摘要
高鞘苔草是多年生根茎型无性系莎草,主要分布于贫营养泥炭沼泽中。在生长季中期的小兴安岭贫营养泥炭沼泽中,高鞘苔草无性系种群分株数量以营养株占优势(2次取样平均占94.09%)。分株分蘖节可营养繁殖3代,并由3个龄级组成,呈稳定型年龄结构。根茎最大存活年限为12年,共划分为8个龄级,呈衰退型年龄结构。活动芽由4个龄级组成,呈稳定型年龄结构,分株分蘖节对活动芽的贡献远大于根茎。7,8月2次取样间,3种构件的年龄结构类型无变化,全体分株数量和根茎的累积长度与生物量均无显著差异(P>0.05),但8月份的分株平均单重和1龄级根茎单位长度生物量显著降低21.50%和20.26%(P<0.05),各龄级活动芽数量均显著增加1倍以上(P<0.05)。在生长季中期,高鞘苔草向活动芽和根茎转移营养物质,通过降低单位长度干物质的投入来加速1龄级根茎的生长,扩展空间生态位。同时,通过大量增加活动芽的数量,实现种群的持续更新。
Carex middendorffii ,a rhizomatous perennial clonal sedge,is mainly found in oligotrophic mires. In an oligotrophic mire located in the Xiaoxing＇an Mountains,China,during the middle of the growing season,the quantity of vegetative ramets was dominant （with an average percentage of 94.09% in two sampling events）. Tiller nodes of ramets can propagate vegetatively for 3 generations. The ramets consisted of 3 age classes of individuals,and showed a stable age structure. The rhizomes,whose maximum age was 12 years old,were classified into 8 age classes, and showed a declined age structure. 4 age classes which had active buds were recognized, which showed a stable age structure. The tiller nodes of ramets contributed much more to a potential population,theactive bud module,than the rhizomes. In the two sampling events in July and August,the age structures of the three modules had not changed,and no significant differences were found,no matter the quantity of total ramets or cumulative length or biomass of total rhizomes （P〉0.05）. Mean biomass per ramet and biomass per unit length in 1 age class of rhizomes,however,were significantly decreased by 21.50% and 20.20% respectively （P〈0.05）, while more than 1 times of significant increase was found in each age class of active buds （P〈0.05）. At the middle growth season,Carex middendorffii transferred nutrient materials to active buds and rhizomes. By virtue of reducing investment of dry materials per unit length to accelerate growth of 1 age class of rhizomes,the clonal population expanded its spatial niche. In addition,persistent regeneration of the clonal popuiation was able to occur by recruiting many active buds at the middle of the growth season.
出处
《草业学报》
CSCD
2005年第5期124-129,共6页
Acta Prataculturae Sinica
基金
国家自然科学基金项目(50139020
39770536)
东北师范大学青年科学基金项目(111373000)资助
关键词
高鞘苔草
根茎
活动芽
更新
泥炭沼泽
Carex middendorffii
rhizome
active bud
regeneration
mire
