Linn Vassvik
Forsker
(+47) 482 68 342
linn.vassvik@nibio.no
Sted
Ås - Bygg O43
Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 21)
Forfattere
Linn VassvikSammendrag
Agricultural production is highly dependent upon pollinators to achieve maximum yield and increase global food security. Wild pollinators, such as bees, are declining due to a loss of habitat from agricultural intensification, and the use of domesticated honeybees to supplement pollination services is increasing. Apple is an important, pollinator dependent food crop that commonly experiences pollination and production deficits worldwide. In this thesis, I explored whether pollination and production deficits occur in Norwegian apple orchards and what factors might be driving potential deficits. To test for pollination (seed set) and production (yield) deficits I conducted a supplemental pollination experiment for three cultivars, in eighteen orchards, in two distinct growing regions in Norway, over two years. I also assessed which pollinators are present in Norwegian apple orchards and how different groups of bees and their behaviour affect pollination of apple. Lastly, I studied different management practices to increase bee diversity and pollination success, by increasing alternate floral resources and evaluating orchard design that promotes cross-pollination. Pollination and production deficits were found across all locations, with differences in pollination deficits among cultivars. I also found that a high abundance of wild bees increases seed set in apples—a key indicator of pollination success. Behaviour also varied among bee groups, for example bumblebees visited more flowers, while solitary bees were slow, but potentially more thorough, foragers, which increases pollen deposition. Wild bees visited more apple flowers than dandelion flowers (Taraxacum spp.) when orchards were left unmowed. I also found that a higher abundance of dandelions increased bee visitation to apple flowers, suggesting higher floral diversity can increase pollination success and support a greater diversity of bees. In addition, block design orchards appear to limit cross-pollination among apple cultivars, and management actions to decrease the distance among compatible apple cultivars is needed to achieve sufficient pollination. Overall, my results suggest that greater pollination and production of apples in Norway is possible, and management actions should focus on increasing wild bee abundance and diversity, increasing alternate floral resources, and optimising orchard design to facilitate cross-pollination across shorter distances. Such actions have the potential to ensure greater yields of higher quality apples for human consumption and increased economic output for farmers.
Forfattere
Sven Emil Hinderaker Linn Vassvik Synnøve Grenne Elin Blütecher Kristin Daugstad Carl Frisk Mie Prik Arnberg Thomas Holm CarlsenSammendrag
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Forfattere
Astrid Brekke Skrindo Heidi Solstad Ruben Erik Roos Ida Marielle Mienna Joachim Paul Töpper Odd Egil Stabbetorp Mathias Andreasen Harald Bratli Åshild Hasvik Ragnhild Heimstad Ulrika Jansson Marte Olsen Siri Lie Olsen Daniel Ingvar Jeuderan Skoog Linn Vassvik Marianne EvjuSammendrag
Det er ikke registrert sammendrag