A decade-long environmental study around the San Diego and Tijuana border region found the United States and Mexico need to increase joint conservation efforts.
The researchers focused on a 2.8-million-acre study area. It is home to more than 400 species that are endangered, threatened or vulnerable to human impacts.
The Las Californias Binational Conservation Initiative said its study identified more than 120,000 acres of natural habitat lost over the past 10 years to development such as agriculture and urban sprawl on both sides of the border.
Conserved lands increased by fewer than 28,000 acres during the same time period. None of the newly identified conserved lands were on the Mexican side of the border.
“Many conservation investments in San Diego and Imperial counties will be jeopardized unless the natural biological communities to the south, and the natural corridors needed to move northward, are also protected,” the report said.
Jerre Ann Stallcup, senior conservation ecologist at the Conservation Biology Institute and project director for the initiative, said wildlife on both sides of the border is interconnected and interdependent.
Environmental impacts on the Mexican side of the border can result in loss of species, gene flow and biodiversity on the U.S. side, she said.
“By severing connections between landscape, we prevent ecological processes, we prevent predator-prey interactions, pollination dispersal, and connectivity for animals to expand their ranges," Stallcup said.
Desert, mountains and coast converge at the border region to create one of the most biologically diverse natural habitats in the world.
The region belongs to the California Floristic Province, one of 34 global biodiversity hotspots. The designation means it has a unique abundance of biodiversity that is threatened.
Researchers said cross-border collaboration on conservation is key to protect what remains of the habitat.
“We reaffirm a call for all sectors - from government to business, from communities to universities - to embrace and implement a shared binational conservation vision,” said Scott A. Morrison, director of conservation science at The Nature Conservancy, one of the groups in the initiative.
