Climate change impacts on berry shrub performance in treeline and tundra ecosystems

Siegwart Collier, Laura (2020) Climate change impacts on berry shrub performance in treeline and tundra ecosystems. Doctoral (PhD) thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (6MB)

Abstract

Climate variability and warming are directly, indirectly and irrefutably driving widespread changes in global aquatic and terrestrial ecosystems, with disproportionate poleward impacts. Across Arctic treeline and tundra, understanding how current and future changes will negatively affect subsistence resources is critical to mitigating climate change impacts on Indigenous peoples and northern flora and fauna. In this study, I looked to Inuit knowledge and western scientific approaches at local and regional scales across Inuit Nunangat (Inuit regions of Canada, including Nunavut, Nunavik, and Nunatsiavut) to explore and test the impacts of climate variability and warming on treeline and tundra berry species, which are critical resources in Arctic ecological and cultural systems. My central hypothesis, which is rooted in local, traditional and scientific knowledge, is that climate-driven expansion of tall-shrub canopies will negatively impact fruit production of dwarf berry shrubs. Through mixed methods approaches, including participatory interviews, climate analyses, ecological surveys, and experimental warming at different spatial and temporal scales, this study identifies the fundamental role of local processes in driving and explaining changes in dwarf berry shrub growth (abundance and height) and fruit production (occurrence and abundance of fruit) in eastern Low Arctic and Sub-Arctic Canada. The results consistently demonstrate that growth and fruit production of truly prostrate berry shrubs (i.e. Vaccinium vitis-idaea and Empetrum nigrum) with limited phenotypic plasticity in height growth are most at risk from warming and tundra shrubification in comparison to berry shrubs with greater height growth plasticity (V. uliginosum) due to canopy impacts on local resources. With this knowledge, I anticipate that the boundaries between low and tall shrub tundra plant communities will be zones of significant change in berry resources. Local resource mapping, with a specific focus on these transition zones will be critical to identifying priority areas for berry resource conservation and active management to ensure future access to a sustainable source of these culturally important resources.

Actions (login required)

View Item