Sökning: "leaf decomposition rates"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden leaf decomposition rates.
1. Ecosystem functioning in streams : Disentangling the roles of biodiversity, stoichiometry, and anthropogenic drivers
Sammanfattning : What will happen to ecosystems if species continue to go extinct at the high rates seen today? Although ecosystems are often threatened by a myriad of physical or chemical stressors, recent evidence has suggested that the loss of species may have impacts on the functions and services of ecosystems that equal or exceed other major environmental disturbances. The underlying causes that link species diversity to ecosystem functioning include species niche complementarity, facilitative interactions, or selection effects, which cause process rates to be enhanced in more diverse communities. LÄS MER
2. Structuring factors for macroinvertebrate communities and the importance for ecosystem processing
Sammanfattning : Aquatic macroinvertebrates play important roles in our ecosystems and are essential for the ecosystem processing. An improved knowledge of structuring factors, such as competition and predation, and the way in which they operates in the macroinvertebrate community is crucial for our understanding of not only the macroinvertebrates but also the ecosystem in general. LÄS MER
3. Impacts and drivers of insect herbivory on element cycling in forests globally
Sammanfattning : The effects of insect herbivores on forest functioning are not well understood even though they can have important impacts on ecosystem processes by intercepting foliage before resorption and depositing nutrient-rich materials to the soil. In this thesis, I investigated the impact and drivers of insect folivores on carbon (C), nitrogen (N), phosphorus (P) and silica (Si) cycling in broadleaf forests, and how this varies with major climate variables. LÄS MER
4. Importance of tannins for responses of aspen to anthropogenic nitrogen enrichment
Sammanfattning : Boreal forests are often strongly nitrogen (N) limited. However, human activities are leading to increased N inputs into these ecosystems, through atmospheric N deposition and forest fertilization. LÄS MER
5. Functional Traits in Sphagnum
Sammanfattning : Peat mosses (Sphagnum) are ecosystem engineers that largely govern carbon sequestration in northern hemisphere peatlands. I investigated functional traits in Sphagnum species and addressed the questions: (I) Are growth, photosynthesis and decomposition and the trade-offs between these traits related to habitat or phylogeny?, (II) Which are the determinants of decomposition and are there trade-offs between metabolites that affect decomposition?, (III) How do macro-climate and local environment determine growth in Sphagnum across the Holarctic?, (IV) How does N2 fixation vary among different species and habitats?, (V) How do species from different microtopographic niches avoid or tolerate desiccation, and are leaf and structural traits adaptations to growth high above the water table?Photosynthetic rate and decomposition in laboratory conditions (innate growth and decay resistance) were related to growth and decomposition in their natural habitats. LÄS MER
