Factors influencing the distribution of chironomids in lakes distributed along a latitudinal gradient in northwestern Quebec, Canada

Abstract

The effect of 33 environmental variables on the distribution of chironomids was studied in 60 lakes of northwestern Quebec (Canada). A detrended canonical correspondence analysis detected linearity in the chironomid assemblages, thus redundancy analysis was used to identify the variables affecting the chironomid communities. Lake depth, dissolved organic carbon (DOC), mean August air temperature, and surface water temperature were the four variables that best explained the distribution of chironomids. Partial least squares analysis was used to develop new inference models. Among models, the one for mean August air temperature had the highest coefficient of determination (r[Formula: see text] = 0.67) and the lowest root mean square error of prediction (= 1.17 °C). The results indicated that for downcore temperature reconstructions, it might be hard to dissociate the combined effects of temperature, DOC, and depth. Changes in taxa such as Heterotrissocladius brundini-type, Heterotrissocladius subpilosus-type, Heterotrissocladius grimshawi-type, Micropsectra radialis-type, Tanytarsus lugens-type, and Microtendipes can be attributed to changes in lake depth and (or) temperature. Changes in Heterotanytarsus, Dicrotendipes, Cryptotendipes, and Cryptochironomus might be attributed to shifts in temperature and DOC. Relationships among temperature, DOC, and lake depth should be studied in a "neo-ecology" design to better understand their impact on chironomid assemblage composition.

Late-glacial chironomid-based temperature reconstructions for Lago Piccolo di Avigliana in the southwestern Alps (Italy)

“…Walker et al, 1997;Lotter et al, 1997;Olander et al, 1999;Brooks and Birks, 2000b;Larocque et al, 2001;Porinchu et al, 2002;Heiri et al, 2003a;Larocque et al, 2006) and successfully applied to reconstruct millennial-scale climatic oscillations during the late glacial (summary in Brooks, 2006) and patterns of temperature changes (e.g. Palmer et al, 2002;Heiri et al, 2004;Larocque and Hall, 2004) that agreed well with reconstructions obtained from other proxies and archives (e.g.…”

“…To obtain chironomid-inferred temperatures, two models based on Larocque et al (2006) and Larocque et al (2001) were used. The model based on modern surface samples from 100 lakes in Sweden ) was used to infer temperatures from taxa that might have a similar biogeographical distribution similar to those found in the southern Alps.…”

“…However, this transfer function lacked many taxa (e.g. Glyptotendipes, Glyptotendipes type 2, and Endochironomus) that have warmer optima (Larocque et al, 2006) and were well represented in the fossil samples. Also, the taxonomy was less well defined, for example the tribe Pentaneurini was not separated into different taxa in this model.…”

“…Also, the taxonomy was less well defined, for example the tribe Pentaneurini was not separated into different taxa in this model. In contrast, the transfer function from North America (a modification from Larocque et al, 2006; surface samples from 82 lakes) included all taxa present in the fossil samples, and taxonomy more refined than that of the Swedish transfer function. Other studies have reconstructed temperature for sites located outside the spatial range of the transfer functions' training-set sites, though from similar biogeographical areas (e.g.…”

Long-term climate-associated dynamics of a tropical seagrass meadow: implications for the future

“…Our study had 16 observations (years) and 30 variables, and many of the variables were collinear. This technique has commonly been used to analyse a range of ecological data sets (Amand et al 2004, Larocque et al 2006, Carrascal et al 2009). …”