Modelling Current and Future Potential Habitats for Plantations of Eucalyptus grandis Hill ex Maiden and E. dunnii Maiden in Uruguay

Modeling for Predicting the Potential Geographical Distribution of Three Ephedra Herbs in China

Ephedra species are beneficial for environmental protection in desert and grassland ecosystems. They have high ecological, medicinal, and economic value. To strengthen the protection of the sustainable development of Ephedra, we used occurrence records of Ephedra sinica Stapf., Ephedra intermedia Schrenk et C.A. Mey., and Ephedra equisetina Bge., combined with climate, soil, and topographic factors to simulate the suitable habitat of three Ephedra based on ensemble models on the Biomod2 platform. The results of the models were tested using AUC, TSS, and kappa coefficients. The results demonstrated that the ensemble model was able to accurately predict the potential distributions of E. sinica, E. intermedia, and E. equisetina. Eastern and central Inner Mongolia, middle and eastern Gansu, and northeastern Xinjiang were the optimum regions for the growth of E. sinica, E. intermedia, and E. equisetina, respectively. Additionally, several key environmental factors had a significant influence on the suitable habitats of the three Ephedra. The key factors affecting the distribution of E. sinica, E. intermedia, and E. equisetina were annual average precipitation, altitude, and vapor pressure, respectively. In conclusion, the results showed that the suitable ranges of the three Ephedra were mainly in Northwest China and that topography and climate were the primary influencing factors.

Impacts of 1.5 °C and 2 °C global warming on Eucalyptus plantations in South America

Even if the maximum global warming thresholds established by the Paris Agreement (1.5 and 2 °C relative to pre-industrial levels) are not exceeded, part of the climate system impacts resulting from this warming will be unavoidable. Forestry industries may be especially vulnerable, due to water shortages and the inability of growing certain forest species. An important part of the South American economy depends on the forestry sector (between 2 to ~7% of the Gross Domestic Product), mainly products derived from Eucalyptus, and so evaluating water availability considering the temperature thresholds established by the Paris Agreement will be fundamental. This study analyzed increased global average temperatures at 1.5 °C and 2 °C, and the impacts on water availability, using the Climatic Water Balance (CWB), and also studied possible impacts on Eucalyptus plantations in South America. Monthly temperature and precipitation data obtained from a set of simulations and projections of 26 General Circulation Models (GCMs) were used, in four Representative Concentration Pathway (RCP) scenarios. The CWB was calculated for three periods: i) the pre-industrial period (1861-1890), ii) the present period (1975-2005), and iii) the period when temperature projections are expected to reach global average increases of 1.5 °C and 2 °C. Due to changes in the CWB, with increases in actual evapotranspiration, water deficits, and a reduced water surplus, Eucalyptus plantations will be negatively affected and economically unfeasible for about 49.2% to 56.7% of all of South America, including a large part of the Amazon region, northern South America, midwestern and northeastern Brazil, western portions of Bolivia, Paraguay, central/northern Argentina, and northern Chile. Only some parts of South America, like the southern and southeastern regions of Brazil, Uruguay, southern Argentina and Chile, Andes Mountain Range, and northwestern South America, will not suffer water deficits, and Eucalyptus plantations will be less impacted in these regions. Large parts of South America will suffer from changes in water availability. The future of the forestry industry, and especially Eucalyptus plantations in these regions, will depend on urgent and effective adaptation measures.