Sökning: "soil disturbance"

Visar resultat 6 - 10 av 37 avhandlingar innehållade orden soil disturbance.

1. 6. Vibration transfer process during vibratory sheet pile driving : from source to soil

   Författare :Fanny Deckner; Staffan Hintze; Kenneth Viking; Steinar Nordal; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ground vibrations; sheet piles; vibratory driving; vibration transfer process; instrumentation system; field tests; numerical modelling; vibration prediction; markvibrationer; spont; vibrodrivning; vibrationsöverföringsprocessen; instrumenteringssystem; fältförsök; numerisk modellering; vibrationsprognosticering; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning : Vibratory driven sheet piles are a cost-effective retaining wall structure, and in coming decades the continued use of this method will be crucial for minimising costs within the construction sector. However, vibratory driven sheet piles are a source of ground vibrations, which may harm structures or induce disturbance. LÄS MER

3. 7. Tillage practices and their impact on soil organic carbon and the microbial community

   Författare :Sofia Hydbom; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillage; Agriculture; Long-term field experiment; Microorganism; Clayey soil; Soil organic carbon; Farmer; Sweden;

   Sammanfattning : Soil microorganisms are important for climate regulation as well as for plant nutrition. In agricultural soils the microorganisms are affected by management choices, like which type of tillage that is used. LÄS MER

4. 8. Cryogenic soil processes in a changing climate

   Författare :Marina Becher; Jonatan Klaminder; Johan Olofsson; Jan Karlsson; Niclas Börlin; Philip Wookey; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-sorted circle; Carbon storage; Soil motion; Terrestrial photogrammetry; Cryoturbation; Carbon fluxes; naturgeografi; Physical Geography;

   Sammanfattning : A considerable part of the global pool of terrestrial carbon is stored in high latitude soils. In these soils, repeated cycles of freezing and thawing creates soil motion (cryoturbation) that in combination with other cryogenic disturbance processes may play a profound role in controlling the carbon balance of the arctic soil. LÄS MER

5. 9. Pollinators, Enemies, Drought, and the Evolution of Reproductive Traits in Primula farinosa

   Författare :Per Toräng; Jon Ågren; Johan Ehrlén; Rebecca Irwin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alternative reproductive strategies; climate change; facilitation; floral display; flowering phenology; frequency-dependent selection; genetic diversity; life-history strategies; local adaptation; pollination; predation; Primula farinosa; reproductive effort; soil disturbance; stochastic growth rate; Ekologi;

   Sammanfattning : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. LÄS MER

7. 10. The ecological significance of sexual reproduction in peat mosses (Sphagnum)

   Författare :Sebastian Sundberg; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Bryophyte; colonisation; disturbance; experiment; longevity; mire; safe site; spore; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : Peat mosses (Sphagnum) are widely distributed and are a major component of mire vegetation and peat throughout the boreal and temperate regions. Most boreal Sphagnum species regularly produce sporophytes, but the ecological role of the spore has been questioned. LÄS MER