水菜花种群潜在生境选择与空间格局预测

Potential Habitat Selection and Spatial Pattern Prediction of Ottelia cordata

摘要:

国家二级保护野生植物水菜花(Ottelia cordata)，喜生于清洁的水环境中，对环境变化极为敏感，是检验湿地环境及气候变化的关键指示物种之一，在我国仅零星分布于海南北部的火山熔岩湿地区，生存状况不容乐观。研究水菜花种群潜在生境选择及其空间格局演变，有利于加强濒危物种保护保育及湿地生态系统修复、管理。该研究基于GIS平台和MaxEnt模型，结合气候、地形和土壤因子，探究水菜花种群环境限制因子及其在气候变化背景下潜在适宜生境的演变格局。结果表明，水菜花种群对温差与降水量变化敏感，等温性、最冷季度降水量、土壤类型和年均降水量对水菜花种群分布影响显著；全新世中期-当前-2070年气候变化背景下，水菜花适宜生境面积先减小后增大，分布重心呈西南-东北-西南转移格局；未来气候情景下，水菜花种群高度和中度适宜生境缩减，低适宜生境增加，南部地区将出现新增适宜生境，东北、西北及西南部适宜生境将发生消减。该研究从气候环境角度论证了水菜花种群的潜在生境选择及空间变化特征，可为濒危物种保护保育、湿地管理及其生物多样性维护工作提供参考和指导。

关键词:水菜花;气候变化;潜在生境;环境因子

Abstract:

Ottelia cordata, a wild plant under State second-class protection, likes to be grown in clean water, and is extremely sensitive to environmental changes. It is one of the key indicator species for testing wetland environment and climate change. In China, it is only distributed sporadically in volcanic lava wetland in northern Hainan, the survival condition is not optimistic. The study of potential habitat selection and spatial pattern evolution of O. cordata population will help strengthen the conservation of endangered species and the restoration as well as the management of wetland ecosystem. Based on GIS platform and MaxEnt model, combining with climate, topography and soil factors, the environmental limiting factors of O. cordata population and the evolution pattern of potential suitable habitat in the context of climate change were studied. The results showed that O. cordata population was sensitive to temperature difference and precipitation change. Besides, isothermality, precipitation in the coldest quarter, type of soil and annual precipitation were key environmental factors affecting the distribution of O. cordata population. Under the background of climate change from the middle Holocene to current to 2070s, the area of suitable habitat of O. cordata decreased first and then increased, and the distribution center showed a transfer pattern from southwest to northeast to southwest. Under the future climate scenarios, the highly and moderately suitable habitats were decrease, while the low suitable habitats will increase. The new habitats will appear in the southern region, and the suitable habitats will decrease in the northeast, northwest and southwest. Therefore, the potential habitat selection and spatial distribution characteristics of O. cordata population were discussed from the perspective of climate environment, which could provide reference and theoretical basis for endangered species conservation, wetland management and biodiversity maintenance.

Key words:Ottelia cordata;Climate change;Potential habitat;Environmental factor