Soil moisture conditions control nutrient accumulation, carbon storage and tree growth in boreal forest landscapes
Forest and soil properties change across landscapes due to the complex interactions between various environmental factors. In many landscapes, topography exerts a major influence on the variation in soil moisture conditions, which in turn largely affects soil properties and processes. This thesis sy...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | Swedish English |
| Published: |
2023
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| Online Access: | https://pub.epsilon.slu.se/32195/ https://pub.epsilon.slu.se/32195/1/larson-j-20231117.pdf |
| Summary: | Forest and soil properties change across landscapes due to the complex interactions between various environmental factors. In many landscapes, topography exerts a major influence on the variation in soil moisture conditions, which in turn largely affects soil properties and processes. This thesis synthesises the results from four studies (papers I-IV), with the underlying aim to increase the understanding of how environmental factors, in particular, soil moisture, control the variation of nutrient accumulation, carbon storage, and tree growth within boreal landscapes. The four studies were all based on an extensive survey of a 68 km2 boreal forest landscape in northern Sweden. In Paper I, soil moisture conditions were predicted using multiple terrain indices. The results emphasised within-study validation and how digital elevation model resolution together with user-defined thresholds influence prediction accuracy. Paper II focused on how multiple environmental drivers influence the variation in soil carbon-to-nitrogen (C/N) ratios, with a noteworthy result that the ratio decreases as soil moisture conditions increase. Paper III presented how, soil moisture conditions significantly controls the distribution and partitioning of carbon stocks, with large increases in total carbon stock observed as soil moisture conditions increases, which was observed at both plot and landscape scale. The results in paper IV showed that, estimates of forest site quality decrease in response to increased soil moisture conditions. In conclusion, the research discussed in this thesis emphasises the importance of studying forest ecosystems on a landscape scale, an approach that can provide key insights into the factors that influence variation of different attributes of boreal forest ecosystems. |
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