Line Johansen

Research Scientist

(+47) 908 47 904
line.johansen@nibio.no

Place
Trondheim

Visiting address
Statens Hus, Prinsensgate 1, 7013 Trondheim .

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Abstract

Understanding how drivers of change affect ecosystem services (ES) is of great importance. Indicators of ES can be developed based on biophysical measures and be used to investigate the service flow from ecosystems to socio-ecological systems. However, the ES concept is multivariate and the use of normalized composite indicators reduces complexity and facilitates communication between science and policy. The aim of this study is to analyze how land use change affects ES and species richness and how the effects are modified by environmental factors by using composite indicators based on biophysical indicators. Using multivariate and regression analyses, we analyze the effect of grazing management abandonment in semi-natural grasslands in Norway on six ES: nutrient cycling, pollination, forage quality, aesthetics and global and regional climate regulation in addition to species richness along soil and climate gradients. Nutrient cycling, forage quality, regional climate regulation, aesthetics and species richness are larger in managed compared to abandoned grasslands. There are trade-offs among ES as different management strategies provide various ES and these trade-offs vary along environmental gradients. Management policies that aim to conserve ES need to have conservation goals that are context dependent, should recognize ES trade-offs and be adapted to local conditions.

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Abstract

Semi-natural grasslands are hotspots of biodiversity in Europe and provide amounts of flower resources for pollinators. We present data on composition and spatial turnover of herb species and flower resources in and between semi-natural grasslands in Romania mown at different times during the growth season (early, intermediate, late). The data include herb species occurrences, their phenological stage, flower resources, and measures of spatial turnover of the species occurrences and flower resources based on Detrended Correspondence Analyses (DCA), in the start of August. The dataset is provided as supplementary material and associated with the research article “Traditional semi-natural grassland management with heterogeneous mowing times enhances flower resources for pollinators in agricultural landscapes” [1] Johansen et al.. See Johansen et al. for data interpretation.

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Abstract

For a diverse pollinator fauna it is important that pollen and nectar are available over the entire summer at spatially relevant scales. Semi-natural hay meadows are among the most important sources of flower resources for pollinators, but the resources are strongly affected by the timing of mowing. Management recommendations for hay meadows often prescribe late mowing on order to allow undisturbed flowering during most of the summer. Traditional practices, however, often include also earlier mowing. We investigate the link between the temporal variation of flower resources and traditional mowing practices of semi-natural hay meadows in a low-intensity agricultural landscape in Romania. In early August, we botanically surveyed meadows that were cut early, intermediately, or late in the season. We recorded all herb species, their phenological stage, and the number of reproductive units of each species. Data were analysed using DCA, LM and GLM. Plant species richness and composition are not affected by the time of mowing, but different sets of species flower in semi-natural grasslands with different mowing regimes. In August the proportion of species flowering and flower density are highest in the early-mown meadows due to re-flowering after mowing. Analyses of phenological stages indicate that late-mown meadows are the main pollen and nectar sources in July, whereas meadows mown early are the main resource from August to the end of the season. The results demonstrate that for pollinator conservation, heterogeneous mowing times within a landscape need to be encouraged when possible, and that strict focus on late mowing may lead to shortage of flower resources late in the summer. Studies of low-intensity agriculture has a great potential for learning about management methods that can be used in other parts of the world where traditional practices have been lost. Such studies can thereby contribute with important knowledge to manage global pollinator loss.

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Abstract

Worldwide semi-natural habitats of high biological value are in decline. Consequently, numerous AgriEnvironment Schemes (AESs) intended to halt biodiversity loss within these habitats have been implemented. One approach has been the application of “adaptive management”, where scientific knowledge is applied alongside the traditional ecological knowledge (TEK) of stakeholders in order to establish an integrated approach that is adjusted as outcomes are assessed. In this paper we examine the effectiveness of the adaptive management approach of Norway’s Action Plan for Hay Meadows (APHM). Twenty-nine hay meadows from fourteen farms in the county of Møre og Romsdal were ecologically surveyed over a 2 year period. Interviews were also conducted with owners and land managers to explore TEK and management issues. The interdisciplinary study found that the disembedding of hay meadow management from its initial commercial purpose (in particular the loss of much of the livestock from the region) has contributed to a significant loss of TEK – which is now largely limited to knowledge of how the fields were managed recently. While, the APHM is limiting biodiversity decline by promoting traditional practices there were indications that the standardisation of management actions might negatively affect species composition in the long term. More critically, continued farm abandonment within the region means that without alternatives to management by farmers many of these meadows are likely to disappear in the next couple of decades. We conclude that adaptive management provides an effective short-term means of preserving hay meadows, but long term conservation will require a means of addressing the continued decline of local farming communities.

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Abstract

Land use change can affect biodiversity, and this has an impact on ecosystem services (ESs), but the relationships between biodiversity and ESs are complex and poorly understood. Biodiversity is declining due to the abandonment of extensively grazed semi-natural grasslands. We therefore aim to explore relationships between biodiversity and ESs provided by extensively managed semi-natural grasslands. Focusing on vascular plant species richness, as well as the ESs fodder quantity, quality, and stability, allergy control, climate regulation, nutrient cycling, pollination, and aesthetic appreciation, we carried out botanical field surveys of 28 paired extensively grazed and abandoned semi-natural grassland plots, with four subplots of 4m2 in each plot. The management of the semi-natural grasslands is and has been at low intensity. We calculated the influence of abandonment on the ES indicators, measured the correlation between the biodiversity measure of vascular plant species richness and ES indicators, and finally determined how the relationships between plant species richness and the ES indicators were affected by the cessation of the extensive management. ES indicators are often, but not always, positively correlated with species richness. Cessation of extensive grazing has both negative and positive effects on ES indicators but the relationships between species richness and ES indicators are often different in extensively managed and abandoned semi-natural grasslands. The relationships between species richness and ES indicators are less pronounced in the extensively managed semi-natural grassland than for the abandoned. One possible reason for this outcome is high functional redundancy in the extensively managed semi-natural grasslands.

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Abstract

Questions What are the effects of abandonment on plant diversity in semi-natural grasslands? Do the effects of abandonment on taxonomic and functional diversity vary along environmental gradients of climate and soil? Location West and mid-Norway. Methods Plant composition was surveyed in 110 subplots of 4 m2 in 14 sites across grazed and abandoned semi-natural grasslands. Climate data were extracted and soil composition analysed. To reduce the number of explanatory variables and deal with collinearity, we performed PCA. Data on the plant species vegetative height (H), leaf dry matter content (LDMC), specific leaf area (SLA), seed mass (SM) and number of seeds per plant (SNP) for 175 species were extracted from the LEDA database. Measures of plant diversity (species richness, CWM of functional traits and functional diversity (evenness and range)) were calculated for each subplot. To estimate the effects of abandonment on plant diversity and examine how these effects are moderated by gradients in soil and climate, we fitted mixed models to the data including site as a random effect. Results Species richness in the subplots was lower in abandoned semi-natural grasslands, especially on more calcareous soils. CWM H, LDMC and SM were higher in abandoned semi-natural grasslands. CWM LDMC was only higher in the driest subplots. The ranges in H, SLA and SM, as well as evenness in LDMC were also higher in abandoned semi-natural grasslands,but the range in LDMC was lower. Conclusions It is important to assess both taxonomic and functional diversity to understand ecosystem processes. The species pool in ecosystems influenced by a long history of intermediate grazing includes a high proportion of low stature, grazing-tolerant plant species. Abandonment of extensive land-use practices will cause a decline in taxonomic diversity (plant species richness) in such systems due to increased abundance of plants with high stature that outcompete the lower, grazing-tolerant plants. This process is predominant especially if moisture, soil fertility and pH are at intermediate levels. Changes in species communities due to abandonment will also influence ecosystem functioning, such as nutrient turnover and fodder production resilience.

Abstract

Semi-natural grasslands are in decline due to land use changes. To conserve grassland ecosystems, agrienvironmental schemes facilitate low intensity management of semi-natural grasslands of high nature value. In addition to management of the meadows themselves, the nature value of the hay meadows also depends upon the surrounding landscape. The aim of this study was to assess the importance of the landscape on the biological value of semi-natural hay meadows implemented in the Action Plan for Hay Meadows (APHM) in Norway. The biological value was estimated by richness of all vascular plant species and of vascular plant species associated with semi-natural grassland. Richness was high in semi-natural grasslands, particularly in hay meadows implemented in the APHM. However, the landscape context also influenced the richness of the hay meadows. Species richness increased with hay meadow area and length and edge density of semi-natural habitats types in the landscapes.

Abstract

Semi-natural grasslands are important habitats for pollinators because of high abundance of flowering plants. The aim of this study was to assess effects of mowing time on flower resources for pollinators in semi-natural hay meadows. Flowering species in semi-natural hay meadows throughout a landscape in Maramures, Romania were used as indicators of flower resources for pollinators. Botanical surveys were performed in 31 hay meadows and all herbs and shrubs were recorded in hay meadows cut early, intermediate and late in the growing season. All hay meadows included a high number of flower species but the mowing time influenced the available floral resources for pollinators. If mowing time varies between hay meadows within a landscape, flower resources for pollinators will be available throughout the growing season, which is essential in pollination conservation in agricultural landscapes.

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Abstract

Grazing is an important management action to conserve biodiversity in semi-natural grasslands but it is important to understand how grazing influences the life-history components and population dynamics of plant species. In this study, we analysed effects of grazing intensity and abandonment on population dynamics of the semi-natural grassland species Knautia arvensis which is an important nectar source for pollinating species and an indicator of biodiversity in agricultural landscapes. We recorded life-history stage, survival, establishment of seedlings and ramets, number of inflorescences and grazing marks on permanently marked individuals in eight populations in mid-Norway for three consecutive years. Matrix modelling was used to estimate population growth rates and elasticities, and life Table response experiments (LTREs) were used to assess the contribution of different life-history components to the observed variation in population growth rates between different management treatments. Generalized linear mixed effects models (GLMMs) were used to investigate the effect of management on vital rates and number of inflorescences as well as damage to K. arvensis individuals. Populations in abandoned grasslands had more inflorescences, a lower proportion of seedlings and a higher proportion of flowering ramets compared to populations in grasslands under high grazing intensity. There were no differences in population growth rates between different grazing intensities. Fecundity however, contributed more to the growth rate in grazed grasslands compared to abandoned grasslands where clonal regeneration contributed the most. Survival of non-flowering rosettes made the largest impact to overall growth rates. Our results indicate that a long life-span and clonal growth buffer the effect of environmental change in abandoned grasslands and that there is a trade-off between fertility and clonal regeneration in K. arvensis populations.

Abstract

The Action plan for hay meadows in Norway is an instrument used to manage hay meadows of high biological value. The mowing management is regulated by a specific date and we aimed to assess the suitability of this date. We compared proportions of mature plants of species associated with semi-natural grasslands at the defined mowing date in 2014 and 2015. Numbers of mature species differed between the two years, but even in the warmest year the percentage of mature plants was only 44%. In order to plan a more successful agri-environmental scheme, the cutting date should be more site-specific and based on knowledge of the former practices that originally created and maintained the biological values.

Abstract

In this study potential links between biodiversity, ecosystem service (ES) indicators and agricultural land use were examined. Semi-natural grasslands, either actively used for sheep grazing or abandoned, were surveyed and all vascular plant species recorded. Based on this survey, species richness (per 4 m2), fodder quality and quantity, as well as pollination, were estimated. We found lower species richness and indications of lower fodder quantity and quality, but of higher pollination in abandoned grasslands. The relationships between ES indicators and species richness were both negative and positive, and differed in managed and abandoned semi-natural grasslands.

Abstract

Climate, available resources and disturbance by agricultural land use influence ecosystem service (ES) delivery. In our project we studied how ES provision from managed and abandoned semi-natural grasslands vary along soil and climatic gradients. Information on climate (temperature and precipitation) and soil (pH-value and phosphorous content) were used to test whether ES varied along these environmental gradients. 13 ES indicators were calculated and assigned to nine ES. Some of the ES varied along the gradients, but the results indicate that the effects of soil and climate on ES are modified by agricultural land use.

Abstract

The effect of abandonment of sheep grazing management in semi-natural grasslands were studied in 14 sites in Norway. Data of species and vegetation composition, functional traits and pollination resources were used as indicators for nine selected ecosystem services (ES). The majority of the ES were negatively affected by abandonment of sheep grazing management. We therefore conclude that abandonment diminishes delivery of ES.

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Abstract

In boreal ecosystems, traditionally diverse agricultural landscapes were composed of a mosaics of intensively used fields (monocultures), low intensively used vegetation types such as semi-natural grasslands and forests. The landscapes are now changing to less diverse landscapes of fields and forests. Agricultural landscapes are potential suppliers of ecosystem services such as aesthetic, genetic, pollination and agricultural production. The ongoing process of landscape change will influence provision of ecosystem services but little is known about in which directions. The aim of this project is to shed light on potential outcomes of the land-use changes on ecosystem services in agricultural boreal landscapes.

Abstract

The objective of this pilot study was to compare resource use in a mountainous summer farming landscape between old and modern dairy cow breeds during a five-day period. The modern breed used a larger part of the landscape than the old breed, most likely due to differences in habitat patterns. The old breed group preferred semi-natural pastures, while the modern breed preferred overgrown semi-natural meadows, intermediate fen, intermediate wooded fen, and grass-rich sub-alpine birch woodland. Both breeds spent most time grazing grasses, but the modern breed showed a higher frequency of grasses and Vaccinium myrtillus in its diet, while the old breed showed a higher frequency of bushes and trees. The pilot study shows some trends supplementing and strengthening earlier results on how modern and traditional cattle breeds are differing in their impact on vegetation based on their use of space and their different diets.

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Abstract

Predicting how human induced vegetation changes affect ecosystems and their biological communities is one of the most urgent tasks in ecology. In Norwegian lowlands one of the main threats to biodiversity is abandonment of low intensive land-use areas. Effects of changed land-use on vegetation are generally made by assessing the effect on the number of species as indicators of biodiversity. However, community structure changes and ecosystem processes are not necessarily well described by this biodiversity indicator only. Functional trait responses might better predict structures and processes than species richness. Therefore, studies of functional traits and biodiversity indexes of these might provide deeper insight. In addition, to predict reliable future vegetation changes, multifactorial determinants have to be considered as vegetation is not driven by one determinant only.