MIRANDA, Brazil — Brazil’s booming soy industry and cattle ranches are threatening one of the richest wildlife havens on the planet, where packs of jaguars, caimans, marsh deer and macaws have roamed freely for eons.

The Pantanal region, the world’s largest tropical wetlands, is starting to wither. Over the last 15 years, about 8,700 square miles of the area, which straddles Brazil, Paraguay and Bolivia, have been altered, with fast-growing patches of yellow, arid land introduced into the lush biome, which covers roughly 70,000 square miles, or about the size of Syria.

This degradation of the Pantanal is seen by critics as one sign of Brazil’s weakening resolve to protect its environment.

While the Brazilian government earlier this year hailed a modest achievement in its signature environmental fight — containing the deforestation of the Amazon — it has been embarrassed by other trend lines. The country’s greenhouse gas emissions increased by 9 percent last year, compared with 2015, marking the highest output since 2008.