珍稀濒危植物绣球茜(Dunnia sinensis Tutcher)的生境特征和繁殖技术

The habitat and propagation techniques of Dunnia sinensis Tutcher,a critically rare and endangered plant in southern China

对中国特有珍稀濒危植物绣球茜(Dunnia sinensis Tutcher)开展了分布范围、种群大小、生境特征、繁殖技术和保护状况研究。研究结果表明,绣球茜主要分布于广东省境内龙门县南昆山省级自然保护区、台山市北峰山森林公园、台山市古兜山林场和阳春市八甲峨凰嶂省级自然保护区、新会市崖西镇鹅坑水库、珠海高栏岛东侧海岸、电白县罗坑镇马房村等7个地点的公路边坡次生疏林或荒坡上,其所在群落的植物多样性较低,绣球茜是阳生性种类,其主要伴生种是芒萁(Dicranopteris linearis Underw)。绣球茜所在群落的土壤为酸性赤红壤,土层较薄,养分含量较高。该种野外个体约有2380株,因公路、水库和工厂建设导致绣球茜丧失栖息地是导致其种群减少的主要原因。本文所研究的4个地点的绣球茜种群,有台山市北峰山和龙门县南昆山的2个种群处于衰退中。根据世界自然保护联盟(International Union for Conservation of Nature,IUCN)标准,该种可列为极濒危级(CR)。绣球茜的种子在湿润河沙+泥炭生境下自然发芽率仅8%,生根剂ABT、萘乙酸、IBA吲哚-3-丁酸浸泡后的扦插条存活率为分别为13.3%、20.0%和20.0%。建议:(1)对该种加强就地保护,对保护区外的分布点设立保护小区,同时防止保护小区内乔木层郁闭影响绣球茜的更新;(2)对所有分布点的植株进行有遗传多样性代表性的迁地保护;(3)开展全球变化背景下的野外回归;(4)在引种驯化的基础上开展种苗生产和栽培基质等商品化生产研发。研究结果对这类需要适度干扰的珍稀濒危植物的保护和可持续利用有参考价值。

The distribution,population size,habitat characteristics,propagation technology and conservation status of Dunnia sinensis Tutcher,an endemic,rare and endangered plant in southern China,were studied.The results showed that it was mainly distributed at the edge of secondary sparse forests or barren land of road slope in lower subtropical area.The plant diversity of its community was low,and its associated species was Dicranopteris linearis Underw.It grew well on the acid soil in the sunny environment.It was estimated that approximately 2380 individuals in the field in total.Two of the four populations investigated were in decline due to the absence of emerged seedlings or existence of few young individuals.D.sinensis should be categorized as Critically Endangered according to evaluation criterion on the International Union for Conservation of Nature(IUCN).The seed germination rate under natural condition was only 8%,and the survival rate of cuttings soaked with rooting agent was 13%-20%.We have recommended an integrated species-conservation plan for the species that includes strengthening in situ protection,establishing an ex situ living collection that contains the entire wild genetic diversity(accomplished by cuttings from representative wild individuals),and implementing reintroduction to augment the wild population,and facilitating propagation for commercial use.The results are valuable for the protection and sustainable utilization of similar rare and endangered plants.