中国福建省亚热带山地4000年来植被变化的孢粉记录   总被引：1，自引：0，他引：1  

《亚热带资源与环境学报》2006,1(1):11-23

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中全新世以来黑龙江同江地区的孢粉组合与植被、气候演化   总被引：2，自引：11，他引：2  

张玉兰  杨永兴 《地理科学》2002,22(4):426-429

对黑龙江省同江县96－QP剖面从下至上划分4个孢粉组合带：1是以蒙古栎－桦属－蒿属－苔草属－木本科－水龙骨科为主组合带；2是以蒿属－莎草科－禾本科－桦属－栎属为主组合带；3是以桦属－蒙古栎松属－蒿属－莎草科－禾本科为主组合带；4是以松属－桦属－蒙古栎－蒿属－苔草属为主组合带。这4个孢粉组合带清楚地反映了古植被，古气候演替4个阶段；依次为温性落叶阔叶林－针，阔叶混交林→以落叶阔叶树稍多的针、阔叶混交林－草原→以松占优势的针、阔叶混交林。其气候变化是温暖湿润－温和略干－温和略湿－温凉湿润。  相似文献   

CELLULOSE DECOMPOSTION IN TROPICAL PEAT SWAMPS     

Hjh Dulima Jali 《湿地科学》2003,1(1):40-50

Given that organic soil is a complex substrate and there are many environmental factors which directly or indirectly control its decomposition processes, the use of standard substrate simplify the system in that the effect of substrate quality could be eliminated and influence of certain environmental conditions such as edaphic factors, acidity and moisture could be focused on. In addition to the forest floor, decomposition potential down the peat profile can also be examined. Cotton strip assay was used to estimate decomposition potentials in tropical peat swamp occupied by different Shorea Albida peat swamp forest communities, The 'Alan Batu' , the ' Alan Bunga' , the 'Alan Padang' and the ' mixed Alan' forest communities.Greatest decay rates on the peat surface took place during the wet period. The moist condition of the wet months appeared to favour the growth and stimulate activities of decomposer population and soil invertebrates. Generally, 50% of cotton tensile loss is achieved after four weeks  相似文献   

我国贫营养泥炭沉积的物质组成、理化特性及水化学环境分析     

冷雪天  王升忠  赵红艳  林庆华  洪冰  王羽 《矿物岩石地球化学通报》2003,22(2):114-119

泥炭藓是贫营养泥炭类型中的建群植物，由于生态水环境主要靠大气降水补给，少受其他水源的污染，可自然反映古降水、古湿度的情况，所以是古气候研究最理想的纤维素同位素测试材料之一。因此，弄清我国贫营养泥炭沉积的物质组成及水化学环境特征，具有重要意义。笔根据多年来的国内外野外调查，结合收集到的资料，以东北大小兴安岭山地的泥炭辞贫营养泥炭地为基础，与美国、加拿大以及俄罗斯等国家的同类泥炭地相比较，对我国贫营养泥炭沉积的物质组成、理化特性及水化学环境做了系统的分析研究，并就此讨论了湿地保护中的一些实际问题，以及相应的对策。  相似文献   

过去5000年西太平洋副热带高压活动的泥炭纤维素碳同位素记录   总被引：8，自引：2，他引：8       下载免费PDF全文

洪业汤  洪冰  林庆华  朱泳煊  姜洪波  王羽 《第四纪研究》2003,23(5):485-492

文章以金川和红原两组泥炭纤维素Δδ¹³C时间序列值的反向变化来指示西太平洋副热带高压活动变化.结果表明,在过去5000年中,西太平洋副热带高压的活动可分为4个阶段,即西太平洋副热带高压位置在2800～2200B.C.期间持续偏北,2200～600B.C.期间持续偏南,600B.C.～1200A.D.期间在北进与南移之间频繁波动,以及1200～1900A.D.期间再次持续偏北,它们导致降雨量在中国大陆上不同的分布.从约1900A.D.起西太平洋副热带高压的活动似乎又开始一个新的偏南阶段,值得进一步加强研究.  相似文献   

有机质在中国东北部森林沼泽区化探异常追踪和查证中的应用   总被引：4，自引：0，他引：4  

孔牧  杨少平  刘应汉 《物探与化探》2003,27(6):452-454,461

在东北森林沼泽区的几个矿区(点)上,通过以泥炭、腐殖层土壤为采样介质的区域化探异常追踪查证方法技术试验研究,发现Au、Ag、Cu、Pb、Zn等主要成矿元素的测量结果与水系碎屑沉积物、残坡积物的基本一致,对矿体均有良好的反映.研究结果表明在这类景观区化探找矿工作中有机质是可以利用的.  相似文献   

Mid‐Holocene sub‐blanket‐peat alluvia and sediment sources in the upper Liffey valley,Co. Wicklow,Ireland     

Martin Thorp  Peter Glanville 《地球表面变化过程与地形》2003,28(9):1013-1024

A recently exposed section across a ?rst‐order valley buried beneath the regional blanket peat on hillside slopes in the upper Liffey valley, Co. Wicklow, is described. The section shows two alluvia within a shallow valley form underlain by an extensive boulder and stone line over regional till and weathered granite. ¹⁴C dates from wood in the alluvia indicate the older alluvium to have formed between 4324 ± 53 BP and 4126 ± 45 BP and the younger between 3217 ± 53 BP and 2975 ± 53 BP . The basal layer of the overlying peat yielded a date of 2208 ± 61 BP . The younger alluvium shows the effects of soil paludi?cation prior to the peat expansion. Dated pollen analyses elsewhere in the upper catchment con?rm the spread of blanket peat over most areas above 350 m after 4000–3600 BP . The buried valley was contributing sediments to the mid‐Holocene ?oodplains in the upper Liffey valley prior to the extension of blanket peat over the catchment after which sediment yields from it and the other catchment slopes declined. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

泥炭档案气候变化重建的定量模型   总被引：3，自引：1，他引：3  

陶发祥  洪业汤  李汉鼎  冷雪天 《矿物岩石地球化学通报》1997,(2)

泥炭档案气候变化重建的定量模型＊陶发祥洪业汤（中国科学院地球化学研究所，贵阳５５０００２）李汉鼎冷雪天（东北师范大学地理系，长春１３００２４）关键词泥炭档案纤维素稳定同位素气候变化定量模型用泥炭档案定量重建大气ＣＯ２浓度的研究已取得重要进展［１］，但...  相似文献   

山东淄博地区晚古生代成煤环境演替     

王嘹亮  米家榕 《吉林大学学报(地球科学版)》1996,(3)

淄博地区本溪期—石千峰期沉积环境经历了障壁岛—泻湖—台地环境，三角洲环境，曲流河环境体系的演替。相应的泥炭形成环境有不稳定的局限泻湖泥炭坪，较开阔泻湖泥炭坪，中等稳定的开阔泻湖泥炭坪，三角洲平原分流河道两侧的泥炭沼泽，洪泛平原上的泥炭沼泽。成煤植物上，本溪期以Ｃｏｒｄａｉｔｅｓ，Ｌｅｐｉｄｏｄｅｎｄｒａｌｅｓ，Ｎｅｕｒｏｐｔｅｒｉｓ为主，太原期华夏植物群发展，Ｌｅｐｉｄｏｄｅｎｄｒｏｎ，Ｃｏｒｄａｉｔｅｓ继续发育，真蕨纲和种子蕨纲占越来越重要的地位。山西期以Ｏｄｏｎｔｏｐｔｅｒｉｓｓｐ．，Ａｎｎｕｌａｒｉａｏｒｉｅｎｔａｌｉｓ，Ｐｅｃｏｐｔｅｒｉｓｏｒｉｅｎｔａｌｉｓ，Ｐ．ｎｏｒｉｎｉ为主。自煤系形成至今，本区经历了海西印支期的普遍沉降埋藏、燕山期的普遍抬升局部断陷、喜山期的剥蚀、新构造运动期的差异沉降等阶段。古构造、古气候对本区成煤环境有重要的控制作用。  相似文献   

Hydrological connectivity of soil pipes determined by ground‐penetrating radar tracer detection     

Joseph Holden 《地球表面变化过程与地形》2004,29(4):437-442

Soil pipes are common and important features of many catchments, particularly in semi‐arid and humid areas, and can contribute a large proportion of runoff to river systems. They may also signi?cantly in?uence catchment sediment and solute yield. However, there are often problems in ?nding and de?ning soil pipe networks which are located deep below the surface. Ground‐penetrating radar (GPR) has been used for non‐destructive identi?cation and mapping of soil pipes in blanket peat catchments. While GPR can identify subsurface cavities, it cannot alone determine hydrological connectivity between one cavity and another. This paper presents results from an experiment to test the ability of GPR to establish hydrological connectivity between pipes through use of a tracer solution. Sodium chloride was injected into pipe cavities previously detected by the radar. The GPR was placed downslope of the injection points and positioned on the ground directly above detected soil pipes. The resultant radargrams showed signi?cant changes in re?ectance from some cavities and no change from others. Pipe waters were sampled in order to check the radar results. Changes in electrical conductivity of the pipe water could be detected by the GPR, without data post‐processing, when background levels were increased by more than approximately twofold. It was thus possible to rapidly determine hydrological connectivity of soil pipes within dense pipe networks across hillslopes without ground disturbance. It was also possible to remotely measure travel times through pipe systems; the passing of the salt wave below the GPR produced an easily detectable signal on the radargram which required no post‐processing. The technique should allow remote sensing of water sources and sinks for soil pipes below the surface. The improved understanding of ?owpath connectivity will be important for understanding water delivery, solutional and particulate denudation, and hydrological and geomorphological model development. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献