关键词: 广东, MaxEnt模型, 沙田柚, 适生区预测

Abstract:

To rationally plan the planting distribution of Shatian pomelo in Guangdong, this study employed the ENMeval-optimized Maximum Entropy (MaxEnt) model and ArcGIS software, utilizing 25 geographical distribution records of Shatian pomelo and 27 environmental factors. The aim was to simulate the potential suitable planting areas under historical climatic conditions and future scenarios based on the CMIP6 Shared Socioeconomic Pathways (SSPs), specifically SSP1-2.6 and SSP5-8.5. Additionally, the dominant environmental factors influencing the distribution of Shatian pomelo were analyzed. The simulation was performed using the Maximum Entropy Model (MaxEnt), optimized by the ENMeval package, and analyzed using ArcGIS software. The goal was to identify and analyze the dominant environmental factors influencing the distribution of Shatian pomelo. The results showed that: (1) the MaxEnt model effectively simulated the distribution of suitable cultivation areas for Guangdong Shatian pomelo, with the area under the curve (AUC) reaching 0.912, indicating high model accuracy. (2) During the historical period (1970−2000), low−suitability areas for Guangdong Shatian pomelo covered the largest extent, approximately 105600 km², accounting for 58.7% of the total land area of Guangdong province. These areas were mainly located in the western region of Guangdong, the Pearl river delta and the eastern coastal areas. In contrast, medium− and high−suitability areas, covering about 55900km² (31.1% of the province’s total area), were primarily concentrated in the cities of Meizhou, Heyuan, Shaoguan, Qingyuan and Zhaoqing cities. Among these, Meizhou had the largest highly suitable area, followed by Shaoguan. (3) The dominant environmental factors influencing the suitable cultivation of Shatian pomelo were identified as the precipitation of the wettest month (Bio13), the mean diurnal temperature range (Bio2), the precipitation of the warmest quarter (Bio18) and slope aspect (ASPECT). (4) Under the SSP1−2.6 and SSP5−8.5 scenarios, the total area of medium− and high−suitability zones for Shatian pomelo in Guangdong was projected to expand by 2.5 and 2.3 times, respectively, during the period 2021 to 2040 compared with the historical period. The SSP1−2.6 scenario was expected to produce the largest area of highly suitable zones, covering approximately 57200km², or 31.8% of Guangdong's total land area. Overall, climate change was expected to contribute to the expansion of suitable areas for Shatian pomelo cultivation in Guangdong province. Based on these findings, it is recommended that experimental trials for Shatian pomelo planting be conducted in the western part of Guangdong and the northern cities and counties of the Pearl river delta to assess the comprehensive environmental suitability and explore the feasibility of large−scale cultivation and introduction of Shatian pomelo.

Key words: Guangdong, MaxEnt model, Shatian pomelo, Fertile zone prediction