25 Result(s)
within
Oliver Heiri
Earth Sciences
English
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Article
Open AccessAquatic invertebrate mandibles and sclerotized remains in Quaternary lake sediments
Subfossil remains of aquatic invertebrates found in lacustrine sediments are useful paleoenvironmental indicators. Strongly scleroticized chitinous body parts from the exoskeleton or exuviae from invertebrates...
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Open Access14,500 years of vegetation and land use history in the upper continental montane zone at Lac de Champex (Valais, Switzerland)
Forests in the upper continental montane zone are important ecotones between lowland and subalpine forest ecosystems. A thorough understanding of the past vegetation dynamics at mid elevation is crucial to ass...
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Open AccessThe Little Ice Age signature in a 700-year high-resolution chironomid record of summer temperatures in the Central Eastern Alps
Despite the fact that the Little Ice Age (LIA) is well documented for the European Alps, substantial uncertainties concerning the regional spatio-temporal patterns of temperature changes associated with the LI...
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The last hornbeam forests in SW Europe: new evidence on the demise of Carpinus betulus in NW Iberia
Carpinus betulus L. is a mesic, usually considered late-successional tree widely distributed in Europe, but almost absent from Iberia, where it is generally assumed that disappeared during the co...
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Article
Warm Mediterranean mid-Holocene summers inferred from fossil midge assemblages
Understanding past climate trends is key for reliable projections of global warming and associated risks and hazards. Uncomfortably large discrepancies between vegetation-based summer temperature reconstructio...
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Article
Multiple causes of the Younger Dryas cold period
The last deglaciation was interrupted by a cool period known as the Younger Dryas. Numerical simulations suggest that the cold interval was the result of a combination of changes in ocean and atmospheric circu...
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Global change revealed by palaeolimnological records from remote lakes: a review
Over recent decades, palaeolimnological records from remote sites have provided convincing evidence for the onset and development of several facets of global environmental change. Remote lakes, defined here as...
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Are fossil assemblages in a single sediment core from a small lake representative of total deposition of mite, chironomid, and plant macrofossil remains?
How representative of the whole-lake fossil assemblage are analyses from a single sediment core taken in the centre of a small lake? This question was addressed in five shallow Norwegian lakes that ranged in l...
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Article
Testing intra-site transfer functions: an example using chironomids and water depth
Most calibration data sets used to infer past environmental conditions from biological proxies are derived from many sites. An alternative strategy is to derive the calibration data set from within a single si...
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Open AccessEfficiency of different mesh sizes for isolating fossil chironomids for stable isotope and radiocarbon analyses
We examined the effects of sieving with different mesh sizes on the efficiency of processing fossil chironomids from lake sediments for isotope analyses. Results obtained for three different sediments indicate...
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Article
Open AccessMidges of the genus Pseudodiamesa Goetghebuer (Diptera, Chironomidae): current knowledge and palaeoecological perspective
Larvae of the genus Pseudodiamesa Goetghebuer, which includes 12 described valid species and is divided by Makarchenko and Makarchenko (1999) into two species groups, Pseudodiamesa branickii group and Pseudodiame...
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Article
Open AccessHow does taxonomic resolution affect chironomid-based temperature reconstruction?
The resolution achievable for chironomid identifications has increased in recent years because of significant improvements in taxonomic literature. However, high taxonomic resolution requires more training for...
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Article
Open Access500 years of trophic-state history of a hypertrophic Dutch dike-breach lake
We present a palaeolimnological study encompassing five centuries of trophic-state change of the dike-breach lake De Waay located on the Rhine-Meuse delta (the Netherlands). Diatom-inferred total phosphorus (T...
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Open AccessLate Glacial and Holocene temperature changes at Egelsee, Switzerland, reconstructed using subfossil chironomids
A temperature reconstruction using chironomids was attempted at Egelsee, Switzerland, a site where pollen and macrofossil records showed a correspondence between vegetation and climatic changes inferred by oth...
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Article
Paleotemperature reconstruction in tropical Africa using fossil Chironomidae (Insecta: Diptera)
Fossil assemblages of chironomid larvae (non-biting midges) preserved in lake sediments are well-established paleothermometers in north-temperate and boreal regions, but their potential for temperature reconst...
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Article
Open AccessFossil chironomid δ13C as a proxy for past methanogenic contribution to benthic food webs in lakes?
We used a series of experiments to determine whether stable carbon isotope analysis of modern and fossil larval head capsules of chironomids allowed identification of their dietary carbon source. Our main focu...
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Article
Open AccessTetraether membrane lipid distributions in water-column particulate matter and sediments: a study of 47 European lakes along a north–south transect
We studied the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) in water-column particulate matter and the top 5 cm of sediment from 47 lakes along a transect from southern Italy to the northern p...
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Article
Comparison between chironomid-inferred July temperatures and meteorological data AD 1850–2001 from varved Lake Silvaplana, Switzerland
Inferred temperatures from chironomids preserved in the varved sediment of Lake Silvaplana in the Eastern Swiss Alps were compared with instrumental data obtained from a meteorological station in Sils-Maria, o...
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Article
Seasonal temperatures for the past ∼400 years reconstructed from diatom and chironomid assemblages in a high-altitude lake (Lej da la Tscheppa, Switzerland)
We analysed a 42 cm long sediment record from Lej da la Tscheppa, a high-altitude lake (2,616 m a.s.l.) in the Upper Engadine valley (Switzerland) for subfossil diatoms, chironomids and pollen. The chronology ...
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Article
Sciaridae in lake sediments: indicators of catchment and stream contribution to fossil insect assemblages
The larval head capsules of Sciaridae (black fungus gnats) are transported into lakes from terrestrial habitats, in most cases via streams or rivers, and preserve well in lake sediments. The abundance of sciar...
