扎龙湿地芦苇分株生态可塑性及其对土壤因子的响应

扎龙湿地的芦苇既可形成大面积的单优群落,也可形成不同群落斑块。采用大样本抽样调查与统计分析方法,对湿地内水生生境、湿生生境、旱生生境和盐碱生境芦苇种群分株高度和生物量进行比较。结果表明,6—10月份,4个生境芦苇种群分株高度及生物量均以水生生境最高,盐碱生境最低,水生生境株高为盐碱生境的1.5—2.3倍,分株生物量为2.0—5.1倍,生境间的差异性以及差异序位均相对稳定。4个生境株高生境间变异系数(19.45%—31.56%)均高于生境内变异系数(8.07%—17.61%),分株高度在生境间的可塑性更大;分株生物量中水生生境、湿生生境和盐碱生境3个生境间的变异系数(33.43%—55.61%)均低于生境内变异系数(44.85%—79.82%),分株生物量在生境内的可塑性更大。不同生境条件下芦苇种群分株,在生长和生产上均存在较大的生态可塑性,表现出明显的环境效应,其中土壤含水量是该地区芦苇分株生态可塑性变异的主要驱动因子(R0.80),为正向驱动。

The ecological plasticity and its responses to soil factors of ramets of Phragmites australis in Zhalong wetland

Phragmites australis in the Zhalong wetlands can not only form large areas of mono-dominant communities, but also form different community patches. By using large sample sizes and statistical analysis, a comparative study was performed on the height and biomass of ramets of P. australis populations in aquatic, wet, xeric, and saline-alkali habitats in wetlands. The results showed that in these four habitats, from June to October, the height and biomass of ramets of P. australis population were the highest in the aquatic habitat, and the lowest in the saline-alkali habitat; the height of ramets in the aquatic habitat was 1.5-2.3 times higher than that in the saline-alkali habitat; and the biomass of ramets in the aquatic habitat was 2.0-5.1 times larger than that in the saline-alkali habitat, while the difference and different orders among habitats were relatively stable. In the four habitats, the coefficients of variance in ramet height (19.45%-31.56%) among habitats were higher than those within habitats (8.07%-17.61%). The ramet height had a greater plasticity among habitats, while the coefficients of variance in ramet biomass (33.43%-5.61%) among the aquatic, wet, and saline-alkali habitats were lower than those within the habitats (44.85%-79.82%). Additionally, the ramet biomass had a greater plasticity within habitats. The ramets of P. australis populations in different habitats had great morphological plasticity in growth and production, showing obvious environmental effects, in which the soil moisture was the main positive driving factor (R > 0.80) of plasticity variation.