Sökning: "hållbart jordbruk"

Visar resultat 11 - 15 av 15 avhandlingar innehållade orden hållbart jordbruk.

1. 11. The dynamics in harvested populations

   Författare :Anders Wikström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fluctuations; temporal; state-space; Harvest; cod; vendace; elasticity; stage-structured; stochastic; growth-rate; Baltic Sea; Bothnian Bay;

   Sammanfattning : We are interested in the effect of harvesting on population fluctuations and for that purpose we develop and analyze an age-structured model where recruitment is a stochastic process and the adult segment of the population is harvested. When a constant annual harvest is taken the coefficient of variation of the adult population increases for most parameter values due to the age truncation effect, i. LÄS MER

3. 12. The impact of past land-use change on floristic diversity in southern Sweden : a quantitative approach based on high-resolution pollen data

   Författare :Daniel Fredh; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis explores the relationship between land-use and floristic diversity over the last three millennia in the uplands of southern Sweden. A quantitative approach based on high-resolution pollen data was applied, using the Landscape Reconstruction Algorithm (LRA), historical maps/aerial photographs, palynological richness and new ways to estimate past evenness at regional and local spatial scales, which enable estimates of the rate and degree of change in land-use and floristic diversity. LÄS MER

4. 13. Exploring synergies between the palm oil industry and bioenergy production in Indonesia

   Författare :Fumi Harahap; Semida Silveira; Dilip Khatiwada; José Roberto Moreira; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; palm oil industry; bioenergy; resource efficiency; sustainability; land allocation; palm oil biomass; biorefinery; policy coherence analysis; techno-economic analysis; spatio-temporal optimisation model; BeWhere Indonesia; Energy Technology; Energiteknik;

   Sammanfattning : Climate change along with increasing demand for food and fuel call for sustainable use of natural resources. One way to address these concerns is through efficient use of resources, which is also vital for the achievement of the Sustainable Development Goals and the Paris Agreement. LÄS MER

5. 14. Effects of farmland heterogeneity at multiple spatial and temporal scales on house sparrow (Passer domesticus) population ecology

   Författare :Maria von Post; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Farmland heterogeneity; house sparrow; agricultural intensification; farm specialisation; landscape complementation; resource separation; population limitation;

   Sammanfattning : Strong declines of European farmland birds in recent decades are assumed to be caused by decreased food availability resulting from agricultural intensification and concomitant loss of farmland heterogeneity. One of the species suffering particularly strong declines in NW European countries is the house sparrow. LÄS MER

7. 15. Natural enemies: Functional aspects of local management in agricultural landscapes

   Författare :Helena Hanson; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Agricultural intensification; sustainable agriculture; land use; management intensity; landscape scale; ecosystem services; biological control; species trait; pesticides; predatory arthropods; parasitoids; pollen beetles;

   Sammanfattning : Agricultural intensification has raised the global food production but also caused major concerns about environmental and health effects, including contamination by pesticides. Pesticide applications may induce toxicity not only on the target pest species but especially on non-target species. LÄS MER