Sökresultat

Terpene emissions from the top-canopy layer (at 20 m) of one 118-year-old Norway spruce tree were measured between June and September 2013 using a branch chamber. Total terpene emissions varied from 0.05 to 332.5 μg gdw -1 h-1 with a peak in August. Monoterpenes dominated throughout the summer and on average accounted for 65% of the total terpene mass, followed by sesquiterpenes (29%) and isoprene

Ecological intensification of agriculture implies managing ecological processes to improve performance of agricultural systems. However, impacts on relevant ecological functions such as insect pollination from other crop management factors are poorly explored. Pest insects and crop resources such as water availability can directly affect crop yields, but it is unknown if there are indirect effects

We propose a model to consider data dependencies and assess spatial and temporal variability in land use specific floral coverage across landscapes. Data dependence arising from repeated measurements across the flowering season is taken into account using hierarchical Archimedean copulas, where the correlation is assumed to be stronger within seasonal periods than between periods. For each seasona

Strawberry and oilseed rape are economically important and co-flowering insect-pollinated crops that may affect each other via shared pollinators. One potential negative effect of pollinator sharing is stigma clogging, i.e. that pollen from one plant species covers the stigma and prevents pollination in the other. We tested if application of oilseed rape pollen on strawberry receptacles reduces po

The integrated dynamic ecosystem models SAFE and ForSAFEVEG were used to estimate critical loads for nitrogen using different chemical and biological criteria, and attempting to account for possible effects of climate change. The study is based on a model application on a set of 640 sites earlier used for critical loads assessments in Sweden, focusing on the ecological effect of nitrogen pollution

The contribution of forest harvesting to base cation losses and soil acidification has increased in recent years in Sweden, as the demand for bioenergy has increased and the sulphur deposition has decreased. Thus, new policy tools are required to evaluate the progress of the recovery from acidification, and as a basis for forest management recommendations. In this study we introduce and test a con

Hunting in tropical forests decimates large mammals, and this may have direct and indirect effects on other trophic levels and lead to trophic cascades. We compared replicated sites of hunted and protected forests in southeastern Nigeria, with respect to community composition of primates, other mammals, birds, plant seedlings, and mature trees. We make predictions regarding the community compositi

Increasing cultivation of oilseed rape may have consequences for pollinators and wild plant pollination. By providing pollinating insects with pollen and nectar, oilseed rape benefits short-tongued, generalist insect species. Long-tongued bumble bee species, specialized to other flower types, may instead be negatively affected by increased competition from the generalists (e.g. due to nectar-robbi

Over and above food, agricultural landscapes provide citizens with crucial public-good ecosystem services, such as biodiversity conservation, cultural values, recreational opportunities, and food security. Because continuing agricultural intensification undermines the ability of landscapes to provide public goods, policies have been implemented to preserve landscape multifunctionality, but with li

Mass-flowering crops lead to spatial redistributions of pollinators and to transient shortages within nearby semi-natural grasslands, but the impacts on plant-pollinator interactions remain largely unexplored. Here, we characterised which pollinator species are attracted by oilseed rape and how this affected the structure of plant-pollinator networks in nearby grasslands. We surveyed 177 networks

We outline a conceptual strategy for implementing conservation interventionsin a multiscale, multiactor, and multilevel governance world. Using farmlandas an example, we argue that conservation interventions should be implementedwithin a multiscale framework of guiding ecological principles. Inthis context, findings from multilevel governance research can inform a nuancedunderstanding of the role

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to wh