Knut Anders Hovstad

Head of Department/Head of Research

(+47) 971 21 414
knut.hovstad@nibio.no

Place
Trondheim

Visiting address
Statens Hus, Prinsensgate 1, 7013 Trondheim .

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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.

Abstract

In a project focusing on semi-cultivation of European blueberry (EB) from 2008 to 2011, a botanical survey was undertaken in two experimental fields in the municipalities of Snåsa and Lierne in the county of Nord-Trøndelag, Norway. The focus was mainly on growth of EB and Vaccinium vitis-idaea. We examined the effects of fertilization and cutting of EB to evaluate if established practices in the semicultivation of the wild American lowbush blueberry (Vaccinium angustifolium), also had potential for semi-cultivation of EB. We assigned four levels of fertilization randomly per block, with five replications. The Snåsa and the Lierne fields were clearcut, 25 and 5 years prior to the survey, respectively. We pruned the remaining trees and shrubs to the ground when the experiment was established. Before application of fertilizer and cutting, we conducted a vegetation survey, recording the percentage cover of all plant species. Furthermore, we recorded maximum, minimum, and middle canopy height of EB and estimated percent cover and thickness of plant litter at the forest floor in 2008 and 2011. The survey consisted of three plots of one m2. We placed each of them in the center of a fertilization plot, randomly distributed across the four fertilization treatments of each block at both sites. Twenty-six species were present in the fields, and the changes in botanical diversity were influenced by year, location, fertilization, and pruning of shrubs. Suggestions of how development of European blueberry in forest fields could be strengthened, and subsequently how the competitors could be weakened are presented. We showed that Pruning of EB decreased canopy cover, maximum- and middle- height, which was still lower three years after pruning than unpruned plants, and that V. vitis-idaea had a lower nutrient demand than EB.

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

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

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

The present agricultural landscape reflects a long history of changing land-use and farming practices, caused by e.g. technological development, urbanization processes and climate changes. A deeper understanding of how agricultural practices have altered the landscape is essential for the management of biodiversity and conservation of semi-natural grasslands. In this study, we explore the influence that changes in agricultural land-use, and grassland abandonment, have on successional changes in vegetation. The distribution, patch size, and plant species composition of semi-natural grasslands in a Central Norwegian agricultural landscape were mapped during two summers. Semi-natural grassland species decreased from managed grasslands to late regrowth successional phase, while number of forest species increased. Structural changes, e.g. increasing litter and tree cover, were also seen along the succession. Variation in species composition was related to management intensity and successional phase along the main gradient.

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 2012, the Norwegian Environmental Agency funded an extension to the Global Pollination Project, coordinated by the FAO (Food and Agriculture Organization of the United Nations) to expand the number of connected countries from 7 fully participating to in total 13 countries. This international effort seeks to build capacity for pollination studies and add to the knowledge base for the Intergovernmental Platform for Biodiversity and Ecosystem Services (IPBES). IPBES is currently conducting its first fast track case study on pollination. Specifically, the Global Pollination Project implements the “Protocol to detect and assess pollination deficits in crops: a handbook for its use” (Vaissière et al. 2011), developed through the FAO. The proto-col outlines a unified method to investigate pollination and measure pollination deficits in vari-ous agricultural systems around the world. NINA (the Norwegian Institute for Nature Research) was tasked with setting up a Norwegian collaboration to implement the protocol in Norway, to analyse its applicability to Nordic conditions and evaluate its strength in relation to alternative research strategies. The present report is the result of this effort. This report does not communicate the final results of the analyses, as they will be conducted in the two larger “host-projects” that made the implementation of the protocol possible. Instead, it outlines the rationale of the protocol, and evaluates its potential for providing management rel-evant information on pollination deficits, with particular emphasis on Norway. We discuss the state and trends of pollination dependent crops in Norway, as a background for the need for pollination in Norwegian Agriculture. The protocol is general enough to be applied to a wide variety of settings, and we did not expe-rience any fundamental problems of implementing it in a Nordic setting. We did however notice challenges to an effective implementation, which might be especially pronounced in a Norwe-gian or Scandinavian setting. First, it can be difficult to find a wide enough range of factors that influence pollinators to efficiently analyse the importance of pollination without resorting to ma-nipulative treatments. For example, the amount of flower resources and fragmentation of habi-tat are factors known to influence pollinators. But many crops are spatially aggregated to rela-tively narrow valleys and therefore experience similar surroundings. Secondly, it can be chal-lenging to find enough replicate farms since Norway is a relatively small agricultural nation. Thirdly, pollinators in Norway (as in many other parts of the world) are intractably linked to ag-ricultural and animal husbandry practices that provide a diversity of flowering resources neces-sary for pollinating insects, yet these practices and resulting resources in the surrounding land-scape is not sufficiently captured by the survey protocol. The protocol is designed to estimate differences in yield given differences in pollination, and various methods are available to approach optimal pollination, that acts as benchmark. Esti-mating the effect of pollination on yield is the foundation to understanding the status of pollina-tion deficits for any crop. The protocol appears to be a successful effort to create a unified standard of measuring pollination and pollination deficits by this definition. It thus marks a great improvement for pollination research in agriculture internationally. Pollination, Ecosystem services, Bees, Bumble bees, Pollination deficit Protocol, FAO, IPBES, Policy, apple, red clover, Norway, pollinering, økosystemtjenester, bier, humler, protokoll for polline-ringsunderskudd, FAO, IPBES, eple, rødkløver

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Abstract

Plant litter is an important determinant of seed germination and seedling establishment. Positive effects of litter have received considerable attention, but few studies have explicitly tested whether seedlings are more facilitated by conspecific litter compared to heterospecific litter. In order to contrast conspecific and heterospecific facilitative effects on seedling establishment, we used Anthriscus sylvestris, Angelica sylvestris, Pimpinella saxifraga and different combinations of their seeds and litter seedbeds as a model system. Although litter had a significant species-specific effect on seedling emergence, we found no evidence of strictly conspecific facilitation. Anthriscus sylvestris displayed a positive response to all types of litter. In contrast, there was a clear negative effect of conspecific litter in Pimpinella saxifraga. Activated carbon did not modify the negative effect, indicating that chemical compounds were not the cause. Our study suggests a high level of idiosyncrasy in response to litter at the species level.

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Abstract

In modern agricultural landscapes, large herbivores are often restricted in their mobility or are found at low densities, and other animal vectors may therefore be important for seed dispersal. In our study, a range of plant species were able to disperse by attaching seeds to, and having their seeds retained in, the fox fur some distance. We suggest that the red fox may be an important vector for epizoochorous seed dispersal in the agricultural landscape.