Leaf breakdown, detrital resources, and food webs in streams affected by mine drainage

摘要: Breakdown of leaf litter is essential for providing detrital resources food webs but can be impaired by anthropogenic activities, which may disrupt energy flow to consumers. We investigated the relationship between breakdown and web structure in 12 streams with or without mining impacts on South Island, New Zealand. Six received inputs acid mine drainage (pH 2.5–4.9), three were naturally acidic ~5.0), circumneutral ~6.8). Streams affected either had highly water <3) iron precipitates present substrata. rates leaves significantly lower mining-affected than (by almost 50%) not driven primarily microbial activity, as shredding invertebrates often absent. Mining-affected stream simplified structures fewer species links those other streams. With few process transfer resources, AMD disrupted both mechanisms responsible flow. While faster associated larger webs, limited function maintained was sufficient support primary consumers small webs.