Apparent and real bias in numerical transfer functions in palaeolimnology

Racca, Julien M.J.; Prairie, Yves T.

doi:10.1023/b:jopl.0000013283.51877.72

Cited by 20 publications

(8 citation statements)

References 13 publications

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“…Jackknifederived predicted TN and TDS values matched the measured values well (Fig. 6), and the residuals plotted against predicted values (Racca and Prairie 2004) indicated no bias in the models (Fig. 6).…”

Section: Relationship Between Benthic Algae Communities and Environmementioning

confidence: 61%

Spatial distribution of benthic algae in the Gangqu River, Shangrila, China

Tang

Cai

2007

Aquat Ecol

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This study consisted of sampling benthic algae at 32 sites in the Gangqu River, an important upstream tributary of the Yangtze River. Our aims were to characterize the benthic algae communities and relationships with environmental variables. Among the 162 taxa observed, Achnanthes linearis and Achnanthes lanceolata var. elliptica were the dominant species (17.10% and 14.30% of the total relative abundance, respectively). Major gradients and principal patterns of variation within the environmental variables were detected by principal component analysis (PCA). Then non-metric multidimensional scaling (NMS) divided all the sites into three groups, which were validated by multi-response permutation procedures (MRPP). Canonical correspondence analysis (CCA) indicated that three environmental variables (TN, TDS, and TP) significantly affected the distribution of benthic algae.Weighted averaging regression and cross-calibration produced strong models for predicting TN and TDS concentration, which enabled selection of algae taxa as potentially sensitive indicators of certain TN and

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Section: Relationship Between Benthic Algae Communities and Environmementioning

confidence: 61%

Spatial distribution of benthic algae in the Gangqu River, Shangrila, China

Tang

Cai

2007

Aquat Ecol

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“…4, R 2 = 0.91, RMSEP = 0.18). The residuals plotted against predicted values (Racca & Prairie, 2004) indicated no bias in the model (Fig. 4).…”

Section: Diatom Community -Environment Relationshipsmentioning

confidence: 86%

Benthic Diatom Communities in Subalpine Pools in New Zealand: Relationships to Environmental Variables

et al. 2006

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In spite of their potential use as indicators of both present and past environmental conditions, little is known about the diatom communities in the many small water bodies at high altitudes in New Zealand. We sampled benthic diatoms at 20 sites in a typical subalpine mire pool/tarn complex near Arthur's Pass in South Island, New Zealand in the austral spring 2001. The aims were to characterise the diatom communities, including identification of a possible endemic component, and to investigate relationships with environmental variables. The community at genus level was consistent with the peat-bog diatom flora reported from elsewhere except for the common occurrence of the Tasmania/New Zealand endemic genus Eunophora. At the species level, 27 of the 52 most common taxa appear to correspond to known species from the Northern Hemisphere and are therefore presumed to be cosmopolitan in their distribution. Just two taxa are known from the Southern Hemisphere only, however identification of the remaining common species proved problematic. Analysis using the BIO-ENV procedure of the PRIMER computer program confirmed an expected strong association between diatom community composition and pH, with water conductivity and gilvin also important. Weighted averaging regression and cross-validation using C 2 software enabled selection of four diatom species as potentially sensitive indicators of certain pH levels. Neither species of Eunophora showed a strong preference for pH or for any of the other environmental variables measured, indicating that other factors are determining their distributions. The strength of the species-environment relationships found in this small survey suggests good potential for monitoring current conditions and for palaeoecological applications. Extension of the dataset with information from other alpine/subalpine areas is desirable, as is the compilation of a regional diatom identification guide for these habitats.

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“…NO 3 -N, altitude, and QHEI weight-averaging taxa optima were calculated using the full dataset (n ¼ 44), and the results are presented for the taxa with effective numbers of occurrences (i.e. >20; Jackknife-derived predicted NO 3 -N, altitude, and QHEI values matched the measured values well (Figure 3), and the residuals plotted against predicted values (Racca and Prairie 2004 ) indicated no bias in the models. The models for Ca 2þ and TP performed poorly (not shown).…”

Section: à2mentioning

confidence: 92%

Spatial distribution of benthic macroinvertebrates in the Erhai basin of southwestern China

Xing-zhong

Cai

Tang

et al. 2011

Journal of Freshwater Ecology

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The macroinvertebrate communities and relationships with environmental variables were characterized in the Erhai basin by sampling at 44 sites. Among the 76 taxa observed, Baetis sp., Tubificidae, Simulium sp., Eukiefferiella sp., Gammarus sp. and Parakiefferiella sp. were the dominant taxa. Canonical correspondence analysis indicated that seven environmental variables, namely altitude, Ca 2þ , chemical oxygen demand, NO 3 -N, total phosphorus, streambed width, and a qualitative habitat evaluation index (QHEI), were significantly related to the distribution of benthic macroinvertebrates. Two-way indicator species analysis divided total sampling sites into four groups. Weighted-averaging regression and crosscalibration produced strong models for predicting NO 3 -N, altitude, and QHEI, which enabled the selection of the following benthic taxa as potentially sensitive indicators of certain levels of NO 3 -N, altitude, and QHEI: Aracina, Atrichops morimotoi, Ceratopsyche sp., Guttilelopia sp., and Nemoura sp. for NO 3 -N; Heptagenia sp. and Parakiefferiella sp. for altitude; and Aracina for QHEI.

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Apparent and real bias in numerical transfer functions in palaeolimnology

Cited by 20 publications

References 13 publications

Spatial distribution of benthic algae in the Gangqu River, Shangrila, China

Spatial distribution of benthic algae in the Gangqu River, Shangrila, China

Benthic Diatom Communities in Subalpine Pools in New Zealand: Relationships to Environmental Variables

Spatial distribution of benthic macroinvertebrates in the Erhai basin of southwestern China

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