汉江水生植物多样性研究

STUDIES ON THE DIVERSITY OF AQUATIC PLANTS IN HANJIANG RIVER

  • 摘要: 对汉江沿途13个地区的所在江段进行了水生植物种类组成、分布、生物多样性调查.结果表明,在汉江共有水生植物26科36属54种;物种α多样性在丹江口最高,H、D和R指数由上游汉中江段至下游汉口段表现出上升-下降-上升的三折线及四折线变化趋势;β多样性在水深梯度及距离梯度上表现为β下>β上>β中,说明下游江段的生境异质性程度高;γ多样性是γ上>γ中>γ下,对各个江段而言以中游老河口江段γ多样性最大为2种,丹江口和襄樊江段次之,汉口段最小.中游地区水生环境和生态因子更适合于水生植物的生长,而下游人类活动导致水环境趋于恶化限制了水生植物的生长和分布.

     

    Abstract: The species compositions, distribution and biodiversity of aquatic plants in 13 belt transect along Hanjiang River have been surveyed in two years'field studies. There were 54 species of aquatic plants belonging 36 genera and 26 families in Hanjiang River.The index of H, D and R showed that the up-down-up three folded to four folded changing tend from the Hanzhong spot on the upper reaches to the Hankou spot on the lower reaches. Along the gradient of water depth and horizontal distance from upper to lower reaches of Hanjiang River, βdiversity showed the result of βlowerβupperβmiddle, indicating higher habitat heterogeneity in the lower reach than in the upper and middle reaches. γdiversity showed γupperγmiddleγlower. While among spots, γdiversity was the highest in Laohekou spot(29 species). The next were at Danjiangkou spot and Xiangfan spot, and the lowest value was at Hankou spot. In summary, aquatic plants were rich in middle reaches of Hanjiang River where water was clear and low in the lower reaches due to water pollution and human disturbance.

     

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