Colonization and production of macroinvertebrates on artificial substrata: upstream–downstream responses to a leaf litter exclusion manipulation

Abstract

1. Macroinvertebrate colonization dynamics were examined on artificial substrata in a stream with terrestrial litter inputs excluded, downstream of the litter‐exclusion treatment, and in a reference stream. 2. Short‐term examination of the rates of organic matter accrual and invertebrate colonization demonstrated significantly lower accumulation of leaf detritus and invertebrates in the litter‐excluded reach and a short distance downstream of that reach. 3. All major fractions of organic matter and invertebrates declined on artificial substrata during the 3‐year litter exclusion. Further, secondary production on artificial substrata in the litter‐excluded reach decreased from 6.2 to 1.5 g AFDM m−2 year−1 from pretreatment to the third year of litter exclusion, respectively. 4. Downstream, fine particulate organic matter on artificial substrata decreased during litter exclusion, and there was a significant reduction in colonization of collector‐filterers. Total secondary production downstream of the litter exclusion declined >70%, demonstrating that downstream colonization dynamics are linked to upstream detritus inputs and processing by stream invertebrates.

Assessing impact of eucalyptus plantations on benthic macroinvertebrate communities by a litter exclusion experiment

“…Organic matter was the variable manipulated in our study through changes in its amount and quality. Several authors describe a close relationship between amount of organic matter and invertebrate density at low order stream reaches (Baer et al 2001, Rowe & Richardson 2001. Similarly, positive relationships between organic matter and shredder invertebrates are abundant in the literature (e.g.…”

Environmental effects and urban impacts on aquatic macroinvertebrates in a stream of central Brazilian Cerrado

“…This fact could have had a large effect on ecosystem function, since the reduction of the density of organisms in some feeding groups, such as shredders, can change the functioning of aquatic ecosystems, causing a trophic cascade effect (e.g., Chapin-III et al 2000). Baer et al (2001), for example, found that secondary production in streams in North Carolina (USA) was reduced by more than 70 % after the exclusion of litter, and, consequently a variety of changes occurred in the colonization dynamics of macroinvertebrates and in detritus processing.…”

Trophic structure of macroinvertebrates in Amazonian streams impacted by anthropogenic siltation

“…Chapin III et al 2000;Allan & Castillo 2007). Baer et al (2001), for example, found that secondary production in streams in North Carolina (USA) was reduced by more than 70% after the exclusion of litter and, consequently, a variety of changes occurred in the colonization dynamics of macroinvertebrates and in detritus processing. The majority of shredders collected in streams sampled in the Urucu Petroleum Province were associated with non-impacted streams (Table 7).…”