Arroyo La Junta – A biodiversity jewel in the Sierra La Laguna Biosphere Reserve

Mining projects continue to be proposed throughout the U.S. and Mexico, often in remote natural regions that lack baseline biodiversity knowledge. This is the case for the region of Arroyo La Junta in the Sierra La Laguna of Baja California Sur. The large open pit gold mine “Los Cardones” has been proposed within the Sierra La Laguna Biosphere Reserve, as decreed by both Mexico and UNESCO.

In an effort to provide objective and baseline scientific information, N-Gen in collaboration with the Mexican Commission for Natural Protected Areas (CONANP), the Botanical Research Institute of Texas, UC MEXUS, with multiple participating academic institutions, local NGOs, and members of the local community have produced the detailed report presented below. This project bridges multiple sectors of society in the effort to document the biodiversity of the La Encantada zone of Arroyo La Junta to guide future management decisions.

Our international team of 29 scientists from 19 institutions conducted a biodiversity survey inside the Sierra La Laguna Biosphere Reserve in Baja California Sur, Mexico. This eight-day expedition was undertaken at the request of, and in collaboration with CONANP to document the diversity encountered on ca. 1,235 acres of land currently petitioned for use as the open pit gold mine project Los Cardones. From December 4th to 11th of 2015 the participating scientists documented the presence of 877 species, including 381 plants, 29 mammals, 77 birds, 366 insects, and 24 reptiles and amphibians. The true diversity of the region is expected to be double that documented in the week-long excursion. The majority of the diversity was found associated with the La Junta riparian system at the core of the proposed mine site. Twenty-nine species, protected under Mexican law due to their inclusion on the endangered species list (NOM-059-SEMARNAT-2010), were discovered inside the project footprint, as well as 107 species endemic to the Cape Region. The biodiversity found in and around Arroyo La Junta and its tributaries forms the base of a complex food-web. Based on the high levels of diversity and endemism, especially the multitude of life forms associated with aquatic habitats, the findings of this initial survey support the prior designation by Mexican and international bodies of this region as a protected area.

See the full report here:  Vanderplank S, BT Wilder, E Ezcurra. 2016. Arroyo la Junta: Una joya de biodiversidad en la Reserva de la Biosfera Sierra La Laguna / A biodiversity jewel in the Sierra La Laguna Biosphere Reserve. Botanical Research Institute of Texas, Next Generation Sonoran Desert Researchers, and UC MEXUS. 159 pg.

Comparison with the Los Cardones Environmental Impact Statement (MIA) [pdf]

Related Coverage:

Lawyers, Guns and Money: Gold Mining and Biodiversity in the Biosphere Reserve. Journal del Pacifico

Hundreds of unexpected species found in Mexican UNESCO site slated for gold mine. MONGABAY (Spanish version)

Investigadores registran más de 900 especies en zona donde quiere instalarse Los Cardones. BCSNoticias

Protecting Mexico’s biodiversity from environmental degradation. Latin American Science

Aterran las omisiones en los estudios de impacto ambiental en México: experto. La Jornada

Hundreds of species found in contested Mexican gold mine project. Latin American Post

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