流动沙丘上生态垫防风固沙效果初步评价

北京及其周边地区分布的大量裸露沙荒地是北京近年来沙尘暴频发的主要沙源之一,而增加其地表覆盖状况则是遏止就地扬沙起尘的有效措施之一。以北京西北部河北宣化黄羊滩为例,对流动沙丘上铺设生态垫并栽植灌木的防风固沙效果进行了初步研究。研究结果表明,与沙柳沙障相比,生态垫确实可以降低近地表的输沙率,提高生态垫下土壤的养分含量,一定程度上提高柠条的地径和高度,可见生态垫是一种很好的促进流沙固定和植被恢复的地表覆盖材料;与其它两种生态垫铺设方式(品字状和带状)相比,全铺可以显著降低近地表的输沙率,提高其下土壤的养分含量,但柠条的生长状况却略差,这可能与全铺降低了小雨入渗的可能性有关;就两种部分铺设的方式而言,无论从降低近地表的输沙率还是促进柠条的生长上来看,品字状都明显优于带状。从生态和经济的角度综合考虑,品字状铺设显然是该区域流沙防治措施中较好的选择。     

南京和九江两地黄土母质发育的土壤性质比较

本文对南京和九江两地黄土母质发育的土壤性质作了较系统的分析研究,并进行了比较,发现这些土壤的属性存在较大的差别,因而这些土壤不宜归属于同一土壤类型。按《中国土壤系统分类》(首次方案),它们应分别归属于铁硅铝土纲、湿润铁硅铝土亚纲中的黄棕壤土类和棕红壤土类。     

Environmental variability and allocation trade-offs maintain species diversity in a process-based model of succulent plant communities

Ecological theory suggests that environmental variability can promote coexistence, provided that species occupy differential niches. In this study, we focus on two questions: (1) Do allocation trade-offs provide a sufficient basis for niche differentiation in succulent plant communities? (2) What is the relative importance of different forms of environmental variability on species diversity and community composition? We approach these questions with a generic, individual-based simulation model. In our model, plants compete for water in a spatially explicit environment. Species differ in their size at maturity and in the allocation of carbon to roots, leaves and storage tissue. The model was fully specified with independent literature data. Model output was compared to characteristics of a species-rich community in the semi-arid Richtersveld (South Africa). The model reproduced the coexistence of plants with different sizes at maturity, the dominance of succulent shrubs, and the level of vegetation cover. We analyzed the effects of three forms of environmental variability: (a) temporal fluctuations in precipitation (rain and fog), (b) spatial heterogeneity of water supply due to run-on and run-off processes and (c) ‘rock pockets’ that limit root competition in space. The three types of variability had differential effects on diversity: diversity exhibited a strong hump-shaped response to temporal variation. Spatial variability increased diversity, with the strongest increase occurring at intermediate levels of temporal variability. Finally, rock pockets had the weakest effect, but contributed to diversity by providing refuges for small species, particularly at low temporal variability. The model thus shows that spatio-temporal variation of resource supply can maintain diversity over long time scales even in small systems, as is the case in the Richtersveld succulent communities. Trade-offs in allocation provide the basis for necessary niche differentiation. By describing resource competition between individual plants, our model provides a mechanistic basis for the link from species traits to community composition at given environmental conditions. It thereby contributes to an understanding of the forces shaping plant communities. Such an understanding is critical to reduce the threats environmental change poses to biodiversity and ecosystem services.     

混凝土生态膜法污水处理工艺生物相及其水处理实验研究

研究了混凝土生态膜污水处理工艺的循环挂膜过程.综合考察了混凝土膜片表面生物膜的生长变化情况、细菌数量及其微型动物的组成演化.生物膜成熟以后,投加实际生活污水连续运行:COD的平均去除率为76.0%;BOD5平均去除率为94.9%,出水均小于8.00 mg/L;NH3-N的去处理效果明显,第5周达到54.1%,出水可达到广东省一级排放标准中的相关规定.     

东南沿海中生代侵入岩及与火山岩的时空关系

东南沿海中生代侵入岩可分为三套,与火山活动有关的第二套,第三套侵入岩在浙东——闽东区有成分上对应的火山岩。下火山岩系和第二套侵入岩是挤压条件下地壳分熔的英安质岩浆经分离结晶形成;上火山岩系和第三套侵入岩是扩张条件上地幔和下地壳分熔形成的双峰式系列,形成高碱流纹岩和碱性花岗岩的A型岩浆地幔物质所占比例最高,由北而南,火山岩覆盖面积渐小,粤东区第二套侵入岩与下火山岩系相比,缺中性岩类,下地壳分熔形成同熔型二长花岗岩及其火山岩,黑云母花岗岩是熔融区上升迁移的结果,第三套侵入岩出露局限。     

乡村经济功能分类的初步研究——以黄淮海地区为例

本文通过黄淮海地区乡村经济功能类型的实例研究,阐述乡村经济功能分析与乡村功能类型的概念、原理和分类方法,并结合区域农村商品生产和经济结构调整方向,提出不同功能类地区农村产业经济的开发途径。     

闽西南花岗质岩浆作用与成矿

重点讨论了闽西南地区花岗岩类的同位素年龄和演化，将其划分为五期七个阶段，初步确定各阶段花岗岩类的岩石系列和组合及其与区域构造演化的关系。讨论了推覆构造与岩浆作用的关系，并认为与本区成矿作用有关的岩浆岩主要为两类花岗质岩石。研究区良好的矿源层和有利的赋矿层位以及海西期以来幔源岩浆的多次活动，使研究区成为十分有远景的成矿集中区。     

Geoecological analysis of the Korea alpine and subalpine plants and lands

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中低产水稻土障碍类型图编制雏议——以广东博罗县龙溪镇为例

中低产水稻土障碍类型图是通过各种不同形状的图斑与符号,反映区域内中低产水稻土的障碍因素、土壤环境、土壤物理和土壤化学性质的空间分布状况。本文是编制1:5万中低产水稻土障碍类型图的初步偿试。通过对37个具有代表性的中低产水稻土障碍性剖面的实地勘查、119个样品的理化分析结果,以及参考有关的图件资料,运用野外考察及室内分析的方法进行制图。该障碍类型图,可为区域中低产水稻土的改良利用提供科学依据。     

园林生物质中离子液体-复合菌剂共降解体系的筛选与构建

园林生物质的绿色高效降解是实现生态系统物质循环的重要环节,离子液体-生物酶作为环境友好型降解体系备受关注.通过合成1-丁基-3-甲基咪唑（[Bmim]）和1-乙基-3-甲基咪唑（[Emim]）型离子液体衍生物,比较了温和条件下各离子液体对园林生物质的溶解再生性.结合复合微生物菌剂开展酶解试验,通过考察酶解率、纤维素酶活力、降解失重率和木质素含量变化等,筛选并构建最优降解体系组合.结果表明,两种离子液体的盐取代物对园林生物质有着较好的溶解再生性,当质量分数为70%~80%时,[Emim]型离子液体-复合菌剂体系的酶解率和酶活力最高.在降解末期,[Emim]Ac_75%和[Emim]FeCl_4·75%体系的降解失重率分别为46.9%和52.6%,均为阳性对照组的1.6倍,同时木质素含量分别减少41.7%和47.2%.[Emim]FeCl_4·75%-复合菌剂体系对园林生物质有着更为显著的降解效应.