扎龙湿地芦苇种群不同龄级根茎构件的季节动态

克隆植物根茎具有营养繁殖和扩展种群的功能,也是芽和分株生理整合的通道。根茎构件具有出生、死亡及年龄等种群统计特征,不同龄级根茎的季节动态可以反映根茎的存活和衰老过程。采用单位土体挖掘取样,对扎龙湿地4个生境芦苇种群根茎构件进行野外调查,比较不同龄级根茎长度、生物量和干物质贮量的季节动态。结果表明:7—10月份,1a根茎长度、生物量和干物质贮量均呈指数函数增加,在生长季中后期有一个持续时间较长的生长和物质积累时期。6—10月份,2a、3a根茎长度呈线性函数增加,4—6a根茎长度呈线性函数减少;2—4a根茎生物量和2—5a根茎干物质贮量呈二次函数先减少后增加,5a、6a根茎生物量和6a根茎干物质贮量呈幂函数减少。整个生长期内,根茎长度和根茎生物量均以3a最大,根茎长度以最高的6a最小,根茎生物量以最低的1a最小;根茎干物质储量以5a最大,以最低的1a最小。4个生境芦苇种群根茎长度、生物量和干物质贮量在龄级间的差异及差异序位稳定,在新根茎的产生、老根茎的存活以及根茎寿命与养分消耗和储藏上均具有稳定的生物学特性,不同龄级根茎在种群中的地位和作用以及对种群的贡献不同。

Seasonal dynamics of rhizome modules in different age classes of Phragmites australis populations in the Zhalong Wetland

Clonal plant rhizomes not only function in vegetative propagation and population expansion, but also act as a physiological channel, integrating buds and ramets. Examining the rhizome components can reveal information regarding the birth, death, and age of the plants, and the seasonal dynamics of rhizomes at different ages can reflect survival and senescence processes. A field investigation was carried out on the rhizomes of Phragmites australis populations in different habitats of the Zhalong Wetland. Soil from a unit area was sampled to assess the seasonal dynamics of rhizome length, biomass, and dry matter storage at different ages. The results showed that rhizome length, biomass, and dry matter storage of 1st increased exponentially from July to October and that there was a long period of growth and material accumulation in the middle and late growing period. From June to October, the rhizome lengths of 2nd and 3rd increased linearly, and the rhizome length of 4th to 6th decreased linearly. The rhizome biomass of 2nd to 4th and the dry matter storage of 2nd to 5th decreased initially and then increased quadratically. The rhizome biomass of 5th or 6th and the dry matter storage of 6th decreased with the power function. During the entire growing period, the rhizome length and biomass of 3rd were the highest and the rhizome length of the 6th were the lowest and the biomass of the 1st the lowest; The dry matter storage of 5th was the highest and that of 1st was the lowest. There was a relatively stable difference and differential sequence between age classes in rhizome length, biomass, and dry matter storage of P. australis populations in the four different habitats. The emergence of new rhizomes, survival of old rhizomes, lifetime of rhizomes, and nutrient consumption and storage showed relatively stable biological characteristics. The status and function of rhizomes and their contribution to the population varied in different age classes.