Climate change is undeniably one of the grandest challenges that society is, and will be, facing over the next decades. With individual citizens, cities, corporations, and countries now acutely aware of potentially severe impacts entailed by rising CO₂ emissions and temperatures, the call for natural climate solutions grows louder. “Negative emissions technologies” are becoming increasingly popular—in particular, the strengthening of carbon capture in trees and forests. However, the common notion that dense tall vegetation mitigates climate change is not straightforward in arid lands such as the US Southwest. This is because dense forest is darker than the underlying desert soil, and therefore absorbs more solar energy. This energy is mostly released as heat, and antagonizes the cooling effect of CO₂ removal from the atmosphere. The big and complex question is: What is the optimal vegetation structure and density to maximize the climate cooling potential of arid environments?

Within the BEST-CLIM project, students and researchers work closely together to address the above question and build a stronger scientific basis for ecosystem management and restoration initiatives in the US Southwest. Our long-term goals are to:

• Develop wall-to-wall maps of desired vegetation conditions for the US Southwest;
• Determine how these optimal conditions compare to current conditions;
• Develop forward-looking scenarios of land-cover change and disturbance dynamics (e.g., fire) to inform adaptive ecosystem management.

Students engaged in BEST-CLIM gain hands-on experience with fieldwork, lab work, data analysis and curation, as well as with dissemination of our findings to administrative, scientific, and public audiences. Students focus on one or multiple connected research tasks, including:

• Establishing and maintaining a network of permanent ecological sampling plots across the Sky Islands to represent forest, woodland, and shrubland systems;
• Assessing the vegetation structure, density, and surface energy balance of each plot, and the entire region, using remote sensing;
• Quantifying the growth and productivity of woody vegetation using dendroecological methods and ecological scaling;
• Estimating the evapotranspiration cooling associated with a given vegetation type;
• Considering the disturbance dynamics and impacts associated with a given vegetation type;
• Homogenizing and curating field observations and laboratory measurements to develop an efficient project database;
• Analyzing and visualizing data to better understand vegetation-climate feedbacks;
• Describing and interpreting results to facilitate their presentation within UArizona, to the broader scientific community, and to stakeholders and ecosystem managers.

Participating students are strongly encouraged to provide critical input and constructive suggestions and ideas that may open up new research avenues and shape the VIP. Our expectation is that BEST-CLIM members, regardless of their career stage, form a collaborative, diverse, and inclusive unit where everyone’s voice is being heard. At the individual level, students have the chance to gain a variety of transferrable and analytical skills that will empower them on their future career path. In addition, BEST-CLIM collaborates closely with local and regional land managers and practitioners, including the US Forest Service, which will offer students further insight into possible career opportunities.