Effects of deforestation from cattle ranching over time on protected rainforest streams in the Rama-Kriol Territory, Nicaragua

Recent waves of illegal deforestation for cattle pasture are damaging the Indio Maiz Biological Reserve and Rama-Kriol Territory of Nicaragua, with negative consequences to aquatic ecosystems and the people they support. This study creates a framework for how deforestation from cattle ranching causes shifts in stream community structure, mediated by changes in stream habitat over time. It integrates temporally explicit land use information with stream habitat, macroinvertebrate, freshwater shrimp, and fish community data to assess impacts of cattle ranching on 15 headwater streams. The deforestation history measure (DHM), a product of deforestation amount and time since deforestation for each catchment, strongly predicted stream habitat and biotic responses. Delayed effects of land-use change such as decreased allochthonous inputs (large wood, debris) and increased bank destabilization, sedimentation, flashiness, and the scouring effect were apparent in longer deforested catchments, causing lower richness and density and higher evenness of macroinvertebrates; lower shrimp abundance; and distinct changes in fish and invertebrate community composition. Both recently and longer deforested catchments had degraded riparia and smaller sized game fish. Otherwise, recently deforested catchments were more similar to forested catchments. Nicaragua's understudied primary rainforest ecosystems should be high priority for research and conservation before they are lost.