Abstract. Vegetation changes in a semi‐natural grassland of wooded meadow type that had been grazed for centuries are described following the introduction of various management regimes: mowing each year, mowing every third year, burning, mechanical removal of woody plants, chemical treatment of woody plants, continuous grazing and abandonment. The experiment was established in southern Sweden in 1972 and has been in progress for 15 years. In 1972, 1980 and 1986 the botanical composition in these plots was investigated in permanent subplots. The study clearly demonstrates that mowing or grazing is necessary to preserve community structure and that mowing is to be preferred in cases where maintaining species richness is of primary concern. Mowing every third year delayed vegetation change and prevented woody species from spreading. Therefore, periodic mowing might be an alternative way to preserve the flora. In contrast, yearly burning does not seem to be a viable management in this type of semi‐natural grassland. To preserve the open landscape regeneration of woody plants has to be prevented. However, in plots where woody plants were removed the typical grassland flora declined. Abandonment resulted in closed forest.

Summary 0[ Set!aside _elds have been an important element of the European agricultural landscape since the introduction of the set!aside scheme by the European Community[ However\ countries in the European Community di}er in their rules for managing set!aside owing to di}erent priorities[ 1[ In Sweden\ a major goal is to reduce the total use of agricultural pesticides\ consequently their use is prohibited in set!aside[ The options for weed control are therefore cutting and:or the use of a cover crop[ 2[ In this study\ we describe the course of succession following the abandonment of farmland managed in di}erent ways[ The~oristic composition was followed over a 09!year period[ Temporal trends in community development are described[ 3[ The experiment began in 0864 on farmland at six localities\ distributed from southern to northern Sweden[ The management treatments involving the application of fertilizers and cutting were applied to plots sown with a cover crop and to plots in which the succession started from bare ground[ 4[ We found that competitive interactions between species largely determined the successional course in our study[ The competitive success of species was related to the management practices applied but there were also interactions between management and site conditions[ 5[ We propose that natural succession can be recommended on poor sites in com! bination with cutting\ mainly to prevent the invasion of woody species[ On fertile sites a cover crop should be used to suppress perennial weeds\ and cutting is recommended mainly to increase species diversity[ Key!words] cutting\ fertilization\ long!term experiment\ old!_eld succession\ sec! ondary succession[ Journal of Applied Ecology "0887# 24\ 647Ð660

SummaryThe 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°C for 4 weeks. The other half of the pots were initially placed in a dark room at 2°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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Today, the aim of weed management is to keep the weed community at an acceptable level rather than to keep the crop totally free of weeds. Satisfactory control of weeds may often be obtained when herbicides are used at lower doses than normally recommended. To facilitate the decision of what is an adequate dose in a specific field, the farmer needs support. In 1988 and 1989, a total of 10 field trials in spring cereals were initiated in Sweden with the objective of studying long-term effects of herbicide application according to recommendations from guidelines: the guidelines were developed at the Swedish University of Agricultural Sciences and consisted of printed cards designed for in-field use. Treatments also included a full and a half dose and an untreated control. As an average over the experimental time, i.e., until 1997, the dose used in the guideline treatment varied at different sites between 20 and 70% of a full dose. In 1998, i.e., 1 yr after the last herbicide application, the plant densities of annual weeds in the guideline treatment, the half and the full doses were 51, 57, and 67% lower, respectively, than in the untreated control when averaged over sites. At two and four sites, the half and full doses resulted in significantly lower weed densities than where guidelines had been used. Compared with the control, the full and half doses increased the proportion of difficult-to-control weed species significantly at five and four sites by 21 and 24%, respectively. In the guideline treatment the proportion of difficult-to-control weeds was increased at one site. In 1998, weed counts were higher where guidelines had been used than in the full dose for common lambsquarters and common chickweed at three sites each and for wallflower mustard, catchweed bedstraw, field violet, Galeopsis spp., and Lamium spp. at one site each. At three sites, no significant treatment effects on crop yields were found, whereas yields at the remaining seven sites were higher where guidelines had been used than in other treatments in several years. It is concluded that application of dose rates according to recommendations from guidelines can be a fruitful way to reduce herbicide use.

Running title: Burning and grassland management 60 word "summary of what is exciting about the MS": Within the context of evidence-based conservation, we provide clear evidence that spring burning is not a viable long-term alternative to grazing or mowing. We do this by using odds ratios for finding indicator species, rather than using more traditional methods of vegetation analyses, and by meta-analyses of the outcomes from 11 field trials. 1 Abstract Question:The 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, potentially cheaper than mowing and grazing, a viable management tool for species-rich grasslands?Location: Long-term field trials in 11 grasslands in southern Sweden. Methods:We calculated the odds for a species being an indicator of good management, an indicator of poor management, and an indicator of nitrogen influence in spring-burnt plots, grazed plots, and annually mowed plots. Odds ratios contrasting spring-burnt plots with grazed plots and spring-burnt 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. Results:Compared with mowed and grazed plots, the odds of the four different indicators of good management decreased in spring-burnt 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-burnt plots becomes impoverished over time relative to traditional management. Conclusions:Spring 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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Species‐rich semi‐natural grasslands in Europe are becoming more fragmented and many species that depend on this habitat type are rare and threatened today. Management methods like mowing and grazing are needed to preserve remaining grasslands. Because management is costly it is important to use the most cost‐effective as well as the most beneficial management method, but few studies have compared mowing and grazing. We investigated the effect of mowing and grazing on grassland vegetation using data from 11 long‐term field trials situated in southern Sweden. We calculated the change in the odds of finding species belonging to three different groups of indicators at the start of the treatment and after 8 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 increase in finding indicators of excess nitrogen in grazed plots. The odds of finding indicators of poor management remained unchanged. Results from sub‐analysis of the grazing intensity showed a more negative effect from grazing with low grazing intensity than normal/high grazing intensity. Therefore, mowing is the best long‐term management method for semi‐natural grasslands in Sweden and grazing using a low grazing intensity should be avoided.