Anders Nielsen
Head of Department/Head of Research
Authors
Gaute Velle Anders Bryn Kyrre Kausrud Lawrence R. Kirkendall Martin Malmstrøm Brett Kevin Sandercock Paul Ragnar Berg Kjetil Hindar Johanna Järnegren Erlend Birkeland Nilsen Eva Bonsak Thorstad Anders NielsenAbstract
This report examines how co-occurring non-native species can interact to create cumulative impacts on ecosystems. Non-native species may interact in additive, antagonistic, or synergistic ways. Through literature review, we found theoretical foundations and empirical examples showing that such interactions often occur. Synergistic interactions are of particular concern. Certain ecosystems appear particularly susceptible, including agricultural landscapes, urban environments, riparian systems, shipping-influenced marine areas, and islands with naïve fauna. We conclude that cumulative effects are ecologically important, and that it would be beneficial to incorporate multispecies interactions into risk assessments of non-native species in Norway.
Authors
Linn Vassvik Anders Nielsen Michael Garratt Bjørn Arild Hatteland Joseph Chipperfield Jørund Johansen Silje Maria Midthjell Høydal Erik Trond AschehougAbstract
Insect pollinators are important drivers of fruit quality and yield in horticultural systems. The global reduction in wild bee populations has increased the demand for managed honeybees, despite honeybees relatively low pollination efficiency. Here, we assessed how bee communities, bee behaviour, and orchard design in Norwegian apple orchards affects apple pollination success, an important determinant of apple quality. We placed pan and vane traps in 18 apple orchards, in six distinct locations, within the two main apple growing regions in Norway. We also tracked individual bees (honeybees, bumblebees, and solitary bees) throughout the apple flowering season, and recorded their flower handling time, number of flower visits, stigma contact, and movement between apple flowers. Finally, we calculated the seed set rate (ovules developed into seeds / total number of ovules) from 908 harvested apples to estimate pollination success. Our key finding is that pollination success was driven by the abundance of wild bees and overall orchard planting design. We found lower pollination success in block design orchards where a single cultivar is planted continuously over a large area, compared to orchards with an integrated design where compatible cultivars are planted within the orchard. We also found that stigma contact decreased as apple flowering progressed, and that solitary bees visited fewer flowers per foraging event but were potentially more thorough foragers. Our results highlight the importance of promoting wild bees in apple orchards while also ensuring there is compatible pollen in the orchards for optimal pollination.
Authors
Lawrence R. Kirkendall Daniel Flø Martin Malmstrøm Anders Nielsen Paul Ragnar Berg Anders Bryn Kjetil Hindar Johanna Järnegren Kyrre Kausrud Erlend Birkeland Nilsen Brett Kevin Sandercock Eva Bonsak Thorstad Gaute VelleAbstract
VKM has assessed the potential risk to Norwegian biodiversity associated with the import of the Turkestan cockroach, Periplaneta lateralis, as live food for hobby animals. Populations of the cockroach are nearly always found in or near buildings, and non-native populations have never been observed in natural environments. No previous observations of P. lateralis have been reported for Norway and it is very unlikely the species will be able to establish and spread into Norwegian nature due to the low winter temperatures and short summers. Furthermore, VKM find that there is low risk associated with the potential effects on biodiversity, if it against all odds, were to establish in Norway. Therefore, VKM concludes that there is low risk associated with import and keeping of P. lateralis in relation to its potential negative effect on Norwegian biodiversity.
