Application of sediment traps in global change research in mountain lakes

Abstract

Representativity of biota in the biosphere also have similar significance in the lithosphere after their death.

Effects of production, sedimentation and taphonomic processes on the composition and size structure of sedimenting cladoceran remains in a large deep subalpine lake: paleo-ecological implications

“…and Bosmina sp., whatever the considered abundance unit [remains (g dW) -1 or remains m -2 year -1 ]. The rates are of similar order of magnitude as previous estimates on a small lake {86% [remains m -2 year -1 ] and 95% [remains (g dW) -1 ] for Daphnia maximal loss rate, Kattel et al (2007) and Kattel (2009), respectively}. Therefore, the magnitude of taphonomic processes might be similar between small and large deep lakes, and the physical characteristics of lake (i.e.…”

“…Such patterns might rather arise either from specificities of the lake cladoceran community, or from some methodological issues. First, the differences of representativity between Daphnia and Bosmina were usually observed in lakes in which Daphnia appeared in low abundance (Kattel et al, 2007;Kattel, 2009;Nykänen et al, 2009 in Table 1), contrary to Lake Aiguebelette. It is acknowledged that species which appear in low abundance in the source community may be absent or show a low representation in the fossil assemblages compared to the most abundant species (Frey, 1986;Kattel et al, 2007;Nykänen et al, 2009) and this might contribute to under-representation of Daphnia in the fossil assemblages of these lakes.…”

“…These studies consistently showed that taphonomic processes do not operate equally between zooplankton taxa (Frey, 1960;Hann et al, 1994;Rautio et al, 2000), since cladoceran exoskeletons, in contrast to copepods and rotifers, are well-preserved in lake sediments. Preservation of remains might even differ among cladoceran species with Bosmina and chydorid well represented by different body part (Frey, 1988) in contrast to Daphnia which are usually under-represented in sediment samples compared to Bosmina (Frey, 1960;Kattel et al, 2007;Kattel, 2009;Nykänen et al, 2009). This under-representation has been interpreted as a result of poor preservation of Daphnia remains compared to Bosmina remains (Frey, 1960;Kattel et al, 2007;Kattel, 2009;Nykänen et al, 2009).…”

“…Preservation of remains might even differ among cladoceran species with Bosmina and chydorid well represented by different body part (Frey, 1988) in contrast to Daphnia which are usually under-represented in sediment samples compared to Bosmina (Frey, 1960;Kattel et al, 2007;Kattel, 2009;Nykänen et al, 2009). This under-representation has been interpreted as a result of poor preservation of Daphnia remains compared to Bosmina remains (Frey, 1960;Kattel et al, 2007;Kattel, 2009;Nykänen et al, 2009). Several other sources of taphonomic biases would yet deserve deeper investigation to broaden our understanding of the picture provided by cladoceran fossil assemblages.…”

Is there a bias between contemporary and subfossil cladoceran assemblages?

“…Despite the increasing use of these palaeoecological data for climatic reconstructions, relatively few studies have investigated taphonomic processes in lacustrine biota, whereas marine or terrestrial fossils have been studied more extensively from this perspective (Kattel, 2009). Most of the investigations in freshwater ecosystems have focused on molluscs (e.g., Helama & Valovirta, 2007) and fishes (e.g., Zohar et al, 2008), whereas remains from other groups have attracted less attention.…”