Abstract:

Based on data of Torreya fargesii distribution collected from literature and specimen records, as well as a field survey which covered 57 county-scale plots, the Genetic Algorithm for Ruleset Production (GARP) modeling approach was applied to predict its potential distribution range in China and analyze its distribution pattern and endangered causes. Our results indicated that:environmental factors, such as solar radiation, minimum temperature, maximum temperature and frost days, greatly influenced size of the potential range, while flow accumulation, mean annual temperature, wet days and water vapour pressure had little impact on the distribution. T. fargesii distributed disjunctively in subtropical mountains from 800 to 2 700 m and scattered in coniferous and broad-leaved forests, hillside thickets and ravine region. Potential distribution estimation indicated that the mountains in Central China would be the optimum habitats for T. fargesii to grow. Potential areas that we predicted suitable for growth of T. fargesii were much larger than its actual areas, suggesting that T. fargesii had been experiencing its extinct process. Most of the T. fargesii populations had a narrow distribution with very small population density, therefore, the habitat conservation would be crucial for T. fargesii protection.

Key words: Torreya fargesii, GARP, potential distribution estimation, geographic distribution, conservation