Tavera said a lack of rain had plunged trees into hydric stress, making them more vulnerable to diseases, pests and fires.

"Even ditched and tiled they're marginal because the hydric soils are still there," says Steinke, a wildlife biologist who once owned a wetland mitigation business.

“There is a real threat to the hydric security of Rio de Janeiro’s metropolitan area,” the statement said, adding suggestions to handle the crisis.

The Brunswick newspaper reports that a solar panel won’t be developed at a site in Thalmann after a wetland study determined soil on the property to be hydric.

As he points out, that species requires hydric communities of cool climates, and in the Wisconsin Glacial age such climates probably prevailed in the high mountainous region where San Josecito is located.