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Brief review on climate change and tropical peatlands 被引量:1
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作者 Lee Yit Leng Osumanu Haruna Ahmed mohamadu boyie jalloh 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第2期373-380,共8页
In 2008, the very extensive tropical peats were estimated to be about 182 million ha spanning South America, Asia and Africa. About 20.3%(36.9 million ha) of this area exist in Asia. Peats are classified based on thei... In 2008, the very extensive tropical peats were estimated to be about 182 million ha spanning South America, Asia and Africa. About 20.3%(36.9 million ha) of this area exist in Asia. Peats are classified based on their degree of decomposition, namely Fibrists, Hemists, Saprists and Folists. This makes them different in characteristics. The activities of microorganisms vary in different types of peat due to, for example, the sapric layer of well humified peat can provide water and food to microorganisms during heat stress. In another scenario, deeper peat is older and typically has lower levels of labile carbon to provide substrate for microbes compared to surface peat. A complete understanding of the microbial communities in different layers of peat is essential as microorganisms play major roles in peat decomposition and are important to ecosystem processes. These peats are a very important global carbon(C)store or reserve and could severely impact climate change if not managed well. Peatlands can store as much as 40 to 90 Gt C. Mis-management of peats could severely impact the environment particularly the emission of carbon into the atmosphere. For instance, clearing of peatlands using fire has been reported to release an estimated 88 t C ha^(-1) to the atmosphere. There are several factors which influence the environmental consequences of tropical peat especially in relation to climate change. The main influences are:(i) changes in temperature,(ii) changes in precipitation or rainfall,(iii) changes in atmospheric composition, and(iv) fire and haze. This paper is a brief review on these four influences in relation to climate change. It is apparent from the brief review that there is a need for continued short and long-term research to better understand tropical peats and how they affect our climate. This will hopefully provide the basis for predicting better what could happen under various scenarios. 展开更多
关键词 TROPICAL peats Climate change Carbon METHANE Decomposition MICROORGANISMS
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有机氮肥对马来西亚沙捞越州酸性土壤玉米干物质产量及铵态氮和硝态氮含量的影响 被引量:2
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作者 Susilawati Kasim Osumanu Haruna Ahmed +4 位作者 Nik Muhamad Ab.Majid Mohd Khanif Yusop mohamadu boyie jalloh 王艳群 孙志梅 《腐植酸》 2011年第2期30-34,共5页
腐殖质中的腐植酸和黄腐酸可以提高土壤中可交换性铵(NH4+)的回收率。这两种酸固定和保持NH4+的能力已经在许多研究中得到了证实,二者通过提高植株的光合作用速率、促进根系发育影响植物的生长和养分吸收。因此,本研究调查了这两种酸(液... 腐殖质中的腐植酸和黄腐酸可以提高土壤中可交换性铵(NH4+)的回收率。这两种酸固定和保持NH4+的能力已经在许多研究中得到了证实,二者通过提高植株的光合作用速率、促进根系发育影响植物的生长和养分吸收。因此,本研究调查了这两种酸(液态)对玉米干物质产量、土壤铵态氮和硝态氮(NO3-)含量的影响。根据液态有机氮肥的组成,采用标准方法分离提纯腐植酸。有机氮肥在玉米种植后第10天、第28天分别施入盆栽土壤,然后在种植后第54天或孕穗期采集植株和土壤样品。土壤样品分析pH、铵态氮和硝态氮含量,植株样品测定干物质产量。结果表明,在酸性条件下,液态有机氮肥(黄腐酸、腐植酸或二者同时施用)的施用可以提高土壤中NH4+的累积量。随土壤活性碳储量的增加,腐植酸分子上羧基官能团对土壤NH4+的吸附能力增强。然而,酸含量较低时对干物质产量的影响明显减小。各处理间硝态氮的有效性没有达到统计上的差异显著水平。较低的pH值能抑制土壤硝化作用进程,同时降低土壤NO3-含量。这表明液态腐植酸和/或黄腐酸在提高尿素利用效率方面发挥着重要作用。然而,与腐植酸分子特性有关的作用机理还需要进一步详细研究。本研究为液态和叶面有机肥料的发展提供一定的依据。 展开更多
关键词 腐植酸 黄腐酸 氮肥 液态肥料 铵态氮 硝态氮 玉米
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