| 1. |
- Agestam, E, et al.
(författare)
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Productivity scenarios for the Asa Forest Park
- 2002
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Ingår i: Developing principles and models for sustainable forestry in Sweden. - 1402009992 ; , s. 355-380
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
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| 3. |
- Antonsson, Kjell, et al.
(författare)
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Occurrence of the hermit beetle (Osmoderma eremita), in Sweden.
- 2003
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Ingår i: Entomologisk tidskrift. - 0013-886X. ; 124:4, s. 225-240
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Tidskriftsartikel (refereegranskat)abstract
- We have compiled data on the occurrence of a threatened beetle, Osmoderma eremita, in Sweden. The species inhabits tree hollows with wood mould. The data were compiled from field surveys conducted in 1993-2003, using pitfall traps at 401 localities and using wood mould sampling at 104 localities. We have also gone through published data and all larger Swedish museums and registered old records. O. eremita was recorded at about 30% of the field surveys. In Sweden, oak is by far the most important host tree species, but the beetle has also been found in other deciduous trees, such as beech, alder, ash and lime. Currently, 270 localities with Osmoderma eremita, defined as records of living adults, larvae, fragments of adult body parts, or excrements situated at least 1 km from each other, are known in Sweden. 129 of these localities are records of live beetles or larvae made after 1990. The species is found in the southern third of Sweden only, and there are more localities in the eastern part compared to the western. The great majority of the localities have been discovered during the last ten years. At some of the localities only excrements or fragments have been recorded, and the species might actually be extinct at some of these localities. Due to low search intensity historically, it is impossible to use these data to discover any changes in the distribution or occurrence over time. Because old, hollow oaks were much more frequent 200 years ago, we suggest that the species has decreased severely in Sweden since that time. Today, old oaks are rarely cut down but instead lack of grazing cattle is a threat because many sites regrow with dense tree stands which outcompete the old hollow trees. Many local extinctions could also be expected during the next few decades, because many of the localities have too few hollow trees and are too isolated. At many localities, lack of younger trees which can take over the role as host trees when the present trees die will also be a problem in the future.
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| 4. |
- Ask, Peter, et al.
(författare)
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Det privata skogsbrukets landskap – En studie av uthålligt brukande i Stenbrohultsområdet
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this investigation the possibilities to achieve three different goals for sustainable forestry in the landscape of Stenbrohult have been studied: Preserved biodiversity, balanced nutrient budgets, and a valuable production of timber. The consequences for the landscape and for the different estates were studied. The case study area of Stenbrohult is situated in southern Sweden, and is made up of 5200 ha of which 73 % is forest. Most of the forest is managed for timber production, and the area is divided into 89 different estates. By using a model for preservation of biodiversity and a model for cation budgets, three different management programs were developed: Balance was a management that would preserve all species found in the landscape today, and keep the cation budgets in balance by regulating the level of harvest. Plus was a management that would not only preserve all species, but also get back some species that has been lost during historic times. The nutrient budgets in this program were balanced by adding cations artificially. The third program, bio balance, soil plus was a combination of the two programs previously mentioned. It was designed to preserve all species of today, and the nutrient budgets were balanced by adding cations artificially. In all three management alternatives the economical production of timber was as high as possible within the limits set up by the other objectives. In many cases this was accomplished by cultivation of pure spruce monocultures on most of the forest land that was not set aside for biodiversity protection. Two reference alternatives were constructed: Certification, where the forest was managed according to the Swedish standards for forest certification by FSC and PEFC, and forestry board where the forest was managed according to the advices usually given by the Swedish boards of forestry. All five management programs were run through a projection model that simulated the different management regimes over a period of 300 years. The economical result from the different programs was analysed, on a landscape level and on two different private estates, and the reference alternatives were evaluated regarding species preservation and cation budgets. The economical result from bio balance, soil plus at the landscape level was about the same as for the reference alternatives. For plus it was slightly lower, and for balance it was considerably lower. On the two different estates that were studied the results differed a lot. On one estate the economical result for balance, plus and bio balance, soil plus was higher than for the reference alternatives. On the other estate the result was much lower. The evaluation of the reference alternative showed that none of them reached the sustainability goals regarding the preservation of species and the nutrient balances. We conclude that in the landscape of Stenbrohult it is possible to reach a sustainable forest management when it comes to biodiversity, nutrient balances and economy. This could be obtained by a management like bio balance, soil plus where large areas are set aside for biodiversity protection while the rest of the forest land is intensively managed with nutrient compensation. The main disadvantage is that it gives very different economical results on the different forest estates. It can also be negative from risk perspective since the timber production is very standardized all over the landscape.
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| 5. |
- Ask, Peter, et al.
(författare)
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Stand characteristics in colour-infrared aerial photographs as indicators of epiphytic lichens
- 2004
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Ingår i: Biodiversity and Conservation. - 0960-3115. ; 13:3, s. 529-542
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Tidskriftsartikel (refereegranskat)abstract
- Information about forest biodiversity has so far been collected mostly by using field inventories, but it is desirable to find other methods that can cover large areas at a lower cost. In a forest landscape covering 2000 ha in southern Sweden we tested if colour-infrared (CIR) aerial photographs on the scale of 1:30000 can be used to interpret forest stand characteristics correlated to the occurrence of epiphytic lichens that are Red-listed or otherwise indicate high nature conservation value ('signal species'). Using logistic regression we found that the interpreted stand variables tree height and crown structure class were significantly correlated to the occurrence of Red-listed species. For signal species, the variables tree height, percentage of southern deciduous trees and crown structure class were significantly correlated to the occurrence. The logistic regression models successfully predicted a significantly higher probability to find Red-listed species in the stands that actually contained such species compared to stands without Red-listed species. The same was true for stands with signal species. We conclude that interpretation of CIR aerial photographs could be a useful method to find certain groups of epiphytic lichens in surveys covering large areas.
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| 6. |
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| 7. |
- De Palma, Adriana, et al.
(författare)
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Predicting bee community responses to land-use changes : effects of geographic and taxonomic biases
- 2016
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 6, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.
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| 8. |
- Drobyshev, Igor, et al.
(författare)
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Lifespan and mortality of old oaks - combining empirical and modelling approaches to support their management in Southern Sweden
- 2008
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Ingår i: Annals of Forest Science. - : Springer Science and Business Media LLC. - 1286-4560 .- 1297-966X. ; 65:4, s. 401-401
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Tidskriftsartikel (refereegranskat)abstract
- Old oaks (Quercus robur L.) play an important role in the southern Scandinavian landscape by providing habitat for a wide range of species, a large proportion of them being currently on the National Redlists. To provide support for the management of these trees, we review data on oak mortality and formulate a mortality-driven stochastic model analysing interactions between mortality rate, oak recruitment rate into 100-150 age class, and amount of oaks older than 200 years. Empirical annual mortality rates varied between 0 and 13% with average 1.68%. Trees older 200 years had an average mortality rate of 1.1%. Oaks in the high density forests showed higher mortality (3.2%) as compared to the trees growing in the low density forests (1.2%). A 400-year long modelling exercises indicated that under current mortality rates (regular mortality being centred around 1% annually; and irregular mortality 7% with average return time of 13 years) the long-term maintenance of 20 trees older than 200 years per ha would require an input rate of 1 to 5 trees x year(-1) x ha(-1) into the 100-150 years old class. The modelling highlighted the importance of initial oak abundance affecting amount of old trees at the end of shorter (100 years) simulation period.
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| 9. |
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| 10. |
- Franzén, Markus, et al.
(författare)
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Both population size and patch quality affect local extinctions and colonizations.
- 2010
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 277, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- Currently, the habitat of many species is fragmented, resulting in small local populations with individuals occasionally dispersing between the remaining habitat patches. In a solitary bee metapopulation, extinction probability was related to both local bee population sizes and pollen resources measured as host plant population size. Patch size, on the other hand, had no additional predictive power. The turnover rate of local bee populations in 63 habitat patches over 4 years was high, with 72 extinction events and 31 colonization events, but the pollen plant population was stable with no extinctions or colonizations. Both pollen resources and bee populations had strong and independent effects on extinction probability, but connectivity was not of importance. Colonizations occurred more frequently within larger host plant populations. For metapopulation survival of the bee, large pollen plant populations are essential, independent of current bee population size.
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