Stream size influences stream temperature impacts and recovery rates after clearfell logging

Modelling the time course of shade, temperature, and wood recovery in streams with riparian forest restoration

“…Their measured rates of recovery were similar to, but slightly faster than, our simulations for channels of a given size in scenario B, which probably reflects faster growth of pines in the warmer Coromandel climate. Quinn et al (2008) report remarkably rapid shading and thermal recovery in small streams that were planted with natives 6 years earlier at Whatawhata in the Waikato region (100 km north of our study area) with greater recovery in a 1 m than a 2 m width stream. Jowett et al (2009, this issue) report increased densities of native fish in two small streams (c. 1 m wide) draining the Hakarimata Ranges, north Waikato region (170 km north of our study area), that may be partly attributable to cooling water temperatures (as well as improved cover) since riparian planting 10 years earlier.…”

“…for example, Quinn & Wright-Stow (2008) studied stream temperatures following clearfell harvesting and replanting of pine plantations in the Coromandel area, northeastern Waikato region (c. 200 km north of our study area), and found that rate of recovery of late summer thermal regimes increased strongly with decreasing stream size (channel width ranging from 2 to 12 m). Their measured rates of recovery were similar to, but slightly faster than, our simulations for channels of a given size in scenario B, which probably reflects faster growth of pines in the warmer Coromandel climate.…”

Biodiversity values of small headwater streams in contrasting land uses in the Auckland region

“…The spot measurements in our study did not capture the critical daily and seasonal periods of minimum oxygen and maximum temperature [e.g. small, unshaded streams in similar climates may experience diurnal temperature fluctuations of up to 108C (Quinn & Wright-Stow 2008) and dissolved oxygen fluctuations of up to 6 mg/l (Wilcock et al 1998)]. However, they did indicate that in summer, oxygen levels at several sites reached critically low levels (e.g.…”

“…Other studies (e.g. Quinn & Wright-Stow 2008) show that unshaded headwater streams in similar climates in New Zealand may reach 308C during midsummer, exceeding the temperature tolerances of many insect taxa (Quinn et al 1994). Thus the lower dissolved oxygen and higher temperatures in P than NF sites are likely to be partly responsible for differences in the invertebrate communities among land use types.…”

Importancia de la vegetación ribereña de Nothofagus dombeyi (Mirb.) Oerst. en el régimen térmico de sistemas fluviales andinos del sur de Chile

“…Dicha alteración ha provocado un aumento en la entrada de calor, lo que se traduce en una modificación de los patrones térmicos del agua alterando el funcionamiento fluvial (Vannote & Sweeney 1980, Berner & Berner 1996, Acuña et al 2008, Quinn & Wrightstow 2008. En Chile, a pesar del marcado gradiente térmico latitudinal-altitudinal existente, los estudios de régimen térmico en ecosistemas fluviales son limitados y orientados principalmente a tramos medios y bajos de ríos fuertemente influenciados por la actividad humana (Link et al 2009.…”