辽河口湿地植物多样性及物种功能型空间分布格局

Spatial distribution of plant diversity and functional groups in the Liaohe estuary

辽河口湿地是我国典型的滨海湿地,在过去几十年受人为过度干扰,植被变化明显。本研究拟通过野外实地调查揭示辽河口湿地植物多样性及功能型的空间格局。结果表明,潮上带的物种丰富度和Shannon-Wiener指数均高于潮间带。与潮上带相比,潮间带的盐生植物与湿生植物比例较高,而中性植物、甜土植物、中生植物与旱生植物的比例较低。物种丰富度、Shannon-Wiener指数以及中性植物、甜土植物、中生植物、旱生植物的比例均随着与海岸线距离的增加而增加,盐生植物、湿生植物比例则与之相反。对所调查样地与植物物种的主成分分析(PCA)表明,潮上带主要为芦苇(Phragmites australis)、刺儿菜(Cirsium setosum)、山莴苣(Lagedium sibiricum)等中性和甜土植物,潮间带为盐地碱蓬(Suaeda salsa)、扁秆藨草(Scirpus planiculmis)、水烛(Typha angustifolia)等盐生植物。可见,盐度与水位是决定辽河口湿地植物多样性及物种功能型的关键生态因子。

Liaohe estuary is a typical coastal wetland in Northeast China. Over the past decades, vegetation in this area suffered great change due to human disturbance. The spatial distribution of plant diversity and functional groups was examined in this coastal wetland. Results showed that species richness and Shannon-Wiener index were higher in supratidal zones than in intertidal zones. Compared to supratidal zones, intertidal zones had a higher ratio of halophytes and hygrophytes, but a lower ratio of neutral plants, glycophytes, mesophytes, and xerophytes. Species richness, Shannon-Wiener index, and the ratio of neutral plants, glycophytes, mesophytes, and xerophytes increased with the increasing distances from the coastline, while halophytes and hygrophytes decreased. Principal Component Analysis（PCA） indicated that plant communities mainly composed of neutral plants and glycophytes in supratidal zones, such as Phragmites australis, Cirsium setosum and Lagedium sibiricum, and halophytes mainly distributed in intertidal zones, such as Suaeda salsa, Scirpus planiculmis and Typha angustifolia. Salinity and water table appear to be the key factors in determining plant diversity and functional groups in the Liaohe estuary.