大清河水系滨岸带入侵草本植物分布特征及影响因素

在雄安新区建设大背景下，保障大清河水系生物安全十分重要。为研究大清河水系入侵植物分布规律，探讨影响入侵植物分布的驱动因子，对大清河水系河湖滨岸带开展植被调查，识别滨岸带入侵植物，判定物种的入侵等级，分析物种入侵分布与环境因子和人类活动因素之间的相关性，并提出雄安新区面临的植物入侵风险及防范措施。结果表明：大清河水系有24种入侵植物，其中苋科和菊科合计占54.2%，一年生物种、无意引入物种分别占83.3%、62.5%，原产地为美洲的占62.5%，反枝苋、鬼针草、圆叶牵牛、鳢肠、大狼杷草、苘麻6种植物为流域内广布种；入侵植物种数和入侵性在流域中游的拒马河上游房山山区段、流域下游的牤牛河霸州城市段以及100 m高程分界线附近的山区—平原交接区明显高于其他区域；人类活动是影响植物入侵程度的主要因素，路网密度、建设用地面积占比越高，越有利于入侵植物的分布与扩散；大清河水系植物入侵程度尚可控，但需要在雄安新区建设过程中重视植物入侵定居及扩散风险，早做防范。

Distribution characteristics and influencing factors of invasive herbaceous plants in the coastal zone of Daqing River system

In the context of the construction of Xiong'an New Area, it is very important to ensure the biological safety of Daqing River system. In order to study the distribution of invasive plants in Daqing River system and explore the driving factors affecting the distribution, the vegetation in the river/lake riparian zone of Daqing River system was investigated. The invasive plants in the riparian zone were identified, the invasion grade of each species determined, the correlation between the distribution of species invasion and influencing factors including natural environment and human activities analyzed, and the risk of plant invasion and preventive measures in Xiong'an New Area put forward. The results showed that there were 24 species of invasive plants in Daqing River system, 54.2% of the invasive species were amaranth and compositae, the annual species and unintroduced species accounted for 83.3% and 62.5%, respectively, and 62.5% of the invasive plants originated from American. Six kinds of plants, including Amaranthus retroflexus, Bidens pilosa, Pharbitis purpurea, Eclipta prostrata, Bidens frondosa, Abutilon theophrasti, were widely distributed in the basin. There were three regions in which the number of species and invasiveness of invasive plants were significantly higher than that in other regions, including Fangshan mountain section in the upper reaches of Juma River in the middle reaches of the basin, Bazhou urban section of Mangniu River in the lower reaches of the basin, and the plain and mountain junction area near the 100 m elevation boundary. Human activity was the main factor affecting the degree of plant invasion. The higher the road network density and the proportion of construction land, the more conducive to the distribution and diffusion of invasive plants. The degree of plant invasion in Daqing River system could be controlled currently, but it was necessary to pay attention to the risk of plant invasion, settlement, and diffusion during the construction of Xiong'an New Area and take early precautions.