Abstract:Climate in the last glacial maximum (LGM) is characterized by of the lowest anomaly of orbital forcing-induced insolation, but the greatest volume of Quaternary ice sheets in the northern hemisphere during the last 20000 years.Advaces in data collection, palaeoclimate modelling, land-sea-ice correlation, interpretation of classical proxies and development of new proxies, and international cooperations for the LGM since the last published synthesis of terrestrial palaeodata of the beginning of the 70s have prompted a new evaluation of palaeoclimate and paleovege tat ions.The paper attempts to review recent international publications, syntheses the results of a few of undergoing international cooperation projects, and provides preliminary highlights for the outlooks.LGM boundary conditions can now be specified with greater confidence and precision than was possible when the first simulations of LGM land climates were performed in the end of the 1980s.Palaeoclimate modelling has advanced considerably, due to the availability of faster computers and the progressive refinement of atmospheric models.Simulations including coupling to dynamical ocean models and biosphere models can be now undertaken.Modelling intercomparsiort and therefore data-modelling comparsion can be undergoing in a global scale within the PMIP project.Acquisition of terrestrial palaeodata has continued, and in particular there have been major efforts to obtain proxy records form sediment cores in previously data-sparse regions.Dating accuracy has also been improved thanks to the increasing use of AMS for ¹⁴C-dating small samples of material of identifiably terrestrial origin.Data syntheses have been carried out on a rigorous basis starling with the Global Lake Level Data Base and the regional pollen and lake-level dala compilations carried out within the COHMAP project and continuing through the I GBP-sponsored BIOME 6000 prject, which includes the compilation of pollen records for the LGM and their translation into palaeobiomes using a standard methodology.Understanding and interpreting of the classical proxy data sources have been improved greatly.Multiproxy calibration methods have developed, ancl new proxy data sources have been developed, including the noble gas thermometer in groundwater and δ¹⁸O in speleothems as records of mean annual temperatures on land.Understanding of the temporal context of the LGM has changed drastically, due to the recognition of large, synchronous climate fluctuations during the glacial stages in high-resolution climate records from Greenland ice, marine foraminiferal records’ terrestrial pollen records and loess.Cold-month temperature of LGM was estimated form pollen and plant macrofossi 1 -based elevation shifts of vegetation belts and horizontal displacements of biomes, noble gases in gronudwa-ter and δ¹⁸O in speleothems.Cold-month anomalies ranged from -2 K at low elevations in Indonesia and the southern Pacific through -6 to -8K at many high-elevation sites to -8 to -15K in eastern China and the southeastern USA.Qualitative estimates of plant-available moisture from palaeo-ecological data and regional water balance from lake-level data, indicate LGM conditions wetter than present in westrn USA and the circum-Mediterranean region, likely associated with southward displacement of the jet stream, and at high elevations of Tibetan plateau and high mountains of Pacific islands where the effect of cooling on evaporative demands may have been decisive.The rest large lands of the world, both moisture indices show drier then present conditions elsewhere.These results are consistent with a colder than present ocean surface producing a weaker hydrological cycle and more arid continents.Developments of LGM studies in recent years have created further opportunities for exploiting a series of research projects such as International Global Atmospheric Chemistry, Global Analysis, Interpretation and Modelling, Global Changes and Terrestrial Ecosystem in global change science.

Abstract:This paper summarizes lake changes in the arid or semi-arid inland mainland Asia since the beginning of 20-century, and further investigates the possible causing, especially the effects of climatic change.In the northern Mongolia and eastern Inner Mongolia, the lakes show a general increase in water stand, which is caused by the increase in precipitation.Meanwhile, the temperature rising is favourable for melting the frost underground water and augmenting the soil tension water and runoff.In the western Central Asia, the water level of Caspian Sea has turned to rise since 1978, which is also associated with the increase in moisture condition in the catchment.In the mountainous central Asia, most lakes show a general decrease in water level.These lake level drop are caused either by the trend of dry and warm condition, or by the human activities, or by both.The rainfall record indicates a slightly reduction of rainfall, particularly the reduction of winter rainfall, which presumably related to the increase in winter temperature resulted in the shift of westerlies in winter time.Decrease in precipitation result in more water to be channeled and irrigated, therefore, the lake shrinkages will be speeded up.

Abstract:Poyang Lake is the largest freshwater lake in China with a catchment area of 162000km2.The only outlet to the Changjiang River is at Hukou.The flood regimes in the lake are mainly controlled by the Changjiang River and the 5 tributaries to the lake.The reclamation in the lake area may be traced back to the Song Dynasty.The benefits of reclamation to mankind were inevitably hampered due to the frequent, natural flooding.It was estimated that an area of 15.8 km² had been reclaimed before 1949, among which the standards of many dykes were too low to resist heavy flooding.After 1949, the economic growth as well the urgency for eliminating popular snail fever in the lake beach triggered the large-scale reclamation movement around the lake.Up to 1995, statistics show that a total area of 1466.9km2 has been reclaimed, which brought a series of unfavorable influences on the flood regimes of the lake, such as: (1) the shrinkage of lake area and capacities, (2) the deterioration of flood regulating and functioning, and (3) the ascending of peak floods and corresponding frequencies.The impacts of reclamation on the flood regime of Poyang Lake are analyzed.Five represent -ative flood years, i.e., 1954, 1962, 1976, 1983 and 1995 are selected? as backgrounds for estimation.Comparisons are made between the calculated and observed flood characters of certain typical flood years under present reclamation conditions.Furthermore, the supposing flood peak changes conditioning future reclamation/de-reclamation based on 1954-type flood processes under present vsituation are given.The more de-reclamation, the more will flood regime be alleviated.

Abstract:One of the most dramatic climate change events is the Younger Dryas event (YD), a return to near-glacial conditions that punctuated the last deglaciation.Based chiefly on the lacustrine carbonate isotopic composition, spore-pollen and geochemical element wet-dry index C and CaCO₃ analyses of Bosten Lake, southern Xinjiang, the most striking Younger Dryas cooling event (YD) during last deglaciation has been revealed.This record shows that both the onset and termination of the YD event occurred within 11.0-10.OkaBP, essentially synchronizing with Europe and Greenland, during which climate was characterized by a cold and relative humid regime.Although the mechanism for creating such abrupt and global event is not easly to be explained, the results obtained from southern Xinjiang, the aridest inland area in China, may provide some fresh insights into such abrupt climatic anomalies.

Abstract:Jianghan Plain, a very famous plain fo.r its abundant products and river-lake cross landscape, is the place where Yunmenze palaeolake existed.The Miancheng area is the sedimentation center of Jianghan Plain with lowlying topography.Human activities on this area were comparatively late in history.A 56.18-m-core was collected in Miancheng of Jiang plain in Oct.1992.According to the sediment lithology, cultural remnants, ¹⁴C chronology and human-derived environmental proxies, e.g.pollen, frequency magnetic susceptibility and chemical element phosphorous, the temporal sequences of human activities in Miancheng area since the mid-late Holocene and its relation with palaeoenvironment are discussed in this paper combined with the study on temporal-spatial distribution of cultural relics in this area.The results have shown that the climate was warm and wet in 6.7-3.5 kaBP, and the core site was characterized by fluvial depression or shallow lake environment .In 2.5-1.7 kaBP, the lake was stable and there was no human dwelling, but was slightly influenced by human activities in surrounding area.In 3.5-2.5 kaBP, the influence of human activities was enhanced.The core site was exposed since 1.7 kaBP and there were human residents in this area.All above suggest the human being’s subjection to nature in the era of poor productivity, i.e.human being withdrawing with the lake transgression, and marching with the lake regression.

Abstract:Based on the charateristics of environmental index in respect of granularity, magnetic susceptibility, TOC, δ¹³C and pollen of sediment from ZK2 profile which located in Meijiazhou (116°12'50"E, 29°44'30"N) in Hukou area, Poyang Lake, the paleoenvironmental evolution sequence of Hukou area for over 4500 years has been rebuilt.As a result, the sequence of the paleoenvironmental evolution in Hukou area includes four stages as: (1)4500-3800aBP, it belonged to the stage of hot and wet, inlake delta;(2)3800-3400aBP, cool and dry, river;(3) 3400-2300aBP, climate fluctuated, inlake delta to lake;(4) 2300aBP onwards, cool, floodland.

Abstract:The basic database is established preliminarily on IBM-PC with SYSTAT by using fishery resources data (investigated from 1980 to 1994) of 527 reservoirs of 25 provinces in China.52 targets, which belong to 3 layers : reservoir morphology and natural environment, water physics and chemistry, hydrobiology and fish growth, were analysed preliminarily.The results show that the ratio of valley-, hilly-and plain-typed reservoirs is 3:6:1;the average fish yield of small-sized and valley-typed reservoirs is the highest, and that of small-sized and valley-typed reservoirs is the lowest.On the first layer, the data of each geography and climatology target are normally distributed and the C_v is smaller;the data of most morphology and hydrology targets, except FYR (finished year), MAXD (maximum depth) and MD (mean depth), are skewed distributed, and the C_v is larger.The NPI (total nitrogen to total phosphorus index) has the largest C_v on the second layer, which shows taht the two factors TN and TP are not coordinate in most reservoirs in China.All the targets of IH (illumination hours), NFD(annual no frost days), MAXD, MD, PH (value of pH), BP (biomass of phytoplankton), DZ (density of zooplankton) and BPZ( total biomass of phytoplankton and zooplankton) are significantly different among different fish yield levels.The database also reveals that the fish yield of reservoirs located in 30-35°N, is 6 times of that located in 45-50°N.It is suggested that the national database of fishery resources of reservoirs in China should he established as soon as possible, so that the management information system of reservoir fishery resources could be further established step by step.

Abstract:This paper describes the characteristics of mature 0⁺ crabs, Eriocheir sinensis, and its regression relationship between body weight (BW) and carapace width (CW).For the 0⁺ female crabs, when BW>29.8g(CW>4.03cm), the sexual gland is mature;when BW< 13.lg (CW <3.00cm), the sexual gland is immature.When BW ranges 13.1 -29.8g, some crabss are ma-true, some crab are immature.For the 0⁺ male crabs, when BW >26.Og (CW >3.91cm), all the crabs are mature;when BW< 12.0g (CW<2.66cm), immature.The sexual gland degrades from then on.In the first ten-day period of next July, the ovary looks like the slender thread and there is no complete ovum.

Abstract:The reproduction and survival of the Moina macrocopa Straus under 25X3 and six salinities of seawater (2‰, 3‰, 4‰, 6‰, 8‰ and 10‰) has been studied.The experiment results show the total life span on a decrescendo basis varies with the increasing of salinity.Mean number of young produced per female and total number of young produced and the intrinsic increase rate (r_m) haven't significant differences (2‰-4‰).The results of the experiments also show that the appropriate salinity is 2‰-4‰, while lethal upper salinity limit of reproduction is 6%o.Finally, it is found that after short term training, the lethal upper salinity limit of reproduction and survival of Moina macrocopa may rech 8‰.

Abstract:The isozyme of SOD in Spirulina maxima with four bands by gradient electrophoresis was identified as Fe-SOD, which was purified by ammonium sulfate fractionation followed by DEAE-Celluose and Sephadex G-100 column chromatography.The molecular weight of the enzyme is 39.3KD, and that of its subunit molecular mass is 20KD.Metal analysis showed that the Fe-SOD contains about 0.55 atom of iron per subunit.The enzyme exhibits one absorption maximum at 275.8nm.The enzyme activity could be inhibited by H₂O₂ but unaffected by KCN.The Fe-enz-yme contains more alanine residues.The ratio of acid amino acid and alkaline amino acid is similar to lower plants and procaryotes, obviously higher than those of higher plants.

Abstract:The embryonic development of Megalobrama skoikovii was studied from 1989-1990.The fertilized eggs of Megalobrama skoikovii were obtained by artificial spawning and natural insemination .They were treated in trypsase solution in order to remove the egg membrane, then the naked eggs were cultured consequently in Holtfreter solution and aerated distilled water, 29 development stage characteristics were described and illustrated.

Abstract:This paper studies the practicability and rationality of the application of grey system theory to the assessment of water quality of lakes and proposes the multi-target grey situation decision making method by using grey decision theory.Here, the water sample is taken as an event, the grade of water quality as a strategy, then a situation is set up.By using effect measure to unify the indexes with the grey situation decision making and determining the optimum situation according to the eigenvalues of grade variables, a new method is presented for evaluating eutrophication in lakes.The assessment result of nine lakes' eurtophication shows that it's practicable to assess eutrophication of lakes by using I his method.

Abstract:A great amount of sediment and organic matter are involved in Taihu Lake, which deieoriates the water quality of river and lake, ence of organic pollutants on Taihu Lake water quality quantitatively, a mathematical model is proposed to simulate ihe loss processes and total amount of runoff, erosion and organic matter in typical years, in which two land use conditions of paddy field and dry land are considered.The result shows that the amounts of soil erosion and organic matter loss increase with surface drainage intensity exponentially, and organic matter content in surface runoff increases obviously during storm period.The problem must be highly thought of and some measures reducing the organic pollution should be taken in the water quality planning and management of Taihu Lake besin

Abstract:Nansihu lake, one of the major freshwater lakes in China, is regarded as important water resources in Shandong Province.With construction of the energy base and the development of social economy, many environmental problems in the utilization of water resources and the exploitation of coal resources have been raised in the area.This paper discusses the condition and causes of formation and development of these problems such as falling of ground water stage, water pollution, lake swamping, surface subsidence, soil and water erosion, soil salinization.In the end, some countermeasures of protecting the water environment of this area are put forward.

Abstract:The utilization and protection of the submerged plant resources by pen-crab culturing in Nushan Lake from 1992 to 1994 are studied.The results are summarized as rollows: Crab food was mainly Potamogeton crispus L.Vallisneria spiralis L., P.maackianus A.Been, Ceratophyllum demersum L., P.malaianus.Mig.and Hydrilla verticiliata Royle.etc, among which the frequencies of participation and the ideal biomass of P.crispus and H.verticiliata reach their highest point in Apr., May, June, July, Aug, and Sept., respectively.The changes of species composition and biomass of the submerged plants were closely related to the density of the crabs cultured, a density of crabs below 30ind·hm^-2 significantly results in an increase of the biomass of the submerged plants as well as the dominating group.The submerged plants resources could be reasonably used and protected by large-scale crab cultured only at an appropriate density such as 30ind·hm^-2 inside the pens in Nushan Lake.