In temperate systems, invertebrate consumers have known impacts to ecosystem processes, but in tropical ecology, it is assumed that only plant and microbes affect these processes. This study investigated what impacts common folivores (walking sticks) and detritivores (litter snails) have on decomposition, nutrient cycling and primary productivity in the understory of the Luquillo rainforest (LUQ). To test these effects, we started an enclosure experiment with consumers both present and absent in 2005. We measured leaf decomposition rates with litterbags, and quantified microbial communities using TRFLP. Soil, plant and litter nutrients were measured yearly. We measured plant characteristics yearly until 2008, when plants were harvested. Multiple regressions were used to determine plant biomass at each earlier time period. One year after the experiments ended, plants that grew from the seed bank and into the enclosures vegetatively were again harvested to look at legacy effects. While detritivore presence did not affect decomposition, folivore presence reduced leaf decomposition rates, and the richness and relative abundance of bacteria. Since this herbivore prefers consuming faster, more nutritious decomposing foliage, we hypothesize that less of this foliage falls as litter, while more slowly decomposing litter becomes more abundant. This alters the composition of litter bacteria, in turn reducing rates of leaf decomposition. Also, contrary to my expectations, folivores did not affect plant production or total soil nitrogen, while detritivores decreased the total aboveground biomass and total soil nitrogen. One year after treatments were removed, detritivore treatment enclosures still had significantly less plant biomass, demonstrating a legacy effect of these organisms. We hypothesize that the long-lived, relatively large detritivores sequester nutrients necessary for plant growth. This study shows that invertebrate consumers do affect tropical ecosystem processes. The findings suggest invertebrate consumers should be considered in studies investigating the flow of nutrients in rainforests.