Tracing environmental lead sources on the Ao mountain of China using lead isotopic composition and biomonitoring

Atmospheric lead(Pb) and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collected on Ao Mountain, Central China, to obtain the spatial distributions of Pb in these materials, decipher the possible factors controlling the distribution, and quantitatively distinguish the natural versus anthropogenic sources of Pb through the Pb isotopic tracing and biomonitoring. The results show that soil Pb concentrations(mg/kg) decreased significantly with depth, and they were markedly higher in the O(42.6± 2.7) and A(36.4 ± 2.2) horizons than in the litter(7.20 ± 1.9) and mosses(28.0 ± 3.9). The Pb enrichment in the surface soils(O and A horizons),litter and mosses existed in the relatively high altitudes, which was attributed to the influences from atmospheric wet deposition, plants, soil physicochemical properties and human activity. ThePb isotopic ratios identified the Pb sources as originating mainly from Chinese coal combustion,mining and smelting. Atmospheric Pb from southeastern, southwestern and northwestern regions could be deposited in the alpine ecosystem by long distance atmospheric transport. The anthropogenic Pb reached over 50% in the O and A horizons, and over 70% in the litter and mosses, which corresponded to the concentrations of 26.9, 17.7, 5.92 and 21.2 mg/kg, respectively. The results indicate that the mutual effects of climate and regional human activity could increase the Pb accumulation in remote alpine ecosystems.     

THE MIRE IN NORTHEAST OF CHINA

The northeast region is one of the principal mire distribution regions in China. According to the process of peat formation and accumulation , middle geomorphology type controlling water source supplement and the plant cover, 2 types, 10 subtypes and 27 mire bodies are divided. The mire area decreases gradually from north to south. There is more peat mire in the mountain and there is mainly gley mire without peat in the plain. The paper also explains the mire types in the principal mire distribution region and the utilization of mire in the fields of agriculture, forest, animal husbandry. The mire is a wetland ecosystem. It can reserve a lot of water, adjust rivers, humidify air. Thereby , attention must be paid to protecting ecological balance in the process of reclaiming mire and the mire protection.     

Distribution and accumulation of soil carbon in temperate wetland,northeast China

Estimating carbon sequestration and nutrient accumulation rates in Northeast China are important to assess wetlands function as carbon sink buffering greenhouse gas increasing in North Asia. The objectives of this study were to estimate accreting rates of carbon and nutrients in typical temperate wetlands. Results indicated that average soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) contents were 37.81%, 1.59% and 0.08% in peatlands, 5.33%, 0.25% and 0.05% in marshes, 2.92%, 0.27% and 0.10% in marshy meadows, respectively. Chronologies reconstructed by 210 Pb in the present work were acceptable and reliable, and the average time to yield 0–40 cm depth sediment cores was 150 years. Average carbon sequestration rate(Carbonsq), nitrogen and phosphorus accumulation rates were 219.4 g C/(m~2·yr), 9.16 g N/(m~2·yr) and 0.46 g P/(m~2·yr) for peatland; 57.13 g C/(m~2·yr), 5.42 g N/(m~2·yr) and 2.16 g P/(m~2·yr) for marshy meadow; 78.35 g C/(m~2·yr), 8.70 g N/(m~2·yr) and 0.71 g P/(m2·yr) for marshy; respectively. Positive relations existed between Carbonsq with nitrogen and precipitations, indicating that Carbonsq might be strengthened in future climate scenarios.     

Carbon stock of larch plantations and its comparison with an old-growth forest in northeast China

The overall goal of this study was to understand carbon(C) stock dynamics in four different-aged Japanese larch(Larix kaempferi) plantations in Northeast China that were established after clear-cutting old-growth Korean pine deciduous forests. Four Japanese larch plantations which were at 10, 15, 21, and 35 years old and an old-growth Korean pine deciduous forest which was 300 years old in Northeast China were selected and sampled. We compared the C pools of biomass(tree, shrub and herb), litterfall(LF), and soil organic carbon(SOC) among them. The biomass C stock of larch plantation at 10, 15, 21, and 35 years old was 26.8, 37.9, 63.6, and 83.2 Mg/ha, respectively, while the biomass C stock of the old-growth Korean pine deciduous forest was 175.1 Mg/ha. The SOC stock of these larch plantations was 172.1, 169.7, 140.3, and 136.2 Mg/ha respectively, and SOC stock of 170.4 Mg/ha in the control of old-growth forest. The biomass C stock increased with stand age of larch plantations, whereas SOC stock decreased with age, and C stock of LF did not change significantly(P 0.05). The increase of biomass C offset the decline of SOC stock with age, making total carbon stock(TCS) of larch plantations stable from stand ages of 10–35 years. The TCS in larch plantations was much smaller than that in the old-growth forest, suggesting that the conversion of old-growth forests to young larch plantations releases substantial C into the atmosphere.     

Anthropogenic trace metals in an ice core at Vestfonna,Svalbard, Norway

1　IntroductionAnicecoreobtainedfrom polarglaciersoricesheetsisoneofthemostimportantarchivestoreconstructpaleoclimaticandpaleoatmosphericcondition .Informationonpale o environmentcanbeextractedfromicecoresaschemicaland/orphysicalsignals.Amongthechemicalsignals,heavymetalsarenotedassignalsofterrestrialenvironmentalchangeandanthropogenicpollution (e.g .Murozumietal.1 969;NgandPatterson 1 981 ;Hongetal.1 994) .SinceconcentrationsofmostofthemetalsinpolarsnowincentralGreen landareatorbelowthepptl…     

Vegetation Restoration in Response to Climatic and Anthropogenic Changes in the Loess Plateau,China

A thorough understanding of the vegetation succession in relation to both climatic changes and anthropogenic activities is vital for the formulation of adaptation strategies that address potential ecosystem challenges. Various climatic factors such as temperature, precipitation, and solar radiation, as well as anthropogenic factors such as ecological engineering and population migration, will affect the conditions for vegetation. However, the relationships among various factors remain unclear and the response of vegetation to climate change and anthropogenic activities in the Loess Plateau of China has not been well established. This study investigated the spatio-temporal characteristics and relationships between vegetation coverage and climatic factors in the Loess Plateau for the period of 1985–2015. Further analysis separated the anthropogenic and climatic factors on vegetation succession based on residual analysis. The results showed that the normalized difference vegetation index(NDVI) followed a significant upward trend with annual change rates of 0.15% during 1985–2015. The trend of human-induced NDVI increase was consistent with the spatial distribution of increasing forest areas in the eastern part of the Loess Plateau. Eco-restoration projects were the main driving factors that promoted vegetation coverage on the Loess Plateau. Furthermore, these results demonstrated that migrants to cities in the Loess Plateau could relieve ecological pressures and promote vegetation restoration. Therefore, the government should strive to increase population mobility and restore vegetation to sustain this particularly fragile ecological environment.     

A 200-year record of polycyclic aromatic hydrocarbons contamination in an ombrotrophic peatland in Great Hinggan Mountain,northeast China

Peat bogs are regarded as one of the faithful archives of atmospheric polycyclic aromatic hydrocarbons(PAHs) deposition, and a large number of studies on PAHs accumulation in peatlands have been reported in Europe and North America. Comparatively little information is available on peat chronological records of atmospheric PAHs flux in China. We investigated the concentrations and historical accumulation rates of PAHs(AR PAHs) through geochemical analysis of three 210Pb-dated ombrotrophic peat cores from Great Hinggan Mountain, northeast China. Eight USEPA priority PAHs were detected and they are naphthalene(Nap), acenaphthylene(Acl), acenaphthene(Ace), fluorence(Flu), phenanthrene(Phe), anthracene(Ant), fluoranthene(Fla) and pyrene(Pyr), respectively. The average total eight PAHs(tPAHs) concentrations are 135.98- 262.43 μg kg-1 and the average AR tPAHs over the last two centuries are 96.45- 135.98 μg m-2 yr-1. The Ace, Acl and Phe account for 30.93- 54.04%, 25.29- 35.81%, and 9.14- 19.84% of the tPAHs, respectively, and have significant positive correlations with the tPAH. As a result, they are regarded as the iconic compounds of PAHs pollution in this area. A ca.200-yr atmospheric PAHs contamination history was reconstructed from the temporal sequences of bothconcentration and AR tPAHs, suggesting the variation of local environmental pollution. The main sources of the PAHs are identified by two isomer ratios as petrogenic origin including oil extraction and refining process as well as their combustions for industrial development. In addition, the contribution of coal combustion for industrial activities and resident heating could not be ignored. But prior to 1860, the undeveloped industry and most of agricultural activities might mainly account for the low level of PAHs, although it could infer a long-range input of atmospheric PAHs from other industrial areas. Therefore, there is a global implication to study longterm PAHs pollution records and all the results will provide practical significance in formulating policies to achieve sustainable and healthy development.     

Land-cover survey in northeast China using remote sensing and GIS

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CHANGING FEATURES AND TREND OF LIGHT INDUSTRY DISTRIBUTION IN NORTHEAST CHINA

Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of light industry gave priority to grain processing industry. After occupying northeast China, Japanese vigorously developed heavy industry to meet the needs of munitions and paid more attention to raw materials and semi-finished articles industry for the purpose of the war. Light industry was impeded and developed slowly. After the founding of New China, large-scale economic construction took place in northeast and heavy industry received prior investment and equipment. Northeast region became the first heavy industry base through several five-year plans, the development of light industry made giant strides. The present features of light industry distribution are: difference of light industry distribution, similarity of light industry structure, and imbalance of light industry development. The     

Dissolved copper, lead and cadmium in Pingtan waters, East China Sea

mODUCTIONTheislandsOfHaitan,Yuo,Dalian,DowiangandCaoguinPingtanCoUntyofFu-jianProvincearetogetherthewhtoasPingtan(25'l5'-25o45'E,l19"32'-12o"lo'N,EaStChinaSea).AmngthemHaitangIslanisthedrinoneinPingtanCotmty,andthelargestinFuianProvince.RngtanhaSanatuIalfishinggroUn(SeduMOUntaln)beingrenownedboghoutthecOUnnyandawelldeVfoPedaqUacultUreindusny.Pingtanwa-tersresotirceswerestirveyedforthefirsttimebytheauthorssothattheknowedgegainedcanbeaPPliedforbettereaploitahon,PIDechon,andde…     

Species richness and biodiversity significance of alpine micro-waterbody systems in Gaoligong Mountain,Northwest Yunnan,China

Water quality, size, connectivity and other physical properties of hydrological systems might have different functions in the formation and maintenance of biodiversity, but this remains mostly unclear due to the lack of undisturbed sites for experimental modelling. Alpine freshwater habitats such as micro-waterbodies(MWB) represent a kind of natural system suitable for biodiversity research. In order to assess potential linkages between environmental factors, connectivity of MWBs and aquatic species richness, we conducted a pilot study in two separated MWB systems located in Gaoligong Mountain, northwest Yunnan province, China. A total of 27 MWBs have been analyzed, including 22 connected and 5 isolated bodies. 13 conventional environmental factors were tested while all kinds of aquatic macro-organisms were collected and classified. Results showed a high environmental heterogeneity among MWBs and significant differences between the two systems but only a few environmental variables such as the depth of soil bottom, total Nitrogen and altitude were related to species richness and the formation of the community structure. As a benefit from the high environmental heterogeneity, the cascaded MWB systems provided divergent habitats able to support species richness at a higher level than the same number of randomly selected MWBs. This finding supports the idea that habitat connectivity matters also in extremely small aquatic ecosystems. Moreover, although still a preliminary result, a polarization effect within connected chains where edge MWBs host higher taxa and endemic taxa richness as well as larger populations, was detectable. This study gives interesting insights on the spatial processes driving community structure and a new prospective for biodiversity conservation. Since alpine MWBs have significant effects on the maintenance of watershed biodiversity, further research on such small and crucial ecosystems is encouraged.     

QUATERNARY GLACIATION SERIES ANDGLACIAL LANDFORM IN GONGWANG MOUNTAINS INNORTHEAST PART OF YUNNAN PROVINCE, CHINA

Therearemanyquaternaryglaciallandformsinalpineareasahave3100ma.s.1.intheGongWangMountainsinthenortheastpartofYunnanProvinceofChina.TheglaciationseriesandtheglaciallandformsoftheQuaternaryhaveoncebeencoveredinanarticlesketchily(Yietal.,1991).Onthebasisoffieldinvestigationsinrecentyears,we'11goastepfurthertodiscusstheQuaternaryglaciationseriesandtheglacierlandfo~sthereinthisPaper.I.TabsQU~ANANYG~W~TheGOngWangMountainsissituatedbetweentwobranchesoftheJinshaRiver,theXiaojiangandthePudu…     

Seasonal and spatial distribution of trace metals in alpine soils of Eastern Tibetan Plateau,China

The distribution of trace metals in remote alpine region is an effective way to understand the impacts of regional human activity and vegetation on the alpine ecosystem. In this study, the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the soils of Gongga Mountain, Eastern Tibetan Plateau, were investigated to reveal their seasonal and spatial distribution and enrichment state, and to decipher the effects of atmospheric deposition and vegetation on their distributions among five vegetation zones. The results showed that the concentrations of Cd, Pb, and Zn were higher in the O horizon than in other horizons despite the seasonal changes, whereas Cu was enriched in the C horizon. The enrichment states of the metals studied in the soils decreased in the order of Cd > Pb > Zn > Cu. Cd and Pb were mainly sourced from atmospheric deposition; Zn was from both atmospheric deposition and parent materials, whereas Cu was mainly from parent materials. Seasonally, the trace metals were generally higher in May and December but lower in September, implying the impact of vegetation on the distribution of trace metals under the plant uptake and the litter decomposition. Spatially, the higher enrichment of Cu, Pb, and Zn in the soils existed in the mixed broadleaf-coniferous forests and coniferous forests (approximately 3000 m above sea level). The results suggested that atmospheric deposition and biological processes are main factors controlling the seasonal and spatial distribution of trace metals in the soils of the remote alpine ecosystem.     

Conservation of wetlands especially as waterfowl habitat in northeast China

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Conservation of wetlands especially as waterfowl habitat in northeast China

Wetland is a special ecological system in the earth, which can provide a good habitat for many wild animals. It is a reproduction and overwintering area for many rare waterfowls, too. The northeast region, including Heilongjiang, Jilin, Liaoning provinces, and the east of Inner Mongolia, is a district with the maximum areas and types of wetlands in China. It is the center of the waterfowls reproduction in Northeast Asia and the necessary region moving to the south. The conservation of wetland and waterfowls habitats in northeast China plays an important role in international waterfowls habitats conservation. The northeast weterfowls’ types, number and distribution specific features are studied in three aspects in the paper, so do the rare waterfowls. Existing problems and the administration polices on waterfowls and their habitats conservation in the northeast are also discussed. It shows that the conservation of wetland waterfowls habitats in northeast China is important.     

Anthropogenic Impacts on the Sediment Flux in the Dry-hot Valleys of Southwest China-an Example of the Longchuan River

The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen‘s test. In both the upper reaches (Xiaohekou) and the lower reaches (Xiaohuangguayuan), the sediment fluxes showed a significant increase from 1970 to 2001, despite the fact that the water discharge did not change significantly during the period and numerous reservoir constructions which contribute to the trap of sediment. This can be attributed to the intensification of human activities, especially the activities related to land surface disturbances such as deforestation and afforestation, expansion of agriculture land, and road constructions. This increase is more significant in the lower reaches of the river observed at the place of Xiaohuangguayuan due to the dry-hot climate. The profound increase in sediment flux has significant implications for effective management of the sedimentation problems of the on-going Three Gorges Reservoir.     

Soil phosphorus composition and phosphatase activities along altitudes of alpine tundra in Changbai Mountains,China

Alpine tundra ecosystems have specific vegetation and environmental conditions that may affect soil phosphorus(P) composition and phosphatase activities. However, these effects are poorly understood. This study used Na OH-EDTA extraction and solution31 P nuclear magnetic resonance(NMR) spectroscopy to determine soil P composition and phosphatase activities, including acid phosphomonoesterase(Ac P), phosphodiesterase(PD) and inorganic pyrophosphatase(IPP), in the alpine tundra of the Changbai Mountains at seven different altitudinal gradients(i.e., 2000 m, 2100 m, 2200 m, 2300 m, 2400 m, 2500 m, and 2600 m). The results show that total P(TP), organic P(OP), OP/TP, Na OH-EDTA extracted P and AcP, PD, and IPP activities over the altitude range of 2500–2600 m are significantly lower than those below 2400 m. The dominant extracted form of P is OP(73%–83%) with a large proportion of monoesters(65%–72%), whereas inorganic P is present in lower proportions(17%–27%). The activity of Ac P is significantly positively correlated with the contents of soil OP, total carbon(TC), total nitrogen(TN), and TP(P 0.05), indicating that the Ac P is a more sensitive index for responding P nutrient storage than PD and IPP. Soil properties, P composition, and phosphatase activities decrease with increased altitude and soil p H. Our results indicate that the distribution of soil P composition and phosphatase activities along altitude and Ac P may play an important role in P hydrolysis as well as have the potential to be an indicator of soil quality.     

Simulating alpine vegetation net primary productivity by remote sensing in Qinghai Province,China

Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity （NPP） of ecological system for several years. In this paper, the remotely sensed NPP simulation model of alpine vegetation in Qinghai Province of Tibet Plateau was set up based on the theory of light use efficiency. Firstly a new approach based on mixed pixels and Support Vector Machine （SVM） algorithm were used to correct simulated NPP values derived from Moderate Resolution Imaging Spectroradiometer （MODIS） data. Finally, spatial distribution and monthly variation characteristics of NPP in Qinghai Province detail. The result showed in 2006 were analyzed in that NPP of vegetation in Qinghai Province in 2006 ranged from o to 422 gC/m2/a and the average NPP was 151 gC/m2/a. NPP gradually increased from northwest to southeast. NPP of different vegetation types were obviously different. The average NPP of broad-leaved forest was the largest （314 gC/m2/a）, and sparse shrub was the smallest （101 gC/m2/a）. NPP in Qinghai Province significantly changed with seasonal variation. The accumulation of NPP was primarily in the period （from April to September） with better moist and heat conditions. In July, the average NPP of vegetation reached the maximum value （43 gC/m2）. In our model, the advantage of traditional LUE models was adopted, and our study fully considered typicalcharacteristics of alpine vegetation light use efficiency and environmental factors in the study area. Alpine vegetation is the most important ecological resource of Tibet Plateau, exactly monitoring its NPP value by remote sensing is an effective protection measure.     

Geochemical features of aquatic environment in crater and barrier lakes in northeast of China

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Distribution and sources of polycyclic aromatic, hydrocarbons in main aquacultural areas in Guangdong, China

The environmental quality status of Daya Bay (22.56–22.77°N, 114.51–114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogenic sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.