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土壤中的碳、氮含量是湿地“汇”功能的基础。滇西北高原湿地具有重要的“汇”功能,但不同放牧对其“汇”功能的影响是否存在差异尚缺乏研究。以滇西北高原典型湿地纳帕海为研究对象,对践踏型(牛羊践踏STD)、扰动型(藏香猪翻拱扰动PDD)放牧影响下,以及长期禁牧(NG)草甸土壤容重、表面紧实度及其碳、氮空间分布进行研究。结果表明:(1)土壤容重随土层深度(0~40 cm)的增加均呈增加的趋势,但不同放牧对表层(0~20 cm)土壤容重的影响存在显著差异,其中,STD>NG>PDD。随着土层深度(20~40 cm)的增加,这种影响差异不断减小至无差异。不同放牧干扰对草甸土壤表面紧实度的影响存在显著差异,其中,STD>NG>PDD。(2)不同放牧干扰下,土壤总有机碳(SOC)含量随土层深度的增加均呈现逐渐减少的趋势。但不同放牧干扰下,表层(0~20 cm)土壤SOC含量存在显著差异,其中,NG>STD>PDD。随着土层深度(20~40 cm)的增加,不同放牧干扰对土壤SOC含量的影响不存在显著差异。(3)不同放牧干扰下,土壤全氮(TN)含量均随土层深度(0~40 cm)的增加呈现逐渐减少的趋势。但不同放牧干扰对表层(0~20 cm)土壤TN含量的影响存在显著差异,其中,NG>STD>PDD。到20~30 cm,PDD放牧下的土壤TN含量显著高于NG和STD放牧的。随着土层深度的增加,不同放牧干扰对土壤TN含量的影响不存在显著差异。本研究表明了放牧对湿地表层土壤(0~20 cm)物理性状及其碳、氮营养物质积累存在显著影响,不同放牧对其影响存在差异,进而对湿地生态系统“汇”功能产生影响。研究为加强滇西北高原湿地放牧的分类管理、维护湿地生态系统“汇”的生态服务功能提供了一定的理论依据。
Soil carbon, nitrogen content is wetland “sink ” function basis. The wetland in northwestern Yunnan has an important “sink” function, but there is still a lack of research on the effects of different grazing on its “sink” function. Taking Napahai, a typical wetland in the northwestern Yunnan plateau, as an example, under the grazing conditions of trampling type (STD) and disturbance type (PDD) Compaction and carbon and nitrogen spatial distribution of the study. The results showed that: (1) The bulk density of soil increased with the depth of soil (0-40 cm), but the effects of grazing on soil bulk density of surface layer (0-20 cm) were significantly different. STD> NG > PDD. With the increase of soil depth (20-40 cm), the difference of this kind of influence decreases to no difference. The effects of different grazing disturbance on the compaction of meadow soil were significant, STD> NG> PDD. (2) Under different grazing disturbance, the soil total organic carbon (SOC) content showed a decreasing trend with the increase of soil depth. However, under different grazing disturbance, there was significant difference in soil SOC content between surface layer (0 ~ 20 cm), where NG> STD> PDD. With the increase of soil depth (20-40 cm), there was no significant difference in the effects of grazing disturbance on soil SOC content. (3) Under different grazing disturbance, the content of soil total nitrogen (TN) tended to decrease with the increase of soil depth (0-40 cm). However, the effects of grazing disturbance on TN content in surface soil (0-20 cm) were significantly different, among which, NG> STD> PDD. At 20-30 cm, TN content of soil under PDD grazing was significantly higher than that of NG and STD grazing. With the increase of soil depth, the effect of different grazing disturbance on soil TN content did not differ significantly. This study showed that grazing had significant effects on the physical properties of the surface soil (0-20 cm) and the accumulation of carbon and nitrogen nutrients in wetlands, and the effects of grazing on the differences were significant, which had an impact on the ecosystem function . The research provides some theoretical basis for strengthening the classification management of wetland grazing in the northwestern Yunnan Plateau and maintaining the ecological service function of the wetland ecosystem “sink ”.