川西亚高山、高山森林土壤微生物生物量和酶活性动态特征

为深入了解川西亚高山/高山森林冬季生态学过程,于2008年11月─2009年10月,在土壤冻结初期、冻结期和融化期及植被生长季节,研究了不同海拔岷江冷杉林（Abies faxoniana）土壤微生物生物量和酶活性动态。各海拔森林土壤在冬季维持着较高的微生物生物量含量和酶活性,并随土壤冻融过程不断变化。土壤有机层和矿质土壤层冬季微生物生物量碳和氮含量及转化酶和尿酶活性均表现出受冻结初期土壤冻融循环影响显著降低,在冻结期变化不明显,在融化期急剧增加至融化后显著降低的趋势,且土壤有机层微生物生物量含量和酶活性在融化期具有一个明显的年高峰值。海拔变化显著影响了土壤酶活性,但对土壤微生物生物量不显著。土壤温度与土壤微生物生物量含量相关显著。这表明季节性冻融期是土壤生态过程的重要时期,土壤冻融格局显著影响川西亚高山/高山森林土壤微生物生物量和酶活性动态。     

基于OTIS模型的巢湖十五里河源头段氮磷滞留特征

为揭示巢湖十五里河源头河段氮磷营养盐滞留特征,选择NH4Cl、KH2PO4及NaCl作为示踪剂,开展野外现场示踪实验.根据获得的氯离子浓度和营养盐浓度穿透曲线数据信息,利用OTIS与OTIS-P计算软件,估算水文参数(D、A、As、a等)和营养盐一阶吸收系数(λ、λs).在此基础上,计算暂态存储指标和营养盐吸收相关参数值,定量评估主河道流动水体与暂态存储对NH4+和SRP的损失贡献.结果表明,主河道与暂态存储区NH4+吸收系数平均值分别为3.88×10-6,8.81×10-4s-1,SRP分别为7.80×10-6,7.98×10-8s-1;综合衰减系数k-NH4平均值为1.64×10-4s-1,k-SRP为7.80×10-6s-1;NH4+和SRP的吸收长度Sw-NH4、Sw-SRP相当大,分别为1632.88,25471.32m,意味着该河段经由物理或生态过程去除N、P的可能性低;该河段Vf-NH4、Vf-SRP 值较营养盐浓度低的溪流或小河流偏小,但U-NH4、U-SRP则明显偏大;暂态存储对于NH4+损失的平均贡献率为93.82%,主河道水流对SRP损失的平均贡献率高达99.70%.     

矿区废弃地的恢复生态学研究

矿区废弃地的恢复生态学研究已成为恢复生态学的一个重要的研究领域。本文论述了恢复生态学的主要理论及采矿废弃地的恢复工程技术,并对矿山生态恢复中的生物多样性、景观生态学、植被生态学、生态经济学、安全经济学及可持续发展等学科领域进行了综述。     

Landscape network congruency at the ecoregion scale: can we expect corridor ‘umbrellas’?

Conservation planners are faced with numerous choices regarding ‘what to connect’ when modeling landscape networks on an ecoregion scale. A simplifying assumption is often that coarse-scale corridors may provide overlapping or ‘umbrella’ effects for multiple conservation scenarios. To examine this, we assessed differences in connectivity models arising from four different conservation scenarios for the transboundary Northern Appalachian/Acadian Ecoregion (330,000 km²). Models resulted in networks comprised of varying levels of connectedness, suggesting the presence of local connectivity at several sub-ecoregion scales, but diminished ecoregion-scale connectivity. Our results also indicate that selecting ‘what to connect’ at the ecoregion scale strongly influences the location and extent of modeled corridors. Further, our evidence suggests that landscape networks derived for one scenario are not likely to produce far-reaching corridor umbrellas or highly coincident landscape networks for alternative conservation scenarios with varying goals. As a result, alternative landscape networks should not be considered functionally equivalent.     

基于供需构造的北京水循环动态失衡及修复机理

水资源短缺严重制约着北京21世纪世界城市宏伟目标的实现.在引入基于自然与人然良性互动基础上的成水构造、蓄水构造与用水构造等跨学科概念之后,提出区域水生态“供需构造链条说”.进一步,本研究对半个世纪来北京水循环数据分析发现,水资源总量随降水量而变化,相对多年平均量均减,北京水资源生态系统呈弱化态势;2001~2012年用水总量超过水资源总量,水生态系统失衡.循上述发现,对北京区域水生态系统供需数据进行回归分析、揭示北京气候变化与人然活动水文关联效应,指出水循环动态失衡机理的行为贡献因子.最后,基于用水增长有行为上改进空间的思想,提出北京水循环动态失衡在短期运用行为矫正机制,采用总量管理和水市场调节合理用水,长期上运用水环境动态均衡修复原理,启动北京和周边地区的地下水位复升工程的政策建议.     

Soil organic carbon and total nitrogen stocks as affected by different land use in an Ultisol in Imo Watershed,southern Nigeria

Soil organic carbon (SOC) and soil total nitrogen (STN) concentrations and stocks are essential for improving soil quality and increasing C-reservoir. The study aimed at quantifying the dynamics of soil properties under different land use in Imo watershed where there is no knowledge about the effects of land use on SOC and STN pool. Six land use: arable land (AL), forest land (FL), grassland (GL), shrubland hills (SL), urban built-up green (UL), and freshwater swamp-mangrove wetland (WL) were classified using ArcGIS 10.1 and FAO land use classification system. Soil samples were collected and analyzed from each land use under different soil depths and slope positions with three replications. Topsoil layer (0–30?cm) contributed to more than 90% of the total soil nutrients. Land use significantly affected SOC content, STN content, and bulk density. SOC and STN concentrations were in the order of FL?>?WL?>?GL?>?SL?>?UL?>?AL which revealed the potentials of FL and WL for SOC and STN sequestration. The study provides land users with the information to improve soil quality, conserve C and N stocks for ecological sustainability and climate change mitigation.     

郑州市区域水生态环境污染研究

通过对郑州市水生态环境、水资源的现状的调查,了解到郑州市淡水资源匮乏,水生态环境恶化,制约了城市的经济、社会、环境的可持续发展。通过对郑州市地上水,地下水水质污染、地下水超采、地下漏斗的形成和湿地的减少等一系列水生态环境问题的系统分析,提出了相应的对策。     

石羊河流域的生态环境问题、引发原因与治理对策

石羊河是甘肃省三大内陆河之一,在河西乃至全省经济社会发展中起着十分重要的作用.目前该流域出现森林面积减少,雪线上升,水土流失加重,地下水位下降,水体污染,水质恶化,荒漠化蔓延等一系列生态环境问题,已经严重影响和制约到流域及其周边地区的经济建设和社会安定团结.为实现流域生态大系统及其子系统稳定、健康、持续发展,应坚持"南保水源,中建绿洲,北治风沙"的基本原则.对流域大系统,要切实加强流域水资源统一管理,完善政策体系,加强环境保护的执法、宣传,提高流域民众的生态意识,加强生态建设工程的科技支撑.对流域南部祁连山区,要加强林区管理,理顺体制,加强山区植被保护和建设,提高水源涵养能力,减少水土流失,合理调整水库,减少汛期蓄水.对中部绿洲,要发展二三产业,加快小城镇建设,调整农业产业结构,加强农田防护林体系建设,加大节水力度,实施外流域调水工程.对北部荒漠区,要恢复、重建退化固沙植被,退耕还草还荒,严禁新的土地开垦,适度发展沙产业.     

Comparing urban solid waste recycling from the viewpoint of urban metabolism based on physical input-output model: A case of Suzhou in China

Investigating impacts of urban solid waste recycling on urban metabolism contributes to sustainable urban solid waste management and urban sustainability. Using a physical input-output model and scenario analysis, urban metabolism of Suzhou in 2015 is predicted and impacts of four categories of solid waste recycling on urban metabolism are illustrated: scrap tire recycling, food waste recycling, fly ash recycling and sludge recycling. Sludge recycling has positive effects on reducing all material flows. Thus, sludge recycling for biogas is regarded as an accepted method. Moreover, technical levels of scrap tire recycling and food waste recycling should be improved to produce positive effects on reducing more material flows. Fly ash recycling for cement production has negative effects on reducing all material flows except solid wastes. Thus, other fly ash utilization methods should be exploited. In addition, the utilization and treatment of secondary wastes from food waste recycling and sludge recycling should be concerned.     

WATER QUALITY IN MOUNTAIN RECREATIONAL AREAS1

ABSTRACT: Several seasons of water quality study in the eastern Sierra Nevada have provided much useful information. One study element focused in detail on a representative drainage: Bishop Creek, from sampled locations at 12,800 feet to the Owens River at 4,000 feet. Sub-studies ranged from geohydrology, through chemical and bacterial quality, to benthic ecology. A coordinated study also was made of spatial patterns of use. A second element focused on non-point source monitoring the length of the Inyo National Forest. From physical, chemical, and bacterial standpoints, water quality is generally very good. Strains of pathogenic bacteria have been confirmed, and substantial further work to establish the importance of their presence is needed. Recreational use survey results have been analyzed to produce a methodology permitting management of the resource as needed. In addition, basic policy recommendations to easily minimize risk have been developed.