PALYNOLOGICAL RECORD OF PALEOVEGETATIONCHANGE DURING HOLOCENE AT NORTH TUMDPLAIN IN INNER MONGOLIA,CHINA

I~are~orsruDVThemiddleinnerMongoliaissituatedintherearpartoftheeasternAsianmonsonzone,itissensitivetotheclimatechange,thereforeitsenvironmentchangeintheHOIOcenehasbeenPaidattentiontobythescholarsofpaleoclimateandpal~nvirorunent.Wedidhighr~lutionPOllenanalysisonapeatprofileinpluvialfan,whichwaslocated3kmtothenorthOfQaSq,theheadquarteroftheTumdBanner,InnerMongolia,withaltitudeof1000malerssealevel.Theaverageannualtemperaturewas5.6t,annualprecipitation300--450rum,theclimatewascontinentaland…     

The holocene sedimental characteristicand paleoclimatic evolution of Ebinur Lake,XinJiang

On the basis of lacustrine sedimentary profile of Ebinur Lake, sequences of evolution of paleoclimate and paleoenvironment in Ebinur Lake area have been rebuilt by analysing the sedimentary stratigraphy, bio-stratigraphy and geochemistry as well as the chronological records. The results show that, during the last 10 ka years, the general change trends of the paleoclimate in E-binur Lake area can be divided into three stages: (1) 10. 2 – 8.3 ka B. P., a warm-cool dry climate stage; (2) 8.3–3.5 ka B. P., a warmer moist climate stage (specially, 7.3–6.4 ka B. P., a relatively stable humid temperate stage); (3) 3.5 ka B. P. —present, adraught temperate climate stage, similar to the present climate. In addition, there existed clearly several times of secondary undulations of dry-humid climate, i.e. 8.3 ka and 7.3 ka for dry climate     

Mid-Holocene Climate Variations Recorded by Palaeolake in Marginal Area of East Asian Monsoon： A Multi-proxy Study

Traditionally, the mid-Holocene in most parts of China was thought to be warmer with higher precipitation, resulting from a strong Asian summer monsoon. However, some recent researches have proposed a mid-Holocene drought interval of millennial-scale in East Asian monsoon margin areas. Thus whether mid-Holocene was dry or humid remains an open issue. Here, Zhuyeze palaeolake, the terminal lake of the Shiyang River Drainage lying in Asian monsoon marginal areas, was selected for reconstructing the details of climate variations during the Holocene, especially mid-Holocene, on the basis of a sedimentological analysis. Qingtu Lake (QTL) section of 6.92m depth was taken from Zhuyeze palaeolake. Multi-proxy analysis of QTL section, including grain size, carbonate, TOC, C/N and δ13C of organic matter, was used to document regional climatic changes during 9-3 cal ka B.P. The record shows a major environmental change at 9.0-7.8 cal ka B.P., attributed to a climate trend towards warmth and humidity. This event was followed by a typical regional drought event which occurred during 7.8-7.5 cal ka B.P. And a warm and humid climate prevailed from 7.5 to 5.0 cal ka B.P., attributed to the warm/humid Holocene Optimum in this region. After that, the climate gradually became drier. Moreover, comparison of the climate record from this paper with the summer insolation at 30°N indicates that the climate pattern reflecting the Asian monsoon changes was caused by insolation change.     

Vegetation dynamics and its relationship with climatic factors in the Changbai Mountain Natural Reserve

This study examined the temporal variation of the Normalized Difference Vegetation Index (NDVI) and its relationship with climatic factors in the Changbai Mountain Natural Reserve (CMNR) during 2000-2009.The results showed as follows.The average NDVI values increased at a rate of 0.0024 year-1.The increase rate differed with vegetation types,such as 0.0034 year-1 for forest and 0.0017 year-1 for tundra.Trend analyses revealed a consistent NDVI increase at the start and end of the growing season but little variation or decrease observed in July during the study period.The NDVI in CMNR showed a stronger correlation with temperature than with precipitation,especially in spring and autumn.A stronger correlation was observed between NDVI and temperature in the tundra zone (2,000-2,600m) than in the coniferous forest (1,100-1,700m) and Korean pine-broadleaved mixed forest (700-1,100m) zones.The results indicate that vegetation at higher elevations is more sensitive to temperature change.NDVI variation had a strong correlation with temperature change (r=0.7311,p<0.01) but less significant correlation with precipitation change.The result indicates that temperature can serve as a main indicator of vegetation sensitivity in the CMNR.     

Distribution Patterns and Associations of Dominant Tree Species in a Mixed Coniferous-Broadleaf Forest in the Changbai Mountains

In 2012 a plot was established with 1-ha area in a mixed coniferous-broadleaf forest in the Changbai Mountains, northeastern China for examining local forest processes, structure and succession. A method of O-ring statistics(paircorrelation function) was applied to analyze the spatial patterns and associations of the dominant species within different vertical layers. After the evaluation by their importance values, six tree species(or group)(i.e. Abies nephrolepis, Picea jezoensis, Pinus koraiensis, Tilia amurensis, and species group of Betula ssp. and species group of Acer ssp.) were determined as dominant trees species. It was found that some of these species exhibited closely clustered distributions at fine distances. As spatial distance increased, a random or even regular distribution gradually appeared with the exception of the upper layers of A. nephrolepis and P. koraiensis, and the lower layers of P. jezoensis, P. koraiensis and Betula ssp., which were substantially randomly distributed. Intra- and inter-species spatial associations varied in accordance with species, tree height and reciprocal distances. Positive associations were observedbetween the lower and upper height classes of trees of the same species(except for that of P. jezoensis) at fine distances. This may be owing to limited seed dispersal and geological heterogeneity. The aggregation intensity declines with increasing distances and this consistent with the predictions of self-thinning. Some coniferous trees(e.g. Pinus koraiensis) in the lower height class were positively associated with T. amurensis and group of Betula ssp. of the upper height class at some distances, suggesting that saplings of coniferous trees occupy a broader niche and can grow well under the canopy of the adult of broad-leaved trees. Negative associations were observed between upper coniferous trees and lower broad-leaved trees and between upper P. jezoensis and lower P. koraiensis, suggesting that a canopy of these trees might not provide suitable environment for the survival, establishment, and growth of lower individuals, corresponding well to Janzen-Connell hypothesis.     

Effects of climate change on potential habitats of the cold temperate coniferous forest in Yunnan province,southwestern China

We built a classification tree(CT) model to estimate climatic factors controlling the cold temperate coniferous forest(CTCF) distributions in Yunnan province and to predict its potential habitats under the current and future climates, using seven climate change scenarios, projected over the years of 2070-2099. The accurate CT model on CTCFs showed that minimum temperature of coldest month(TMW) was the overwhelmingly potent factor among the six climate variables. The areas of TMW-4.05 were suitable habitats of CTCF, and the areas of -1.35 TMW were non-habitats, where temperate conifer and broad-leaved mixed forests(TCBLFs) were distribute in lower elevation, bordering on the CTCF. Dominant species of Abies, Picea, and Larix in the CTCFs, are more tolerant to winter coldness than Tsuga and broad-leaved trees including deciduous broad-leaved Acer and Betula, evergreen broadleaved Cyclobalanopsis and Lithocarpus in TCBLFs. Winter coldness may actually limit the cool-side distributions of TCBLFs in the areas between -1.35°C and -4.05°C, and the warm-side distributions of CTCFs may be controlled by competition to the species of TCBLFs. Under future climate scenarios, the vulnerable area, where current potential(suitable + marginal) habitats(80,749 km~2) shift to nonhabitats, was predicted to decrease to 55.91%(45,053 km~2) of the current area. Inferring from the current vegetation distribution pattern, TCBLFs will replace declining CTCFs. Vulnerable areas predicted by models are important in determining priority of ecosystem conservation.     

PROFESSOR ZHU KEZHEN OPENING UP A PATH FOR RESEARCH ON CLIMATIC CHANGE IN CHINA

ＰＲＯＦＥＳＳＯＲ ＺＨＵ ＫＥＺＨＥＮ ＯＰＥＮＩＮＧ ＵＰ Ａ ＰＡＴＨ ＦＯＲ ＲＥＳＥＡＲＣＨ ＯＮ ＣＬＩＭＡＴＩＣ ＣＨＡＮＧＥ ＩＮ ＣＨＩＮＡ ＳｈｉＹａｆｅｎｇ（施雅风）（ＬａｎｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＧｌａｃｉｏｌｏｇｙａｎ...     

Studies on quaternary sporo-pollen assemblage and paleoclimate based on Bohai Sea core Bc−1

Analysis of 13 spore-pollen assemblage zones reflecting environmental changes since the later middle Pleistocene showed the seccession of paleovegetation and the paleogeographic changes in the Bohai Basin and circumjacent area. Paleoclimatic variations here can obviously be divided into 5 cold and 5 warm periods: 2 cold and 1 warm periods in 200,000–100,000 a B.P.(late middle Pleistocene) 3 cold and 3 warm periods in 100,000–12,000 a B.P.(late Pleistocene), and 1 warm period since 12,000 a B.P. Late Pleistocene climate tended to become colder and colder. The coldest period was in the later stage of late Pleistocene, when the study area was a periglacial zone. The mean annual temperature then was about 10°C lower than it is now. In the middle stage of late Pleistocene, climate became warm; the mean annual temperature then was about 3–4°C higher than it is now. By applying principles of climatic stratigraphy, the authors deduced through sporo-pollen analysis, that the boundary between middle and late Pleistocene should be at 178–181 m, and that between Pleistocene and Holocene should be at 12.8 m. The results of climatic stratigraphy are consistent with those of magnetic stratigraphy. This paper was published in Chinese inOceanologica et Limnologia Sinica.18 (3): 253–266, 1987.     

Carbon dynamics in woody biomass of forest ecosystem in China with forest management practices under future climate change and rising CO2 concentration

It is critical to study how different forest management practices affect forest carbon sequestration under global climate change regime. Previous researches focused on the stand-level forest carbon sequestration with rare investigation of forest carbon stocks influ- enced by forest management practices and climate change at regional scale. In this study, a general integrative approach was used to simulate spatial and temporal variations of woody biomass and harvested biomass of forest in China during the 21st century under dif- ferent scenarios of climate and CO2 concentration changes and management tasks by coupling Integrated Terrestrial Ecosystem Carbon budget （InTEC） model with Global Forest Model （G4M）. The results showed that forest management practices have more predominant effects on forest stem stocking biomass than climate and CO2 concentration change. Meanwhile, the concurrent future changes in cli- mate and CO2 concentration will enhance the amounts of stem stocking biomass in forests of China by 12%-23% during 2001-2100 relative to that with climate change only. The task for maximizing stem stocking biomass will dramatically enhance the stem stocking biomass from 2001~100, while the task for maximum average increment will result in an increment of stem stocking biomass before 2050 then decline. The difference of woody biomass responding to forest management tasks was owing to the current age structure of forests in China. Meanwhile, the sensitivity of long-term woody biomass to management practices for different forest types （coniferous forest, mixed forest and deciduous forest） under changing climate and CO2 concentration was also analyzed. In addition, longer rotation length under future climate change and rising CO2 concentration scenario will dramatically increase the woody biomass of China during 2001~100. Therefore, our estimation indicated that taking the role of forest management in the carbon cycle into the consideration at regional or national level is very important to project the forest carbon sequestration under future climate change and rising atmospheric CO2 concentration.     

Middle Holocene warm period and sea level high in coastal areas,North China

Relevant geological, geographical, archaeological data were collected to study the characteristics of middle Holocene warm period and sea level high on North China coast. Middle Holocene climate and sea level change on North China coast were correlated to warm marine environment events in about 8-3 ka B.E The sea level in about 8 ka B.E was higher than present mean sea level, then fluctuated for 5 000 years and after that it became even in 3 ka B.E The highest sea level occurred in about 6-5 ka B.E; the maximum was about 2-3 m and minimum was about 1-2 m.     

VEGETATION CHANGES OF THE TAIHANG MOUNTAINS SINCE THE LAST GLACIAL

1 BACKGROUND The Taihang Mountains is located in the western part of Hebei Province. It is bounded by the North China Plain to the east, the Shanxi Plateau to the west and the Yanshan Mountain to the north; the southern boundary is formed by the Huanghe (Yellow) River. It has an area about 30 000 km2, occupies about 17％ of the total area of Hebei Province. The Taihang Mountains has a continental monsoon climate, with the mean annual temperature between － 1.7℃ to 13℃ and mean ann…     

A singular spectrum analysis on Holocene climatic oscillation from lake sedimentary record in Minqin Basin, China

The total organic carbon (TOC) content series from the lake sediment of Minqin Basin (100°57′–104°57′E, 37°48′–39°17′N) in northwestern China, which has a 10 000-year-long paleo-climatic proxy record, was used to analyze the Holocene climate changes in the local region. The proxy record was established in the Sanjiaocheng (SJC), Triangle Town in Chinese, Section (103°20′25″E, 39°00′38″N), which is located at the northwestern boundary of the present Asian summer monsoon in China, and is sensitive to global environmental and climate changes. Applying singular spectrum analysis (SSA) to the TOC series, principal climatic oscillations and periodical changes were studied. The results reveal 3 major patterns of climate change regulated by reconstructed components (RCs). The first pattern is natural long-term trend of climatic change in the local area (Minqin Basin), indicating a relatively wetter stage in early Holocene (starting at 9.5 kaBP), and a relatively dryer stage with a strong lake desiccation and a declined vegetation cover in mid-Holocene (during 7–6 kaBP). From 4.0 kaBP to the present, there has been a gradually decreasing trend in the third reconstructed component (RC3) showing that the local climate changed again into a dryer stage. The second pattern shows millennial-centennial scale oscillations containing cycles of 1 600 and 800 years that have been present throughout almost the entire Holocene period of the last 10 000 years. The third pattern is a millennial-centennial scale variation with a relatively smaller amplitude and unclear cycles showing a nonlinear interaction within the earth’s climate systems.     

RECONSTRUCTING HOLOCENE PALAEORUNOFF REGIMES FROM PALAEOCLIMATE: AN INITIAL ATTEMPT TO APPLY A CLIMATOLOGICAL APPROACH TO PALAEOHYDROLOGY FOR THE NORTH CHINA PLAIN

１　ＩＮＴＲＯＤＵＣＴＩＯＮＲｕｎｏｆｆｉｓｄｅｆｉｎｅｄａｓｔｈｅｗａｔｅｒｔｈａｔｄｒａｉｎｓｆｒｏｍｔｈｅｌａｎｄｉｎｔｏｃｒｅｅｋｓａｎｄｒｉｖｅｒｓ（Ｌａｎｇｂｅｉｎｅｔａｌ．，１９４９）ａｎｄｔｈｕｓａｖｅｒｙｉｍｐｏｒｔａｎｔｈｙｄｒｏｌｏｇｉｃａｌｐａｒａｍｅｔｅｒｄｅｓｃｒｉｂｉｎｇｑｕａｎｔｉｔｙｓｔａｔｕｓｏｆｓｕｒｆａｃｅｗａｔｅｒ．Ｉｔｉｓｌａｒｇｅｌｙａｆｕｎｃｔｉｏｎｏｆｔｈｅｃｌｉｍａｔｉｃｃｏｎｄｉｔｉｏｎｓｔｈｏｕｇｈｉｔｉｓａｌｓｏａｆｆｅｃｔｅｄｂｙｖｅ…     

RELATIVE BRIGHTNESS INDEX AND IT‘S CLIMATIC SIGNIFICANCE FROM LACUSTRINE SEDIMENT OF NAPAHAI LAKE，NORTHWESTERN YUNNAN PLATEAU，CHINA

Information on the palaeoenvironment from Late Pleistocene to Holocene in northwestern Yannan Plateau has been deduced from a study of a 28.81m-long core taken from Napahai Lake.The results from Relative Brightness In-dex(RBI) as well as those from the lithological analyses of bulk sediments,total organic carbon and granulometric analy-ses have been used to reconstruct the environmental and climatic evolution of the area.The ages were provided by three ^14C datings.The record suggested a climate fluctuation between warm-dry and cool-wet from ca.57 to 32ka B.P.which led a shallowing and swamping of the lake.The water level again increased quickly at ca.32ka B.P.,reached itˊs peak during LGM(Last Glacial Maximum,ca.18-20kaB.P.)and remained relative high until ca.15kaB.P.The high wa-ter level at LGM is attributed to cold-wet conditions.The area experienced an abrupt and unstable climatic changes dur-ing the transition period form 15 to 10ka B.P.with a dominated littoral environment.Awarm-dry climate led to the contrac-tion of the lake during the Holocene and reed-swamps became dominant..After a minor wet-cool pulse during the Late Holocene,the modern climate became to be established.     

Transformation of Carbon and Nitrogen by Earthworms in the Decomposition Processes of Broad-leaved Litters

Earthworms are the important constituents in the decayed food web and the main ecological conditioners in the process of decomposition and nutrient mineralization. The transformation of organic carbon (C) and total nitrogen (N) in the broad-leaved litters ingested by earthworms was researched by means of a laboratory experiment. Experimental samples were collected from broad-leaved Korea Pine mixed forest in Liangshui National Natural Reserve (47°10′50″N, 128°53′20″E) in the northeastern Xiao Hinggan Mountains of Northeast China. The contents of organic C and total N in earthworms, leaf litters and earthworm faeces were analyzed. Results show that the organic C content was in the fol- lowing order: leaf litters>faeces>earthworms, while total N content was contrary to that of the organic C. The organic C contents in the different leaf litters were in the following order: Tilia amurensis>Betula costata>Acer mono, whereas the total N contents in the different leaf litters were: Betula costata>Tilia amurensis>Acer mono. The contents of organic C and total N in the faeces from the different leaf litters were almost consistent with the contents of the leaf litters. After the leaf litters were ingested by earthworms, the organic C, which was transformed to increase earthworms' weights, ac- counted for 3.90%-13.31% of the total ingestion by earthworms, while that in the earthworm faeces accounted for 6.14%-13.70%. The transformed organic C through the other metabolism (e.g., respiration) of earthworms accounted for 75.04%-89.92%. The ingested organic C by earthworms was mostly used for metabolic activities. The N ingested by earthworms was less than organic C. It is estimated that 37.08% of total N was transformed to increase the earthworm's weight, 19.97% into earthworm faeces and 47.86% for the consumption of the earthworm's activities. The earthworms not only increased the content of organic C and total N in the soil, but also decreased the values of C/N in the soil and leaf litters. Earthworms play a major role in the leaf litters' decomposition and transformation.     

ALFISOLS AND CLOSELY RELATED SOILS IN CHINA

Alfisols are important soils in China. They occupy about 1.25 million km3, or about 13% of the land area. In the current Chinese system of soil classification, burozem, yellow-brown earths, Baijiang (Planosol) soils and parts of drab soils. They are mostly forested soils with an estimated 5-13 t / ha · yr of organic matter returned to the soils from temperate mixed conifer and broad-leaved forest. In terms of elemental bio-cycling, Ca is prominent.In a comparison of 30 profiles the average ratio of clay (B/ A) was 1.47 for Cryoboralfs and Eutroboralfs; 1.88 for Hapludaifs and 2.53 for Paleudalfs. From Eutroboralfs to Paleudalfs the average gain (or loss) in clay during soil development is about a factor of seven.The moisture regimes vary considerably between Hapludaifs, Cryoboralfs, and associated Cryaquepts, but the amount of water is always enough to cause significant leaching. In the weathering, and pedogenesis processes TiO2, MgO and Fe2O3 are accumulated, respectively, in both A and BA horizons; b     

Isotopic evidence for holocene climatic changes in Bosten Lake, Southern Xinjiang, China

Based on the δ¹³C and δ¹⁸O fluctuation of lacustrine carbonate, CaCO₃ content and sporo-pollen data, a palaeoclimatic history of Bosten Lake during the Holocene has been outlined, several stages of climatic changes are divided, and the following result es are obtained: (1) Palaeoclimatic changes revealed by carbonate isotope around Bosten Lake are basically identical with that revealed by other geological records in Xinjiang. Environmental changes presented apparent Westlies Style model: during cold period, relative humidity increased, δ¹⁸O, δ¹³C and CaCO₃ appeared low; but in warm periods, the dry regime aggravated. (2) The temperature reflected by δ¹⁸O exist evident features being increase in the late period during the Holocene. Together with the δ¹³C, pollen and CaCO₃ analyses, several cold and warm phases which are of broad regional significance can be identified. The warm peaks occurred at about 11.0 ka B.P., 9.4 ka B.P., 7.5 ka B.P., 5.0 ka B.P., 3.0 ka B.P. and 2.0 ka B.P.; the cold peaks at 11.5 ka B.P., 10.5 ka B.P., 8.8 ka B.P., 5.5 ka B.P., 3.3 ka B.P., 2.2 ka B.P. and 1.5 ka B.P.. (3) Several climatic events with the nature of “abrupt climatic changes” are revealed in the periods of 11.0 ka B.P. −10.5 ka B.P., 9.4 ka B.P. −8.8 ka B.P., 5.5 ka B.P. −5.0 ka B.P. and 2.0 ka B.P. −1.5 ka B.P.. (4) The results show that carbonate isotopic record of lacustrine sediment in arid area is very sensitive to climatic changes, and may be play a very important role in understanding the features and mechanism of palaeoclimatic changes.     

THE HOLOCENE SEDIMENTAL CHARACTERISTIC AND PALEOCLIMATIC EVOLUTION OF EBINUR LAKE，XINJIANG

ＴＨＥＨＯＬＯＣＥＮＥＳＥＤＩＭＥＮＴＡＬＣＨＡＲＡＣＴＥＲＩＳＴＩＣＡＮＤＰＡＬＥＯＣＬＩＭＡＴＩＣＥＶＯＬＵＴＩＯＮＯＦＥＢＩＮＵＲＬＡＫＥ，ＸＩＮＪＩＡＮＧ吴敬禄，王苏民，吴艳宏ＴＨＥＨＯＬＯＣＥＮＥＳＥＤＩＭＥＮＴＡＬＣＨＡＲＡＣＴＥＲＩＳＴ...     

Responses of soil fauna structure and leaf litter decomposition to effective microorganism treatments in Da Hinggan Mountains, China

Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added microorganism is little understood.In this study,in the coniferous and broad-leaved mixed forest of Tahe County in the northern Da Hinggan Mountains,China,three sampling sites(each has an area of 10 m2) were selected.The first two sites were sprinkled with 250 times(EM1) and 1000 times(EM2) diluted effective microorganism(EM) preparations evenly,and the third site was sprinkled with the same volume of water as a control site.The responses of soil fauna structure and leaf litter decomposition to EM treatment were conducted during three years.The results revealed that EM treatment resulted in significant increase of soil organic matter.The number of soil fauna in the EM1 and EM2 sites increased by 12.88% and 2.23% compared to the control site,and among them springtails and mites showed the highest increase.However,the groups of soil fauna in the EM1 and EM2 sites decreased by 6 and 9,respectively.And the changes in the diversity and evenness index were relatively complicated.EM treatment slowed the decomposition of broad-leaved litter,but accelerated the decomposition of coniferous litter.However,the decomposition rate of broad-leaved litter was still higher than that of coniferous litter.The results of this study suggested that the added microorganisms could help individual growth of soil fauna,and this method led to a change in the process of leaf litter decomposition.This paper did not analyze the activity of soil microorganisms,thus it is difficult to clearly explain the complex relationships among litter type,soil fauna and soil microorganisms.Further research on this subject is needed.     

Climatic change and human activities of northeastern sahara in Holocene

Chronology establishment and dating data analyses on lacustrine deposits in northeastern Sahara show that vast fresh lakes existed over there between 9900–2400 a B. P. Especially, great continuous lakes developed and got their maximum extent during the period from 9800 a B. P. to 6450 a B. P. From 6000 a B. P. to 3600 a B. P., the evolution of the lakes experienced a new stage with a property of drastic fluctuations and a periodicity of 600 years, which was the response to the climatic environment changes. On the aspect of the relation between natural environment and the human, the warm-humid period in the Holocene was not only a very important time for human development and evolution, but also was a moment for human reproduction and division. On the other hand, this warm-humid period was also a distinguished time to natural environment changes, the accumulation of the strong weathered debris and fine materials formed the basements for the formation of the Sahara Desert. Supported by the National Natural Science Foundation of China, German Research Foundation and Gansu Provincial Natural Science Foundation.