| 1. |
- Fogelfors, Håkan
(författare)
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Seasonal restrictions of bud growth on roots of Cirsium arvense and Sonchus arvensis and rhizomes of Elymus repens
- 2010
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Ingår i: Weed Research. - : Wiley. - 0043-1737 .- 1365-3180. ; 50, s. 102-109
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Tidskriftsartikel (refereegranskat)abstract
- P>The success of weed management aimed at depleting the regenerative structures of perennial weeds depends largely on the sprouting activity of rhizome and root buds. Seasonal variation in sprouting of these buds on Cirsium arvense, Sonchus arvensis and Elymus repens was studied for plants collected from Denmark, Finland, Norway and Sweden. At 2-week intervals from July to October, 5-cm fragments of roots or rhizomes were cut from plants grown in buckets and planted into soil in pots, half of which were placed immediately into growth chambers at 18 degrees C for 4 weeks. The other half of the pots were initially placed in a dark room at 2 degrees C for 4 weeks before being transferred to the same growth chamber, also for 4 weeks. During the growth chamber period, the numbers of emerged shoots in each pot were counted weekly. The sprouting activity of C. arvense and E. repens was relatively uniform during this period and bud dormancy was not apparent. In all ecotypes of S. arvensis, innate bud dormancy developed during the latter part of the growing season. For all three species, differences in sprouting readiness were found among ecotypes. The results imply that C. arvense and E. repens are more likely to be controlled by mechanical measures in autumn than S. arvensis.
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| 2. |
- Fogelfors, Håkan, et al.
(författare)
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Selective pressure on Cirsium arvense (L.) Scop. and Sonchus arvensis L. growth characteristics on different types of farmland in Sweden
- 2009
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Ingår i: Acta Agriculturae Scandinavica, Section B - Soil and Plant Science. - : Informa UK Limited. - 0906-4710 .- 1651-1913. ; 59, s. 42-49
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Tidskriftsartikel (refereegranskat)abstract
- Changes in cropping systems during the past century have led to selective pressure on weed flora. Species and ecotypes with characteristics enabling them to survive in high-input farmland have increased in numbers, at the cost of plants lacking these characters. Since the 1950s, the perennial weed species Cirsium arvense (L.) Scop. and Sonchus arvensis L. have mainly been controlled by the herbicide group synthetic auxins like MCPA. During recent decades, C. arvense seems to have become less susceptible to MCPA in both Europe and North America but the reasons are unclear.To study the importance of selective pressure on weed ecotypes, both short- and long-term studies were carried out in Uppsala, Sweden. The first consisted of two growth-characteristic greenhouse experiments. The hypothesis was that ecotypes of C. arvense and S. arvensis from high-input farmland were different and displayed a more competitive growth pattern than did ecotypes from low-input farmland.The second study was a field experiment with four ecotypes of C. arvense from low-input farmland to study if selective pressure was in force, over a period of six years. The four ecotypes had different growth characteristics and herbicide sensitivity and they were exposed to crop competition and MCPA treatments during the experimental period. The hypothesis was that ecotypes with a more competitive growth pattern and MCPA tolerance would survive to a greater extent than would other ecotypes. For C. arvense, the results from the growth-characteristic experiment showed that the growth pattern of ecotypes from high-input farmland differed, showing a more directly elongated growth pattern with fewer spines on the leaves compared with ecotypes from low-input farmland, which usually were of rosette-type. Results from the field experiment with C. arvense showed that after six years MCPA-sensitive and/or rosette-type ecotypes had almost disappeared while ecotypes with a more directly elongated growth pattern and less sensitive to MCPA survived to a much greater extent. The conclusion was therefore that when exposed to selective pressure like crop competition and herbicide treatments, ecotypes of C. arvense with a more directly elongated growth pattern and less sensitive to herbicide treatment survived to a greater extent compared with ecotypes missing these traits. Ecotypes from high-input farmland had generally fewer leaf spines than did ecotypes from low-input farmland. This may suggest a trade-off between spine formation and rapid competitive growth. In the growth-characteristic experiment with S. arvensis, no differences between ecotypes from high- and low- input farmland regarding growth characteristics or leaf spines could be detected. This might partly be due to a lower exposure of S. arvensis to selective pressure compared with C. arvense, since S. arvensis generally is less sensitive to MCPA.
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| 3. |
- Fogelfors, Håkan, et al.
(författare)
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Strategic analysis of Swedish agriculture : production systems and agricultural landscapes in a time of change
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This strategic analysis of Swedish agriculture – production systems and agricultural landscapes in a time of change – focuses on climate change, future availability of natural resources and economic regulation in a global food market. The background to the project was that the Faculty of Natural Resources and Agriculture of the Swedish University of Agricultural Sciences identified an urgent need to explore the implications and opportunities of coming changes for agricultural production systems, arable land use and farm landscape functions in Sweden. Another objective was to determine the research needed to ensure that we are equipped to adapt to the coming changes. The analysis was carried out in the form of three literature reviews (Climate Change and Agricultural Land Use in Sweden: A Literature Review, (Eckersten et al., 2008a); Changes in the Global Natural Resource Base Relevant for Future Agriculture in Sweden – A Literature Review, (Johansson, 2008); and Economic Globalisation and Swedish Agriculture – Future Changes Affecting Swedish Agriculture from an Economic Perspective with Special Emphasis on Globalisation, (Holstein, 2008). It also comprised workshops and seminars and finally production of this synthesis report, which summarises the work done and suggests six research themes. Different IPCC emission scenarios describe pathways for those factors that are regarded as important for emissions of greenhouse gases (GHG), such as demography and social, economic and technological development. The projected global temperature increase varies from a little less than 2 °C up to 3.5-4.0 °C by the end of this century. Shrinking glaciers and rising sea levels are some of the consequences of the temperature increase. This climate change will have considerable consequences for agriculture, ecosystem function and human health on a global scale. The conditions for food production in Sweden are projected to become more favourable in terms of potential productivity as a result of future climate change. However, despite more favourable average cropping conditions, there could be drawbacks in the form of more frequent extreme weather events and, for example, more severe crop pathogen attacks and increased risks of nutrient leaching. The temperature increase is predicted to be greater during winter than during summer. Furthermore, precipitation will probably increase and the precipitation pattern will change. The temperature increase may lead to an extension of the growing season by several months in southern Sweden. Swedish agriculture is currently dependent on high inputs of external resources. The situation at present is that agricultural demands are increasing with regard to the natural resource base, e.g. ecosystem services and fossil fuels. The use of fossil fuels to sustain food production cannot continue indefinitely; agriculture world-wide must adopt mitigation strategies. One way is to search for self-sustaining, diversified, low-input, energy-efficient agricultural systems, using local renewable resources and ecosystem services. Another way to meet the challenges of future food supply and at the same time sustain life-support systems might be through intensive high-input agriculture on the 'best' land in order to save other areas for nature conservation. Swedish agriculture and food production are closely linked to the global food and feed market. Increased globalisation means that the profitability of Swedish farms is influenced to an increasing extent by actors on the global market. Conditions for Swedish agriculture in the past have been largely determined by political regulations, national and subsequently by CAP (Common Agricultural Policy in EU), but are gradually becoming more dependent on world market forces. Sweden has a comparative disadvantage in primary production compared with many other countries but the competitiveness of the Swedish food sector as a whole has increased during recent years due to increased exports of processed products. Another opportunity is to increase production of products with added value, e.g. organic products. However, the effects of globalisation on Swedish agriculture are hard to predict. Increased liberalisation will lead to increased competition, which will most probably lead to decreased production in Sweden. However, future changes in land productivity could potentially affect land use more than does the degree of liberalisation in trade. The conclusion that Swedish agriculture will decrease, at least in terms of land use, may very well turn out to be incorrect. This should be clear, not only from scenarios where climate change makes Swedish production more competitive but also from the latest developments on the world market where large increases in demand for agricultural products have been noted. This increase may have the consequence that land in less competitive countries will become sufficiently productive. Twelve climate scenarios for different regions in Sweden were developed within the FANAN project, from south-west Skåne in the south to Övertorneå in the north. Projections of future cropping systems under the new climatic conditions are described for three regions, south-west Skåne, Mälardalen district and the coast region of Västerbotten. There are diametrically opposed scenarios for future land use and appropriate design of agricultural production systems in the literature, which implies a need for a great variety of research. Research in adaptation as well as mitigation strategies will be important. Problems are interlinked and interdisciplinary research will probably be necessary to solve the complex problems concerning agriculture and the food supply of future populations. Six different strategic research themes are presented as a result of the FANAN project: 1.Future analyses of long-term sustainable land use, p.54. 2.Sustainable production systems — crop and animal sciences, p. 55. Cooling crops — crop-soil interactions Crop breeding — perennial cereals Domestic animal production Cultivation techniques 3.Ecosystem services in production systems of the agricultural landscape, p. 59. 4.From words to action, p. 60. 5.Monitoring of agricultural production, p. 62. 6.Multidisciplinary research network, p. 62. Large research programmes rather than small disciplinary projects will promote the solution of future complex problems. It will be necessary to combine empirical research with modelling and synthesis work in order to generate good science that is relevant to the challenges in sustainable agricultural management. FANAN concludes that SLU has a central role to play in developing these sustainable strategies
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| 4. |
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| 5. |
- Milberg, Per, et al.
(författare)
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Annual burning of semi-natural grasslands for conservation favours tall-grown species with high nectar production
- 2018
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Ingår i: Nordic Journal of Botany. - : WILEY. - 0107-055X .- 1756-1051. ; 36:5
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Tidskriftsartikel (refereegranskat)abstract
- Species-rich semi-natural grasslands in Europe are a main target for conservation efforts, and alternative methods to the traditional management of mowing or grazing would be welcome due to the difficulties in maintaining traditional management practices. One such method proposed is burning of grassland vegetation during late winter or spring. To evaluate the effects of annual spring burning vs annual mowing on semi-natural grassland vegetation, we compared the frequency of species in eleven field experiments in southern Sweden after ca 14 years. Out of the 88 species analyzed, five were more frequent in burnt plots compared with mowed plots (Vicia cracca, Cirsium arvense, Urtica dioica, Galium verum, Convallaria majalis). In contrast, 37 species were significantly less frequent in burnt plots compared with mowed ones, those with the largest differences being Ranunculus acris, Briza media, Veronica chamaedrys, Festuca ovina, Plantago lanceolata and Anthoxanthum odoratum. Tall-grown species and those with preferences for N-rich soils increased in frequency under an annual spring-burn regime, compared with annual mowing, as did species producing larger amounts of nectar. Hence, although vegetation composition becomes more trivial with annual spring burns, there might be long-term benefits for nectar-feeding insects.
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| 6. |
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| 7. |
- Milberg, Per, et al.
(författare)
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Is spring burning a viable management tool for species-rich grasslands?
- 2014
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Ingår i: Applied Vegetation Science. - : Wiley-Blackwell. - 1402-2001 .- 1654-109X. ; 17:3, s. 429-441
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Tidskriftsartikel (refereegranskat)abstract
- QuestionThe management of species-rich semi-natural grasslands, a fragmented and threatened vegetation type in Europe, involves costs. Mowing is expensive and grazing can be difficult to achieve and maintain for logistical reasons. Is annual spring burning, which is potentially cheaper than mowing and grazing, a viable management tool for species-rich grasslands?LocationLong-term field trials in 11 grasslands in southern Sweden.MethodsWe calculated the odds for a species being an indicator of good management, an indicator of poor management, or an indicator of nitrogen influence in spring-burned plots, grazed plots and annually mowed plots. Odds ratios contrasting spring-burned plots with grazed plots and spring-burned plots with mowed plots were subjected to meta-analyses in which we compared the odds ratios after 1, 8 and 14 spring burns. For a single trial, we also analysed data after 1, 8, 14, 28 and 39 spring burns.ResultsCompared with mowed and grazed plots, the odds of the four different indicators of good management decreased in spring-burned plots, while the odds for the two indicators of poor management increased. There was no trend in the two indicators of excess nitrogen. Therefore, the conservation value of vegetation in spring-burned plots becomes reduced over time relative to traditional management.ConclusionsSpring burning is not an appropriate long-term management method if the aim is to maintain the conservation value of the vegetation in traditionally managed semi-natural grasslands.
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| 8. |
- Milberg, Per, et al.
(författare)
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The biodiversity cost of reducing management intensity in species-rich grasslands: Mowing annually vs. every third year
- 2017
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Ingår i: Basic and Applied Ecology. - : ELSEVIER GMBH, URBAN & FISCHER VERLAG. - 1439-1791 .- 1618-0089. ; 22, s. 61-74
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Tidskriftsartikel (refereegranskat)abstract
- Mowing is an important management method for species-rich semi-natural grasslands in Europe. Since mowing is costly, it is important to find a balance between mowing frequency and conservation benefits. We compared vegetation data from eleven field trials situated in southern Sweden that involved two mowing regimes, annually and every third year, as well as a no-management control. After approximately 14 years, mowing every third year showed (i) a drop in species richness and Shannon and GiniSimpson diversity indices, (ii) an increase in woody species, and (iii) increases in tall-grown species. However, there were no apparent changes in (iv) species that were indicative of poor management, nor (v) those indicating good management. For one of the trials, data after 38 years were also evaluated. Compared with annual mowing, there were strong negative changes in the number of species in the untreated control, while the results were conflicting for mowing every third year. In conclusion, the expected loss of conservation values from reduced mowing intensity was 5060% of the loss after abandonment. The outcomes, however, varied among the eleven sites. (C) 2017 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.
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| 9. |
- Pye, Alexandra, et al.
(författare)
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Intense fragmentation and deep burial reduce emergence of Rumex crispus L.
- 2011
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Ingår i: Acta Agriculturae Scandinavica, Section B - Soil and Plant Science. - : Informa UK Limited. - 0906-4710 .- 1651-1913. ; 61, s. 431-437
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical control through different tillage methods is a common measure against perennial weeds. However, non-optimal tillage can potentially increase the vegetative regeneration instead of reducing it. Aspects of regenerative capacity in the perennial weed species Rumex crispus L. was studied in three pot and box experiments as follows: (1) regeneration from different root fragments under varying test conditions; (2) effects of root size and burial depth on time of emergence and emergence rate; and (3) effects of burial depth and cutting on biomass production and seed production. In experiment 1, sprouting occurred mainly from the neck of the roots, consisting of underground stem tissue. A few shoots were observed also from the upper half of the true taproot and from a side root. No difference in sprouting was found between test conditions. In experiment 2, total emergence rate was positively related to root size and negatively related to burial depth. Time to first emergence was defined by an interaction between the two factors. Roots larger than 100 g gave rise to a high degree of emergence from all burial depths, while emergence from roots weighing 20-30 g was less than 30% from 12 cm and nonexistent from 18 cm. When emergence and shoot production were tested under different cutting regimes (experiment 3), the separated top fragments of the roots sprouted faster and produced more shoot biomass than intact rootstocks, even at a second harvest. Our results indicate that fragmentation can stimulate sprouting from the regenerative tissue of the taproot. Hence, if tillage is carried out as weed control it is important that root fragments are buried at ploughing depth, especially if the population consists of adult plants.
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| 10. |
- Tälle, Malin, et al.
(författare)
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The conservation benefit of mowing vs grazing for management ofspecies-rich grasslands: a multi-site, multi-year field experiment
- 2015
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Ingår i: Nordic Journal of Botany. - : Nordic Society Oikos. - 0107-055X .- 1756-1051. ; 33:6, s. 761-768
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Tidskriftsartikel (refereegranskat)abstract
- Species-rich semi-natural grasslands in Europe are becoming more fragmented and many species that depend on thishabitat type are rare and threatened today. Management methods like mowing and grazing are needed to preserve remaininggrasslands. Because management is costly it is important to use the most cost-effective as well as the most beneficialmanagement method, but few studies have compared mowing and grazing. We investigated the effect of mowing andgrazing on grassland vegetation using data from 11 long-term field trials situated in southern Sweden. We calculated thechange in the odds of finding species belonging to three different groups of indicators at the start of the treatment and after8 and 14 years. The used indicator groups were indicators of good management, excess nitrogen and poor management.The results revealed an increase in the odds of finding indicators of good management in mowed plots and an increasein finding indicators of excess nitrogen in grazed plots. The odds of finding indicators of poor management remainedunchanged. Results from sub-analysis of the grazing intensity showed a more negative effect from grazing with low grazingintensity than normal/high grazing intensity. Therefore, mowing is the best long-term management method for seminaturalgrasslands in Sweden and grazing using a low grazing intensity should be avoided.
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