

青杨组(Section Tacamahaca Spach)杨树不同种群对土壤干旱和重金属锰污染的生态生理响应

土壤是人类赖以生存的自然环境和农业生产的重要资源，世界面临的粮食、资源和环境问题与土壤密切相关，目前危害土壤的主要因素是干旱和重金属污染。杨树具有适应性强、生长快和丰产等特性，本论文以青杨组杨树为模式植物，采用植物生态、生理及生物化学等方法，研究杨树对土壤干旱和锰胁迫的生态生理反应以及种群间差异，研究成果可为我国干旱半干旱地区营造人工林、防止沙漠化提供理论依据，也为恢复与重建重金属污染地区退化生态系统提供科学指导。主要研究结果如下： 1. 青海杨不同种群对干旱胁迫的响应差异 干旱胁迫显著降低了两个青海杨种群（干旱种群和湿润种群）生物量积累，包括株高、基径、干物质积累等，通过植物结构的调整，有更多的生物量向根部分配。干旱胁迫还显著降低了叶绿素和类胡萝卜素含量，增加了游离脯氨酸和总氨基酸含量。另一方面，干旱胁迫诱导了活性氧的积累，作为第二信使，激活了抗氧化系统，包括抗坏血酸（ASA）含量和酶系统如超氧化物歧化酶（SOD），愈创木酚过氧化物酶（GPX），抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）。这样，杨树既有避旱机制又有耐旱机制，使其在干旱胁迫下有相当程度的可塑性。与湿润种群相比，干旱种群杨树有更多的生物量分配到根部，积累了更多的游离脯氨酸和总氨基酸来进行渗透调节，并且有更有效的抗氧化系统，包括更高含量的ASA 和更高活性的APX 和GR，这些使得干旱种群杨树比湿润种群杨树对干旱有更好的耐性。 2. 喷施硝普钠（SNP）对青海杨阿坝种群干旱胁迫耐性的影响 干旱胁迫显著的降低了青海杨阿坝种群的生长和生物量积累以及叶片相对含水量，还诱导了脯氨酸的合成以进行渗透调节。干旱胁迫下过氧化氢（H2O2）显著累积从而造成对膜脂和蛋白的伤害，使得丙二醛和蛋白羰基含量升高。干旱胁迫下喷施SNP可以减轻干旱胁迫造成的伤害，包括增加叶片的相对含水量，增加脯氨酸和总氨基酸的积累，并激活抗氧化酶系统如SOD，GPX和APX，从而减少丙二醛（MDA）和蛋白羰基（C＝O）的积累，但是在水分良好情况下SNP的效果不显著。 3. 青杨不同种群对锰胁迫的生长与形态响应差异 在同一锰浓度下，干旱种群的耐性指数都要高于湿润种群，这表明青杨对干旱和高锰胁迫具有交叉耐性。两个种群的株高，生物量和叶绿素含量都随锰浓度的升高而逐渐下降。就累积浓度而言，0 和0.1 mM 锰胁迫下，干旱种群积累的锰浓度要高于湿润种群，而在高浓度锰胁迫下(0.5 和1 mM)，湿润种群要高于干旱种群。在0，0.1 和0.5 mM下，锰大多积累在根中，叶片次之，茎中最少。而在1 mM，锰更多的积累在叶片中。就累积总量而言，在各个锰浓度胁迫下，根，茎和叶相比，两个种群青杨都是叶片累积的锰总量要高于根和茎。两个种群间比较，对照中没有显著区别，0.1 mM 锰胁迫下，湿润种群根中累积的锰要高于干旱种群，而在地上部中，干旱种群要高于湿润种群。而0.5 和1 mM 锰胁迫下，根、叶、茎+叶、根+茎+叶中，锰累积总量都是湿润种群高于干旱种群。锰胁迫下，青杨叶片数和叶面积包括总叶面积和平均叶面积都显著降低。叶片横切面的光学显微观察结果表明未经锰胁迫的栅栏组织的细胞饱满，海绵组织发达、清晰；胁迫后杨树叶片栅栏组织细胞出现不同程度的皱缩，海绵组织几乎不可见，此外还发现输导组织在胁迫下密度变小和分生组织严重割裂等现象。 4. 青杨不同种群对锰胁迫的生理与生化响应差异 青杨两个种群脱落酸（ABA）含量在锰胁迫下都显著增加，干旱种群的增幅更大。三种多胺含量在锰胁迫下显示了不同的响应趋势：腐胺在两个种群的各个锰处理下都增加，亚精胺只在干旱种群中显著增加，而精胺除了干旱种群在1 mM 下有所增加外，在锰胁迫下变化很小。谷胱甘肽含量随锰浓度升高而增加，在0.5 mM 锰时达到最高值，1mM 时有所下降。植物络合素（PCs）含量与非蛋白巯基（NP-SH）趋势相似，随锰浓度的升高而增加，且干旱种群中含量要高于湿润种群。锰处理还引起氧化胁迫，表现为过氧化氢和丙二醛含量增加。SOD 活性在湿润种群中，在0 到0.5 mM 锰胁迫下活性升高，但在1 mM 锰胁迫时，其活性有所下降。而在干旱种群中，SOD 活性变化较小，并始终维持在一个较高的水平。APX 活性在两个种群中都随锰浓度的升高而增加，干旱种群活性要高于湿润种群。锰胁迫还显著增加了酚类物质的含量，同时GPX 和多酚氧化酶（PPO）活性也随锰浓度的升高而增加。干旱种群的酚类含量和GPX 与PPO 活性都要高于湿润种群。锰胁迫还改变了氨基酸的含量和构成，根据锰胁迫下浓度变化的不同，可以将游离氨基酸分为三组：第一组包括，谷氨酸，丙氨酸和天门冬氨酸，这一组氨基酸含量在锰胁迫下有所下降。第二组包括缬氨酸，亮氨酸和苏氨酸含量在锰胁迫下基本不变化或变化很小。剩下的氨基酸为第三组，这组氨基酸含量在锰胁迫下显著增加，而根据增加的幅度又可以将它们分为两个亚组，丝氨酸，酪氨酸，苯丙氨酸，组氨酸和脯氨酸，在1 mM 下的含量是对照的4 倍以上。异亮氨酸，赖氨酸，精氨酸和甘氨酸含量在1 mM 下是对照含量的2 倍以下。同时，同一锰浓度下，干旱种群比湿润种群积累的氨基酸含量要高。 Soil is the indispensable environment for human survival and important resource foragriculture development. Food and environmental problems facing the world are all closelyrelated to soil and nowadays it is threatened by many factors, among which drought stress andheavy metal pollution are the most serious ones. Poplars (Populus spp.) are importantcomponents of ecosystem and suitable as a source of fuel, fiber and lumber due to their fastgrowth. In this study, different populations of Section Tacamahaca spach were used as modelplants to investigate the adaptability to drought stress and manganese toxicity and differencesbetween populations from dry and wet climate regions. Our results can provide theoreticalevidence for the afforestation and prevention of desertification in the arid and semi-arid areas,and also can supply scientific direction for the reconstruction and rehalibitation of ecosystemscontaminated by heavy metals. The results are as follows: 1. Differences in ecophysiological responses to drought stress in two contrastingpopulations of Populus przewalskii Drought stress not only significantly affected dry mass accumulation and allocation, butalso significantly decreased chlorophyll pigment contents and accumulated free proline andtotal amino acids. On the other hand, drought also significantly increased the levels ofabscisic acid and reactive oxygen species, as secondary messengers, to induce the entire set ofantioxidative systems including the increase of reduced ascorbic acid content and the activities of superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase and glutathioneredutase. Thus the combination of drought avoidance and tolerance mechanisms conferredpoplar a high degree of plasticity in response to drought stress. Compared with the wetclimate population, the dry climate population showed lower dry matter accumulation andallocated more biomass to root systems, and accumulated more free proline and total aminoacids for osmotic adjustment. The dry climate population also showed more efficientantioxidant systems with higher content of ascorbic acid and higher activities of ascorbateperoxidase and glutathione redutase than the wet climate population. All these made the dryclimate population superior in adaptation to drought stress than the wet climate population. 2. Effect of exogenous applied SNP on drought tolerance in Populus przewalskii Drought stress significantly increased hydrogen peroxide content and caused oxidativestress to lipids and proteins assessed by the increase in malondialdehyde and total carbonylcontents, respectively. The cuttings of P. przewalskii accumulated proline and other aminoacids for osmotic adjustment to lower water potential, and activated the antioxidant enzymes such as superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase to maintain thebalance of generation and quenching of reactive oxygen species. Moreover, exogenous SNPapplication significantly heightened the growth performance of P. przewalskii cuttings underdrought treatment by promotion of proline accumulation and activation of antioxidant enzymeactivities, while under well-watered treatment the effect of SNP application was very little. 3. Morphological responses to manganese toxicity in the two contrasting populations ofPopulus cathayana High concentration of manganese caused significant decrease in shoot height andbiomass accumulation. The tolerance index of the dry climate population was significantlyhigher than that of the wet climate population, suggesting the superior Mn tolerance in theformer and the existence of cross-tolerance of drought stress and high Mn toxicity. Injuries tothe leaf anatomical features were also found as the reduced thickness in palisade and spongyparenchyma, the decreased density in the conducting tissue and the collapse and split in themeristematic tissue in the central vein. As for the Mn concentrations in the plant tissues, under0, 0.1 and 0.5 mM, most of the Mn accumulated in the roots, then leaves, and stem the least, while under 1 mM, most of the Mn accumulated in the leaves. As far as the total amounts ofMn extraction are concerned, the leaf extracted more Mn than the root and stem in the twopopulations under various Mn concentrations. There is no difference between the twopopulations under control. Under 0.1 mM, the wet climate population extracted higher Mn inthe root than the dry climate population, while in the shoot, the dry climate populationextracted much more Mn. Under 0.5 and 1 mM, the wet climate population translocated moreMn both in the root and the shoot than the dry climate population. 4. Physiological and biochemical responses to manganese toxicity in the two contrastingpopulations of Populus cathayana Mn treatment resulted in oxidative stress indicated by the oxidation to lipids, proteinsand DNA. A regulated network of defence strategies was employed for the chelation,detoxification and tolerance of Mn including the enhanced synthesis of ABA and polyamines,the accumulation of free amino acids, especially His and Pro, and the activation of theenzymes superoxide dismutase and guaiacol peroxidase. Contents of non-protein thiol,reduced glutathione, phytochelatins and phenolics compounds and activities of superoxide dismutase, guaiacol peroxidase and polyphenol oxidase also increased significantly forantioxidant or chelation functions. The wet climate population not only accumulated lessabscisic acid, free amino acids, phytochelatins and phenolics compounds, but also exhibitedlower activities of superoxide dismutase, guaiacol peroxidase and polyphenol oxidase thusresulting in more serious oxidative damage and more curtained growth.

遮荫与外源脱落酸喷施对青杨(Populus cathayana Rehd.)不同种群抗旱性的影响

杨树具有分布广、适应性强的特征，在生态环境治理和解决木材短缺方面均占有重要位置。青杨(Populus cathayana Rehd.)是青杨派树种的重要成员之一，也是生长较迅速、易繁殖的重要杨树资源。本研究选取了来自不同气候地区的青杨两种群为材料，采用植物生态学、生理学和生物化学的研究方法，系统地研究了青杨对干旱与遮荫、干旱与外源脱落酸(ABA)喷施的生长、形态、生理和生化响应及种群间差异，研究成果可为我国干旱半干旱地区的造林以及生态恢复提供理论依据和科学指导。主要研究结论如下：1.青杨在干旱胁迫下的适应机制为：生长性状及生物量的分配变化：干旱胁迫下虽然植株生长受抑，株高、基茎及各部分生物量都显著减小，但有相对较多的生物量向根部分配，根/冠比以及细/粗根比增加。青杨对干旱胁迫的光合作用表现为：干旱胁迫降低了青杨的净光合速率、蒸腾速率、气孔导度以及光合氮利用效率，提高了瞬时用水效率。干旱还引起了活性氧的产生，使得膜脂过氧化产物丙二醛(MDA)增加，同时也增强了植物抗氧化酶系统(如超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性的增加)及非酶系统的能力(如抗坏血酸(AsA)含量的增加)。干旱降低了植物叶片的相对含水量，而促进了渗透调节物质(游离脯氨酸及可溶性糖)的积累，增加了植物的渗调能力。干旱下青杨两种群的内源ABA含量显著增加，碳同位素组分(δ13C)也显著提高。这些结果证明植物遭受干旱胁迫后发生一系列的形态、生理和生化响应，这些变化能提高植物在干旱下的存活和生长能力。2.青杨两种群对干旱胁迫反应的种群差异：与来自湿润地区的汉源种群相比，来自干旱地区的乐都种群在干旱条件下生物量向根系分配的可塑性更强，同时具有更强的抗氧化系统能力，所受到活性氧的伤害也更少，并且累积更多的脯胺酸和ABA，具有更高的δ13C。这些都说明了乐都种群对干旱的适应性比汉源种群更强。两种群对干旱的响应差异应归于它们的用水策略的不同：汉源种群来自湿润地区，采用了耗水型的用水策略，抗旱能力较弱；而乐都种群，来自干旱地区，通常采用节水型的用水策略，有更强的抗旱能力。3.遮荫对青杨两种群抗旱性的影响：遮荫对青杨抗旱性的影响决定于遮荫程度的不同，我们的结果表明中度的遮荫可以有效的提高干旱下植物的生长，对干旱胁迫有明显的缓解作用，具体体现在中度遮荫下受旱植物的叶片相对含水量得到提高，使得植物体内水分状况得到了改善；光合速率并未降低，植物光合氮利用效率增加，说明中度的遮荫并未明显限制植物的碳获得；抗氧化酶活性与膜脂过氧化产物MDA含量的同时降低，说明中度遮荫下所受到的活性氧伤害减少；中度遮荫下的ABA及δ13C的变化也不如在全光下变化明显，这也说明中度遮荫缓解了干旱胁迫。但是重度的遮荫却对干旱胁迫有明显的加剧作用，主要表现在重度遮荫降低了植物的光合速率，严重抑制了植物的生长；同时重度遮荫下脯胺酸含量和抗氧化酶活性的急剧下降，导致了植物渗调能力的下降及膜脂过氧化产物MDA的显著升高；重度遮荫还显著降低了内源ABA的累积和δ13C，降低了植物的抗旱能力。此外，青杨两种群在对干旱和遮荫的响应中，也表现出种群差异。汉源种群，来自湿润且年日照辐射较少的地区，表现出相对更强的耐荫性和需水性。而乐都种群，来自干旱且年日照辐射丰富的地区，表现出相对更强的耐旱性和需光性。这说明了植物对环境胁迫的耐受性是其长期适应原生境的结果，并且来自不同气候地区的两种群在面临环境胁迫时会采取不同的生存策略。4. 外源ABA喷施对青杨两种群抗旱性的影响：外源ABA的喷施可以提高两种群的抗旱性，具体表现为外源ABA喷施促进了青杨根系的生长，显著提高了干旱下植物的根/冠比和细/粗根比，减少了比叶面积；在生理生化方面，外源ABA降低了干旱下植物叶片的气孔导度，降低了蒸腾速率和净光合速率，但提高了瞬时用水效率，提高了叶片的相对含水量，增加了干旱下植物的保水能力。外源ABA进一步增加了干旱下植物内源ABA的积累，促进了植物渗调物质如脯胺酸和可溶性糖的积累，增加了抗氧化酶系统(如SOD、APX、CAT)的活性和非酶系统AsA的含量，降低了活性氧(如超氧阴离子(O2和过氧化氢(H2O2))对植株的伤害。此外，外源ABA还进一步提高了干旱下植物的δ13C，提高了植物的长期用水效率，由此提高了植物的抗旱能力。另一方面，两种群对外源ABA和干旱的响应也有所差别。来自湿润地区的汉源种群，对干旱较为敏感，所受干旱的影响也较大，而外源ABA的喷施对汉源种群抗旱性的提高作用也更为突出。乐都种群，由于其长期适应干旱地区的生长，本身已具有较强的抗旱能力，因此外源ABA喷施对其抗旱性的提高不如对汉源种群的效果明显。由此我们可以得出对于一些抗性弱或干旱敏感的物种或者种群，可以采用外施ABA的方法来提高其抗性。Poplars play an important role in lumber supply, and are important component ofecosystems due to their wide distribution and well adaptation. Populus cathayana Rehd.,which belongs to Populus Sect. Tacamahaca Spach, is one of the most important resources ofpoplars for its fast growth and reproductive. In this study, different populations of P.cathayana were used as experiment material to investigate the adaptability to drought stressand population differences in adaptability, and the effects of shade and exogenous abscisicacid (ABA) application on the drought tolerance. Our results could provide a strongtheoretical evidence and scientific direction for the afforestation, and rehabilitation ofecosystem in the arid and semi-arid area, and provide a strong evidence for adaptivedifferentiation of different populations, and so may be used as criteria for species selectionand tree improvement. The results are as follows:1. A large set of parallel response to drought stress: Drought stress caused pronouncedinhibition of the growth and increased relatively dry matter allocation into the root. For thetwo populations, the shoot height, basal diameter and total biomass were decreased but theroot/shoot ratio and fine root/coarse root ratio were increased under drought conditions；Drought stress caused pronounced inhibition of photosynthesis, decreased the stomatalconductance, transpiration rate, and photosynthetic nitrogen-use efficiency (PNUE) butincreased the instantaneous water use efficiency. Drought significantly improved the levels ofreactive oxygen species and malondialdehyde (MDA) and to induce the entire set ofantioxidative systems including the increase of activities of superoxide dismutase (SOD),ascorbate peroxidase (APX), catalase (CAT) and ascorbate (AsA) content. Drought decreased the leaf relative water content (RWC) but improved the capability of osmotic adjustmentindicated by the higher proline accumulation. Drought also increased the ABA content andcarbon isotope composition (δ13C), which indicating the long period water use efficiency wasimproved under drought. These results demonstrate that there are a large set of parallelchanges in the morphological, physiological and biochemical responses when plants areexposed to drought stress; these changes may enhance the capability of plants to survive andgrow during drought periods.2. Difference in adaptation to drought stress between contrasting populations of P.cathayana: Compared with the Hanyuan population (wet climate), the Ledu population (dryclimate) showed higher root/shoot ratio and water use efficiency, exhibited higherantioxidative systems capability thus resulting in less oxidative damage, accumulated moreABA and free proline content under drought conditions. The results suggested that there weredifferent water-use strategies between the two populations. The Ledu population, whichcomes from dry climate region, with higher drought tolerance, may employ a conservativewater-use strategy, whereas the Hanyuan population, which comes from wet climate, withlower drought tolerance, may employ a prodigal water-use strategy. These variations indrought responses may be used as criteria for species selection and tree improvement.3. The effects of shade on the drought tolerance: The reduction in the availability of lightand water affected the morphological and physiological responses of the two P. cathayanapopulations. In addition, the light environment modified the growth responses of P.cathayana seedlings to varying water environments in different ways depending upon theintensity of the light levels considered. There is an apparent alleviation to drought effects bymoderate shade in P. cathayana seedlings, as indicated by the higher leaf RWC, and unchanged net photosynthesis and PNUE, as well as by the lower antioxditative enzymeactivity, MDA, ABA and δ13C levels, which implied moderate shade did not significantlylimited the carbon acquisition or inhibited the plant growth, but ameliorated the detrimentaleffects of drought. On the other hand, an apparent aggravation to drought effects by severeshade was also observed, as indicated by the pronounced decrease of plant growth and net photosynthesis, the lower total biomass, ABA level, δ13C, free proline content andantioxditative enzyme activity and higher MDA accumulation. By contrast, the twopopulations showed different responses to shade and drought. The Hanyuan population,which comes from a riparian basin having a relatively wet climate and less annual solarradiation, is more sensitive to drought but more tolerant to shade. The Ledu population, whichcomes from a mountainous plateau with less rainfall and with more annual solar radiation, ismore tolerant to drought but more sensitive to shade. The results demonstrated that theendurance of plants to stress is a result of long-term evolution and adaptation to theenvironment, as suggested by the different strategies employed by the P. cathayanapopulations originating from contrasting habitats when they were exposed to drought andshade.4. The effects of exogenous ABA application on the drought tolerance: For bothpopulations under drought conditions tested, exogenous ABA application significantlyimproved the root/shoot ratio, fine root/coarse root ratio, and decreased the specifical leaf area.On the physiological and biochemical traits, exogenous ABA application significantlydecreased stomatal conductance, transpiration rate and net photosythesis but increased theinstance water use efficiency and leaf RWC. On the other hand, exogenous ABA applicationsignificantly increased endogenous ABA, proline, solube sugar and AsA content, as well asSOD, APX and CAT activities, thus reduced the damage of reactive oxygen species. Moreover,the long period water use efficiency as indicated by δ13C was also improved by exogenousABA application. In additionally, there was different responsive between the two populationsto drought and exogenous ABA application. The Hanyuan population, which comes from wetclimate region, is more sensitive to drought, and the effect of exogenous ABA is moreobviously than that in the Ledu population, which comes from dry climate region and is moredrought-responsive. Therefore, we can use exogenous ABA application to improve theresistance of plants, especially for the drought- sensitive species or populations.

增强UV-B辐射对粗枝云杉(Picea asperata Mast.)和青杨(Populus cathayana Rehd.)的影响

光是植物赖以生存的重要环境因子，但是植物在获得光的同时不可避免的会受到紫外辐射的伤害。尤其是近年来，人类向大气中排放的大量氮氧化合物和氟氯烃类化合物(CFC’s)引起臭氧分子的分解，导致到达地球表面的紫外辐射增加，特别是UV-B辐射增强。而另一方面，植物对UV-B辐射反应的敏感性在种间和品种间存在差异，主要受植物基因型，生态型和生活型的控制。本项目分别以粗枝云杉和青杨组杨树为模式植物，从形态和生理生化方面分别研究了来自不同水分背景下的粗枝云杉种群和来自不同UV-B背景下的青杨种群在增强UV-B下的反应及其反应差异,并探讨了干旱、喷施外源脱落酸(ABA)对它们抗UV-B能力的影响。研究成果可为生态系统的恢复与重建提供理论依据和科学指导。主要研究结果如下： 1. 粗枝云杉的两个种群，湿润种群(来自四川黑水)和干旱种群(来自甘肃迭部)在水分良好和干旱状况下表现出对增强UV-B的不同响应。同时，干旱对粗枝云杉抗UV-B能力的影响也得到研究：两种胁迫共同作用时，干旱表现出在一定程度上减弱了增强UV-B对粗枝云杉的生理特性的影响。 干旱胁迫显著降低了两个粗枝云杉种群的光合同化速率(A), 气孔导度(gs)和PSII的有效光量子产量(Y), 同时，提高了非光化学猝灭效率(qN)和超氧化物歧化酶(SOD)的活性。与湿润种群相比，干旱种群抗旱性更强，表现为干旱种群拥有更高的SOD和干旱进一步加剧了UV-B的胁迫效应。 本研究中，干旱胁迫单独作用时，显著降低了青杨两个种群的生物量积累和气体交换，具体包括A、gs、蒸腾速率(E)和光合氮利用效率(PNUE)，提高了两个种群的瞬时水分利用效率(WUEi)、长期水分利用效率(WUET)、碳同位素组分(δ13C)和氮含量(N)。同时，UV吸收物质和ABA含量也得到积累。另一方面，增强UV-B对青杨两个种群各个指标的影响，同干旱所引起的效应有着相似的趋势。同低海拔种群相比，高海拔种群有着更强的抗旱和抗UV-B能力，具体表现在高海拔种群有着更多的生物量积累，更强的气体交换和水分利用效率及更高水平的ABA和UV吸收物质含量。相比干旱诱导的生物量积累和气体交换的降低，在干旱和增强UV-B两个胁迫同时作用于青杨时，这种降低表现的更为明显。显著的干旱和UV-B的交互作用还表现在WUEi, WUET, δ13C, 可溶性蛋白含量, UV吸收物质含量, ABA, 叶片和茎中的N含量以及C/N比中。 3. 经过一个生长季的试验观察，增强UV-B、外源ABA及两因子共同作用对青杨的生物量积累、气体交换、内源ABA和UV吸收物质含量、抗氧化系统以及碳、氮含量和碳/氮比均产生显著影响。本试验中，青杨的两个种群分别来自中国西南部的不同海拔地区，高海拔种群来自青海大通而低海拔种群来自四川九寨。外源ABA的胁迫为直接喷施ABA到青杨叶片，而增强UV-B胁迫是利用平方波系统分别保证青杨苗暴露于外界UV-B强度和两倍于外界UV-B强度下。 研究结果显示，增强UV-B显著的降低了两个青杨种群的株高、基茎、总叶面积和总生物量等生长指标，同时也导致其A、gs、E和叶片中碳含量的减少。而显著增加了SOD和过氧化物酶(GPx)活性水平，诱导了过氧化氢(H2O2)和MDA的显著增加，促进了UV吸收物质和不同器官中内源ABA含量的显著积累。另一方面，外源ABA引起了青杨光合同化速率的下降，SOD和GPx酶活性的增强，H2O2 和 MDA含量也表现出显著增加，同时，内源ABA含量得到显著累积。同低海拔种群相比，高海拔种群具有更加抗UV-B和外源ABA的特性。显著的UV-B和ABA的交互作用表现在A, E, SOD和GPx活性，以及叶片和根部的内源ABA等一系列指标中。在所有胁迫下，叶片中的碳和氮含量同其在茎和根中的含量显著相关，另外，叶片和茎中的氮含量同茎中的碳含量显著相关。 Sunlight is an indispensable environment factor for plants survival and development. Meanwhile, photosynthetic organisms need sunlight and are thus, inevitably, exposed to UV radiation. Especially for recent years, ultraviolet radiation, especially UV-B reaching the Earth’s surface increased because of depletion of ozone layer resulted from emission of NxO and CFC’s from human activities. On the other hand, the sensitivity of plants to UV-B radiation depends on the species, developmental stage and experimental conditions. In this experiment, two populations of Picea asperata Mast from different water background and two populations of Populus cathayana Rehder from different altitude background were selected as model plants to assess the effects of enhanced UV-B radiation. Morphological and physiological traits induced by enhanced UV-B in each plant species were observed and the different responses were discussed, furthermore the influences of drought and exogenous ABA on responses induced by enhanced UV-B were studied. The study could provide a strong theoretical evidence and scientific direction for the afforestation and rehabilitation of ecosystem. The results are as follows: 1. Different responses of two contrasting Picea asperata Mast. populations to enhanced ultraviolet-B (UV-B) radiation under well-watered and drought conditions were investigated. And the effects of enhanced UV-B on tolerance of drought were also observed in our study that the UV-B exposure may have alleviated some of the damage induced by drought. Two contrasting populations, originating from a wet and dry climate region in China, respectively, were employed in our study. Drought significantly decreased CO2 assimilation rate (A), stomatal conductance (gs) and effective PSII quantum yield (Y), while it significantly increased non-photochemical quenching (qN) and the activity of superoxide dismutase (SOD) in both populations. Compared with the wet climate population, the dry climate population was more acclimated to drought stress and showed much higher activities of SOD and ascorbate peroxidase (APX), and much lower levels of malondialdehyde (MDA) and electrolyte leakage. On the other hand, enhanced UV-B radiation also induced a significant decrease in the chlorophyll (Chl) content in both populations under well-watered conditions, and a significant increase in UV-absorbing compounds in the wet climate population. After one growing season of exposure to different UV-B levels and watering regimes, the increases in MDA and electrolyte leakage, as induced by drought, were less pronounced under the combination of UV-B and drought. In addition, an additive effect of drought and UV-B on A and gs was observed in the wet climate population, and on the activity of APX and qN in the dry climate population. 2. The significant effects of drought, enhanced UV-B radiation and their combination on Populus cathayana Rehd. growth and physiological traits were investigated in two populations, originating from high and low altitudes in south-west China. Our results showed that UV-B acts as an important signal allowing P. cathayana seedlings to respond to drought and that the combination of drought and UV-B may cause synergistically detrimental effects on plant growth in both populations. In both populations, drought significantly decreased biomass accumulation and gas exchange parameters, including A, gs, E and photosynthetic nitrogen use efficiency (PNUE). However, instantaneous water use efficiency (WUEi), transpiration efficiency (WUET), carbon isotope composition (δ13C) and nitrogen (N) content, as well as the accumulation of soluble protein, UV-absorbing compounds and abscisic acid (ABA) were significantly increased by drought. On the other hand, cuttings from both populations, when kept under enhanced UV-B radiation conditions, showed very similar changes in all above-mentioned parameters, as induced by drought. Compared with the low altitude population, the high altitude population was more tolerant to drought and enhanced UV-B, as indicated by the higher level of biomass accumulation, gas exchange, water-use efficiency, ABA concentration and UV-absorbing compounds. After one growing season of exposure to different UV-B levels and watering regimes, the decrease in biomass accumulation and gas exchange, induced by drought, was more pronounced under the combination of UV-B and drought. Significant interactions between drought and UV-B were observed in WUEi, WUET, δ13C, soluble protein, UV-absorbing compounds, ABA and in the leaf and stem N, as well as in the leaf and stem C/N ratio. 3. During one growing season, significant effects induced by enhanced UV-B radiation, exogenous ABA and their combination on biomass accumulation, gas exchange, endogenous ABA and UV-absorbing compounds concentrations, antioxidant system as well as carbon (C) content, nitrogen (N) content and C/N ratio were investigated in two contrasting Populus cathayana populations, originating from high and low altitudes in south-west China. Exogenous ABA was sprayed to the leaves and enhanced UV-B treatment was using a square-wave system to make the seedlings under ambient (1×) or twice ambient (2×) doses of biologically effective UV-B radiation (UV-BBE). Enhanced UV-B radiation significantly decreased height, basal diameter, total leaf area, total biomass, A, gs, E and carbon (C) content in leaves, and significantly increased activities of SOD and guaiacol peroxidase (GPx), hydrogen peroxide (H2O2) and malonaldehyde (MDA) content as well as the accumulation of UV-absorbing compounds and endogenous ABA concentrations among different organs in both populations. In contrast, exogenous ABA showed significant decrease in A and significant increases in activities of SOD and GPx, H2O2, MDA content and the endogenous ABA concentrations. Compared with the low altitude population, the high altitude population was more tolerant to enhanced UV-B and exogenous ABA. Significant interactions between UV-B and ABA were observed in A, E, activities of SOD and GPx, as well as in endogenous ABA in leaves and roots of both populations. Across all treatments, C and N content in leaves was strongly correlated with those were in stems and roots, respectively. Additionally, leaf and stem N content were significant correlated with stem C content.

Palaeoenvironmental changes from pollen record in deep sea core PC-1 from northern Okinawa Trough, East China Sea during the past 24 ka

A pollen record of core PC-1 from the northern Okinawa Trough, East China Sea (ECS), provides information on vegetation and climate changes since 24 cal. kaBP. A total of 103 samples were palynologically analyzed at 8 cm intervals with a time resolution of 230 a. Four pollen zones are recognized: zone I (812-715 cm, 24.2-21.1 cal. kaBP), zone II (715-451 cm, 21.1-15.2 cal. kaBP), zone III (451-251 cm, 15.2-10.8 cal. kaBP), zone IV (251-0 cm, 10.8-0.3 cal. kaBP), corresponding to Late MIS 3, Last Glacial Maximum (LGM), deglaciation and Holocene, respectively. The LGM is characterized by the dominance of herbs, mainly Artemisia, and high pollen influx, implying an open vegetation on the exposed continental shelf and a cool and dry climate. The deglaciation is a climate warming stage with Pinus percentage increased and Artemisia percentage decreased and a rapid sea-level rise. The Holocene is characterized by predominance of tree pollen with rapid increase in Castanea-Castanopsis indicating the development of mixed evergreen and deciduous broad-leaved forest and a warm, humid climate. Low pollen influx during the Holocene probably implies submergence of the continental shelf and retreat of the pollen source area. The vegetation indicated by pollen assemblage found in this upper zone is consistent with the present vegetation found in Kyushu, Japan. Originating from the humid mountain area of North Luzon of the Philippines, Tasmania and New Zealand, Phyllocladus with sporadic occurrence throughout PC-1 core probably suggests the influence of Palaeo-Kuroshio Current or intense summer monsoon. The observed changes in Pinus and Herbs percentage indicate fluctuations of the sea level, and high Pinus percentage corresponds to high sea level. Spectrum analysis of the pollen percentage record reveals many millennial-scale periodicities, such as periodicities of 6.8, 3.85 2.2, 1.6 ka.

25ka B.P.以来黑潮流域古环境演化对高频全球变化事件的响应

本文利用黑潮流域主流轴上的两个柱状沉积物岩芯MD05-2908以及PC-1为研究材料，在AMS14C测年的基础上，利用高分辨率的有机地球化学分析记录结合浮游有孔虫氧、碳同位素，恢复并重建了过去25,000 cal a BP以来黑潮流域古海洋环境演化的历史。以及表层海水生产力以及物质输送状况的演化历史。通过利用Uk’37古海水温度以及盐度指标恢复重建了过去25,000 cal a BP以来海洋表层海水温度、盐度；通过机碳、氮含量以及同位素变化、长链正构烷烃以及正构烷醇等指标重建了过去7000a B.P.以来的陆源物质输入历史；通过长链不饱和烯酮含量以及有机碳同位素指标恢复了过去7000a B.P.以来海水表层生产力的历史。此外，通过基于以上各种指标的环境信息与区域以及全球其它气候记录进行对比研究以及不同环境指标的时间系列分析，探讨了该区表层环流系统以及生产力的演化对于全球气候变化的响应，揭示了不同尺度的短周期高频率全球变化事件在黑潮流域的具体作用过程和响应机制。通过这些研究取得了以下的主要认识： 基于有机地球化学指标的古气候环境记录与黑潮流域已有的研究成果有很好的对应关系，从我们高分辨率的有机地球化学记录中可以识别出全新世黑潮强弱变化的几次明显的事件；25000a B.P.以来黑潮流域的环境变化与全球环境变化有着很好的对应性，黑潮强弱演化总体趋势与全球气候背景演化相一致，黑潮对高频气候变化事件的记录与全球记录具有同步性，这种同步性尤其体现在末次冰消期以来的气候快速高频振荡以及全新世以来的气候突变事件上。 全球性的高频气候事件对黑潮主体本身及黑潮流域的相邻区域的大气和海洋环流都具有重要的控制作用，这种控制作用主要通过副高、ITCZ以及季风三种气候要素之间相互关联、彼此影响造成的。具体表现为：太阳辐射量的减少导致热力差异减小，这种相对减小弱化了热带西太平洋的对流活动，造成了西太平洋副热带高压长期偏南、偏东，ITCZ平均北界位置偏南，降雨带长时间集中在南部地区，增强的降雨量提高了风化剥蚀以及沉积物向海洋搬运的能力，陆源物质供应量增加；同时，辐射量以及热力差的减小又与加强的东亚冬季风相联系，增强的冬季风导致了近底层“雾状层”物质的向海传输，物质传输效率增高。这种物源供应以及搬运量的双重增加导致了冲绳海槽流域物质通量的增加。 基于有机地球化学指标的海洋表层生产力的变化与陆源物质供应量以及黑潮流的强弱变化存在着对应关系，通常情况增加的海洋表层生产力对应着高的陆源物质输入以及相对较弱的黑潮。这种变化与东亚夏季风的以及冬季风的强弱都有很好的一致性。陆源物质的输入增加了表层营养物质的含量，导致生产力的勃发；陆源物质的输入增加又对应着减少的太阳辐射量，偏南的ITCZ北界位置以及副热带高压，这些对应于减弱的东亚夏季风（增强的东亚冬季风）。 黑潮流域的高沉积速率事件对应于减弱的黑潮强度和增加的ENSO频度，这些事件与上述的副热带高压、ITCZ位移和强弱的变化相一致。黑潮流域过去25000a B.P.以来南北温度的差异有冰期加大而全新世减小的趋势，但这种冰期与全新世的差异很小，我们认为末次盛冰期的时候黑潮主流轴没有移出冲绳黑潮，只是由于强度的减弱受陆架水体的影响有所加大。 黑潮流域很好的记录到了包括数千年尺度的D/O旋回周期到大气——海洋系统内部振荡所致的PDO、NAO等数十年尺度的高频振荡，说明黑潮流域对过去全球及区域环境变化事件有很好的响应。黑潮流域各古海洋指标所记录周期上的一致性说明这些环境因子控制机理上具有的一致性，即大背景上受太阳活动所引起的辐射量变化控制，局部的高频快速气候波动又受到局域性的气候因素如海气相互作用的放大影响。

Variation in joint mode of the tropical Indian-Pacific Ocean thermodynamic anomaly

Previous research has defined the index of the Indian-Pacific thermodynamic anomaly joint mode (IPTAJM) and suggested that the winter IPTAJM has an important impact on summer rainfall over China. However, the possible causes for the interannual and decadal variability of the IPTAJM are still unclear. Therefore, this work investigates zonal displacements of both the western Pacific warm pool (WPWP) and the eastern Indian Ocean warm pool (EIOWP). The relationships between the WPWP and the EIOWP and the IPTAJM are each examined, and then the impacts of the zonal wind anomalies over the equatorial Pacific and Indian Oceans on the IPTAJM are studied. The WPWP eastern edge anomaly displays significant interannual and decadal variability and experienced a regime shift in about 1976 and 1998, whereas the EIOWP western edge exhibits only distinct interannual variability. The decadal variability of the IPTAJM may be mainly caused by both the zonal migration of the WPWP and the 850 hPa zonal wind anomaly over the central equatorial Pacific. On the other hand, the zonal migrations of both the WPWP and the EIOWP and the zonal wind anomalies over the central equatorial Pacific and the eastern equatorial Indian Ocean may be all responsible for the interannual variability of the IPTAJM.

准噶尔盆地滴南凸起中生界层序地层及有利勘探目标优选

Based on the theories of sequence stratigraphy and sedimentology, as well as comprehensive studies of seismic data, drilling data, core interpretation and setting of this area, the thesis presents an analysis for Mesozoic formation in Dinan uplift. By means of recognizing the boundary of the sequence, dividing and correlating the systems tract, Mesozoic of Dinan uplift is divided into ten sequences and twenty-five systems tracts during the establishment of the sequence framework. In the framework, some sequences are featured by mature systems of lowstand, water-transgression and highstand, while some undeveloped systems of lowstand or highstand. The main sedimentary facies in Mesozoic of Dinan uplift are braided river, meandering river, delta and lake. The braided river was divided into sandy river and rudaceous river by the lithology of the river channel and was divided into dry climate and wet climate condition by the color of the flood plain. Additionally, The concept of “wetland” is put forward for the first time and regarded as the consequence of wet climate. The analysis includes the classification of six types of traps: (1) stratigraphic overlap trap, (2) lithologic trap with updip pinchout, (3) stratigraphic unconformity trap, (4) fault-lithology trap, (5) fault trap, (6) anticlinal trap, and combining with the research of the characteristics and distribution rules for the known reservoir, it draws out that “fault control” is the petroleum accumulation pattern in this area, in which fault is the key element of the transporting system. Finally the thesis concludes the distribution characteristics and optimized some targets for the potential exploration zone.

泥河湾盆地大长梁剖面岩石磁学和环境磁学研究

The fluvio-lacustrine sequence in the Nihewan Basin is an important archive of late Pliocene-Pleistocene climate and environment changes in temperate northern China, which provides excellent sources of early human settlements in high latitude East Asia. The recent years have witnessed a considerable progress in the paleomagnetic dating of its stratigraphy, which has notably increased our understanding of a series of important issues such as the early human occupation in the Old World, the infilling history of the Nihewan Basin, and the chronological sequence of the Nihewan faunas. Up to now, the long-term paleoenvironmental changes directly retrieved from this basin, which might influence the evolution and expansion of early humans in the Nihewan Basin, are still poorly constrained, although several paleoclimatic records have been retrieved from this area. In this study, a combined mineral-magnetic and geochemical investigation was carried out on the fluvio-lacustrine sequence from the Dachangliang section at the eastern margin of the basin in order to reveal its rock magnetic and environmental magnetic characteristics and its implications for early human evolution in East Asia. The major findings and conclusions are listed as the following: First, there is an increased cooling coupled with an intensified aridification recorded in the fluvio-lacustrine sequence of the Dachangliang section. The cooling is related to an up-section decrease in propensity to chemical weathering as inferred from an increase in low-field susceptibility after cycling to 700 °C. Close to 700 °C, reacting chlorite is providing the iron source for newly formed very fine-grained ferrimagnetic minerals which enhances the susceptibility signal. The reactivity of chlorite after annealing at temperatures above 600 °C is documented with X-ray diffraction. Second, degrees of chemical weathering in the Nihewan Basin are further estimated by clay mineralogy (i.e. chlorite and illite contents and chlorite/illite ratio) and a series of major element proxies (i.e. Na2O/Al2O3 versus K2O/Al2O3 diagram, Al2O3-(CaO + Na2O)-K2O ternary diagram (A-CN-K), chemical index of alteration (CIA), (CaO + Na2O + MgO)/TiO2, (CaO + Na2O + MgO + K2O)/(TiO2 + Al2O3), CaO/Al2O3 and CaO/TiO2). The up-section decrease in propensity to chemical weathering suggested by the aforementioned rock mangetic measurement is further confirmed by these geochemical analyses. Combining the chemical weathering records from the Nihewan Basin, Chinese Loess Plateau, South China Sea and eastern China, we find that the consecutive decreasing trend in chemical weathering intensity during the late Cenozoic is ubiquitous across China. This pattern may result from a long-term decreasing East Asian summer monsoon and increasing East Asian winter monsoon, and thus a consecutive increasing of aridification and cooling in Asia during the Quaternary. Furthermore, the chemical weathering intensity increased from South China to North China during the Quaternary, in line with the decreasing East Asian summer monsoon and increasing East Asian winter monsoon and thus the gradually intensified aridification and cooling from South China to North China. Third, a combined mineral-magnetic and geochemical investigation provides evidences that the large-amplitude alterations of concentration of magnetic minerals mainly result from preservation/dissolution cycles of detrital magnetic minerals in alternately oxic and anoxic depositional environments. The preservation/dissolution model implies that the high-magnetic and low-magnetic cycles of this sedimentary sequence represent glacial and interglacial climate cycles, respectively. This contribute significnatly to our understanding of the link between climate and magnetic properties. Finally, the paleoclimatic implications of these rock magnetic and geochemical characteristics significantly increase our understanding of the general setting of early humans in high northern latitude in East Asia. We propose that the cold and dry climate may have contributed significantly to the expansion and adaptation of early humans, rather than bringing hardship, as is often thought. The relationship between magnetic properties and climate possibly provides valuable information on the climatic context of the Paleolithic sites in the basin, especially whether the occupation occurred during an interglacial or glacial period.

13万年以来黄土高原东缘与捷克的风成沉积序列

The loess-paleosols in the Chinese loess plateau and Europe are the main eolian sediment sequences in mid-latitude area of north hemisphere. They record not only the paleoclimatic and paleoenvironmental processes since the last interglacial, but also the configuration of magnetic field during polarity transition. Comparisons of environmental magnetism, paleomagnetism and climate proxy analysis has been made for the loess/paleosol sequences in Datong and Czech Republic. The Datong loess/paleosol sequence is composed of the Holocene soil SO, the last glacial loess LI, the last interglacial soil SI and the upper penultimate loess L2. A basalt layer occurs in L2. The main magnetic minerals in LI and SI are magnetite, maghemite and ilmenite. The presence of local volcanic elastics in the loess and the characteristics of the magnetic minerals indicate that there are local materials in Datong loess, which differentiate the Datong loess from the central and eastern loess of the Chinese Loess Plateau. In addition, there are four polarity events in Datong loess, which are generally consistent with Gothenburg> Mono Lake, Laschamp and Blake events. Some signals of the East Asia monsoon were recorded in the Datong loess/paleosol sequences. Magnetic susceptibility, the content of >63um grains and the organic matter are used as climate proxies, which are similar to those of the typical eolian sediments in the loess plateau. In addition, it is possible that the Datong loess also recorded the Younger Dryas and the climatic fluctuations during the Holocene. The main magnetic minerals in the loess/paleosol at Znojmo section are magnetite, maghemite, hematite, pyrite, pyrrhotite and goethite. The morphology of these grains reveals that the iron sulfides originated from the eluvium loam above hypothetical ore deposits in the vicinity of the section or glaciofluvial sediments from nearby glacial margins. The pattern of the susceptibility variation at Dolni Vestonice section is coincident with that of the organic matter content. The grain size variation along the section recorded the climate instability since the last interglacial. The climate events in the Dolni Vestonice section may be correlated with the Heinrich events recorded in North Atlantic sediments, suggesting they controlled by the same marine-continent climate system.

Illness and elevated Human Mortality in Europe Coincident with the Laki Fissure eruption

Grattan, J. Durand, M. Taylor, S., Illness and elevated Human Mortality in Europe Coincident with the Laki fissure eruption. In: 'Volcanic Degassing: Geological Society, Special Publication 213', Oppenheimer, C., Pyle, D.M. and Barclay, J. (eds). Geological Society, London, Special Publications, 410-414, 2003.

Tephra-linked peat humification records from Irish ombrotrophic bogs question nature of solar forcing at 850 cal. yr BC.

This paper investigates evidence for palaeoclimatic changes during the period ca. 1500-500 cal. yr BC through peat humification studies on seven Irish ombrotrophic bogs. The sites are well-correlated by the identification of three mid-first millennium BC tephras, which enable the humification records at specific points in time to be directly compared. Phases of temporarily increased wetness are suggested at ca. 1300-1250 cal. yr BC, ca. 1150-1050 cal. yr BC, ca. 940 cal. yr BC and ca. 740 cal. yr BC. The last of these is confirmed to be synchronous at five sites, suggesting external forcing on a regional scale. The timing of this wet-shift is constrained by two closely dated tephras and is demonstrated to be distinct from the widely reported changes to cooler/wetter conditions associated with a solar minimum at 850-760 cal. yr BC, at which time the Irish sites appear instead to experience drier conditions. The results suggest the possibility of either non-uniform responses to solar forcing in northwest Europe at this time, or the existence of unrelated climate events in the early first millennium BC. The findings caution against the correlation of loosely dated palaeoclimate data if the effects of forcing mechanisms are to be understood.