Supervised by:

Najat Bhiry (Regular Member (Co-researcher))

Co-supervised by:

Dominique Marguerie (Collaborator)

James Woollett (Regular Member (Co-researcher))

Research project description

Study of palsas on the southern part of Aulatsivik Island, Labrador: Paleoecology and ancient plant DNA

Introduction

Humans have had a significant impact on the environment. Inuit communities in the Arctic are no exception. However, human activities are not the only factor affecting ecosystems: climate plays a key role in its evolution. Thanks to paleo-ecological studies combined to ancient DNA study, it is possible to gather valuable information to evaluate how ecosystems respond to those factors.

Objectives

To better understand the interactions between northern people and the environment in the context of climate change, this study will examine the impact of climate and human occupation on peatland palsas in northern Labrador over the last 1 000 years. The objectives of this study are: 1) to reconstruct plant succession and to date the establishment of permafrost at the study site; 2) to establish the relationship between the genetic evolution of plant species and different climate episodes, such as the Little Ice Age; and 3) to determine whether first nations settlements (historical Inuit) in proximity to the study peatland had an impact on plant succession and change.

Study Sites

The peatland palsas are situated in Nain Bay in Labrador; more precisely, on Aulatsivik Island (56° 45′ 51″ N, 61° 30′ 59″ W). It lies on a large terraces situated 4-5 m above the current relative sea level. The island is located at the transition of the arctic and subarctic zones and has a climate that is typical of arctic tundra. Other palsas located at different altitude were also sampled to date their formation. The region of Nain is the main study site of the ANR InterArctic and GRA-Ulaval programs.

Material and methods

The project began with a topographical survey using a DGPS (Differential Global Positioning System). Following the topographical survey, a vegetation survey of the palsa and the surrounding area was conducted. Peatland palsas located near the ruins of the settlement as well as palsas in the “control zone” were described and sampled. Laboratory work will include macrofossil analysis using the Bhiry and Fillion (2001) method. Selected sub-samples will be analysed at the ECOBIO laboratory (U. Rennes 1, France) in order to extract and analyze ancient DNA. Finally, 14C dating will be conducted to establish a timeframe of the evolution of the ecosystem.

Expected results

This study may help to establish the timeframe for permafrost establishment and palsas formed. Furthermore, it will be possible to evaluate the impact of the Medieval Climatic Optimum (1000-1400) and the Little Ice Age (1300-1850) on the evolution of plant species. Finally, we may possibly detect the impact of human activities on vegetation by studying the macrofossils present in the peat.

Research Site Coordinates