中国蔷薇属植物物种丰富度分布格局及其与环境因子的关系

Abstract

物种丰富度的大尺度地理格局及其成因是宏观生态学及生物地理学的中心议题之一。蔷薇属（Rosa L.）植物具有很高的经济价值和生态价值，探讨中国蔷薇属植物的丰富度分布格局及其影响因素可为该属植物资源的保护和合理开发利用乃至其系统进化研究提供重要依据。基于蔷薇属植物在中国的15451条分布数据和11种地理、气候等环境因子进行了物种丰富度分析和相关性分析，研究结果显示：（1）蔷薇属植物在中国分布不均匀。在水平方向上，蔷薇属植物于26.19°-34.29°N带内有较高的物种丰富度，之后随着纬度的增加而降低，且随着经度的增加表现为先增加后减少，于99.10°-108.47°E间存在明显的峰值；在垂直方向上，蔷薇属植物的物种丰富度随海拔的增加表现为先增加后减少，956.46-3518.60m范围内的丰富度最高。西南横断山区为蔷薇属物种分布的中心地区，新疆北部及东北长白山周边地区为局部聚集区。（2）蔷薇属物种丰富度与各能量、水分和生境异质性因子均呈正相关关系，与气候稳定性因子呈负相关关系。表明中国蔷薇属植物在水分和热量条件好、气候季节性变化小且生境异质性程度高的地方，有着更高的物种丰富度。（3）蔷薇属植物丰富度与各因子的关系基本支持了生产力假说、环境稳定性假说和生境异质性假说。但蔷薇属的物种丰富度格局并非完全由这些假说解释，历史环境、地形、土壤、人类活动等其他因子可能也有一定的影响作用。（4）水分因子的单独解释率占34.6%（R²；P<0.001），是影响蔷薇属物种丰富度格局的主导因子，这可能是由该类群的进化历史、生理适应等原因共同决定的。本研究可以为蔷薇属植物的分类、进化、以及野生资源的保护和开发利用提供参考。;Understanding macro-scale spatial patterns in species richness and their underlying mechanisms is an important issue to macroecology and biogeography. Rosa species have a high economic and ecological value. Exploring the geographic patterns of species richness and their environmental determinants of Rosa in China will facilitate the resources protection and rational utilization, as well as systematic and evolutionary research of the genus. In this study, datasets of 15451 distributional records and 11 environmental factors were used to conduct species richness and correlation analyses. The results show that (1) Rosa is unevenly distributed in China. The species richness is the highest at latitudes ranging from 26.19°N to 34.29°N, and decreases as the latitude increase. The richness of Rosa is the highest at longitudes ranging from 99.10°E to 108.47°E, and decreased from this optimal range to the west and the east. The species richness shows unimodal pattern that increases first and then decreases with the increase of altitude, with the maximum value between 956.46 m and 3518.60 m. The central aggregation areas are located in the mountain areas around Sichuan Basin as well as Hengduan Mountains, and Chang Bai Mountains region and northern Xinjiang are the local aggregation areas. (2) The energy, water and habitat heterogeneity are positively associated with species richness. In addition, there are negative correlations between species richness and environmental stability. The Rosa has higher species richness in regions with the suitable hydrothermal conditions, the steady climate, and the great habitat heterogeneity. (3) The relationship between the species richness and the environment factors basically supports the productivity hypothesis, the environmental stability hypothesis and the habitat heterogeneity hypothesis. However, the hypotheses cannot fully explain the species richness pattern of Rosa, which indicates that other factors such as historical environment, terrain, soil properties or human activity probably have played a role in shaping the richness pattern of Rosa species. (4) Water factors account for 34.6% (P<0.001) of the species richness patterns of Rosa, so water is the dominant factor, which might be determined by the evolutionary history, physiological adaptation and other reasons. Our results can provide valuable information for the classification, evolution, protection and exploitation of wild resources of the Rosa species.