In the Trans-Mexican Volcanic Belt in central-western Mexico, drought stress causes the decline of two of the most ecologically and economically important conifers: Abies religiosa and Pinus pseudostrobus. Since P. pseudostrobus is distributed immediately below the lower elevation limit of A. religiosa, it would be a logical choice of species to fill gaps that may be created by the decline of A. religiosa. We assessed the feasibility of upward assisted migration and explored the effect of rain reduction using four P. pseudostrobus provenances in a rain exclusion field test at the border of the Monarch Butterfly Biosphere Reserve (MBBR) in Mexico. Our results show that, although populations were transferred between − 1.4 and − 3.3 °C mean annual temperature, and 30% of the precipitation (− 200 mm) was excluded, no statistically significant differences were found among treatments or populations for height increment (overall average 1.52 m) or survival (overall average 87%). These findings suggest that it is feasible to migrate P. pseudostrobus upward, towards the MBBR border, which also coincides with the sites where A. religiosa is in decline. This may present the additional benefit of discouraging change in land use from forestry to potato production by maintaining a healthy barrier of trees. If assisted migration is not included in management and reforestation programs, climate change could induce significant mortality in the present A. religiosa forest, facilitating expansion of the agricultural frontier toward the MBBR.

在墨西哥中西部的跨墨西哥火山带中，干旱胁迫导致两个在生态和经济上最重要的针叶树的数量下降：冷杉（Abies religiosa）和松木（Pinus pseudostrobus）。由于P. pseudostrobus的分布紧邻到A. religiosa的海拔较低限，因此合理地选择物种来填补由A. religiosa的衰退造成的缺口。我们评估了向上辅助迁移的可行性，并探索了使用四根假单胞菌进行减雨的效果墨西哥君主蝴蝶生物圈保护区（MBBR）边界的雨水排除田间试验的种源。我们的结果表明，尽管种群在平均年均温度-1.4至-3.3°C之间转移，并且排除了30％的降水量（-200 mm），但是在处理或种群之间未发现高度增加的统计学差异（总体平均1.52 m）或生存率（整体平均87％）。这些发现表明，将拟假单胞菌向上迁移至MBBR边界是可行的，该边界也与菩提假单胞菌的位置重合。在下降。通过保持树木的健康屏障，这可能会带来阻止从林业到马铃薯生产的土地利用变化的额外好处。如果在管理和重新造林计划中不包括辅助移民，那么气候变化可能会在目前的菩提树森林中造成大量死亡，从而促进农业领域向MBBR的扩展。