Results 51 to 60 of about 7,285 (204)

Carbon cycling of forest ecosystems in response to global nitrogen deposition: a review [PDF]

open access: yes, 2007
森林土壤和植被储存着全球陆地生态系统大约46%的碳,在全球碳平衡中起着非常重要的作用。过去几十年来,森林生态系统的碳循环和碳吸存受到了全球氮沉降的深刻影响,因为氮沉降改变了陆地生态系统的生产力和生物量积累。以欧洲和北美温带森林区域开展的研究为基础,综述了氮沉降对植物光合作用、土壤呼吸、土壤DOM及林木生长的影响特征和机理,探讨了森林生态系统碳动态对氮沉降响应的不确定性因素。热带森林C、N循环与大部分温带森林不同,人为输入的氮对热带生态系统过程的影响也可能不同 ...
李燕燕   +5 more
core  

Island restoration to rebuild seabird populations and amplify coral reef functioning

open access: yesConservation Biology, Volume 39, Issue 1, February 2025.
Abstract Mobile organisms like seabirds can provide important nutrient flows between ecosystems, but this connectivity has been interrupted by the degradation of island ecosystems. Island restoration (via invasive species eradications and the restoration of native vegetation) can reestablish seabird populations and their nutrient transfers between ...
Ruth E. Dunn   +5 more
wiley   +1 more source

不同类型氮肥与施氮量下夏玉米水、氮利用及土壤氮素表观盈亏

open access: yesShuitu Baochi Xuebao, 2006
以两个夏播玉米品种为材料,研究了不同类型氮肥与不同施氮量下华北平原夏玉米的水分与氮素利用及土壤氮素表观盈亏.结果表明:(1)随施氮量增大.产量、耗水量及水分生产效率(WPE)增大,氮肥利用率(NUE)降低;(2)夏玉米WPE与NUE具有较明显的基因型差异。WPE郑单958较大。NUE农大108较大;(3)wPE与NUE均受到氮肥类型的影响.WPE郑单958复合肥〉普通尿素〉包膜尿素.农大108处理间差异较小,以复合肥略大,普通尿素和包膜尿素相当。与普通尿素相比,包膜尿素与复合肥利用率较高 ...
易镇邪   +9 more
doaj   +2 more sources

Nitrogen Sources, Transports and Transformations in Headwater Catchment [PDF]

open access: yes, 2007
过量施肥、化石燃料的燃烧等人类活动带来的氮负荷问题对陆地和水生生态系统的影响迅速扩大,引起了全世界的关注。当流域陆地生态体系的氮素饱和后,过量的氮素会通过地表径流和地下潜流排入溪流、湖泊、河流和海洋中。因为溪流直接迁移了流域体系过多的氮素,研究氮在溪流中的循环过程之前了解流域氮素流失到溪流的过程机制至关重要。因此,对五川流域氮素流失的过程机理进行研究以及探讨氮在溪流中的迁移转化行为,有利于阐明流域体系的氮在溪流中的循环过程。 本研究融合多学科知识,在GIS技术支持下,综合运用现场定位试验、模型模拟 ...
王吉苹
core  

滴灌施肥技术对作物生长及氮素的影响

open access: yes水利电力技术与应用, 2023
张伯志, 王艳秋, 李伟霞
semanticscholar   +1 more source

Pharmacology of drugs used in autoimmune dermatopathies in cats and dogs: A narrative review

open access: yesVeterinary Dermatology, Volume 35, Issue 4, Page 453-476, August 2024.
Immunosuppressive drugs are the mainstay of treatment for many feline and canine autoimmune skin diseases, either as monotherapy or in combination with other drugs. Treatment with these drugs is often lifelong and may have long‐term consequences on the affected animal's overall quality of life.
Heng L. Tham, Jennifer L. Davis
wiley   +1 more source

地下水埋深与控肥对夏玉米氮素吸收和产量的影响

open access: yesShuitu Baochi Xuebao, 2021
为探明地下水埋深与减施氮肥对夏玉米氮素吸收利用及产量的影响,基于大型地中渗透仪,研究了地下水埋深和施氮量对夏玉米氮素利用效率、植株氮素积累量、产量及其形成要素的影响,其中地下水埋深设2 m(G1),3 m(G2)和4 m(G3)3个水平,施氮量设减氮20%处理(240 kg/hm2,N1)、常规施氮处理(300 kg/hm2,N2)2个水平,不控水不施氮处理(G0N0)作为对照,共计7个处理。结果表明:(1)减氮20%条件下,夏玉米产量随地下水埋深增加呈减小趋势,氮素收获指数在埋深2 m下显著高于埋深3,
佘映军   +8 more
doaj  

受污染湖泊沉积物中氮素转化对有机污染物降解的促进效应与机制

open access: yesEarth Science-Journal of China University of Geosciences, 2022
G. Qu   +7 more
semanticscholar   +1 more source

Dutch landscapes have lost insect‐pollinated plants over the past 87 years

open access: yesJournal of Applied Ecology, Volume 61, Issue 6, Page 1323-1333, June 2024.
This study implies that Dutch landscapes are losing insect‐pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect‐pollinated plants support the necessity and urgency of taking conservation initiatives.
Kaixuan Pan   +3 more
wiley   +1 more source

缓/控释氮素肥料玉米苗期养分释放特点

open access: yesShuitu Baochi Xuebao, 2006
采用盆栽试验.模拟田间生态环境.研究施用不同种缓/控释氮素肥料玉米苗期土壤尿素态氮、硝态氮、铵态氮和速效态氮含量,分析比较其在玉米苗期氮素养分释放特点。研究表明,在玉米苗期,施用醋酸酯淀粉包膜脲酶抑制剂nBPT涂层尿素肥料。土壤中尿素态氮和铵态氮的积累量最多.分别为21.72mg/kg和48.31mg/kg;醋酸酯淀粉包膜尿素肥料,硝态氮和速效氮含量最多.分别为102.90mg/kg和135.25mg/kg;丙烯酸树脂包膜脲酶抑制剂nBPT涂层尿素肥料,尿素自膜内迁移到土壤中的量较少 ...
李东坡   +5 more
doaj   +2 more sources

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