Intra-lake patterns of aquatic insect and mite remains

Spatial uniformity in depth optima of midges: evidence from sedimentary archives of shallow Alpine and boreal lakes

“…Previous results have shown that the distribution of midge taxa is strongly influenced by water depth in the shallow lakes of the present data sets (Luoto 2009a(Luoto , 2010(Luoto , 2011. In general, the calculated water depth optima of midge taxa showed closely similar patterns with the taxa tolerances in range (Fig.…”

“…This study involves very different lake types but the data sets have similar depth range. Detailed site and sample descriptions together with the community compositions are provided elsewhere (Luoto 2009b(Luoto , 2010(Luoto , 2011Luoto, and Helama 2010).…”

“…The influence of water depth is mostly indirect and mediated through habitat distribution, such as availability of macrophytes and the type of substrate, which have been found to be of direct importance for midges (Learner et al 1989;Nyman et al 2005). Fossil remains of midges, mostly Chironomidae, usually accumulate close to their living habitats (Eggermont et al 2007;Kurek, and Cwynar 2009a;Luoto 2010Luoto , 2011Engels, and Cwynar 2011). Hence, it is possible to use these fossil assemblages to infer past changes in their habitats from downcore sediment profiles.…”

Stream flow intensity of the Saavanjoki River, eastern Finland, during the past 1500 years reflected by mayfly and caddisfly mandibles in adjacent lake sediments

“…reaccumulation of fossil remains. Transportation and reaccumulation of remains in water systems can be especially strong in lakes with steep bathymetry or river contribution, but in small enclosed basins the transportation can be insignificant (Luoto 2012). In previous studies, intralake fossil midge distribution patterns were used to construct a calibration method to detect past stream flow events in Lake Pieni-Kauro (Luoto, 2010;Luoto and Helama, 2010).…”

“…The paleoecological archives in lake deposits include plant macrofossils, pollen, algae, and various invertebrate remains. Previous studies have shown that the intralake distribution of aquatic animal fossils is strongly related to the species' living habitats (Luoto, 2012;Nevalainen, 2012), thus enabling habitat-specific reconstructions of environmental change, including local hydrology, from downcore sediment sequences. The within-lake hydrology is controlled by regional climate through water input (precipitation, surface and river inflow) and output (evapotranspiration, river outflow) that makes it possible to interpret paleolimnological stream flow data in paleoclimatological context.…”