Disease-Driven Amphibian Declines Alter Ecosystem Processes in a Tropical Stream

摘要: Predicting the ecological consequences of declining biodiversity is an urgent challenge, particularly in freshwater habitats where species declines and losses are among highest. Small-scale experiments suggest potential ecosystem responses to species, but definitive conclusions require verification at larger scales. We measured metabolism used whole-ecosystem stable isotope tracer additions quantify nitrogen cycling a tropical headwater stream before after sudden loss amphibians fungal pathogen Batrachochytrium dendrobatidis. Tadpoles normally dominant grazers such streams, greater than 18 may co-occur densities often exceed 50 individuals m−2. Loss 98% tadpole biomass corresponded with 2× increases algae fine detritus 50% reduction uptake rate. Nitrogen turnover rates suspended deposited organic sediments were also significantly lower decline. As consequence, cycled less rapidly, downstream exports particulate N reduced. Whole respiration was following decline, indicating biological activity sediments. Contrary our predictions, grazing invertebrates, or any invertebrate functional groups, did not increase over 2 years tadpoles. Thus, reductions processes linked amphibian decline compensated for by other, functionally redundant consumers. Declining animal has ecosystem-level that be offset redundancy, even biologically diverse regions as Neotropics.