The soil propagule bank along an elevation gradient - a key to understanding climate change dynamics
Master thesis
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https://hdl.handle.net/11250/3091673Utgivelsesdato
2023Metadata
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Sammendrag
Spanning Northern Europe, Asia, and North America, the boreal forest represents Earth's most expansive terrestrial vegetation zone, constituting approximately one-third of global forests and accounting for nearly 40% of Norway's land mass. This biome is currently under considerable threat from climate change, leading to a consequential necessity for forest species to either acclimate, adapt, or relocate to survive. One such adaptive strategy is 'bethedging,' which leverages dormant propagules in the soil to sustain species amidst environmental change. Despite its significance, our understanding of climate change's impact on boreal forests' propagule bank, including bryophytes and ferns, is limited. This study examines the species composition and richness of the propagule bank in a boreal pine forest compared to the standing vegetation. It investigates the influence of local environmental factors on the propagule bank's species composition and assess the role of the propagule bank as a bet-hedging strategy in response to environmental changes.
Results from this study show that the propagule bank held fewer species than the standing vegetation as the reproductive mechanisms of many boreal forest species seem to rely on clonal reproduction, which likely contributed to the lower species composition in the propagule bank. The propagule bank exhibited lower species richness compared to the standing vegetation, and a decline in species richness was observed along the elevation gradient.
Despite the recognized potential of propagule banks in buffering against environmental change by maintaining species richness and influencing community composition, this study show that the boreal forest propagule bank may lack sufficient diversity to support current plant communities under evolving climatic conditions. With a likely dominance of few species not closely resembling the existing vegetation, the propagule bank's role in climate resilience could be undermined. Hence, rather than acting as a buffer or bet-hedging strategy, the propagule bank may instead indicate potential future vegetation structure and composition.
Beskrivelse
Master's Thesis in Climate Change Management