【作者】 迟传德；

【导师】 潘根兴；

【作者基本信息】 南京农业大学 ， 土壤学， 2006， 硕士

【摘要】 湿地生态系统与森林和海洋一起被誉为全球三大生态系统，又因其巨大的生产功能和生态环境效益被称为“人类的摇篮”、“生物基因库”和“自然之肾”。随着人口的急剧增长和社会经济的快速发展，自然湿地受到人类强烈的干扰，导致湿地面积萎缩、污染严重、功能退化甚至丧失，并已引起全世界的广泛关注。一般认为湿地是二氧化碳的“汇”和全球尺度上的气候“稳定器”，在全球环境变化研究中有重要意义，因此湿地生态系统碳循环的研究已成为世界性的研究热点。目前，我国湿地碳循环的研究主要集中在东北的三江平原、大小兴安岭和青藏高原东部的若尔盖高原等泥炭堆积的沼泽区域。长江中下游地区自古是淡水湿地广布的地区，上世纪60年代以来因围湖造田湿地面积大为萎缩。至今，沿长江的河网地带仍有一定面积的淡水湿地分布，这些湿地土壤的C、N、P等重要生源要素的循环特点及其环境意义还少有研究资料报道。 升金湖湿地是长江下游平原河湖湿地的一部分，位于安徽省南部池州市境内，濒临长江，境内湿地生态系统保存完好，是我国和东亚地区最重要的水禽越冬地和歇息地之一。本研究以升金湖湿地土壤为对象，重点研究湿地土壤碳、磷的变化，以期为了解长江流域淡水湿地土壤有机碳和磷的变化特点及其与陆地生态系统碳、磷变化的关系，进一步为评价和保护湿地生态系统提供参考依据。研究结果如下： 1、升金湖湿地土壤具有较高的有机碳密度，高于国内自然土壤及水稻土，但低于国内外中高纬度地区湿地土壤。湿地土壤剖面有机碳含量随深度的变化符合幂函数，有机碳的表层积累强于耕作土壤，且分布较深，与湿地植被的根系分布有关。但受到沉积过程和植被的生长等因素的影响，湿地土壤碳氮的水平分异明显。供试湿地表层土壤的有机碳和全氮含量均高于农田土壤，可见湿地土壤有明显的碳／氮的汇效应； 2、湿地土壤速效磷与全磷含量随深度的变化均符合指数函数关系，与湿地土壤的特有环境有关。湿地土壤无机磷组分以被氧化铁胶膜包裹的闭蓄态磷为主，其次为Fe-P，其余几种形态的次序为：Ca₁₀-P＞Ca₂-P＞Al-P＞Ca₈-P。各级无机磷在土壤剖面中的变化表现为，Ca₂-P、Ca₈-P、Al-P和Fe-P的变化趋势较一致，并与全磷的变化相似，而Ca₁₀-P和O-P的变化较为复杂； 3、利用相关系数来分析讨论各形态无机磷含量变化与Olsen-P磷的相关性，结果表明，Olsen-P与Ca₂-P、Ca₈-P、Al-P、Fe-P关系显著，即它们对有效磷的含量影响较大，由于Olsen-P法提取的有效磷主要为Ca₂-P形态的，故可以认为Ca₈-P、Al-P、更多还原

【Abstract】 Wetland, forest and ocean are the three most important ecosystems on the Earth. Wetland is called "the cradle of mankind",or "a gene pool of living things" and "the kidney of nature" because of the big productivity and significant ecological and environmental function. Particularly, Wetland is generally considered as carbon dioxide "sinks" and climate "stabilizer" on the global scale and has the vital significance in the global change study. With the rapid increase of world population and development of economy, wetland ecosystems have been degraded due to areal decline, water pollution and biodiversity reduction. Up to now, studies on wetlands of China have been concentrated on peat marshs of the Sanjiang Plain, of the Xing’an range and of the Nuo-ergai in the eastern part of Qinghai-Tibet Plateau. Freshwater wetlands had been extensive in the middle and lower reaches of the Yangtze River. Since the 1960’s, wetland area in this region had been greatly declined due to cultivation by embankment. However, there are still some areas of freshwater wetlands left in the region. There has not been much available data of storage and cycling life elements such as C, N, and P in the wetland ecosystems.Shengjin Lake wetland, located in Chizhou Municipality, southern Anhui Province besides Yangtze River, is one of the fresh water marshes in the lower reach of Yangtze River. Taking Shengjin Lake wetland soil as an example, storage and distribution of C and P was studied in order to describe the sink effect of wetlands on C and P and offer some references for evaluation and protection of wetland ecosystems research results are as follows:1, Soil organic carbon （SOC） mean density was 10.82±1.90kg·m^-2, being higher than the adjacent natural soils and paddy soils and lower than those of high latitudes. Distribution of SOC down the profiles generally followed a power function. Moreover, SOC accumulation in the topsoil was found stronger than the cultivated paddy soil due to deep rooted zone. Spatial variability of SOC and N was shown prominent as affected by更多还原