浅论黑龙江省的土地盐碱化

一、分布概况 黑龙江省的盐碱地主要分布在松嫩平原西部低洼闭流地带，总面积1887300hm^。其中松嫩平原分布面积1744000hm：，约占松嫩平原的14％，耕地盐碱化面积为567000hm^2。其中以安达和大庆两市盐碱化最为严重。安达市有盐碱化面积153740hm^2，耕地盐碱化面积34535hm^2，草原122806hm^2。     

蒙古包:芳草天涯任我游

这首自南北朝时期流传至今的古代歌谣《被勒川》，把中国北方广袭无垠、牧蕈肥美、牛羊遍地的草原景色．生动形象地展现在人们的眼前．激起人们对蓝天白云、牧歌悠扬的蒙古草原的无限向往。     

锡林浩特草原CO2通量特征及其影响因素分析

利用锡林浩特国家气候观象台开路涡度相关系统、辐射土壤观测系统,测得的长期连续通量观测数据,对锡林浩特草原2009—2011年期间的CO₂通量观测特征进行了分析。结果表明:CO₂通量存在明显的年际、季节和日变化特征。3 a中NEE年际变率达到200 g·m^-2,季节变率最大达到460 g·m^-2,日变化幅度生长季最大达到0.25 mg·m^-2·s^-1。通过不同时间尺度碳通量与温度、水分、辐射等环境因子的分析,认为CO₂通量日变化主要受温度和光合有效辐射影响,而季节变化和年变化主要受降水和土壤含水量的影响。降水强度及时间分布是制约牧草CO₂吸收的关键因素,大于15%的土壤含水量有利于促进牧草生长。     

悠长的草原经历

转瞬间,六天的草原观星之旅便结束了。 六天时光,如一轮新月,那样短暂,又那样柔长;似一抹香茗,那样轻描淡写,又那样回味悠扬……看了很多,见了许多,闻了许多,赏了许多,遇了许多,学了许多,品了许多,悟了许多。不只是蓝天、碧水,青草、野芳,鸣虫、飞鸟,繁星、夕阳……     

天似穹庐 心如草原——2011年辉腾锡勒草原星空大会散记

阳光带走了草原一望无垠的碧绿,轻风给清澈如水的蓝天抹上一层深邃,缀上几点钻石,捂上白日吵吵嚷嚷的蟋蟀的嘴,向仰望苍穹的大地撒上一层银辉。     

草原生态系统土壤多功能性及影响机制研究进展

草原是陆地生态系统的关键组成部分,为维持区域生态安全发挥着极为重要的作用。土壤多功能性（soil multifunctionality,SMF）是衡量土壤系统提供多种功能的综合指标,对评估草原生态系统功能和区域可持续发展具有重要指导意义。然而,目前SMF研究仍处于初步阶段,研究对象多为农田生态系统,对于草原等自然生态系统的研究较少。此外,对草原生态系统SMF与植物和土壤微生物的关系以及全球变化对草原生态系统SMF影响机制的认识十分有限。因此,本文从SMF的概念和内涵、量化指标及方法、植物和土壤微生物与SMF的关系、全球变化对SMF的影响以及SMF的空间变异性5个方面论述SMF的研究进展,梳理了草原生态系统SMF的变化特征及影响机制。根据当前研究中存在的问题提出了今后研究应重点关注的内容：（1）统一规整SMF量化体系;（2）SMF在不同空间尺度上的转换机制;（3）不同类型草原生态系统SMF驱动机制;（4）土地利用变化、降水增加、气候变暖和氮沉降等全球变化交互作用对SMF的影响;（5）地上植物功能与SMF的联系和互馈机制;（6）根系功能性状对SMF的影响和植物在不同组织水平对SMF的贡献;...     

Soil and vegetation seasonal changes in the grazing Andean Mountain grasslands

Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna（Vicugna vicugna） and alpaca（Lama pacos）. The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined： total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. Soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.     

Higher species diversity occurs in more fertile habitats without fertilizer disturbance in an alpine natural grassland community

Are there some relationships among species diversity and soil chemical properties of high altitude natural grasslands？ Plant community composition and chemical properties of soil samples were compared to investigate the relationship between soil and species diversity, and the richness in Tibetan alpine grasslands. Results showed that species diversity was significantly positively related to soil organic matter （SOM）, total nitrogen （TN）, available nitrogen （AN）, total phosphorus （TP）, available phosphorus （AP）, and available potassium （AK） in the high alpine grasslands. Margalefs species richness index was also significantly positively related to SOM, TN, AN, and TP. Most soil chemical properties showed significantly positive correlation with species diversity and Margalef＇s richness index. Our results suggested that higher plant species richness index and diversity occurred in more fertile soil habitats in high altitude natural grassland community. In practice, fertilization management for the restoration of degraded grassland should be conducted with reference to the nutrient levels ofnatural grassland without the additional artificial fertilizer and with higher species-diversity and richness index.     

Radiative forcing over China due to albedo change caused by land cover change during 1990–2010

Land cover change affects surface radiation budget and energy balance by chang- ing surface albedo and further impacts the regional and global climate. In this article, high spatial and temporal resolution satellite products were used to analyze the driving mechanism for surface albedo change caused by land cover change during 1990-2010. In addition, the annual-scale radiative forcing caused by surface albedo changes in China＇s 50 ecological regions were calculated to reveal the biophysical mechanisms of land cover change affecting climate change at regional scale. Our results showed that the national land cover changes were mainly caused by land reclamation, grassland desertification and urbanization in past 20 years, which were almost induced by anthropogenic activities. Grassland and forest area decreased by 0.60% and 0.11%, respectively. The area of urban and farmland increased by 0.60% and 0.19%, respectively. The mean radiative forcing caused by land cover changes during 1990-2010 was 0.062 W/m2 in China, indicating a warming climate effect. However, spatial heterogeneity of radiative forcing was huge among different ecological regions. Farmland conversing to urban construction land, the main type of land cover change for the urban and suburban agricultural ecological region in Beijing-Tianjin-Tangshan region, caused an albedo reduction by 0.00456 and a maximum positive radiative forcing of 0.863 WIm2, which was presented as warming climate effects. Grassland and forest conversing to farmland, the main type of land cover change for the temperate humid agricultural and wetland ecological region in Sanjiang Plain, caused an albedo increase by 0.00152 and a maximum negative radiative forcing of 0.184 W/m2, implying cooling climate effects.     

匈奴消失之谜谁能解得开

公元前3世纪前后,中国北方草原上匈奴族兴起,到秦汉之际,第一代单于头曼单于建“头曼城”,以今内蒙古黄河河套及阴山为驻牧及统治中心,建立了强大的部落联盟国家,