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Jonsson, Bengt-Gunnar
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Ljunggren, J., Bylund, D., Jonsson, B.-G., Edman, M. & Hedenström, E. (2020). Antifungal efficiency of individual compounds and evaluation of non-linear effects by recombining fractionated turpentine. Microchemical journal (Print), 153, Article ID 104325.
Open this publication in new window or tab >>Antifungal efficiency of individual compounds and evaluation of non-linear effects by recombining fractionated turpentine
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2020 (English)In: Microchemical journal (Print), ISSN 0026-265X, E-ISSN 1095-9149, Vol. 153, article id 104325Article in journal (Refereed) Published
Abstract [en]

A combination between a reductive and a holistic assay was employed to investigate whole fraction, synergistic, antagonistic and individual compound efficacy of vacuumdistilled turpentine fractions against the economically important brown-rot fungus Coniophora puteana. The fungus was subjected to recombinations of turpentine fractions at a concentration of 1000 ppm. All combinations exhibited useful antifungal properties, but some antifungal mixtures showed a more pronounced effect than the expected level of inhibition. Synergistic effects by a two-fold factor and minor antagonistic effects were observed. Complete growth inhibition of C. puteana was observed by a fraction obtained after distilling 1 L turpentine at 111–177°C (0.5 mbar) as well as by mixing it with another fraction withdrawn at 70–79°C (0.5 mbar). Chemical compositions of distilled fractions were determined through GC–MS analysis and Orthogonal Partial Least Squares (OPLS) multivariate data analysis of GC–MS chromatograms was employed to zoom in on the most active compounds responsible for antifungal activity. Isomers of epicubenol, the hydrocarbon aromatic compound ar-himachalene and α-cadinol are suggested as effective antifungal compounds. In addition, a subsequent fractionation of the most effective fraction was performed with preparatory gas chromatography and subfractions showed similar or better efficacy than previously observed. Our work demonstrates the possibility to retain adequate synergistic antifungal efficiency and offers an opportunity to explore the effects of individual compounds originating from the same crude sample.

Keywords
Turpentine composition, Bioassa, yConiophora puteana, Growth inhibition, Fractions, Synergism, Antagonism
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:miun:diva-38174 (URN)10.1016/j.microc.2019.104325 (DOI)000514218800008 ()2-s2.0-85075369850 (Scopus ID)
Available from: 2020-01-02 Created: 2020-01-02 Last updated: 2020-03-26Bibliographically approved
Ekström, M., Sandring, S., Grafström, A., Esseen, P.-A., Jonsson, B.-G. & Ståhl, G. (2020). Estimating density from presence/absence data in clustered populations. Methods in Ecology and Evolution, 11(3), 390-402
Open this publication in new window or tab >>Estimating density from presence/absence data in clustered populations
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2020 (English)In: Methods in Ecology and Evolution, ISSN 2041-210X, E-ISSN 2041-210X, Vol. 11, no 3, p. 390-402Article in journal (Refereed) Published
Abstract [en]

Inventories of plant populations are fundamental in ecological research and monitoring, but such surveys are often prone to field assessment errors. Presence/absence (P/A) sampling may have advantages over plant cover assessments for reducing such errors. However, the linking between P/A data and plant density depends on model assumptions for plant spatial distributions. Previous studies have shown, for example, how that plant density can be estimated under Poisson model assumptions on the plant locations. In this study, new methods are developed and evaluated for linking P/A data with plant density assuming that plants occur in clustered spatial patterns. New theory was derived for estimating plant density under Neyman–Scott-type cluster models such as the Matérn and Thomas cluster processes. Suggested estimators, corresponding confidence intervals and a proposed goodness-of-fit test were evaluated in a Monte Carlo simulation study assuming a Matérn cluster process. Furthermore, the estimators were applied to plant data from environmental monitoring in Sweden to demonstrate their empirical application. The simulation study showed that our methods work well for large enough sample sizes. The judgment of what is' large enough’ is often difficult, but simulations indicate that a sample size is large enough when the sampling distributions of the parameter estimators are symmetric or mildly skewed. Bootstrap may be used to check whether this is true. The empirical results suggest that the derived methodology may be useful for estimating density of plants such as Leucanthemum vulgare and Scorzonera humilis. By developing estimators of plant density from P/A data under realistic model assumptions about plants' spatial distributions, P/A sampling will become a more useful tool for inventories of plant populations. Our new theory is an important step in this direction. 

Keywords
independent cluster process, intensity, Matérn cluster process, plant monitoring, sample plots, spatial models, Thomas cluster process, vegetation survey
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-38421 (URN)10.1111/2041-210X.13347 (DOI)000511348700001 ()2-s2.0-85079182130 (Scopus ID)
Available from: 2020-02-17 Created: 2020-02-17 Last updated: 2020-03-09Bibliographically approved
Skytt, T., Nors Nielsen, S. & Jonsson, B.-G. (2020). Global warming potential and absolute global temperature change potential from carbon dioxide and methane fluxes as indicators of regionalsustainability – A case study of Jämtland, Sweden. Ecological Indicators, 110, Article ID 105831.
Open this publication in new window or tab >>Global warming potential and absolute global temperature change potential from carbon dioxide and methane fluxes as indicators of regionalsustainability – A case study of Jämtland, Sweden
2020 (English)In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 110, article id 105831Article in journal (Refereed) Published
Abstract [en]

This study presents a regional model showing the balance of carbon dioxide and methane fluxes in the Swedish county Jämtland, applying a Global Warming Potential 20-year time horizon (GWP20) to meet the Paris agreement horizon and regional policy goals. The results clearly show the necessity to take both anthropogenic and non-anthropogenic emissions into consideration in analyses to be able to make proper priorities in future action strategies. The total annual impact from Jämtland calculated as carbon dioxide equivalents (CO2eq) is an uptake of 2.4 Mton (19 ton per capita). Jämtland shows large annual uptakes in forests (12.7 Mton CO2), but also large emissions of methane (80 kton corresponding to 6.7 Mton CO2eq), mainly from lakes, mires and ruminants. Anthropogenic carbon Greenhous gas emissions are dominated by transportation, working machines and consumption (mainly imported indirect emissions).

As a complement to GWP also the Absolute Global Temperature Change Potential (AGTP) as degree K response, is presented per sector and total for Jämtland County, for yearly emissions (as a pulse) and continuous emissions over 200 years. A yearly pulse from Jämtland gives a temperature response of about 0 K after 10 years and about −4 μK (cooling effect) after about 50 years). Using both GWP and AGTP as indicators improves the possibilities to find ways how to optimize regional climate policies to reduce global warming until a specific year.

Strategies and action plans should be developed focusing on the following:

- Reduced regional transportation and consumption activity.

- Increased (prioritized) use of renewable fuels for working machines in forestry and agriculture, as well as for heavy trucks.

- Evaluate the potential to reduce emissions of methane from wetlands and mires.

- Increase/optimize carbon dioxide assimilation in forests.

Keywords
Regional sustainability, Carbon based fluxes, Sustainability indicators, Carbon dioxide emissions, Methane emissions, Nature emissions, AGTP response
National Category
Climate Research
Identifiers
urn:nbn:se:miun:diva-37686 (URN)10.1016/j.ecolind.2019.105831 (DOI)000507381800012 ()2-s2.0-85074161364 (Scopus ID)
Funder
Interreg Sweden-Norway, 20201304
Available from: 2019-11-15 Created: 2019-11-15 Last updated: 2020-03-31Bibliographically approved
Stahl, G., Ekstrom, M., Dahlgren, J., Esseen, P.-A., Grafstrom, A. & Jonsson, B.-G. (2020). Presence-absence sampling for estimating plant density using survey data with variable plot size. Methods in Ecology and Evolution, 11(4), 580-590
Open this publication in new window or tab >>Presence-absence sampling for estimating plant density using survey data with variable plot size
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2020 (English)In: Methods in Ecology and Evolution, ISSN 2041-210X, E-ISSN 2041-210X, Vol. 11, no 4, p. 580-590Article in journal (Refereed) Published
Abstract [en]

Presence-absence sampling is an important method for monitoring state and change of both individual plant species and communities. With this method, only the presence or absence of the target species is recorded on plots and thus the method is straightforward to apply and less prone to surveyor judgement compared to other vegetation monitoring methods. However, in the basic setting, all plots must be equally large or otherwise it is unclear how data should be analysed. In this study, we propose and evaluate five different methods for estimating plant density based on presence-absence registrations from surveys with variable plot sizes. Using artificial plant population data as well as empirical data from the Swedish National Forest Inventory, we evaluated the performance of the proposed methods. The main analysis was conducted through sampling simulation in artificial populations, whereby bias and variance of density estimators for the different methods were quantified and compared. Both for state and change estimation of plant density, we found that the best method to handle variable plot size was to perform generalized least squares regression, using plot size as an independent variable. Methods where plots smaller than a certain threshold were excluded or their registrations recalculated were, however, almost as good. Using all registrations as if they were obtained from plots with the nominal plot size resulted in substantial bias. Our findings are important for plant population studies in a wide range of environmental monitoring programmes. In these programmes, plots are typically randomly laid out and may be located across boundaries between different land-use or land-cover classes, resulting in subplots of variable size. Such splitting of plots is common when large plots are used, for example, with the 100 m(2) plots used in the Swedish National Forest Inventory. Our methods overcome problems to estimate plant density from presence-absence data observed in plots that vary in size.

Keywords
divided plots, intensity, plant density, plant monitoring, point pattern, Poisson model, quadrats, vegetation survey
National Category
Forest Science
Identifiers
urn:nbn:se:miun:diva-38615 (URN)10.1111/2041-210X.13348 (DOI)000515565300001 ()2-s2.0-85083623018 (Scopus ID)
Available from: 2020-03-11 Created: 2020-03-11 Last updated: 2020-05-05Bibliographically approved
Sandström, J., Edman, M. & Jonsson, B.-G. (2020). Rocky pine forests in the High Coast Region in Sweden: structure, dynamics and history. Nature Conservation, 38, 101-130
Open this publication in new window or tab >>Rocky pine forests in the High Coast Region in Sweden: structure, dynamics and history
2020 (English)In: Nature Conservation, ISSN 1314-6947, E-ISSN 1314-3301, Vol. 38, p. 101-130Article in journal (Refereed) Published
Abstract [en]

Almost all forests in Sweden are managed and only a small fraction are considered natural. One exception is low productive forests where, due to their limited economical value, natural dynamics still dominate. One example is the Scots pine (Pinus sylvestris L.) forests occurring on rocky and nutrient-poor hilltops. Although these forests represent a regionally common forest type with a high degree of naturalness, their dynamics, structure and history are poorly known. We investigated the structure, human impact and fire history in eight rocky pine forests in the High Coast Area in eastern Sweden, initially identified as good representatives of this forest type. This was done by sampling and measuring tree sizes, -ages, fire-scarred trees, as well as dead wood volumes and quality along three transects at each site. The structure was diverse with a sparse layer of trees (basal area 9 m(2) and 640 trees larger than 10 cm ha(-1)) in various sizes and ages; 13 trees ha(-1) were more than 300 years old. Dead wood (DW), snags and logs in all stages of decay, was present and although the actual DW (pine) volume (4.4 m(3) ha(-1)) and number of units (53 ha(-1)) was low, the DW share of total wood volume was 18% on average. Dead wood can be present for several centuries after death; we found examples of both snags and logs that had been dead more than 300 years. Frequent fires have occurred, with an average cycle of 40 years between fires. Most fires occurred between 1500-1900 and many of them (13) during the 1600s. However, fires were probably small since most fire years were only represented at one site and often only in one or a few samples. The rocky pine forests in the High Coast Area are representative of undisturbed forests with low human impact, exhibiting old-growth characteristics and are valuable habitats for organisms connected to sun-exposed DW. Management of protected rocky pine forests may well include small-scale restoration fires and the limited DW volumes should he protected.

Keywords
boreal; coarse woody debris; dendrochronology, fire history, natural forest, pine heath forest, shingle field pine forest
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-34827 (URN)10.3897/natureconservation.38.34870 (DOI)000529802000001 ()
Available from: 2018-10-26 Created: 2018-10-26 Last updated: 2020-05-15Bibliographically approved
Jonsson, B.-G., Svensson, J., Mikusiński, G., Manton, M. & Angelstam, P. (2019). European Union's last intact forest landscapes are at a value chain crossroad between multiple use and intensified wood production. Forests, 10(7), Article ID 564.
Open this publication in new window or tab >>European Union's last intact forest landscapes are at a value chain crossroad between multiple use and intensified wood production
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2019 (English)In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 10, no 7, article id 564Article in journal (Refereed) Published
Abstract [en]

Research Highlights: The European Union's last large intact forest landscapes along the Scandinavian Mountain range in Sweden offer unique opportunities for conservation of biodiversity, ecological integrity and resilience. However, these forests are at a crossroad between intensified wood production aimed at bio-economy, and rural development based on multi-functional forest landscapes for future-oriented forest value chains. Background and Objectives:We (1) estimate the area of near-natural forests potentially remaining for forest harvesting and wood production, or as green infrastructure for biodiversity conservation and human well-being in rural areas, (2) review how forest and conservation policies have so far succeeded to reduce the loss of mountain forests, and (3) discuss what economic, socio-cultural and ecological values that are at stake, as well as different governance and management solutions.Materials andMethods: First, we estimated the remaining amount of intact mountain forests using (1) the Swedish National Forest Inventory, (2) protected area statistics, (3) forest harvest permit applications and actually harvested forests, (4) remote sensing wall-to-wall data on forests not subject to clear-felling since the mid-1950s, (5) mapping of productive and non-productive forestland, and (6) estimates of mean annual final felling rate. Second, we review policy documents related to the emergence of land use regulation in north Sweden, including the mountain forest border, and illustrate this with an actual case that has had significant policy implementation importance. Results: There is a clear difference between the proportions of formally protected productive forestland above the mountain forest border (52.5%) and north Sweden in general (6.3%). A total of 300,000 ha of previously not clear-felled mountain forest outside protected areas remain, which can support novel value chains that are not achievable elsewhere. Conclusions: The mountain forests in Sweden provide unique conservation values in the European Union. Since the beginning of the 1990s, policy regulations have been successful in limiting forest harvesting. Currently, however, mountain forests are a battle ground regarding intensification of forest use, including logging of forests that have never been subject to clear-felling systems vs. nature conservation and wilderness as a base for rural development. The ability of mountain municipalities to encourage sustainable rural forest landscapes must be strengthened. 

Keywords
Amenity values, Biodiversity conservation, Bioeconomy, Comprehensive planning, Continuous cover forestry, Forest policy, Green belt, Landscape stewardship, Rural development, Sustainability
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-36834 (URN)10.3390/f10070564 (DOI)000482080800053 ()2-s2.0-85068580279 (Scopus ID)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-09-23Bibliographically approved
Sandström, J., Bernes, C., Junninen, K., Lõhmus, A., Macdonald, E., Müller, J. & Jonsson, B.-G. (2019). Impacts of dead-wood manipulation on the biodiversity of temperate and boreal forests - A systematic review. Journal of Applied Ecology, 56(7), 1770-1781
Open this publication in new window or tab >>Impacts of dead-wood manipulation on the biodiversity of temperate and boreal forests - A systematic review
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2019 (English)In: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 56, no 7, p. 1770-1781Article in journal (Other academic) Published
Abstract [en]

Dead wood (DW) provides critical habitat for thousands of species in forests, but its amount, quality and diversity have been heavily reduced by forestry. Therefore, interventions aiming to increase DW might be necessary to support its associated biodiversity, even in protected forests, which may be former production forests. Our aim was to synthesize the current state of knowledge drawn from replicated experimental studies into solid quantitative evidence of the effects of DW manipulation on forest biodiversity, with a focus on protected forests.

We conducted a full systematic review of effects of DW manipulation on forest biodiversity in boreal and temperate regions. We included three intervention types: creation of DW from live trees at the site, addition of DW from outside the site and prescribed burning. Outcomes included abundance and species richness of saproxylic insects, ground insects, wood-inhabiting fungi, lichens, reptiles and cavity-nesting birds. In total, we included 91 studies, 37 of which were used in meta-analyses. Although meta-analysis outcomes were heterogeneous, they showed that increasing the amount of DW (“DW enrichment”) has positive effects on the abundance and richness of saproxylic insects and fungi. The positive effect on saproxylic pest insect abundance tended to be less than that on saproxylic insects in general. No significant effects were found for ground insects or cavity-nesting birds.

Although reviewed studies were mainly short term, our results support that management that increases DW amounts has the potential to increase the abundance of DW-dependent species and, in most cases, also their species richness. Studies of burning showed positive effects on the abundance of saproxylic insects similar to those of other interventions, even though burning on average resulted in a smaller enrichment of DW amounts.

Policy implications. The findings of the review suggest that manipulating dead wood (DW) can be an effective part of conservation management to support biodiversity in protected areas. The findings also indicate that the diversity of DW types is important, a mix of DW qualities should be favoured. Burning seems to be an effective method to increase biodiversity but to benefit cavity-nesting birds, snag losses need to be minimized.

Keywords
coarse woody debris, dead wood, diversity, forest conservation, forest restoration, habitat management, prescribed burning, saproxylic species
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-34829 (URN)10.1111/1365-2664.13395 (DOI)000474270200023 ()2-s2.0-85066074163 (Scopus ID)
Available from: 2018-10-26 Created: 2018-10-26 Last updated: 2019-08-09Bibliographically approved
Svensson, J., Andersson, J., Sandström, P., Mikusiński, G. & Jonsson, B. G. (2019). Landscape trajectory of natural boreal forest loss as an impediment to green infrastructure. Conservation Biology, 33(1), 152-163
Open this publication in new window or tab >>Landscape trajectory of natural boreal forest loss as an impediment to green infrastructure
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2019 (English)In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 33, no 1, p. 152-163Article in journal (Refereed) Published
Abstract [en]

Loss of natural forests by forest clearcutting has been identified as a critical conservation challenge worldwide. This study addressed forest fragmentation and loss in the context of the establishment of a functional green infrastructure as a spatiotemporally connected landscape-scale network of habitats enhancing biodiversity, favorable conservation status, and ecosystem services. Through retrospective analysis of satellite images, we assessed a 50- to 60-year spatiotemporal clearcutting impact trajectory on natural and near-natural boreal forests across a sizable and representative region from the Gulf of Bothnia to the Scandinavian Mountain Range in northern Fennoscandia. This period broadly covers the whole forest clearcutting period; thus, our approach and results can be applied to comprehensive impact assessment of industrial forest management. The entire study region covers close to 46,000 km2 of forest-dominated landscape in a late phase of transition from a natural or near-natural to a land-use modified state. We found a substantial loss of intact forest, in particular of large, contiguous areas, a spatial polarization of remaining forest on regional scale where the inland has been more severely affected than the mountain and coastal zones, and a pronounced impact on interior forest core areas. Salient results were a decrease in area of the largest intact forest patch from 225,853 to 68,714 ha in the mountain zone and from 257,715 to 38,668 ha in the foothills zone, a decrease from 75% to 38% intact forest in the inland zones, a decrease in largest patch core area (assessed by considering 100-m patch edge disturbance) from 6114 to 351 ha in the coastal zone, and a geographic imbalance in protected forest with an evident predominance in the mountain zone. These results demonstrate profound disturbance of configuration of the natural forest landscape and disrupted connectivity, which challenges the establishment of functional green infrastructure. Our approach supports the identification of forests for expanded protection and conservation-oriented forest landscape restoration. 

Keywords
change detection, clearcutting, cobertura continua de bosque, configuración de paisaje, continuidad del bosque, continuity forest, continuous cover forest, detección de cambios, forest core areas, forest fragmentation, fragmentación de bosque, imagen satelital, landscape configuration, satellite image, Suecia, Sweden, tala uniforme de árboles, áreas nucleares de bosque
National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-35143 (URN)10.1111/cobi.13148 (DOI)000455121500016 ()29882221 (PubMedID)2-s2.0-85056773579 (Scopus ID)
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2020-02-20Bibliographically approved
Grafström, A., Ekström, M., Jonsson, B.-G., Esseen, P.-A. & Ståhl, G. (2019). On combining independent probability samples. Survey Methodology, 45(2), 371-387
Open this publication in new window or tab >>On combining independent probability samples
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2019 (English)In: Survey Methodology, ISSN 0714-0045, E-ISSN 1492-0921, Vol. 45, no 2, p. 371-387Article in journal (Refereed) Published
Abstract [en]

Merging available sources of information is becoming increasingly important for improving estimates ofpopulation characteristics in a variety of fields. In presence of several independent probability samples from afinite population we investigate options for a combined estimator of the population total, based on either a linearcombination of the separate estimators or on the combined sample approach. A linear combination estimatorbased on estimated variances can be biased as the separate estimators of the population total can be highlycorrelated to their respective variance estimators. We illustrate the possibility to use the combined sample toestimate the variances of the separate estimators, which results in general pooled variance estimators. Thesepooled variance estimators use all available information and have potential to significantly reduce bias of a linearcombination of separate estimators.

Place, publisher, year, edition, pages
Statistics Canada, 2019
Keywords
Horvitz-Thompson estimator, Inclusion probabilities, Linear combination estimator, Variance estimation
Identifiers
urn:nbn:se:miun:diva-36835 (URN)2-s2.0-85068768578 (Scopus ID)
Note

In French: Combinaison d’échantillons probabilistes indépendants

Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Grafström, A., Ekström, M., Jonsson, B.-G., Esseen, P.-A. & Stahl, G. (2019). On combining independent probability samples. Survey Methodology, 45(2), 349-364
Open this publication in new window or tab >>On combining independent probability samples
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2019 (English)In: Survey Methodology, ISSN 0714-0045, E-ISSN 1492-0921, Vol. 45, no 2, p. 349-364Article in journal (Refereed) Published
Abstract [en]

Merging available sources of information is becoming increasingly important for improving estimates of population characteristics in a variety of fields. In presence of several independent probability samples from a finite population we investigate options for a combined estimator of the population total, based on either a linear combination of the separate estimators or on the combined sample approach. A linear combination estimator based on estimated variances can be biased as the separate estimators of the population total can be highly correlated to their respective variance estimators. We illustrate the possibility to use the combined sample to estimate the variances of the separate estimators, which results in general pooled variance estimators. These pooled variance estimators use all available information and have potential to significantly reduce bias of a linear combination of separate estimators.

Keywords
Horvitz-Thompson estimator, Inclusion probabilities, Linear combination estimator, Variance estimation
National Category
Probability Theory and Statistics
Identifiers
urn:nbn:se:miun:diva-36809 (URN)000473107900009 ()
Available from: 2019-08-09 Created: 2019-08-09 Last updated: 2020-01-21Bibliographically approved
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