水文干扰对不同盐生境下盐地碱蓬的影响

摘要

Soaked in fresh water and seawater were designed to simulate the river flooding and inwelling to study the effects of hydrological interference on the individuals and population of Suaeda salsa in different saline habitats.The results showed that soaked in fresh water improved the seed germination rate and uniformi-ty,while soaked in seawater reduced the seed germination rate under different salinity.The allocation of plant biomass was changed by hydrological interference in the growth period of S.salsa,and the same hydrological interference had different influence to biomass under different soil salinity.Under low soil salinity,soaked in fresh water and seawater could promote the accumulation of dry matter at the same level;the promoting effect was more obvious when soaked in fresh water than that soaked in seawater under moderate salinity;the promo-ting effect of the two hydrological interference was not obvious under high soil salinity.The hydrological inter-ference reduced the population density and the intensity of intraspecific competition,and expanded the in-traspecific niche of S.salsa.Moreover,hydrological interference could improve the productivity of S.salsa un-der low soil salinity.%本试验通过淡水淹和海水淹模拟黄河三角洲地区河水漫灌和海水倒灌两种水文干扰对不同盐生境下盐地碱蓬个体和种群的影响。结果表明：种子萌发期，淡水淹可以提高不同盐生境下盐地碱蓬种子的萌发率和整齐度，而海水淹会降低种子的萌发率。在盐地碱蓬的生长期进行水文干扰会改变各盐生境下植株生物量的分配，而且相同的水文干扰对不同盐生境下盐地碱蓬生物量的影响程度不同：在低土壤盐分下，海水淹和淡水淹会在相同程度上促进干物质的积累；在中度土壤盐分下，淡水淹的促进作用比海水淹明显；在高度土壤盐分下，两种水文干扰作用都不明显。对于盐地碱蓬种群来说，水文干扰都会降低种群密度和种内竞争强度，同时也扩大了盐地碱蓬的种内生态位。此外，水文干扰可以提高低盐分梯度下的盐地碱蓬的生产力。