荒漠化--可怕的恶魔

全球荒漠化面积已达到3600万平方公里，占到整个地球陆地面积的1／4，相当于俄罗斯、加拿大、中国和美国国土面积的总和。土地荒漠化的危机已经迫在眉睫了。     

蕨类植物利用师法自然是成功之道

蕨类植物门是植物界中一个自然的类群.它与藻类植物门、菌类植物门、地衣植物门、苔藓植物门和种子植物门并列成为现代植物界的六大门类之一.在陆地生态系统的形成与演化过程中,蕨类植物是先锋植物类群,对陆地生态系统的形成起到重要作用.至今,蕨类植物仍是地球上生物多样性的重要组成成分.但是,蕨类植物的生态特征与植物界的其他类群有所不同.     

“零排放”系统可在沙漠中养殖海鱼

海鱼味道鲜美,营养丰富,但由于过度捕捞,种类和数量在逐年减少。针对这种情况,以色列GFA公司的科学家开发出了一种在陆地养殖海鱼的新方法。     

让山更青水更绿天更蓝树更壮——访全国人大代表、吉林森工集团董事长柏广新

“林业行业代表的曝光率越来越高，大的背景是生态文明建设不断得到重视，直接原因是雾霸问题关系到每个人的身心健康。森林是陆地生态系统的主体，被称为地球之肺，肺的作用就是新陈代谢、吐故纳新，我来自传统的森林工业企业，     

陆地生态系统土壤呼吸研究进展

对陆地生态系统土壤呼吸的研究进展进行了简要总结分析了影响土壤呼吸时空变化的主要因素及与土壤呼吸的关系,提出了土壤呼吸的研究趋势以及进一步的研究方向。     

温室土壤食物网静态和动态结构特征

Soil food web structure is fundamental to ecosystem process and function; most studies on soil food web structure have focused on agro-ecosystems under different management practices and natural terrestrial ecosystems, but seldom on greenhouses. This study explored the static and temporal variability of soil food structure in two greenhouses of Shandong Province, North China over a two-year period. The static properties were measured directly by surveying functional group composition and a series of parameters portraying the species properties, link properties, chain properties and omnivory properties of the web, as well as indirectly through calculation of nematode indices, enrichment index （EI）, structure index （SI）, and channel index （CI）. The dynamic variability of greenhouse soil food structure was described by the dynamics of functional groups, Bray-Curtis （BC） similarity and cluster analysis. The results showed that the greenhouse soil food web contained 14 functional groups, with microbes having the highest mean biomass, followed by protozoa. Of the three functional groups of protozoa, flagellates were the dominant group on most sampling dates, amoebae only became the dominant group during the summer, while ciliates were the least prevalent group. All nematodes were assigned into one of the four functional groups, bacterivorous, fungivorous, herbivorous and omnivorous, and the fungivorous nematodes had the lowest mean biomass. Mites were assigned into three functional groups and the omnivorous noncryptostigmatic mites were the dominant group. All the functional groups showed significant seasonal changes. The soil food web connectance was 0.15, the maximum food chain length was 5, and the average food chain length was 3.6. The profiles of the EI and SI showed that the food web was resource- depleted with minimal structure. The results of CI indicated that the bacterial decomposition pathway was the dominant pathway in the food web of the greenhouse soils studied and the results of BC similarity showed that the soil food web had higher variability and instability over time. The cluster analysis showed that the functional groups located at high trophic levels with low biomass were in a cluster, whereas those at low trophic levels with high biomass were closer. Compared with the food web structure of agroecosystem and natural terrestrial ecosystem soils, the structure of greenhouse soil food web was simple and unstable, which was likely driven by high agricultural intensification, particularly over application of fertilizers.     

陆地生态系统碳循环对土地利用变化的响应

陆地生态系统碳循环在全球碳循环中占有重要地位,而土地利用变化是估测陆地生态系统碳储存与释放的最大不确定性因素。植被和土壤是陆地生态系统的两大碳库,是碳循环中的两个重要纽带,土地利用变化影响陆地生态系统土壤和植被碳的固定、积累与释放,从而影响整个碳循环过程。本文主要从土壤和植被碳库的角度出发,综述了近年来土地利用变化对陆地生态系统碳循环的影响及其机理,以及研究方法进展,着重分析了模型在此方面的应用;并提出了未来研究方向的展望。     

陆地生态系统N_2O排放源研究进展

N2O是一种痕量气体,不仅能产生温室效应,而且对臭氧同温层有严重的破坏作用。随着人类活动的加剧,大气中N2O浓度每年以0.2%～0.3%的速度增加,N2O排放问题引起了人们的广泛关注。目前,对大气N2O排放的源与汇还缺乏全面认识,N2O在大气中增加量的40%～50%尚不知来源。综述了陆地生态系统N2O排放的自然源和人为源,分析了N2O排放的影响因素,并对今后N2O的研究提出了展望。     

用点杂交方法定量检测植物病毒RNA负荷量

用RNA点杂交与用放射性成像仪直接读取放射性活度相结合的方法定量测定植物病毒RNA相对负荷量 ,检测了 0 0 0 1～ 1 0ppm浓度范围内二氢茉莉酸丙酯(PDJ)对烟草组织中烟草花叶病毒 (TMV)RNA的影响。结果表明 :在PDJ处理 3d时 ,与对照相比低浓度 ( 0 0 0 1ppm)PDJ处理的TMVRNA病毒负荷量无明显差异 ,但随着浓度的升高 ,PDJ对TMVRNA的复制和积累具有促进作用 ;浓度越高 ,促进作用越显著。同时用传统的枯斑接种法验证了上述结果。两种方法相比 ,点杂交结合放射性成像仪读取放射性活度的方法所受的人为误差干扰较小 ,能够相对精确地定量测定植物组织中病毒RNA负荷量。     

陆地生态系统二氧化碳通量网的建设和发展

介绍了陆地生态系统CO2通量网和三个地域性CO2通量网（欧洲通量网，美洲通量网和亚洲通量网）的建设与发展状况，并着重对其建设目的，组织结构和数据共享原则等进行了评述。对欧洲通量网与美洲通量网所能提供的共享数据库的研究地点概况，数据特点和主要研究者也进行了介绍，以便国内同行进行对比研究使用。参考全球陆地在不同海拔，不同植被类型的分布比例，在陆地生态系统CO2通量网的分布进行了对比分析。并结合我国科学家在本领域的研究，对陆地生态系统CO2通量网今后的发展方向尤其是在亚洲大陆地区（我国）的研究侧重点进行了讨论。