甘南尕海湿地退化过程中植被生物量变化及其季节动态  

Changes in plant biomass and its seasonal dynamics during degradation succession in the Gahai wetland

作　　者：马维伟[1] 王辉[1] 李广[1,2] 石万里[1] 赵锦梅[1] 罗永忠[1] 聂志刚[3] 薛景文 

机构地区：[1]甘肃农业大学林学院,兰州730070 [2]兰州大学草地农业生态系统国家重点实验室,兰州730020 [3]甘肃农业大学信息科学技术学院,兰州730070 [4]甘肃则岔自然保护区管理局,碌曲747200

出　　处：《生态学报》2017年第15期5091-5101,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41561022;31260155;31560343);甘肃省自然科学资金(1506RJZA015);甘肃省高等学校科研项目(2015A-067;2014A-058);高等学校博士学科点专项科研基金(20126202110006);草地农业生态系统国家重点实验室开放课题资助(SKLGAE201408);林学院中青年科技基金资助项目

摘　　要：为探讨尕海湿地退化过程中植被生物量变化规律,以尕海泥炭沼泽和沼泽化草甸为例,采用定位样地调查方法,研究了不同退化程度湿地植被生物量的时空分布格局。结果表明,1)随着湿地退化演替,两类湿地植被地上生物量逐渐减小,泥炭沼泽未退化(PⅠ)、退化阶段(PⅡ)地上生物量依次为334.19,290.72 g/m^2,沼泽化草甸未退化(SⅠ)、轻度退化(SⅡ)、中度退化(SⅢ)地上生物量依次为378.40,308.07,261.21 g/m^2;地上生物量季节动态规律均为单峰型,8月中下旬达到峰值;同一湿地类型各退化阶段地上生物量绝对增长率(AGR)和相对增长率(RGR)在同一年份变化趋势基本相同,但不同年份间存在差异,而同一湿地类型不同阶段AGR和RGR的大小存在差异。2)地下生物量也随退化程度加剧显著减小(P<0.05),PⅠ,PⅡ地上生物量依次为23081.46,12607.72 g/m^2,SⅠ,SⅡ,SⅢ地下生物量依次为4583.16,3008.63,1290.73 g/m^2;地下生物量季节变化均表现出愈接近生长季始末值愈大;地下生物量由土壤表层向深层显著下降(P<0.05),总体呈"T"形分布,0—10cm土层,泥炭沼泽、沼泽化草甸地下生物量都最大,分别占各自总地下生物量50%和70%以上。3)尕海2类高寒湿地5—9月平均根冠比均表现未退化高于退化,根冠比季节动态为越接近生长季始末值越大,生长旺盛季值越小。Wetlands are important contributors to the global carbon （C） cycle because they store large quantities of C in their vegetation and soil and exchange CO2 actively with the atmosphere through photosynthesis and respiration. Plant biomass is a critical part of the primary production in wetland ecosystem that maintains the wetland health and quality. It also provides many ecosystem functions, such as C sequestration in alpine wetland. Therefore, biomass is the main link that relates aboveground and belowground ecosystem processes. We used the peatlands and swamp medows areas in the Gahai wetland of south Gansu province to investigate changes to plant biomass during degradation succession in an alpine wetland. The time-space distribution pattern of the area at different stages of wetland degradation was analyzed using the sample-plot survey method. Significance testing was conducted using one-way variance analysis （ One-way ANOVA） and the Schaffer method. The results showed that 1 ） the aboveground biomass decreased gradually in the peatlands and swamp medows as degradation succession progressed. The reduction in aboveground biomass followed the order non-degraded peatlands （PI） （ 334.19 g/m^2 ） 〉degraded peatlands （PII） （ 290.72 g/m^2 ）, and was non-degraded swamp meadows （SI） （ 378.40 g/m^2 ） 〉lightly degraded swamp meadows （SII） （308.07 g/m^2） 〉moderately degraded swamp meadows （SIII） （261.21 g/m^2 ）. The curves for the aboveground biomass seasonal dynamics for the two sites were seasonal dynamics of aboveground biomass was single apex types, the variation trends were the same, and they reached a peak value in August. The changes in the absolute growth rate and relative growth rate of aboveground biomass at each degradation stage on the same wetland types were consistent for each degradation stage on the same wetland types over the years the survey took places, but the values were different between years. The values for absolute growth rate and relative growt

关 键 词：湿地退化 植物生物量 根冠比 季节动态 

分 类 号：Q948.1[生物学—植物学]