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以洞庭湖典型湿地植物辣蓼为目标植物，短尖苔草为邻近植物，通过控制实验研究不同水位（30、0和-30 cm）和竞争（无竞争、全部竞争、地上竞争和地下竞争）模式下目标植物生长及生态化学计量特征的变化.结果表明：水位处理显著影响不同竞争模式下的生物量积累，辣蓼生物量随水位增加显著降低；-30 cm水位无竞争模式下生物量最大，为10.84±1.52 g.在30 cm和0 cm水位梯度下，不同竞争模式下的生物量间无显著差异.但-30 cm水位下，地下竞争模式下的辣蓼生物量积累较全竞争模式和地上竞争模式下显著增多，说明非胁迫条件下，辣蓼和苔草的竞争以地上竞争为主.水位处理对辣蓼叶片、茎和根的氮、磷含量影响显著，30 cm水位下，叶片氮、磷含量显著高于其他水位下的含量.在-30 cm水位下，叶片C：N和C：P显著高于其他水位下的比值，分别为48.08±3.85、590.3±43.4.相比于对照处理（无竞争），竞争作用下的辣蓼总氮含量降低，而C：N值增加，N：P值降低，这可能是因为竞争作用导致辣蓼对氮的吸收减少所致.;Taking Polygonum hydropiper as the target plant and Carex brevicuspis as the adjacent plant, the changes of growth and ecological stoichiometry characteristics of P. hydropiper under different water levels(30 cm, 0 cm and -30 cm)and competition patterns (no competition, full competition, above-ground competition and below-ground competition) were studied through outdoor control experiments. The results showed that:the biomass accumulation of P. hydropiper was significantly affected by water level under different competition patterns, and which decreased significantly with the increase of water level. The maximum biomass was 10.84±1.52 g in the no competition pattern with the -30 cm water level. Under 30 cm and 0 cm water levels, the biomass accumulation of P. hydropiper had insignificant difference under different competition patterns. However, at -30 cm water level, the biomass accumulation of P. hydropiper under the below-ground competition pattern was significantly higher than that under the full competition pattern and the above-ground competition pattern, which indicated that the competition between P. hydropiper and C. brevicuspis was dominated by the above-ground competition under the non-stress condition. The nitrogen and phosphorus contents in leaves, stems and roots of P. hydropiper were significantly affected by water level. The nitrogen and phosphorus contents of leaves were significantly higher at 30 cm water level than those at other water levels. At -30 cm water level, the ratio of C:N and C:P was significantly higher than those at other water levels, which was 48.08±3.85 and 590.3±43.4, respectively. Compared with the control treatment, competition decreased the total nitrogen content of P. hydropiper, while the C:N ratio increased and the N:P ratio decreased, which may be due to that the competition reduced the nitrogen absorption of P. hydropiper.
Xu et al. (Tue,) studied this question.