The Future Climate under Different CO2 Emission Scenarios Significantly Influences the Potential Distribution of Achnatherum inebrians in China

Abstract

The threat posed by poisonous weeds to grassland ecosystems may be exacerbated by climate change mainly driven by carbon dioxide (CO2) emissions. Achnatherum inebrians is a common and poisonous grassland weed that is seriously endangering the sustainable development of prairie animal husbandry in Western China. Understanding the influence of future climate change under different CO2 emission scenarios on the potential distributions of A. inebrians is critical for planning agricultural strategies to manage the continued invasion. An ecological niche model (ENM) was developed using Maxent to predict the potential distribution of A. inebrians under three different CO2 emission scenarios. Occurrence records of A. inebrians were selected utilizing the nearest neighbor method. Six environmental variables, which were identified through principal component analysis, correlation analysis and their contribution rates, were used to perform the ENM. At the same time, considering the uncertainties of predicting future climates, four global circulation models were used for the Maxent projections with average results calculated. Our results demonstrate differential influences of various CO2 emission scenarios on the potential distributions of A. inebrians. Before 2050, high CO2 emission scenarios resulted in a wider potential distribution of A. inebrians, when compared to low CO2 emission scenarios. However, after 2050, the low CO2 emission scenarios were more conducive to an expanded potential distribution. In addition, after 2050, high CO2 emission scenarios maintain the geographical distribution centroids of A. inebrians in lower latitudes, while low CO2 emission scenarios result in distribution centroids rising to higher latitudes. Further, low CO2 emission scenarios resulted in the average potential distribution elevation dropping lower than in high CO2 emission scenarios.