Assessing the Effects of Climate Change and Land Use on Northern Labrador Forest Stands Based on Paleoecological Data

File Identifier: 13113_iso.xml

Metadata Language: eng; CAN

: utf8

Resource Type: Dataset

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Individual Name: Polar Data Catalogue

Organisation Name: Canadian Cryospheric Information Network

Role: Point Of Contact

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Voice: (519) 888-4567 x32689

Street Address: 200 University Avenue West, University of Waterloo

City: Waterloo

Province/State: Ontario

Postal Code/ZIP: N2L 3G1

Country: Canada

E-Mail Address: pdc@uwaterloo.ca

Metadata Date: 2019-10-28

Metadata Standard Name: North American Profile of ISO 19115:2003

Metadata Standard Version: 2009-01-01

Abstract: In total, four monoliths were excavated down to the level of the mineral substrate using a shovel. The stratigraphy of the peat was documented and the onsite vegetation was also inventoried. Macrofossil analysis was conducted following the protocol outlined by Bhiry and Filion (2001). Each 1 cm thick slice contained 25 cm3 of organic sediment. Sediments were treated with a weak 5% aqueous KOH solution and boiled for a few minutes to deflocculate. The material was then wet-screened through a series of sieves (850, 425, and 180 um meshes). We analysed the upper part of the monoliths either in a continuous manner, that is every cm, or at 2 cm intervals. Thus, for the Nain1 monolith, we used the following intervals: 1 cm at the top section (0-16 cm), 2 cm in the top-middle section (17-32 cm) and 4 cm at the lower half section (32-64 cm). For the Nain2 monolith, the intervals were 2 cm between 0 and 16 cm and 4 cm between 16 and 35 cm; for KAM, the intervals were every cm between 14 and 21 cm and 2 cm from 22 to 40 (0-14 cm consists of present day vegetation); and for WB, the analysis intervals were every cm between 7 and 15 cm and 2 cm from 15 to 30 cm (0-7 cm consists of present day vegetation). Macrofossils were identified under a binocular microscope at magnifications between 4x and 40x. Bryophytes present in the organic matrix were identified and their respective percentages were calculated relative to the total volume of the section (25 cm3). The remains of vascular plants and aquatic invertebrates were sorted, counted, and identified. For Sphagnum, the percentage of each species was determined based on a subsample of 100 leaves. Data were plotted using Paleo Data Plotter software (Juggins, 2002). Pollen and spore analyses were carried out on the Nain1 monolith. Subsamples of 1-3 cm3 of material were prepared and processed following the procedure of Faegri and Iversen (1989). A Lycopodium pollen suspension of known volume and concentration was added to each subsample in order to determine the pollen concentration. Analysis was carried out at 2 cm intervals for the top 40 cm and then at 4 cm intervals for 40-64 cm. Thirteen sub-samples were submitted for accelerator mass spectrometry (AMS) radiocarbon dating. Radiocarbon dates (14C yr BP) were calibrated (cal yr BP) using the Calib 7.1 program (Stuiver et al., 2014) and the INTCAL09 data set (Reimer et al., 2009). Modern dates (1950-2010) were calibrated using CALIBomb (Hua et al., 2013).

Purpose: We reconstructed the late Holocene vegetation of the Nain region (northern Labrador, Canada) in order to assess the influence of climate and land use on shifts in forest composition. Chronostratigraphy was used in combination with macrofossil and pollen data from monoliths. We reconstructed the late Holocene vegetation of the Nain region (northern Labrador, northeastern Canada) in order to assess the influence of climate and historic land use on past shifts in forest composition. Chronostratigraphy was used in combination with macrofossil and pollen data from monoliths sampled from four peatlands. Paleoecological reconstructions produced a vegetation history spanning 4900 years for the Nain region that is largely concordant with other studies in Labrador. An initial open forest tundra phase was followed by an increase in tree cover at around 2800 cal yr BP. Paludification began ~200 cal yr BP. A decline in Picea and its subsequent disappearance from most of the sites occurred ~170 cal yr BP (AD 1780) in a period of relatively mild conditions during the Little Ice Age. This event was followed by the establishment of Larix laricina in the region. Local anthropogenic factors are likely responsible for these later developments, as they were not observed in other regional studies. The period around AD 1780 corresponds to the establishment of the Moravian missionaries on the Labrador coast, which increased the need for fuel and lumber. We conclude that changes in land use are reflected in the patterns of vegetation and hydrological change at the study sites.

Language: eng; CAN

Citation:

Contact Info:

Title: Assessing the Effects of Climate Change and Land Use on Northern Labrador Forest Stands Based on Paleoecological Data

Date:

Date: 2019-10-28

Date Type: Publication Date

Individual Name: Bhiry, Najat

Role: Principal Investigator

Individual Name: Lemus-Lauzon, Isabel

Role:

Individual Name: Woollett, James

Role:

Point Of Contact:

Individual Name: Polar Data Catalogue

Organisation Name: Canadian Cryospheric Information Network

Role: Point Of Contact

Contact Info:

Voice: (519) 888-4567 x32689

Street Address: 200 University Avenue West, University of Waterloo

City: Waterloo

Province/State: Ontario

Postal Code/ZIP: N2L 3G1

Country: Canada

E-Mail Address: pdc@uwaterloo.ca

Online Resource: polardata.ca

Topic Category: Environment and Conservation

Keyword Collection:

Keyword: Bryophytes

Keyword: Climate change

Keyword: Climate history

Keyword: Forests

Keyword: Holocene

Keyword: Labrador

Keyword: Nain

Keyword: Nunatsiavut

Keyword: Paleoecology

Keyword: Pollen

Keyword: Radiochronology

Keyword: Spores

Keyword: Vegetation

Associated Thesaurus: Polar Data Catalogue Thesaurus (Canada)

Keyword: Nain, Nunatsiavut, Newfoundland and Labrador, Canada - AAPBP

Spatial Extent:

West Bounding Longitude: -62.07667

East Bounding Longitude: -61.62639

North Bounding Latitude: 56.90694

South Bounding Latitude: 56.46389

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Access Constraints: Other Restrictions

Use Constraints: Other Restrictions

Other Constraints: Terms of Use of the Polar Data Catalogue: https://www.polardata.ca/pdcinput/public/termsofuse

Distribution Format:

Format Name: Digital file

Format Version: 1.0

Distributor:

Distributor Contact:

Individual Name: Polar Data Catalogue

Organisation Name: Canadian Cryospheric Information Network

Role: Distributor

Contact Info:

Voice: (519) 888-4567 x32689

Street Address: 200 University Avenue West, University of Waterloo

City: Waterloo

Province/State: Ontario

Postal Code/ZIP: N2L 3G1

Country: Canada

E-Mail Address: pdc@uwaterloo.ca