56 research outputs found
Plantation Forestry, Tree Breeding, and Novel Tools to Support the Sustainable Management of Boreal Forests
Successful stand regeneration is one of the keystone elements of sustainable forest management. It ensures that ecosystems submitted to stand-replacing disturbances return to a forested state so that they can maintain the provision of wood fiber, biodiversity, carbon sequestration, and other ecosystem services. This chapter describes how plantation forestry, including tree breeding, and novel tools, such as genomic selection, can support the sustainable management of boreal forests in the face of climate change by, among other benefits, reducing management pressure on natural forests and favoring ecosystem restoration
Within-site adaptation: growth and mortality of Norway spruce, Scots pine and silver birch seedlings in different planting positions across a soil moisture gradient
Adapting to site conditions is a central part of forest regeneration and can be done through selec-tion of different planting positions. Requirements are tree species specific, and the use of soil moisture maps could be a way to support decision making in forest regeneration planning. At two experimental sites with varying soil moisture conditions in southern Sweden Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and silver birch (Betula pendula Roth) seedlings were planted in four different planting positions following mounding site preparation; Depression, Hinge, Mound and Unscarified. Soil moisture estimates were obtained from a high-resolution depth-to-water raster for each planting spot. The effect of soil moisture, planting position and their interactions on mortality, height and diameter was evaluated for each tree species. In wet conditions mounds proved to be the best option to minimize seedling mortality for conifers, but with decreasing soil moisture, differences between the planting positions decreased. Birch on the other hand had the greatest survival in the hinge. The coniferous species displayed increased height and diameter when planted in mounds independent of the soil moisture conditions, whereas silver birch was less dependent on a specific planting position. Results from this study shows that a soil moisture map can explain mortality, height and diameter and thus can be a useful tool when choosing planting position in different soil moisture conditions
Successful spruce regenerations - impact of site preparation and the use of variables from digital elevation models in decision-making?
Various site preparation methods are used in Swedish forestry. However, some methods can lead to unnecessary disturbance, which could be avoided by using variables from digital elevation models in management decisions. The current study aimed to investigate how different site preparation methods, and their intensities, affect Norway spruce (Picea abies (L.) Karst.) regeneration. Additional aims were to clarify how these methods affect soil disturbance and vegetation development, along with how variables from digital elevation models could be used in silvicultural decision-making. Experimental sites were established in southern Sweden to assess five different site preparation treatments with different planting densities: (1) conventional disc trenching 2500 seedlings/ha (DT2500); (2) low intensity disc trenching 1250 seedlings/ha (LDT1250); (3) low intensity disc trenching 2500 seedlings/ha (LDT2500); (4) low-intensity patch-wise 1250 seedlings/ha (PW1250); and (5) patch-wise 2500 seedlings/ha (PW2500). Site preparation intensity had no effect on seedling growth and, survival or vegetation development; the tested treatments differed in terms of soil disturbance. Planting spot properties and weather conditions influenced the seedling performance. DTW and slope could not substantially explain either seedling growth or survival. The results indicate that the choice of site preparation method should consider flexibility when planting while adapting the level of disturbance accordingly
Measures against pine weevil Hylobius abietis also reduce damage by Hylastes cunicularius and Hylastes brunneus
Hylastes species are known to cause damage to conifers in plantations in northern Sweden, and in recent years an increase in seedling damage has been observed in southern Sweden. However, there are few studies on Hylastes spp and the damage it can cause, so there is a lack of knowledge regarding pest management. In order to investigate an eventual interaction between damage by Hylastes spp and the more well-known Hylobius abietis (L) we registered damage by these species. Unprotected spruce seedlings were compared with seedlings protected from Hylobius abietis by a mechanical coating or with an insecticide. The effect of mechanical site preparation (MSP) was studied, with half of the seedlings being planted in unprepared soil and the other half after MSP. Both seedling protection and MSP significantly reduced the level of damage caused by Hylastes spp. MSP reduced the proportion of affected and killed seedlings and reduced the level of damage at the root collar. Protecting the seedlings reduced the level of damage, and no difference was found between seedlings treated with an insecticide and those provided with a coating. Similar responses were observed with both containerized and plug plus seedlings. In conclusion, measures against Hylobius abietis seem to also prevent damage by Hylastes spp
Effect of drought and pine weevil damage on mechanically protected Norway spruce seedlings
Pine weevils (Hylobius abietis L.) pose a significant threat to conifer seedlings by feeding on the bark, thus damaging or killing seedlings. Historically, insecticides were used to suppress such damage, but were slowly phased out in Sweden due to environmental and health concerns. This study aimed to assess field performance of an alternative protection method: mechanical coating applied to the stem of planted Norway spruce (Picea abies) seedlings. Field trials were conducted on 14 sites in south Sweden, using four different types of mechanical protection (Cambiguard, Conniflex, Ekovax, Hylonox), standard insecticide (Merit Forest), and ambient control. Seven sites were established in the drought year of 2018 and seven more in 2019. This allowed for additional investigation of the effect of drought on seedling establishment and possible interaction with pine weevil damage. Seedlings were surveyed for survival and height after the first, second and fourth growing season. Results show drought as the main source of damage for seedlings planted in 2018, with no significant effect of insecticide or mechanical protection on survival of seedlings. However, mechanical protections performed equally well as insecticide and positively increased survival by 30 %, compared to untreated, four growing seasons after planting for seedlings planted in 2019. Seedling height was not significantly affected by planting year or any of the treatments, suggesting no adverse effects of coating application. However, a synergistic effect between pine weevil damage and drought was observed, where even low levels of pine weevil damage resulted in high mortality for seedlings planted in 2018, compared to those planted in 2019. Additionally, for seedlings planted in 2019, damage to the top of the stem did not result in significant mortality, until high damage levels were reached (40 % and above). The opposite was found for seedlings planted in a 2018 drought year, where both damage to the top and the bottom of the stem followed a linear response. In conclusion, we show that investigated mechanical protection methods can be considered a viable replacement for insecticides, but our results also highlight the importance of considering multiple environmental stressors such as drought and pest damage on seedling establishment
Coffee maker patterns and the design of energy feedback artefacts
Smart electricity meters and home displays are being
installed in peopleâs homes with the assumption that
households will make the necessary efforts to reduce their
electricity consumption. However, present solutions do not
sufficiently account for the social implications of design.
There is a potential for greater savings if we can better
understand how such designs affect behaviour. In this
paper, we describe our design of an energy awareness
artefact â the Energy AWARE Clock â and discuss it in
relation to behavioural processes in the home. A user study
is carried out to study the deployment of the prototype in
real domestic contexts for three months. Results indicate
that the Energy AWARE Clock played a significant role in
drawing householdsâ attention to their electricity use. It
became a natural part of the household and conceptions of
electricity became naturalized into informantsâ everyday
language
The demand of hybrid aspen (Populus tremula Ă P. tremuloides) on site conditions for a successful establishment on forest land
Hybrid aspen ( L. Ă Michx.) is a deciduous tree species suitable for producing large amounts of renewable biomass during short rotations. Its potential under North European conditions could be largely extended if not only agricultural land but also forest land was used for cultivation. Unfortunately, the knowledge of appropriate forest site conditions and effects of site preparation methods on hybrid aspen establishment is limited. In this paper, two studies that explore these questions are presented. In the first study, the sensitivity to acid soils was tested under greenhouse conditions in two type of soils: a) peat soil limed to certain pH levels (3.4Ăą5.7) and b) collected forest soils where pH varied from 3.9 to 5.3. The lowest pH level resulted in reduced growth, elsewhere no significant differences were found. The second study was applied in the field and investigated the effect of four site preparation methods on survival and growth. The methods were: 1) control with no site preparation, 2) patch scarification, 3) mounding and 4) soil inversion. While no differences were found for survival, mounding was generally the method with the highest growth and patch scarification was least successful. The result was probably an effect of good soil aeration and less competition from vegetation after mounding. The field study also revealed clonal differences in growth performance, which stresses the importance of clone selection prior to planting. The results of these studies indicate that hybrid aspen is less sensitive to variation in pH and site preparation methods compared with other poplar species, as have been found in similar studies.Populus tremulaP. tremuloide
Att leva som man lÀr? En kvalitativ fallstudie om intern demokrati i Organisationen för sÀkerhet och samarbete i Europa
Uppsatsen utgörs av en fallstudie som syftar till att skapa en djupare förstÄelse för fenomenet intern demokrati inom internationella organisationer. Studien fokuserar pÄ Organisationen för sÀkerhet och samarbete i Europa och genom det teoretiska ramverk som utarbetats Àmnar vi kartlÀgga den interna demokratin i nÀmnda organisation. KartlÀggningen sker genom att applicera fem olika teoretiska dimensioner som pÄ ett eller annat sÀtt interagerar med intern demokrati inom internationella organisationer. Den metodologiska ansatsen Àr teoriprövande och teoriutvecklande, detta i hopp om att besvara vÄr frÄgestÀllning pÄ ett uppfyllande sÀtt. Studien förklarar deskriptivt hur organisationen interna demokrati kan te sig olika beroende pÄ vilken dimension man studerar. Uppsatsen finner att somliga dimensioner uppvisar en hög grad av intern demokrati, medan andra dimensioner saknar aspekter för att organisationen ska anses verkligt demokratisk
Will intensity of forest regeneration measures improve volume production and economy?
The prevailing regeneration methods in Scandinavian countries are artificial regeneration methods including measures such as site preparation and planting. These measures are considered to be a part of a more intensive forest management and require an initial investment. The use of artificial regeneration measures can, however, increase the growth of a forest stand. In this study, the purpose was to investigate if such an investment is profitable by comparing three different intensity levels (low, medium and high) applied during the regeneration phase, with aspect on both economics (LEV, land expectation value) and growth (MAI, mean annual increment) after a full rotation. The forest stands used in this study were regenerated between 1984 and 1988 and the future growth of the stands was simulated using Heureka StandWise. It was clear that naturally regenerated (low intensity) stands resulted in better economics than stands actively regenerated (medium and high intensity). However, actively regenerated stands resulted in both higher volume production and growth, and the uncertainty of regeneration success was reduced using artificial regeneration measures. These factors are important when considering both the ongoing mitigation of carbon dioxide in the atmosphere and future access to raw material
Trap catch data are poor predictors of damage caused by pine weevil (Hylobius abietis) to conifer seedlings
Damage to planted conifer seedlings caused by the pine weevil Hylobius abietis (L.) is a severe and persistent threat to successful forest regeneration in Europe. Various countermeasures are available, which vary in effectiveness, costs and environmental impact, but none are ideal for all situations. Therefore, there is strong interest in robust assessments of damage risks, as they would enable more cost-effective and environmentally friendly forest pest management. It has been suggested that numbers of adult pine weevils caught in host-odour baited traps placed in regeneration sites may be valuable in such risk assessments. However, published studies provide at most weak support for the hypothesis that trap catch data provide adequate predictions of damage. Therefore, we conducted a two-year field study, designed to determine the relationship between weevil trap catch and subsequent damage at 10 regeneration sites in central Sweden. Site factors that might influence pine weevil feeding on seedlings were recorded and used as explanatory variables in the analysis. Stoniness was the only site factor identified as having a significant effect; damage mainly increased with increases in stoniness. No significant correlation was detected between damage to planted conifer seedlings and numbers of pine weevils trapped in the same locations. We suggest that this lack of correlation between weevil numbers and damage is due to planted seedlings only constituting a minor part of the weevils food intake and considerable between-site variation in availability of food sources other than seedlings. Therefore, assessment of pine weevil numbers appears unlikely to be useful for predicting damage risk at specific regeneration sites
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