Diatom-inferred depth models in 8 Canadian boreal lakes: inferred changes in the benthic:planktonic depth boundary and implications for assessment of past droughts

Laird, Kathleen R.; Kingsbury, Melanie V.; Lewis, C F M; Cumming, Brian F.

doi:10.1016/j.quascirev.2011.02.009

Cited by 45 publications

(78 citation statements)

References 64 publications

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“…Meekin Lake is a relatively large (surface area = 78 ha, maximum depth = 13 m), firstorder circumneutral lake (pH = 6.5) that is oligotrophic (total phosphorus (TP) = 9.7 µg/L) and moderately colored (dissolved organic carbon (DOC) = 7.7 mg/L; Kingsbury et al, 2012). Importantly, this lake had a gently sloping eastern basin (Figure 1b), from which the near-shore core was taken from a depth chosen based on changes in modern diatom assemblages (Laird et al, 2011). study lakes (Meekin, ELA Lake 239, and Gall Lake) that are located within the Winnipeg River Drainage Basin.…”

Section: Study Sitesmentioning

confidence: 99%

“…For example, in Meekin Lake, the present-day abundance of S. pinnata reaches a maximum abundance of ~20% in the surface samples between a modern depth of 8 and 9 m (Laird et al, 2011). However, this taxon achieved a sustained and high relative abundance of greater than 40% in the early-to-mid-Holocene period.…”

Section: Early To Mid-holocene Changes In Effective Moisturementioning

confidence: 99%

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Diatom-based evidence of regional aridity during the mid-Holocene period in boreal lakes from northwest Ontario (Canada)

2014

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Boreal regions and their freshwater ecosystems may be susceptible to future climate change under projected warmer conditions. Northwest Ontario is a boreal region adjacent to the climatically sensitive prairie-forest ecotone (PFE). Pollen records spanning the Holocene from near the Manitoba/Ontario border to lakes up to ~300 km east of the PFE indicate a warmer and possibly wetter mid-Holocene period across northwest Ontario from ~8000 to 4500 cal. yr BP. To date, only one Holocene-scale record of changes in effective moisture, as indicated through diatom-inferred changes in lake level (Experimental Lakes Area (ELA) Lake 239), is available from this region. Our study expands the regional context of Holocene climate changes, with the analysis of diatom assemblages in sediment cores from two additional lakes, which span a distance of over 200 km across the present-day boreal forest, from 80 km west of ELA Lake 239 to ~150 km to the northeast. In cores from both lakes, benthic taxa predominate in the early-to-mid-Holocene period, with a low abundance of planktonic taxa, suggesting lower lake levels by ~2–5 m. Increases in the abundance of planktonic taxa to >50% occurred in both lakes beginning ~4500–4000 cal. yr BP suggesting positive water balance over the last 4000 years in comparison with the mid-Holocene period. This new evidence supports a regional mid-Holocene period of aridity, with reduced water levels across the boreal region of northwest Ontario. If future climate change results in lower effective moisture, then conditions could become similar to the mid-Holocene period aridity, leading to real challenges for the management of water resources across the region.

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Section: Study Sitesmentioning

confidence: 99%

Section: Early To Mid-holocene Changes In Effective Moisturementioning

confidence: 99%

Diatom-based evidence of regional aridity during the mid-Holocene period in boreal lakes from northwest Ontario (Canada)

2014

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“…The ratio of benthic and planktonic diatoms (P / B ratios) has been used to infer past fluctuations in lake level and precipitation (Laird et al, 2011). Based on this assumption, the variation in P / B ratios in our study was used as a proxy of paleo-precipitation.…”

Section: Proxies Evaluationmentioning

confidence: 99%

Late Holocene environmental reconstructions and their implications on flood events, typhoon, and agricultural activities in NE Taiwan

Wang

Behling²,

Lee

et al. 2014

Clim. Past

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Abstract. We reconstructed paleoenvironmental changes from a sediment archive of a lake in the floodplain of the Ilan Plain of NE Taiwan on multi-decadal resolution for the last ca. 1900 years. On the basis of pollen and diatom records, we evaluated past floods, typhoons, and agricultural activities in this area which are sensitive to the hydrological conditions in the western Pacific. Considering the high sedimentation rates with low microfossil preservations in our sedimentary record, multiple flood events were. identified during the period AD 100-1400. During the Little Ice Age phase 1 (LIA 1 -AD 1400-1620), the abundant occurrences of wetland plant (Cyperaceae) and diatom frustules imply less flood events under stable climate conditions in this period. Between AD 500 and 700 and the Little Ice Age phase 2 (LIA 2 -AD 1630-1850), the frequent typhoons were inferred by coarse sediments and planktonic diatoms, which represented more dynamical climate conditions than in the LIA 1. By comparing our results with the reconstructed changes in tropical hydrological conditions, we suggested that the local hydrology in NE Taiwan is strongly influenced by typhoontriggered heavy rainfalls, which could be influenced by the variation of global temperature, the expansion of the Pacific warm pool, and the intensification of El Niño-Southern Oscillation (ENSO) events.

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“…The correlation between diatom assemblages and water depth has been well established, and multiple lake depth calibrations have been developed for down-core reconstructions (e.g. Brugam et al 1998;moser et al 2000;sHinneman et al 2010;Wolin & stone 2010;lairD et al 2011), whereas a number of diatom studies have also developed single-lake calibration sets across a water-depth gradient to infer past changes in lake level (Yang & DutHie 1995;Brugam et al 1998;nguetsop et al 2004;moos et al 2005). stone & FritZ (2004) used threedimensional modeling of habitat areas to further assess the planktonic:benthic diatom ratios in relation to water depth.…”

Section: Introductionmentioning

confidence: 99%

Linking spatial distributions of sediment diatom assemblages with hydrological depth profiles in a plateau deep-water lake system of subtropical China.

Wang¹,

Yang²,

Hamilton³

et al. 2012

Fottea

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Abstract:The spatial distributions of approximately 160 diatom taxa from surface sediments of the plateau deep-water Lugu Lake were investigated. The results exhibited a change in the sediment diatom composition with increasing water depth. The main patterns of variation, derived from a principal component analysis (PCA) and detrended correspondence analysis (DCA), showed that diatom community composition was divided into three depth gradients (near-shore zone; mid-depth zone; profundal deep zone). With increasing depth, the pattern of predominantly periphytic taxa in the shallow waters changed to planktonic assemblages dominated by Cyclotella ocellata, Asterionella formosa and Cyclostephanos dubius. Diatom species diversity decreased from the shallow near-shore zone to the deeper open waters. In addition, there was an increase in the ratio of planktonic to periphytic diatoms at depths >30 m. These distinct spatial patterns in diatom distribution are clear markers of current water levels within Lake Lugu and represent a benchmark for evaluating paleolimnological changes in water levels, which can be an indirect proxy of regional climate in this monsoon region of southern Asia.

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Diatom-inferred depth models in 8 Canadian boreal lakes: inferred changes in the benthic:planktonic depth boundary and implications for assessment of past droughts

Cited by 45 publications

References 64 publications

Diatom-based evidence of regional aridity during the mid-Holocene period in boreal lakes from northwest Ontario (Canada)

Diatom-based evidence of regional aridity during the mid-Holocene period in boreal lakes from northwest Ontario (Canada)

Late Holocene environmental reconstructions and their implications on flood events, typhoon, and agricultural activities in NE Taiwan

Linking spatial distributions of sediment diatom assemblages with hydrological depth profiles in a plateau deep-water lake system of subtropical China.

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