THE INFLUENCE OF TUNDRA VEGETATION ON SOIL TEMPERATURES

Abstract

The arctic has experienced more rapid global warming and is more sensitive to temperature changes compared with the rest of the world. We can already see how vegetation distributed across the arctic tundra has changed in composition, height, and abundance. It’s not only that climate can change the vegetation; it has also been shown that the vegetation can have an impact on the climate and global warming through buffering effects on soil temperatures. This study aimed to investigate what influence alpine vegetation has on tundra soil temperatures by comparing the temperature difference between the vegetation canopy (representing the air temperature) and the soil and ground in places with different amounts and types of vegetation during the summer and winter season. 64 plots were installed on the tundra around Latnjajaure field station in northern Sweden with microclimate loggers to measure temperatures. A vegetation survey was performed at every plot to document vegetation cover and the types of species present. The coverage of shrubs in the plot was significantly related to soil temperatures in the summer, whereby a higher coverage of shrubs led to lower soil temperatures, but the same effect was not seen in surface temperatures. The abundance of moss in the plot had a significant effect in the winter season; more moss correlated with higher soil and ground temperatures compared to air temperatures. The amount of bare soil also showed significance where more bare soil correlated with lower soil temperatures. This study supports the claim that alpine vegetation significantly influences the soil temperatures on the tundra. It’s also suggested that tundra vegetation could lower soil temperatures, offsetting the effects of increasing temperatures on the tundra and thereby influence the speed of permafrost thaw and greenhouse gas emissions.