Prediction of Suitable Future Natural Areas for Highland Barley on the Qinghai-Tibet Plateau under Representative Concentration Pathways (RCPs)

Abstract

Global climate change, mainly characterized by warming, has resulted in significant migration of temperature-sensitive crops from traditional planting areas, making crops more vulnerable to climate change and natural disasters, increasing yield losses caused by disasters. Based on the MaxEnt model, combining Representative Concentration Pathways 4.5 and 8.5, the potential suitable areas for highland barley planting on the Qinghai-Tibet Plateau were estimated, and the results showed that: (1) Over 30% of the Qinghai-Tibet Plateau is unsuitable for highland barley cultivation, the area of moderately suitable area for highland barley planting is close to 50%, and the marginally suitable and highly suitable area is less than 20%; (2) From the past distribution to the near and medium-term distributions, the unsuitable area for highland barley planting is gradually shrinking. In the moderately suitable area for highland barley planting, some of the area with relatively low suitability was transformed from unsuitable area, and some of the area with relatively high suitability was transformed into marginally suitable area, so that the total area remained basically unchanged. A small part of the marginally suitable area was converted into high-suitability area, which increased the highly suitable area; (3) From the perspective of different scenarios, in the near and medium term, the area with a slight decrease or no change in suitability under RCP 8.5 was smaller than under RCP 4.5, but the area with a significant increase was larger than under RCP 4.5. The areas with a small decrease or no change in suitability accounted for 23.66–33.77% of the total plateau area and were concentrated in the northwestern Qinghai-Tibet Plateau and the Qaidam Basin. Areas with a large increase in suitability accounted for 3.47–15.64% of the total area and were located in the southern, central, and eastern parts of the Qinghai-Tibet Plateau, this area increased significantly with time; (4) Judging from the average altitude change in highland barley planting, the average altitude of the highly suitable area will rise from 3759 m to 3937 m (RCP 4.5) and 3959 m (RCP 8.5) in the near term. By the medium term, the average elevation of the highly suitable area will increase from 3759 m to 4017 m (RCP 4.5) and 4090 m (RCP 8.5). The trend of rising average altitude continues to strengthen.