检索结果-南通市图书馆

维普期刊数据库

Terrestrial denitrification:challenges and opportunities

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2012年第1期1卷 1-11页

作者： Peter M groffman cary Institute of Ecosystem Studies 2801 Sharon TurnpikeMillbrookNY 12545USA

Denitrification is a process of great environmental importance but is difficult to study in terrestrial *** for quantifying the process are problematic,variability in activity is high,and temporal and spatial scaling challenges are *** methods are problematic for a variety of reasons;they change substrate concentrations,disturb the physical setting of the process,lack sensitivity or are prohibitively costly in time and *** fundamentally,it is very difficult to quantify the dominant end-product(N_(2))of denitrification given its high background concentration in the *** and temporal variation in denitrification is high due to control of the process by multiple factors(oxygen,nitrate,carbon,pH,salinity,temperature etc.)that each vary in time and space.A particular challenge is that small areas(hotspots)and brief periods(hot moments)frequently account for a high percentage of N gas flux *** phenomena are challenging to account for in measurement,modeling and scaling *** need for scaling is driven by the fact that there is a need for information on this microscale process at the ecosystem,landscape and regional scales where there are concerns about nitrogen effects on soil fertility,water quality and air *** this review,I outline the key challenges involved with denitrification and then describe specific opportunities for making progress on these challenges including advances in measurement methods,new conceptual approaches for addressing hotspot and hot moment dynamics,and new remote sensing and geographic information system–based scaling *** of these opportunities suggests that we are poised to make great improvements in our understanding of terrestrial *** improvements will increase our basic science understanding of a complex biogeochemical process and our ability to manage widespread nitrogen pollution problems.

关键词： scaling process landscape

Integrating beneficiaries into assessment of ecosystem services from managed forests at the Hubbard Brook Experimental Forest,USA

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2016年第4期3卷 243-257页

作者： Jesse caputo colin M.Beier Valerie A.Luzadis Peter M.groffman SUNY college of Environmental Science and Forestry Department of Forest and Natural Resources Management Syracuse NY 13210 USA cary Institute of Ecosystem Studies Millbrook 12545 NY USA

Background：Forests contribute to human wellbeing through the provision of important ecosystem ***：In this study,we investigated how the perceived importance of ecosystem services may impact the overall benefit provided by managed watersheds at the Hubbard Brook Experimental Forest over a 45-year period,using standardized measures of service capacity weighted by service importance weights derived from a survey of ***：The capacity of watersheds to regulate water flow and quality was high in all watersheds throughout the study period,whereas cultural services such as scenic beauty declined after *** on greenhouse gas regulation depended on the efficiency with which harvested biomass was *** revealed that stakeholders placed high value on all ecosystem services,with regulating and cultural services seen as more important than provisioning *** service metrics were weighted by survey responses and aggregated into a single measure,total service provision followed the same overall trend as greenhouse gas *** biomass use was less efficient in terms of greenhouse gas emissions,harvesting resulted in an overall ＂ecosystem service debt＂;where use was more efficient,this ＂ecosystem service debt＂ was ***＇ educational backgrounds significantly affected overall assessment of service *** with college or university degrees incurred smaller ＂ecosystem service debts＂ and were less negatively affected by harvesting ***：This study highlights the importance of including empirical measures of beneficiary preference when attempting to quantify overall provision of ecosystem services to human beneficiaries over time.

关键词： Ecosystem services Forests Long-term ecological research Hubbard Brook Experimental Forest Regulating services

维普期刊数据库

Non-Algorithmically Integrating Land Use Type with Spatial Interpolation of Surface Soil Nutrients in an Urbanizing Watershed

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2017年第1期27卷 147-154页

作者： WU Qian LI Qingliang GAO Jinbo LIN Qiaoying XU Qiufang Peter M.groffman YU Shen Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021 China Zhejiang A&F University Lin'an 311300 China University of chinese Academy of Sciences Beijing 100049 China cary Institute of Ecosystem Studies Millbrook NY 12545(USA)

Integrating land use type and other geographic information within spatial interpolation has been proposed as a solution to improve the performance and accuracy of soil nutrient mapping at the regional scale. This study developed a non-algorithm approach, i.e., applying inverse distance weighting （IDW） and ordinary kriging （OK）, to individual land use types rather than to the whole watershed, to determine if this improved the performance in mapping soil total c （Tc）, total N （TN）, and total P （TP） in a 200-km2 urbanizing watershed in Southeast china. Four land use types were identified by visual interpretation as forest land, agricultural land, green land, and urban land. One hundred and fifty soil samples （0-10 cm） were taken according to land use type and patch size. Results showed that the non-algorithm approach, interpolation based on individual land use types, substantially improved the performance of IDW and OK for mapping Tc, TN, and TP in the watershed. Root mean square errors were reduced by 3.9% for Tc, 10.770 for TN, and 25.9% for TP by the application of IDW, while the improvements by OK were slightly lower as 0.9% for Tc, 7.7% for TN, and 18.1% for TP. Interpolations based on individual land use types visually improved depiction of spatial patterns for Tc, TN, and TP in the watershed relative to interpolations by the whole watershed. Substantial improvements might be expected with denser sampling points. We suggest that this non-algorithm approach might provide an alternative to algorithm-based approaches to depict watershed-scale nutrient patterns.

关键词： geographic information system inverse distance weighting non-algorithm approach ordinary kriging spatial pattern

维普期刊数据库

Nitrogen regulation by natural systems in“unnatural”landscapes:denitrification in ultra-urban coastal ecosystems

在线全文

学校读者我要写书评

暂无评论

Ecosystem Health and Sustainability 2018年第9期4卷 17-37页

作者： Bernice R.Rosenzweig Peter M.groffman chester B.Zarnoch Brett F.Branco Ellen K.Hartig James Fitzpatrick Helen M.Forgione Adam Parris Environmental Sciences Initiative Advanced Science Research Center at the Graduate CenterCity University of New YorkNew YorkNYUSA Earth and Environmental Sciences Brooklyn CollegeCity University of New YorkBrooklynNYUSA cary Institute of Ecosystem Studies MillbrookNYUSA Natural Sciences Baruch College and Graduate CenterCity University of New YorkNew YorkNYUSA New York city Department of Parks and Recreation Natural Resources GroupNew YorkNYUSA HDR Inc.New YorkNYUSA The Natural Areas conservancy New YorkNYUSA Science and Resilience Institute at Jamaica Bay BrooklynNYUSA

Dense cities represent biogeochemical hot spots along the shoreline,concentrating fixed nitrogen that is subsequently discharged into adjacent coastal receiving ***,the ecosystem services provided by natural systems in highly urban environments can play a particularly important role in the global nitrogen *** this paper,we review the recent literature on nitrogen regulation by temperate coastal ecosystems,with a focus on how the distinct physical and biogeochemical features of the urban landscape can affect the provision of this ecosystem *** use Jamaica Bay,an ultra-urbanized coastal lagoon in the United States of America,as a demonstrative case *** on simple areal and tidal-based calculations,the natural systems of Jamaica Bay remove~24%of the reactive nitrogen discharged by wastewater treatment ***,this estimate does not represent the dynamic nature of urban nitrogen cycling represented in the recent literature and highlights key research needs and *** review reveals that ecosystem-facilitated denitrification may be significant in even the most densely urbanized coastal landscapes,but critical uncertainties currently limit incorporation of this ecosystem service in environmental management.

关键词： Nitrogen denitrification urban coastal anammox wetlands

在湿润亚热带农业生态系统中越冬豆科作物对磷、钾、钙和镁循环的作用

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

农业资源与环境学报 1988年第2期 31-32+35页

作者： Peter M. groffman 戴祖林

在美国东南部越冬豆科作物作为覆盖作物日益普遍。覆盖作物对水土保持是必需的,同时,越冬豆科作物能产生有效氮供给夏收作物。由于减少了对氮肥的需要,越冬豆科作物作为覆盖作物对农业生态系统中能量储备、经济效益以及土壤保持都产生... 详细信息

在美国东南部越冬豆科作物作为覆盖作物日益普遍。覆盖作物对水土保持是必需的,同时,越冬豆科作物能产生有效氮供给夏收作物。由于减少了对氮肥的需要,越冬豆科作物作为覆盖作物对农业生态系统中能量储备、经济效益以及土壤保持都产生影响。虽然越冬豆科作物的氮动力学研究已非常彻底,但越冬豆科作物在其它养分循环方而的作用几乎没有研究。众所周知,氮肥的形态对植物获得阳离子和磷的影响,但很少

关键词：豆科作物覆盖作物美国美利坚合众国北美洲农业生态系统生态系黑麦麦类作物自然带亚热带副热带

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

免耕与常规耕作土壤肥力的分异

南京农业大学学报 1987年第2期 82-89页

作者：吴珊眉 groffman P.M. 南京农业大学土壤教研室佐治亚州立大学生态研究所

研究表明免耕土壤表层0—5厘米内土体疏松,酸度适中,土壤有机质氮、磷、钙、硼和锌等元素富集,持水能力强。0—5厘米以下土壤紧实,酸度增加,含水量骤降,且碳、氮、磷、钙、硼和锌的含量甚至比常规耕作土壤的相应层次少。此外,免耕土壤0... 详细信息

研究表明免耕土壤表层0—5厘米内土体疏松,酸度适中,土壤有机质氮、磷、钙、硼和锌等元素富集,持水能力强。0—5厘米以下土壤紧实,酸度增加,含水量骤降,且碳、氮、磷、钙、硼和锌的含量甚至比常规耕作土壤的相应层次少。此外,免耕土壤0—21厘米内弱酸溶性铜、锰、钼、铅、钴和镍以及活性铝、铁和硅的含量均低于常规耕作土壤。免耕和常规耕作土壤肥力的分异是由于不同的土壤耕作和管理措施,导致常规耕作土壤旱耕熟化和免耕土壤人为生草化过程的结果、因地制宜地改进免耕机具,变免耕表面施肥为划土施肥,并控制其地面残体的数量,或改长期免耕为交替免耕等,将有助于提高免耕土壤常年生产力水平并发挥其综合效能。

关键词：免耕有机质积累氮素转化微量元素