首页 > 分享 > 根部水淹和土壤养分提升对三峡库区消落带水蓼生长和繁殖特性的影响

根部水淹和土壤养分提升对三峡库区消落带水蓼生长和繁殖特性的影响

花匠小妙招
2025-01-07 06:30

摘要：

水淹和土壤养分是影响三峡库区消落带植物生长的主要环境因子。消落带不同高程的植物长期经历不同的淹水强度和土壤养分条件。该研究假设同一物种来自于消落带不同高程的植株可能产生性状分化, 从而对根部淹水和土壤养分变化具有不同的生长和繁殖响应策略。为了验证以上假设, 选取在三峡库区消落带高低高程均广泛分布的物种水蓼(Polygonum hydropiper)为研究对象, 采集自然种群的种子。在温室同质园条件下, 研究了根部水淹和土壤养分提升对高低高程水蓼植株生长和繁殖特性的影响。研究结果表明根部水淹显著或趋于显著降低了水蓼植株功能叶的叶长、叶宽、总分枝数、叶生物量、花生物量和总生物量; 低养分处理显著或趋于显著降低了水蓼植株的总节数、总分枝数、根生物量、花生物量和总生物量, 表明根部水淹和低土壤养分对水蓼的生长和繁殖能力具有抑制作用。同时, 根部水淹和土壤养分的交互作用显著影响植株的根生物量, 表明根部水淹条件下高土壤养分更有利于植株根生物量的积累。高高程植株的根生物量和叶生物量显著或趋于显著高于低高程植株, 而低高程植株的始花时间早于高高程植株, 且繁殖分配也显著高于高高程植株, 表明高低高程水蓼植株对资源的分配策略不同。该研究结果表明水蓼的生长和繁殖特性受根部水淹和土壤养分共同限制, 但对根部水淹条件下高土壤养分生境具有较好的适应性; 同时, 低高程植株可以通过调整其生长和繁殖特性以提高对所处生境胁迫的适应性。

关键词: 三峡库区, 根部水淹, 土壤养分, 高程, 湿地植物, 繁殖分配

Abstract:

Aims Flooding and soil nutrients are the main environmental factors that affect plant growth in the hydro-fluctuation belt of the Three Gorges Reservoir Region (TGRR). Flooding intensity and concentration of soil nutrients experienced by riparian plants at different elevations of the hydro-fluctuation belt are different; therefore, we hypothesized that growth and reproductive responses of plants of the same species from different elevations to waterlogging and increased soil nutrients are also different.
Methods In this study, the riparian species Polygonum hydropiper, which is widely distributed at low and high elevations of the hydro-fluctuation belt of the TGRR, was selected and its seeds were collected from natural populations. Effects of waterlogging and soil nutrients on growth and reproductive traits of P. hydropiper from high- and low-elevation areas were studied in a common-garden greenhouse experiment.
Important findings Waterlogging significantly, or with marginal significance, decreased length and width of functional leaves, total branch number, leaf biomass, flower biomass, and total biomass of plants; low nutrient treatment significantly or marginal significantly decreased total node number, total branch number, root biomass, flower biomass, and total biomass of plants, indicating that both waterlogging and low soil nutrients inhibited growth and reproduction of P. hydropiper. Moreover, the interaction between waterlogging and soil nutrients significantly affected root biomass, showing higher root biomass accumulation at high soil nutrient conditions upon waterlogging. The high-elevation plants had significantly or marginal significantly higher leaf and root biomass than those from low elevation; however, flowering time of the low-elevation plants was significantly earlier, and reproduction allocation was higher than the high-elevation plants, indicating that resource allocation strategy was different between the high- and the low-elevation plants. The results indicate that growth and reproduction of P. hydropiper are inhibited by both waterlogging and soil nutrients, and this species has high adaptability at high soil nutrient conditions to waterlogging; meanwhile, low-elevation plants can adjust their growth and reproductive characteristics to improve their fitness under environmental stress.

Key words: Three Gorges Reservoir Region, waterlogging, soil nutrients, elevation, wetland plant, reproduction allocation