Marine subsidies produce cactus forests on desert islands

In island systems, nitrogen-rich seabird guano is a marine subsidy that can shape terrestrial plant communities. In zones of nutrient upwelling such as the Gulf of California, copious seabird guano is commonplace on bird islands. Several bird islands host regionally unique cactus forests, especially of the large columnar cactus, cardón (Pachycereus pringlei). We show that a chain of interactions across the land-sea interface yields an allochthonous input of nitrogen in the form of seabird guano, fueling the production of some of the densest cactus populations in the world.

Sonoran Desert - Central Gulf Coast

The Central Gulf Coast sub-division of the Sonoran Desert exists in west-central Sonora (as well as eastern Baja California) and hugs areas near the coastline. In Sonora it exists from just south of Guaymas to the coastline west of Caborca and generally extends inland around 50 to 80 kilometers.

It is extremely arid receiving less than 6" per year. Its rainfall is even more sporadic than much of the southwest, but occasionally receives high-volume downpours in late summer and fall from tropical storms or remnants.

Oasis at the Desert Edge: Flora of Cañón del Nacapule, Sonora, Mexico

Cañón del Nacapule cuts into the southeastern flank of the Sierra El Aguaje, a rugged volcanic range about 20 kilometers northwest of Guaymas. Nacapule is included in the Sonoran segment of the Gulf Coast subdivision of the Sonoran Desert. The bi-seasonal (summer and winter) rainfall is highly variable. Many plants of tropical origin reach their northern limits in this region or do not extend farther north in the arid coastal desert of western Sonora.

Big Projects Surprise Small Communities

Development proposals sneak up on remote and unsuspecting towns in the Gulf of California region, such as Bahia Kino, Santa Rosalillita, Bahia de Los Angeles, El Golfo de Santa Clara, Puerto Libertad, and Punta Colonet. Many of the residents have no basic services, water, drainage, light, and roads. Meanwhile, government representatives offer these facilities to infrastructure megaproject companies, which pass along to their investors the profits obtained through the subsidies.