Assisted Migration 2020

Dr. Cuauhtémoc Sáenz-Romero, his colleagues and students continue their experiments of reciprocal transplants of provenances of oyamel (Abies religiosa) seedlings at contrasting altitudes. After more than one year, at the site where most of the seedlings were planted at a higher altitude than that where they originated, i.e. at 3400 m altitude, the seedlings continued to have a very good survival (generally between 97 and 100%). However, seedlings that were planted at a lower altitude (2600 m elevation), in a site chosen to mimic a climate warmer by up to 5.6 °C than where some of them originated, the survival rate was 53%. In other words, shifting seed sources at higher altitudes up to 400 m, does not have a negative effect confirming what we have been suspecting all along that when seed sources are transferred to warmer sites, mortality is higher. This strategy is proposed as an adaptative management tool to face climatic change and is called assisted migration. It has been shown in previous field experiments by Carbajal-Navarro as published in the Frontiers of Ecology and Evolution Journal. In contrast, moving to warmer sites, emulating the effects of climatic change, has a very negative effect. Most of the mortality happen in April, at the end of the warm and dry season. Below images of seedlings planted at high, intermediate and low elevations in common garden experiments.