Sonoran-Sinaloan transition subtropical dry forest


The Sonoran-Sinaloan transition subtropical dry forest is a tropical dry broadleaf forest ecoregion in northwestern Mexico.

Geography

This ecoregion forms a transition belt between the Sonoran Desert to the north and the Sinaloan dry forests to the south, running south from the foothills of the Sierra Madre Occidental highlands of the state of Sonora to the Pacific Ocean coasts of Sonora and Sinaloa. This region is also part of the transition zone between the Nearctic and Neotropical realms and as such habitats of the region range from sparse semi-desert in the north to dry forest in the south. It covers an area of from sea level to.

Climate

The climate is subtropical and semi-arid. Annual rainfall is, and comes mostly in the summer months.

Flora

The characteristic vegetation is deciduous thorn forest and woodland, with areas of thorn scrub. Characteristic trees include the boat-thorn acacia, tree catclaw , and palo santo. Cacti are common, including organ pipe cactus, jumping cholla and barrel cactus.

Fauna

Large mammals include white-tailed deer, javelina, jaguar, and coyote.
As in the Sonoran Desert, nectar-feeding long-tongued bats like the Mexican long-tongued bat and Pallas's long-tongued bat are important pollinators. The ecoregion has over 90 species of butterflies.
Birds of the ecoregion include the black-throated magpie-jay.

Threats and preservation

This woodland is vulnerable to logging and clearance for livestock grazing, particularly around the cities of Navojoa and Álamos, while the wildlife is vulnerable to hunting. Areas of particular conservation importance include the Yaqui River basin.
A 2017 assessment found that 2,029 km², or 4%, of the ecoregion is in protected areas. 13% of the unprotected area is has relatively-intact habitat.