WebMar 11, 1990 · Diatoms and pH Reconstruction. TL;DR: Reconstruction of past lake-water pH from diatom data involves two steps; regression, where responses of modern diatom abundances to pH are modelled and calibration, where the modelled responses are used to infer pH fromdiatom assemblages preserved in lake sediments. Abstract: … WebModern diatom in Tunisia as indicators of water chemistry and their use for hydrologic and climatic reconstruction
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WebIn addition a calibration data-set of surface sediment diatoms and water chemistry from 170 lakes was constructed and archived on DISCO, the UCL diatom database. This data-set … WebDiatom assemblages in the annually laminated sediments of two neighboring, pre-alpine lakes (Ammersee and Starnberger See, Southern Germany) were analyzed and compared year by year. Within both varve records of the last decades, the same 4-phase-succession of planktonic diatom species is preserved, consisting of 1. a dominance of Cyclotella …
WebThe 167 sample SWAP diatom-pH data-set from lowland or upland lakes in the UK, Norway, and Sweden has a RMSEP of 0.29 and a maximum bias of 0.23 pH units and r2 of 0.86. The pH optima, as estimated by weighted averaging and Gaussian regression, are compared for the three data-sets (AL:PE, SWAP, AL:PE epilithon). WebWhile a number of factors may control diatom or foraminifera distribution (e.g. pH, grain size, salinity, organic content, substrate) (Berkeley et al., 2007; Sullivan and Currin, 2000; Vos and de Wolf, 1993), studies repeatedly show that elevation, related to tidal inundation and a proxy for salinity, is a primary control of diatom and ...
WebMar 15, 2013 · In palaeolimnology, quantitative reconstructions using diatoms and chironomids have been developed for a wide range of environmental variables. Early models attempted to quantify long-observed relationships between organisms and pH and salinity (e.g. Battarbee, 1984; Fritz et al., 1991) but since then the range of reconstructed … WebJan 5, 2024 · Diatoms are one of the most widely used indicators in paleoenvironmental and current ecology studies in wetlands because they are highly sensitive to changes in …
WebPalaeolimnological diatom data comprise counts of many species expressed as percentages for each sample. Reconstruction of past lake-water pH from such data involves two steps; (i) regression, where responses of modern diatom abundances to …
WebDiatoms, a common siliceous alga, are effective paleoclimate and pollution indicators. They have been used in northern, eastern, and southern Africa as such because of well-documented ecologies of many taxa. In southwestern Africa, however, the country of Angola lacks similar modern assemblage studies. To close this gap, modern diatoms were … diane stuckey age 68WebJan 1, 2008 · In the acidification phases of the cores discrepancies in pH inference between models appear to be linked to differences in pH optima for a minority of taxa. Current (2006) diatom-inferred pH values from the most recent sediment traps, when compared with sediment core tops, provide evidence of recovery at most sites but its extent, so far, is ... diane strictly partnerWebSUMMARY 1 The diatom stratigraphy of 210Pb-dated sediment cores is used to reconstruct the recent trophic histories of four oligo/mesotrophic lakes in the lower peninsula of Michigan, U.S.A. Quantitative trends in total phosphorus concentrations are reconstructed from the cores with a calibration data set based on modem diatom assemblages and … citf-idlive.herokuapp.comWebFeb 10, 2024 · The reconstruction of an environmental variable of interest (e.g., pH, TP, salinity) based on diatom assemblages is calibrated using a set of samples for which … diane sue whalenWebMar 22, 2013 · The 167 sample lake-water pH-diatom calibration data-set created as part of the Palaeolimnology Programme within the Surface Water Acidification Project (SWAP) is re-analysed numerically using nine different numerical methods, six based on simple two-way weighted-averaging (WA), and the other three involving Gaussian logit regression … citf immunityWebThe first major sign of acidification is the loss of planktonic diatoms at pH values between about 5.5 and 5.8. ... (1997) Diatoms and pH reconstruction, Philosophical Transactions of the Royal Society of London. B, Biological Sciences, 327:1240, (263-278), Online publication date: 12-Mar-1990. diane stupar-hughesWebJan 20, 2024 · Distribution of freshwater diatoms in 64 Labrador (Canada) lakes: species environment relationships along latitudinal gradients and reconstruction models for water colour and alkalinity. Canadian Journal of Fisheries and Aquatic Sciences, Vol. 59, Issue. 2, … cit financing login