Recognizing that sound science is key to effective conservation, we support scientific research, including habitat and species assessments, with direct relevance to conservation in the overwintering sites. Our research funding supports scientists studying ecology and the conservation of monarchs in Mexico.
Survival Evaluation of 2018 Reforestations
In coordination with MBF, Alternare A.C. has promoted reforestation activities in the San Juan Zitácuaro River micro-watershed from 2010 to 2019. During this period, 250,368 plants have been established in 208.56 hectares. However, it is necessary to evaluate the survival of tree plantations to make sure we’re doing it adequately, give priority to the areas that require it most and to learn from the process to improve it.
After our analysis we determined an average survival rate of 61% in the 2018 reforestations, considering the eight sites evaluated that add a total 19.02 hectares (91% of the area reforested in 2018). The best place in terms of survival rates was El Canal in Crescencio Morales with 92%. The greatest mortality was presented at the Site Toma de Agua in Nicolás Romero, in which we estimated a survival rate of 9%.
An important lesson learned was that in the event that the inhabitants propose sites to reforest with steep slopes and soil erosion, it is advisable to implement conservation works prior to reforestation; these activities will increase the survival percentages. Soil management also will help regulate ecosystem processes such as nutrient absorption, decomposition and greater water filtration that allow rapid adaptation of trees and making it easier to obtain necessary nutrients.
An average mortality of 39% was determined due to agents such as herbaceous vegetation, excess shade, livestock, and rodents. By identifying the agents causing the death of the trees, techniques can be established that benefit most from the development and adaptation of trees at the plantation sites.
Assisted Migration 2020
Dr. Cuauhtémoc Sáenz-Romero and his colleagues continue their experiments in assisted migration at Ejido La Mesa. Unusually warmer and dry temperatures at the beginning of the year resulted in seedling mortalities in the altitudinal reciprocal transplants of Abies religiosa provenances tested at contrasting elevations. Oyamels planted last July 2019 at an elevation of 3400 m and placed under the shade of a mesh (imitating the effect of nurse plants), had a very good survival rate (around 95 %). However, when planted at a site chosen to imitate a climate about 2 °C warmer than the usual to forecast what would happen under climatic change (2600 m elevation), the rate was only about 80 %. Therefore, we can conclude that that when seed sources are transferred to warmer sites, mortality is higher. The figures below show the results.
High altitude: 3400 m, Llano Grande
Intermediate altitude: 3000 m, Ejido La Mesa
Low altitude: 2600 m, Tlalpujahua; notice the brownish seedlings, that are dead or nearly dead, due to an usually warm and dry February and March.