| 1. |
- Felton, Adam, et al.
(författare)
-
The tree species matters : Biodiversity and ecosystem service implications of replacing Scots pine production stands with Norway spruce.
- 2020
-
Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 49:5, s. 1035-1049
-
Forskningsöversikt (refereegranskat)abstract
- The choice of tree species used in production forests matters for biodiversity and ecosystem services. In Sweden, damage to young production forests by large browsing herbivores is helping to drive a development where sites traditionally regenerated with Scots pine (Pinus sylvestris) are instead being regenerated with Norway spruce (Picea abies). We provide a condensed synthesis of the available evidence regarding the likely resultant implications for forest biodiversity and ecosystem services from this change in tree species. Apart from some benefits (e.g. reduced stand-level browsing damage), we identified a range of negative outcomes for biodiversity, production, esthetic and recreational values, as well as increased stand vulnerability to storm, frost, and drought damage, and potentially higher risks of pest and pathogen outbreak. Our results are directly relevant to forest owners and policy-makers seeking information regarding the uncertainties, risks, and trade-offs likely to result from changing the tree species in production forests.
|
|
| 2. |
- Holmström, Emma, et al.
(författare)
-
Productivity of Scots pine and Norway spruce in central Sweden and competitive release in mixtures of the two species
- 2018
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 429, s. 287-293
-
Tidskriftsartikel (refereegranskat)abstract
- A 53 year old growth and yield study of monocultures and mixture of two species, Scots pine and Norway spruce, was analysed. The replacement design of the experiment (at the time of establishment same density in all treatments and 50/50 proportion in the mixture) in ten blocks enables the comparison of site and species specific growth, as well as the species specific response to competition. In monocultures Scots pine, produced 126% more stem wood biomass than Norway spruce. Scots pine benefitted from the mixture and tended to grow as in a reduced spacing. Norway spruce, the subdominant tree species, suffered from the competition, and produced less than expected, with a lower mean diameter compared to the monoculture. Hence, no facilitative or complementary effects was possible to prove when growing the species in mixture. However, the experiment demonstrates that if the uncertainties in choice of species at the time of regeneration is high, then the mixture of two species could be an option. The lower density of the highest yielding species in the mixture compared to the monoculture, could be compensated in growth by the competition release.
|
|
| 3. |
- Nilsson, Kerstin, et al.
(författare)
-
The transfer of knowledge between younger and older employees in the health and medical care: An intervention study
- 2017
-
Ingår i: Open Journal of Social Sciences. - : Scientific Research Publishing, Inc.. - 2327-5952 .- 2327-5960. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- In the ageing society more old employees need to stay in working life for longer. However, the society also needs to take care of the increased amount of elderly in a more effective and respectful way. To take care of older employees experience knowledge to make the elderly care and the care employees work situation better and self-crediting to go on in an extended working life, new methods and measures are needed to be developed and evaluated. The overall purpose of this article was to evaluate how the participant in the intervention project experienced the project and its methodology. The intervention project followed three different methods: i) through interviews of the participants and the supervisor; ii) through participant observation; and iii) through an evaluation questionnaire to participants after the project was completed. The intervention project did transfer knowledge between different fields, that are, between generations, between different departments and between the municipality and county. The participation was described as not only a place for reflection and knowledge, but also a protected zone where participants could talk about the kind of problems they would ponder over. Several participants felt that it was important to develop and continue the work that the intervention project set in motion. The participants’ experience was made to be visible and their professional competence has been strengthened. They indicated that there had been an exchange of knowledge and between not only the generations but also the different kinds of work. The organisations also seem to have gained from the project by allowing the participants to unload, become more positive, develop more knowledge of experience, increase their propensity for reflection and get a better consensus between the municipality and county. The intervention project seems to have fulfilled the stated purpose and also the expectations of the participants.
|
|
| 4. |
- Aldea, Jorge, et al.
(författare)
-
Evaluation of growth models for mixed forests used in Swedish and Finnish decision support systems
- 2023
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 529
-
Tidskriftsartikel (refereegranskat)abstract
- Interest in mixed forests is increasing since they could provide higher benefits and positive externalities compared to monocultures, although their management is more complex and silvicultural prescriptions for them are still scarce. Growth simulations are a powerful tool for developing useful guidelines for mixed stands. Heureka and Motti are two decision support systems commonly used for forest management in Sweden and Finland respectively. They were developed mostly with data from pure stands, so how they would perform in mixed stands is currently uncertain. We compiled a large and updated common database of well-replicated experimental research sites and monitoring networks composed by 218 and 1,160 plot-level observations of mixed stands from Sweden and Finland, respectively. We aimed to evaluated the accuracy of Heureka and Motti basal area growth models in those mixed-species stands and to detect any bias in their short-term predictions. Basal area growth simulations (excluding mortality models) were compared to observed stand-level values in a period-wise process with update of the start values in each period. The residual plots were visually examined for different stand mixtures: Norway spruce (Picea abies Karst.)-birch (Betula spp), Scots pine (Pinus sylvestris L.)-birch and Scots pine-Norway spruce. We observed that the basal area growth models in both decision support systems performed quite well for all mixtures regardless of the proportion of species. Motti simulations overestimated growth in Scots pine-Norway spruce mixtures by 0.063 m(2)center dot ha(-1)center dot year(-1) which may be acceptable for practical use. Therefore, we corroborated that both decision support systems can be currently utilized for shortterm forest growth simulation of mixed boreal forests.
|
|
| 5. |
- Appiah Mensah, Alex, et al.
(författare)
-
Modelling potential yield capacity in conifers using Swedish long-term experiments
- 2022
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 512
-
Tidskriftsartikel (refereegranskat)abstract
- Information on forest site productivity is a key component to assess the carbon sequestration potential of boreal forests. While site index (SI) is commonly used to indicate forest site productivity, expressions of SI in the form of yield capacity (potential maximum mean annual volume increment) is desirable since volume yield is central to the economic and ecological analyses of a given species and site. This paper assessed the functional relationship between SI and yield capacity on the basis of yield plot data from long-term experiments measured over several decades for Norway spruce (Picea abies), Scots pine (Pinus sylvestris), Lodgepole pine (Pinus contorta) and Larch (Larix decidua and Larix sibirica) in Sweden. Component models of total basal area and volume yield were also developed. SI was determined by existing height development functions using top height and age, whereas functions for stand-level (m2 ha- 1) basal area development were constructed based on age, SI and initial stand density using difference equations and nonlinear mixed-effects models. The relation between volume yield (m3 ha- 1) and top height was adjusted with total basal area production through nonlinear mixed-effects models. Species-specific parametric regression models were used to construct functional relationships between SI and yield capacity. The root mean square errors of the species-specific models ranged from 2 to 6% and 10-18% of the average values for the basal area and volume equations, respectively. For the yield capacity functions, the explained variations (R2) were within 80-96%. We compared our yield capacity functions to earlier functions of the species and significant differences were observed in both lower and higher SI classes, especially, for Scots pine and Norway spruce. The new functions give better prediction of yield capacity in current growing conditions; hence, they could later be used for comparing tree species' production under similar site and management regimes in Sweden.
|
|
| 6. |
- Ara, Mostarin, et al.
(författare)
-
Pre-commercial thinning in Norway spruce-birch mixed stands can provide abundant forage for ungulates without losing volume production
- 2022
-
Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 520
-
Tidskriftsartikel (refereegranskat)abstract
- Mixed stands of Norway spruce and birch have the potential to simultaneously produce timber and provide large ungulates with a significant amount of forage during the regeneration phase. While the growth and yield of such mixtures are well studied, little is known about potential trade-offs between timber and forage production and which management techniques are suitable for meeting both goals. In this study, four different pre-commercial thinning (PCT) strategies were used to study the trade-offs between production and available forage for free-ranging ungulates in a Norway spruce-birch mixture. The four PCT strategies were: 1) retaining 2000 birch stems ha(-1) with 2000 Norway spruce ha(-1), 2) removing all birches within a 0.75 m radius around Norway spruce stems, 3) removing all birches and other broadleaves, and 4) no PCT (control). Growth of Norway spruce was higher in the 2000 birch ha(-1) and full removal treatments compared to the untreated control, but these two treatments did not differ from one another in volume production of Norway spruce. We found a negative effect of PCT on forage availability but no effect on ungulate browsing. Therefore, PCT strategies that provide both sufficient birch forage and maximize volume production of Norway spruce can be implemented.
|
|
| 7. |
- Carlén, Emma, et al.
(författare)
-
Random regression models for genetic evaluation of clinical mastitis in dairy cattle
- 2009
-
Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1100-1108
-
Tidskriftsartikel (refereegranskat)abstract
- A genetic analysis of longitudinal binary clinical mastitis (CM) data recorded on about 90000 first-lactation Swedish Holstein cows was carried out using linear random regression models (RRM). This method for genetic evaluation of CM has theoretical advantages compared to the method of linear cross-sectional models (CSM), which is currently being used The aim of this study was to investigate the feasibility and suitability of estimating genetic parameters and predicting breeding values for CM with a linear sire RRM. For validation purposes, the estimates and predictions from the RRM were compared to those from linear sire longitudinal multivariate models (LMVM) and CSM. For each cow, the period from 10 days before to 241 days after calving was divided into four 1-week intervals followed by eight 4-week intervals. Within each interval, presence or absence of CM was scored as '1' or '0' The linear RRM used to explain the trajectory of CM over time included a set of explanatory variables plus a third-order Legendre polynomial function of time for the sire effect The time-dependent heritabilities and genetic correlations from the chosen RRM corresponded fairly well with estimates obtained from the linear LMVM for the separate intervals. Some discrepancy between the two methods was observed, with the more unstable results being obtained from the linear LMVM. Both methods indicated clearly that CM was not genetically the same trait throughout lactation. The correlations between predicted sire breeding values from the RRM, summarized over different time periods, and from linear CSM were rather high. They were, however, less than unity (0.74 to 0.96), which indicated some re-ranking of sires. Sire curves based on the time-specific breeding values from the RRM illustrated differences in intercept and slope among the best and the worst sires. To conclude, a linear sire RRM seemed to work well for genetic evaluation purposes, but was sensitive for estimation of genetic parameters.
|
|
| 8. |
- Ekström, Sara, et al.
(författare)
-
Effect of Acid Deposition on Quantity and Quality of Dissolved Organic Matter in Soil-Water.
- 2011
-
Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 45:11, s. 4733-4739
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to explore how acid deposition may affect the concentration and quality of dissolved organic matter (DOM) in soil-water. This was done by a small-scale acidification experiment during two years where 0.5 × 0.5 m(2) plots were artificially irrigated with water with different sulfuric acid content, and soil-water was sampled using zero-tension lysimeters under the O-horizon. The DOM was characterized using absorbance, fluorescence, and size exclusion chromatography analyses. Our results showed lower mobility of DOM in the high acid treatment. At the same time, there was a significant change in the DOM quality. Soil-water in the high acid treatment exhibited DOM that was less colored, less hydrophobic, less aromatic, and of lower molecular weight, compared to the low acid treatment. This supports the hypothesis that reduction in sulfur deposition is an important driver behind the ongoing brownification of surface waters in many regions.
|
|
| 9. |
- Ekström, Sara M., et al.
(författare)
-
Increasing concentrations of iron in surface waters as a consequence of reducing conditions in the catchment area
- 2016
-
Ingår i: Journal of Geophysical Research - Biogeosciences. - 2169-8953 .- 2169-8961. ; 121:2, s. 479-493
-
Tidskriftsartikel (refereegranskat)abstract
- Recent studies report trends of strongly increasing iron (Fe) concentrations in freshwaters. Since Fe is a key element with a decisive role in the biogeochemical cycling of major elements, it is important to understand the mechanisms behind these trends. We hypothesized that variations in Fe concentration are driven mainly by redox dynamics in hydraulically connected soils. Notably, Fe(III), which is the favored oxidation state except in environments where microbial activity provide strong reducing intensity, has several orders of magnitude lower water solubility than Fe(II). To test our hypothesis, seasonal variation in water chemistry, discharge, and air temperature was studied in three Swedish rivers. Methylmercury and sulfate were used as indicators of seasonal redox changes. Seasonal variability in water chemistry, discharge, and air temperature in the Eman and Lyckeby Rivers implied that the variation in Fe was primarily driven by the prevalence of reducing conditions in the catchment. In general, high Fe concentrations were observed when methylmercury was high and sulfate was low, indicative of reducing conditions. The Fe concentrations showed no or weak relationships with variations in dissolved organic matter concentration and aromaticity. The seasonal variation in Fe concentration of the Ume river was primarily dependent on timing of the snowmelt in high- versus low-altitude areas of the catchment. There were long-term trends of increasing temperature in all catchments and also trends of increasing discharge in the southern rivers, which should increase the probability for anaerobic conditions in space and time and thereby increase Fe transport to the aquatic systems.
|
|
| 10. |
- Ekström, Sara M., et al.
(författare)
-
Reactivity of dissolved organic matter in response to acid deposition
- 2016
-
Ingår i: Aquatic Sciences. - : Springer. - 1015-1621 .- 1420-9055. ; 78:3, s. 463-475
-
Tidskriftsartikel (refereegranskat)abstract
- Fluvial export of organic matter from the terrestrial catchment to the aquatic system is a large and increasing carbon flux. The successful reduction in sulfuric acid deposition since the 1980s has been shown to enhance the mobility of organic matter in the soil, with more terrestrially derived dissolved organic matter (DOM) reaching aquatic systems. Changes in soil acidity also affect the quality of the DOM. In this study we explore the consequences this may have on the reactivity and turnover of the terrestrially derived DOM as it reaches the aquatic system. DOM of different quality (estimated by absorbance, fluorescence and size exclusion chromatography) was produced through extraction of boreal forest O-horizon soils from podzol at two sulfuric acid concentrations corresponding to natural throughfall in spruce forest in Southern Sweden around 1980 and today. Extraction was done using two different methods, i.e. field leaching and laboratory extraction. The DOM extracts were used to assess if differences in acidity generate DOM of different reactivity. Three reactivity experiments were performed: photodegradation by UV exposure, biodegradation by bacteria, and biodegradation after UV exposure. Reactivity was assessed by measuring loss of dissolved organic carbon and absorbance, change in fluorescence and molecular weight, and bacterial production. DOM extracted at lower sulfuric acid concentration was more susceptible to photooxidation, and less susceptible to bacterial degradation, than DOM extracted at a higher sulfuric acid concentration. Thus the relative importance of these two turnover processes may be altered with changes in acid deposition.
|
|
