How do the functional groups change in abundance through the stream orders?

Shredders: High abundance in forested headwaters (low order) where CPOM (like leaves) is the main food source. Collectors: Large-particle collectors dominate in mid-order streams. Fine-particle collectors become more important in high-order streams due to FPOM abundance. Grazers: Peak in mid-order streams where periphyton production is high (e.g., more light and less canopy cover). Filter Feeders: Increase downstream as FPOM becomes abundant and flow dynamics support suspension feeding. Sediment Burrowers: More common in low-gradient, large rivers with soft sediments.