Avocado Cover Expansion in the Monarch Butterfly Biosphere Reserve, Central Mexico

Avocado cultivation has reduced the extent of forest ecosystems in central Mexico, even in natural protected areas such as the Monarch Butterfly Biosphere Reserve (MBBR) where information on the extent and expansion dynamics of avocado cover is scant. This study aimed to identify avocado plantations within the MBBR through photo interpretation for the 2006–2018 period. Change rates of the avocado cover extent were calculated for the northern, central, and southern zones of the MBBR, and topographic attributes such as elevation, soil type, slope, and slope aspect were identified. A total extent of 958 ha is covered by avocado plantations within the MBBR. The southern zone hosted the largest area under avocado cultivation (570 ha), but the northern zone had the highest change rate between 2006 and 2018 (422%). Most avocado orchards have been established mainly in Acrisol soils, south-facing slopes, on steep hillsides, and in elevations between 2050 and 2800 m. The conversion from traditional agricultural lands has been the main mechanism for the establishment of avocado orchards. However, 40 ha under avocado cultivation derived from deforestation, mainly in the central zone. The expansion of avocado plantations could trigger environmental impacts, even threatening the overwintering habitat and the migratory phenomenon of the monarch butterflies