Sökning: "insect outbreak"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden insect outbreak.

1. 1. Impacts and drivers of insect herbivory on element cycling in forests globally

   Författare :Bernice Hwang; MERGE: ModElling the Regional and Global Earth system; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biogeochemical cycling; folivory; insect cadavers; insect frass; insect herbivory; litter decomposition; nutrient cycling; carbon; nitrogen; phosphorus; silicon; silica;

   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

3. 2. Spatial and temporal dynamics of subarctic birch forest carbon exchange

   Författare :Michal Heliasz; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mountain birch; eddy covariance; carbon budget; insect outbreak; forest expansion; temporal variability; spatial variability;

   Sammanfattning : High northern latitudes are of special importance for the global carbon budget as they store large amounts of organic matter in the soil and are expected to be the most strongly affected by climate change. Here we investigate carbon exchange in the subarctic mountain birch forest growing on the limit where tree growth is possible. LÄS MER

4. 3. Biogeochemistry in Subarctic birch forests : Perspectives on insect herbivory

   Författare :Jeppe Ågård Kristensen; MERGE: ModElling the Regional and Global Earth system; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biogeochemistry; Aboveground-belowground interactions; Herbivory; Insects; Subarctic; Birch; soil microbes;

   Sammanfattning : Herbivory can influence ecosystem processes, partly through long-term changes of the plant community compositions, but also more rapidly through the herbivores’ digestive alteration of the organic matter that is cycled through the soil and back to the primary producers. In the Subarctic mountain birch (Betula pubescens ssp. LÄS MER

5. 4. Resistance and recolonization of bryophyte assemblages following disturbances : - detecting patterns and exploring mechanisms

   Författare :Martin Schmalholz; Kristoffer Hylander; Jari Kouki; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bryophytes; boreal forest; boulders; clear-cutting; disturbance; establishment; insect outbreaks; microtopography; recolonization; resistance; spatial heterogeneity; succession; wildfires; Biology; Biologi; Plant Ecology; växtekologi;

   Sammanfattning : Disturbances are ubiquitous features of most northern forest ecosystems. The subsequent response of plant assemblages on both short (resistance or not) and long term (recolonization or not) will depend on a number of factors operating at several spatial scales. LÄS MER

7. 5. Monitoring insect defoliation in forests with time-series of satellite based remote sensing data - near real-time methods and impact on the carbon balance

   Författare :Per-Ola Olsson; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Forests are of major importance to climate change mitigation due to their strong capacity to sequester carbon. Nearly half of the terrestrial carbon is stored in forests, and forests contribute to half of the terrestrial primary productivity, with forests in the mid- and high latitude ecosystems as major contributors. LÄS MER