Analysis of Stratigraphical Data

Birks, H. J. B.

doi:10.1007/978-94-007-2745-8_11

Cited by 41 publications

(31 citation statements)

References 73 publications

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“…Changes in pollen composition were detected using constrained hierarchical clustering (where the number of significant pollen zones was evaluated by comparison with the broken-stick model (Birks and Gordon, 1985;Bennett, 1996). The calculation and computation of the pollen zones were carried out using the R platform (R Development Core Team, 2012) and rioja package (Juggins, 2011).…”

Section: Pollen and Microcharcoal Analysismentioning

confidence: 99%

A high resolution 15,600-year pollen and microcharcoal record from the Cederberg Mountains, South Africa

Valsecchi

Chase

Slingsby

et al. 2013

Palaeogeography, Palaeoclimatology, Palaeoecology

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Section: Pollen and Microcharcoal Analysismentioning

confidence: 99%

A high resolution 15,600-year pollen and microcharcoal record from the Cederberg Mountains, South Africa

Valsecchi

Chase

Slingsby

et al. 2013

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…The diatom and chironomid stratigraphies were subdivided into assemblage zones with the technique of optimal splitting by information content (Birks and Gordon, 1985) and the number of statistically significant zones was identified using the Psimpoll 4.27 software (Bennett, 2009). Surface samples (slices 0-1, 1-3, 3-5, and 5-7 cm) were sent to Columbia Analytical Services, Inc. (www.caslab.com) to measure iron-bounded Phosphorus following the method detailed by Psenner et al (1998).…”

Section: Sediment Analysesmentioning

confidence: 99%

Section: Diatomsmentioning

confidence: 99%

“…The taxa are in percentages. The zones were created using the technique of optimal splitting by information content (Birks and Gordon, 1985) and the number of statistically significant zones was identified using the Psimpoll 4.27 software (Bennett, 2009). had no diatoms. In zone 7 (1998-2012 AD) the inferred TP oscillated around the average (vertical line in Figure 6) but still represented hyper/eutrophic conditions.…”

Section: Diatomsmentioning

confidence: 99%

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Using paleolimnology to find restoration solutions: the case of Lake Muzzano, Switzerland

Larocque‐Tobler¹,

Pla‐Rabès

2015

Front. Ecol. Evol.

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Lake Muzzano (45 • 59 ′ 50 ′′ N 8 • 55 ′ 41 ′′ E, 337 m a.s.l.) is a hyper-eutrophied lake located in the Tessin region of Switzerland. Almost every year, algal blooms (Microcystis) cover the lake with a thickness of 1-2 cm. These blooms associated with periods of anoxia in summer have led to fish kills in 1967 and 1994. In the hope of avoiding these blooms, a bypass bringing water away from the lake has been established in 1999. This solution was not adequate as blooms kept reoccurring. Sediment removal was then proposed by the Tessin Canton as a possible remediation technique and The L.A.K.E.S Institute had a mandate in 2010 to study the lake (present and past state) to determine the reasons creating anoxia and algal blooms. The present state of the lake shows that anoxia is still occurring when the algal bloom covers the lake's surface. Subfossil diatom and chironomid analyses show that the baseline conditions were those found before 1922 AD when the lake was oligotrophic and supported a diversified community of chironomids suggesting good oxygenation. After 1922 AD, circulation to the lake was cut out and nutrients accumulated in the lake leading to anoxia and the establishment of Microcystis. Heavy metal analysis in the sediment shows that the concentration is above the national recommendation and thus sediment should not be removed or should be stored with hazardous material. Based on the present status of the lake and paleolimnological results, two solutions are proposed: to further decrease the nutrients coming in the lake (possibly using filtrating plants) followed by flushing to increase lake water circulation. Physical capping of the sediment to avoid exchange of heavy metals and phosphorus release at the water/sediment interface could also be envisaged once the two prime solutions are in place.

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“…Numerical zonation is implemented by stratigraphically constrained clustering or partitioning using an agglomerative or divisive algorithm (Birks, 2012b;Birks and Gordon, 1985) followed by a comparison of the variance of the zones with the variance expected under the broken-stick model to provide a basis for deciding how many zones should be defined (Bennett, 1996). Numerical zonation is implemented by stratigraphically constrained clustering or partitioning using an agglomerative or divisive algorithm (Birks, 2012b;Birks and Gordon, 1985) followed by a comparison of the variance of the zones with the variance expected under the broken-stick model to provide a basis for deciding how many zones should be defined (Bennett, 1996).…”

Section: Single Data-setsmentioning

confidence: 99%

POLLEN METHODS AND STUDIES | Numerical Analysis Methods

Birks

2013

Encyclopedia of Quaternary Science

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Analysis of Stratigraphical Data

Cited by 41 publications

References 73 publications

A high resolution 15,600-year pollen and microcharcoal record from the Cederberg Mountains, South Africa

A high resolution 15,600-year pollen and microcharcoal record from the Cederberg Mountains, South Africa

Using paleolimnology to find restoration solutions: the case of Lake Muzzano, Switzerland

POLLEN METHODS AND STUDIES | Numerical Analysis Methods

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