若尔盖沼泽湿地的萎缩机制

1960年以来,若尔盖沼泽湿地的快速萎缩严重影响黄河上游水量补给和当地湿地生态系统,但其机制尚不清晰。基于2010—2013年野外调查、气象水文资料和遥感影像,分析若尔盖沼泽退化的主要原因与机制。尽管气温的缓慢升高,但降水量并未减少,考虑到沼泽的季节性特征,气候变暖对沼泽萎缩影响相当有限,但不是主要原因。经遥感判读和统计,共识别现有920 km的人工渠道,其疏干的沼泽面积约648.3 km2,占总萎缩面积的27%。人工开渠作为强烈的人类活动干扰,是若尔盖沼泽快速萎缩的重要原因。自然水系的溯源侵蚀长期疏干沼泽、降低地下水水位和放射状地向沼泽内部切穿是沼泽萎缩的重要机制。人工开渠连通自然水系强化沼泽内河床下切和排水作用。     

基于PLSR的典型沼泽湿地植物叶片性状与光谱模型构建——以三江国家级自然保护区为例

通过植物光学特性测量叶片性状是一种非破坏性的、长期的湿地动态监测方法。选择三江国家级自然保护区多种典型湿地植物为研究对象,探究植物性状与叶片光谱之间的联系。研究表明：叶片氮含量与光谱的模型构建效果最好,模型R²为0.61,均方根误差（RMSE）为2.3862;叶片含水量、叶片磷、可溶性糖、纤维素和木质素含量之和的模型一般,R²在0.38~0.55范围内,RMSE在0.0004~10.7019范围内;淀粉含量拟合效果较差, R²为0.29,RMSE为0.0106。光谱预测重要性的结果表明,可见光与近红外边缘范围内的光谱信息对于叶片含水量、叶片氮含量、叶片磷含量、单位叶面积质量、纤维素和木质素之和、可溶性糖和淀粉的预测具有最高的重要性。     

Contribution of climatic and anthropogenic effects to the hydric deficit of peatlands

The present study makes use of a detailed water balance to investigate the hydrological status of a peatland with a basal clay‐rich layer overlying an aquifer exploited for drinking water. The aim is to determine the influence of climate and groundwater extraction on the water balance and water levels in the peatland. During the two‐year period of monitoring, the hydrological functioning of the wetland showed a hydric deficit, associated with a permanent unsaturated layer and a deep water table. At the same time, a stream was observed serving as a recharge inflow instead of draining the peatland, as usually described in natural systems. Such conditions are not favourable for peat accumulation. Field investigations show that the clay layer has a high hydraulic conductivity (from 1·10^?7 to 3·10^?9 m.s^?1) and does not form a hydraulic barrier. Moreover, the vertical hydraulic gradients are downward between the peat and the sand aquifer, leading to high flows of groundwater through the clay layer (20–48% of the precipitation). The observed hydric deficit of the peatland results from a combination of dry climatic conditions during the study period and groundwater extraction. The climatic effect is mainly expressed through drying out of the peatland, while the anthropogenic effect leads to an enhancement of the climatic effect on a global scale, and a modification of fluxes at a local scale. The drying out of the peatland can lead to its mineralisation, which thus gives rise to environmental impacts. The protection of such wetlands in the context of climate change should take account of anthropogenic pressures by considering the wetland‐aquifer interaction. Copyright © 2011 John Wiley & Sons, Ltd.     

Evaporation and energy balance of a wet grassland at Tadham Moor on the Somerset Levels

Wet grasslands are important both for their conservation value and for their important hydrological function. Evaporation is an important component of the water balance of a wetland. Where water is limited rainfall and/or surface (or sub‐surface) inflows are required to balance the summer evaporation and thus become a significant factor in the maintenance and environmental health of a wetland. This study presents an almost complete year of measurements of the water and energy balance of a wet grassland in the Somerset Levels in southwest England. The majority of the radiant energy at this site goes into evaporation. There is a strong seasonality of the controls on evaporation; the roughness length varies by a factor of 10 between winter and summer. The surface resistance to evaporation is low, close to zero, during the winter when the water table is at, or just below the surface. In the summer the water table drops to 80 cm below the surface; there is no sign of soil water stress on the evaporation but a clear effect of the senescence of grass during seed head production and of the subsequent harvest. There is clear evidence that water for evaporation is provided by the drainage ditches through sub‐surface flow. Standard evaporation formulae—such as the Penman‐Monteith equation with constant and standard parameters—provide a reasonable simulation of the total evaporation at this site, although they miss some of the seasonal detail. Copyright © 2008 John Wiley & Sons, Ltd.     

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.     

浅钻技术在若尔盖地区泥炭调查中的应用

泥炭是一种具有多种用途的宝贵自然资源,泥炭中的有机碳储量是研究全球碳库变化及碳循环过程的重要参数。由于泥炭多分布于沼泽中,且泥炭松软含水量大的特性,对于泥炭深度的调查、获取用于测试泥炭原状样品的质量不高,导致泥炭碳储量评价仍存在不确定性和偏差。笔者等在典型泥炭形成地若尔盖沼泽湿地地区,开展了浅钻泥炭调查取样工作,通过在泥炭斑块边缘及中心两种不同沼泽湿地地层开展的试验,验证了轻便钻机在难进入的沼泽湿地的适应性,配套的振动冲击工艺可高质量的获得无扰动的泥炭样品,同时查明了泥炭层的厚度。通过试验初步探索了采用轻便钻机配套振动冲击钻进工艺进行泥炭调查取样的有效性。浅层取样钻探作为泥炭调查取样的一种直接有效的技术手段,可以有效地提高泥炭调查效率和精度,为准确评价泥炭储量数据提供可靠的钻探技术服务支撑。     

全国云端地质大标本园建设工作思考——以自然资源实物地质资料中心为例

全国云端地质大标本园平台建设将全国百余座典型矿床的大型矿石标本“搬”到了云上,可为社会公众提供一站式云上虚拟漫游体验,全方位、多渠道了解我国矿产资源、能源知识。文章通过分析全国地质资料馆藏机构、博物馆、科研院所等地质大标本园建设现状,提出了全国云端地质大标本园建设原则及思路,以实物资料中心地质大标本园为建设案例,展示了建设内容与架构,分析总结了全国云端地质大标本园建设前景及社会效益。     

全国云端地质大标本园建设工作思考——以自然资源实物地质资料中心为例

全国云端地质大标本园平台建设将全国百余座典型矿床的大型矿石标本“搬”到了云上,可为社会公众提供一站式云上虚拟漫游体验,全方位、多渠道了解我国矿产资源、能源知识。文章通过分析全国地质资料馆藏机构、博物馆、科研院所等地质大标本园建设现状,提出了全国云端地质大标本园建设原则及思路,以实物资料中心地质大标本园为建设案例,展示了建设内容与架构,分析总结了全国云端地质大标本园建设前景及社会效益。     

桂林会仙岩溶湿地土地利用方式对球囊霉素相关土壤蛋白分布的影响

土壤丛枝菌根真菌分泌的球囊霉素相关土壤蛋白(GRSP)是土壤碳库变化的重要指标, 为明确其在会仙岩溶湿地不同土地利用方式下的分布特征及影响因素, 以会仙岩溶沼泽, 并由其转变而来的水稻田、旱地、果园和弃耕地4种不同土地利用方式为研究对象, 采集0–10 cm、10–20 cm和20–40 cm这3个层次的土样, 对不同土地利用方式下球囊霉素相关土壤蛋白分布特征及其与土壤因子的关系进行了研究。结果表明, 不同土层总球囊霉素相关土壤蛋白(T-GRSP)含量为1.08～3.35 mg/g, 占土壤有机碳的12.33%～19.73%, 球囊霉素相关土壤蛋白是湿地土壤中的一个重要碳库。球囊霉素相关土壤蛋白在不同土地利用方式和土层之间均表现出显著差异, 随土层深度的增加表现出降低趋势。沼泽土壤中总球囊霉素相关土壤蛋白、易提取球囊霉素相关土壤蛋白(EE-GRSP)含量和有机碳(SOC)的含量均高于其它4种土地利用方式(水稻田、旱地、园土和弃耕地)。GRSP分别与蛋白酶、SOC和全氮(TN)呈极显著正相关(P＜0.01), 分别与速效氮(AN)、速效磷(AP)、粘粒和粉粒呈显著正相关(P＜0.05)。EE-GRSP与SOC和TN呈极显著正相关(P＜0.01), 分别与蛋白酶和粘粒呈显著正相关(P＜0.05)。主成分分析表明, 粉粒、SOC、AN和TN是影响球囊霉素相关蛋白分布特征和反映会仙岩溶湿地土壤营养状况的主要因子。会仙岩溶湿地土壤中的球囊霉素相关土壤蛋白对土壤碳封存有重要贡献。