Discussion
Our structural equation modelling of the variation in decomposition
rates across the tundra landscape in Western Greenland indicated that:
(1) micro-environmental factors play a minor role in explaining
variation in decomposition at the landscape scale; (2) environmental
predictors differ little in their importance for mass loss of Green Tea
(soil temperature and moisture) and Rooibos Tea (no significant
predictors); and (3) only some indirect effects of vegetation on
decomposition through microclimate were significant, while there was no
evidence for direct (trait) related effects. However, the overall
explanatory power of our SEM was low and the overall fit was
non-significant. This suggests that other factors than the
topographical, vegetation, soil and microclimate variables included here
control the mechanisms behind decomposition across our studied tundra
landscape, such as decomposer communities or annual and seasonal
variation in micro-environmental conditions (see detailed discussion
below). Overall, our results highlight the need for further research to
advance our understanding of decomposition processes and carbon cycling
in the changing Arctic. Below, we discuss the findings in relation to
our research questions and derive some general recommendations for
future decomposition studies in the tundra.