海南省外来入侵植物空心莲子草的分布和生境特征

Habitat Characteristic and Distribution of Invasive Plant Alternanthera philoxeroides in Hainan Province

采用实地调查方式,在海南岛18个市县设置100个样地调查入侵植物空心莲子草的地理分布、伴生植物种类、生境类型和特征,发现空心莲子草在海南15个市县有分布,总体分布频率达0.36,大小顺序为:临高>海口>万宁>澄迈>儋州>琼海>定安>文昌>五指山>白沙>琼中>屯昌>保亭>乐东>东方,临高地区分布频率最高,达0.8333。其分布生境中共有伴生植物67科,192种。不同生境中分布频率大小顺序为:人工湿地、自然湿地和旱地;根据植被类型,其入侵的湿地可进一步划分为沼泽湿地、农田、丢荒农田+菜地、河岸、水库、池塘,其中丢荒农田+菜地中空心莲子草盖度最大为95%。对空心莲子草分布的沼泽、河流、水库水样的总氮、总磷、总钾、化学需氧量、生物需氧量进行分析,水样p H在6.19~7.16之间,空心莲子草对氮、磷、钾浓度有很大的耐受范围。研究表明,空心莲子草在海南适应能力强,分布较广,湿地环境尤其适宜生长;应采取严密控制和防治措施,避免其大规模泛滥,对海南生态系统造成严重的危害。

To assess the geographical distribution,companion species,habitat types and characteristics of Alternanthera philoxeroides(Mart.)Griseb,100 plots in 18 counties of Hainan province were surveyed.Result showed that the occurrence frequency of Alternanthera philoxeroides in 15 counties was Lingao>Haikou>Wanning>Chengmai>Danzhou>Qionghai>Dingan>Wenchang>Wuzhishan>Baisha>Qiongzhong>Tunchang>Baoting>Ledong>Dongfang,with the mean frequency of 0.36.The distribution frequency of Alternanthera philoxeroides in Lingao was the highest,up to 0.8333.There are 192 species of associated plants in 67 families.According to the vegetation types,the invasive wetlands can be further divided into swamp wetland,farmland,abandoned farmland+vegetable field,riverbank,reservoir and pond,among which the coverage of Alternanthera philoxeroides in abandoned farmland+vegetable field is the highest,with 95%.The analysis of total nitrogen,total phosphorus,total potassium,chemical oxygen demand and biological oxygen demand of water samples from marshes,rivers and reservoirs distributed in Alternanthera philoxeroides showed that the pH value of water samples was between 6.19 and 7.16,and Alternanthera philoxeroides had a large tolerance range of nitrogen,phosphorus and potassium concentrations.The results showed that Alternanthera philoxeroides had strong adaptability and wide distribution in Hainan,especially suitable for its growth in wetland environment.Strict control and control measures should be taken to avoid its large-scale flooding and cause serious damage to Hainan ecosystem.