How hydroperiod and species richness affect the balance of resource flows across aquatic-terrestrial habitats
Ecosystem functioning is influenced by the flow of nutrients, detritus, and organisms. Variation in these flows, like that found in temporary ecosystems, affects temporal and spatial patterns of community diversity and secondary production. We evaluated the influence of hydroperiod and ecosystem size on the bi-directional flow of subsidies from intermittent ponds and surrounding forests by quantifying litter deposition and the abundance and biomass of emerging insects and amphibians. In addition, we assessed whether amphibian and insect diversity influenced the magnitude of cross-habitat resource flux. We found substantial spatial and temporal variation in the magnitude, composition, and timing of cross-habitat resource subsidies. Overall, deposition into ponds far exceeded biomass exported via insect and amphibian emergence. We found a negative association between resource flux and the diversity of amphibians and insects. Different species groups contributed to flux patterns unequally, with insects having higher diversity but lower flux compared to amphibians. Organismal flux varied among ponds with amphibians having the highest flux in the shortest hydroperiod pond and insect flux was highest from an intermediate hydroperiod pond. This work reveals how variation in pond size and permanence affects species diversity and ecosystem flows. Species composition played a major role in flux differences across ponds. Further, given the general lack of research and conservation prioritization of temporary ponds, uncovering how these ponds contribute to cross-habitat linkages is necessary to develop fully integrated management strategies.