Substrate‐Mediated Response of Stream Invertebrates to Disturbance

Abstract

The response of aquatic invertebrates to a major watershed (catchment) disturbance, clear-cutting, was examined in a second-order stream in the southern Appalachian Mountains. For 21 mo after the start of logging, invertebrates were sampled in four substrate types: rock face (mosscovered boulders and outcrops), cobble riffles, pebble riffles, and sand. The type of substrate was an important factor in determining the direction and magnitude of the response of many taxa. In the stream that drained the clear-cut watershed, more taxa increased in density (compared with a nearby reference stream) in moss-covered rock face than in any other substrate; cobble riffles were next, followed by pebble riffles and sand. Conversely, the number of taxa with significant reductions in density was highest for sand substrates, followed by pebble, cobble, and rock face. Among functional groups of insects, collector-gatherers and scrapers increased, while the dominant shredder, Peltoperla, declined. The differential response of invertebrates among substrates suggests that biological stability is closely coupled with physical stability; however, moss associated with larger particles may be a factor in enhancing the biological stability of these substrates. Clear-cutting of a watershed is a largescale, low-frequency, anthropogenic disturbance to associated stream ecosystems. Certain successional characteristics of these headwater streams following a major anthropogenic disturbance differ from those observed in streams in which succession may be truncated by frequent disturbances such as flash flooding.

Caddisflies (Trichoptera) as good indicators of environmental stress in mountain lotic ecosystems

“…Erosion reduces abundance (Wooton et al 1996) and affects feeding types of caddisflies (Gurtz & Wallace 1984;Smith-Cuffney & Wallace 1987). Despite their high channel diversity (and thus total habitat diversity), in the most impacted streams (sites 4 and 5) we recorded, reduced taxonomic and functional diversity and equitability; the most likely explanation is the increased amount of fine sediment.…”

Microdistributions of stoneflies of the High Tatra montane streams

“…It also results in a decrease in the frequency of natural wood deposition and debris that leads to lower bottom stability. The subsequent higher portion of biofilms and fine sediments reduce stonefly biodiversity [32,46,47].…”

“…It also results in a decrease in the frequency of natural wood deposition and debris that leads to lower bottom stability. The subsequent higher portion of biofilms and fine sediments reduce stonefly biodiversity [32,46,47].In the Ľubochnianka River, the cumulative curve of stonefly distribution on microhabitats of the stream bed, from fine to coarse substrata and moss, had an exponential form (i.e. reflecting an increase in stonefly density on coarse substrata and moss) [10].…”

Comunidade de Odonata (Insecta) em áreas naturais de Cerrado e monocultura no nordeste do Estado de São Paulo, Brasil: relação entre o uso do solo e a riqueza faunística

“…Várias pesquisas têm demonstrado que a conversão de florestas em pastagens ou áreas residenciais pode influenciar os habitats e as comunidades aquáticas de várias maneiras (GURTZ & WALLACE 1984, LENAT & CRAWFORD 1994, OMETO et al 2000, SPONSELLER et al 2001. Por isso, conhecer a relação da biota aquática com o uso do solo do entorno é de grande importância e oferece suporte na elaboração de estratégias regionais de manejo (ALLAN & JOHNSON 1997).…”