基于MaxEnt和GIS的山西省连翘潜在分布及适宜性分析

POTENTIAL DISTRIBUTION PREDICTION AND SUITABILITY EVALUATION OF FORSYTHIA BASED ON MAXENT AND GIS IN SHANXI PROVINCE

关键词:  连翘  潜在分布  空间分析  最大熵算法  适宜性分析

Key words:  Forsythia suspensa  potential distribution  spatial analysis  Maximum Entropy Model  suitable distribution area

摘要:

目的 连翘是一味常用中药，在山西省分布广泛。预测连翘适宜种植区，有助于优化已有种植区的布局以及科学推广引种适宜种植区域，可为山西省贫困区县连翘合理种植提供参考。方法 文章基于 19 个环境相关数据和98个连翘种植区采样点数据，采用最大熵模型（MaxEnt）和GIS空间分析法，构建自然、人文相结合的种植适宜性模型，预测连翘潜在分布及适宜性，筛选主导环境因子并探究其与存在概率之间关系。结果 连翘在山西省种植的最适宜区、较适宜区、适宜区以及不适宜区面积分别为21 049.74km²、35 655.15 km²、44 707.90km²和65 287.20km²，分别占山西省总面积的12.63%、21.39%、26.82%和39.16%。其中，最适宜区集中分布在山西省的东南部地区，以临汾市、长治市分布最多；较适宜区分布在山西省南部地区，以运城市、晋城市分布最多；适宜区遍布山西省各个地市，但分布零散，受地形、坡度影响较大，不易形成规模生产，连翘的产量和质量均不高。从农户种植便利度、规模化种植灌溉便利度、农业物资运输便利度叠合分析得出，建议连翘的推广区为晋东南长治市、晋城市半丘陵区和太原市、晋中市交界区。刀切法测试表明，年最低气温、气温季节性变动是影响连翘潜在分布的两个最主要环境因子。结论 连翘具有很高的社会经济价值，山西省大多数地区均适宜种植；在推广种植时应考虑农户种植便利度、规模化种植灌溉便利度、农业物资运输便利度等影响。

Abstract:

Forsythia suspensa is commonly used as a traditional Chinese medicine, and is widely distributed in Shanxi province. Predicting the suitable planting areas of Forsythia suspensa can conduce to optimizing the pattern of existing planting areas and scientifically promoting the species introduction to the suitable planting areas, which can provide reasonable references for the targeted poverty alleviation project of Forsythia suspensa reasonably planting in Shanxi. Applying the GIS spatial analysis which was based on the MaxEnt model, this study constructed a planting suitability model combining natural environment and humanity, predicted the potential distribution and suitability of Forsythia suspensa in Shanxi, filtered the dominant environmental factors and explored the relationship between these factors and the probability of existence. The results showed that the areas of ‘the most suitable’, ‘more suitable’, ‘suitable’, and ‘unsuitable’ planting areas were 21 049.74 km², 35 655.15 km², 44 707.90 km² and 65 287.20 km², respectively, accounting for 12.63%, 21.39%, 26.82% and 39.16% of the total area of Shanxi. Among them, ‘the most suitable’ regions were concentratedly located in the southeastern Shanxi, especially in Linfen and Changzhi cities; ‘the more suitable’ areas were located in the southern Shanxi, especially in Yuncheng and Jincheng cities; ‘the suitable’ areas were located all over Shanxi with scattered distribution, and greatly influenced by topography and slope, which resulted that it was not easy to plant in scale and with low yield and quality of Forsythia suspensa. Combining the analysis of the convenience of planting by the farmers, irrigation of large-scale planting and transportation of agricultural material, the proposed extension area was Changzhi city in the southeastern Shanxi, the semi-hilly area in Jincheng city, Jinzhong basin, and junction area between Taiyuan and Jinzhong cities. The jackknife test showed that the two important environmental factors affecting the potential distribution of Forsythia suspensa were lowest temperature in the coldest month and standard variation of temperature seasonal variation. To conclude, Forsythia suspensa has highly social and economic values, and the environmental factor analysis shows that most areas in Shanxi are suitable for planting it. Humanistic factors such as farmers' planting convenience, large-scale planting irrigation convenience and agricultural material transportation convenience should be considered in the planting promotion.