环青海湖地区天然草地和退耕恢复草地植物群落生物量对氮、磷添加的响应

发布时间：2018-01-21 22:31

本文关键词： 高寒草原植物群落生物量氮添加磷添加退耕恢复草地青海湖流域　出处：《植物生态学报》2016年10期 　论文类型：期刊论文

【摘要】：植物群落生物量反映了植被的初级生产能力,是陆地生态系统碳(C)输入的最主要来源,往往受到自然界中氮(N)、磷(P)元素供应的限制。该试验以青藏高原环青海湖地区的高寒草原为研究对象,探讨了天然草地和退耕恢复草地植被群落生物量对N(10 g·m~( 2))、P(5 g·m~( 2))养分添加的响应。N、P添加显著增加了天然草地禾草的生物量,进而促使地上总生物量显著提高。退耕恢复草地禾草和杂类草的生物量对N添加均有一致的正响应,从而促使地上总生物量显著增加174%,群落地上和地下总生物量显著增加34%;而P添加对恢复草地生物量各项参数均无显著影响。回归分析显示:天然草地植物群落地上生物量随土壤中NO_3 -N含量的增加而增加(p0.05),退耕恢复草地植被地上、地下和总生物量均与土壤NO_3 -N含量显著正相关(p0.01),说明环湖地区高寒草原植物生长主要受N供应的限制,P的限制作用随土地利用方式的转变和群落演替阶段的不同而变化;相比天然草地,恢复草地在现阶段植被初级生产力受N的限制作用更强烈,土壤中可利用N含量是限制其植被自然恢复和重建的关键因子。
[Abstract]:Plant community biomass, which reflects the primary production capacity of vegetation, is the main source of carbon C input from terrestrial ecosystems and is often subject to nitrogen N in nature. The limit of P) supply. The study was conducted on the alpine steppe around Qinghai Lake in the Qinghai-Tibet Plateau. The response of natural grassland and restoration grassland community biomass to N ~ (10) g 路m ~ (-1) (P ~ (5 g 路m ~ (2))) was studied. P addition significantly increased the biomass of grasses in natural grassland and promoted the total aboveground biomass to be significantly increased. The biomass of grass and hybrid grasses in restoration grassland showed a consistent positive response to N addition. As a result, the total aboveground biomass increased significantly by 174%, and the total aboveground and underground biomass of community increased significantly by 34%. The regression analysis showed that the aboveground biomass of natural grassland plant community increased with the increase of NO_3 ~ (-N) content in soil. . The subsurface and total biomass were positively correlated with soil NO_3 ~ (-N) content, indicating that the growth of alpine steppe was restricted by N supply. The limiting effect of P varies with the change of land use mode and the succession stage of community. Compared with natural grassland, the primary productivity of restoration grassland is restricted by N at present. The available N content in soil is the key factor to limit the natural restoration and reconstruction of vegetation.
【作者单位】：中国科学院西北高原生物研究所高原生物适应与进化重点实验室;中国科学院大学;
【基金】：国家科技支撑计划(2014BAC05B04) 国家重点研发计划(2016YFC0501905)
【分类号】：S812
【正文快照】： 1015 1027.doi:10.17521/cjpe.2016.0048Methods NH4NO3 and Ca(H2PO4)2·H2O were added in a completely randomized block design,with mediumlevels of 10 g N·m 2 and 5 g P·m 2.Soil NO3 -N and available P contents,and the plant community biomass weremeasur

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