Summary 1.Many grasslands in north-west Europe are productive but species-poor communities resulting from intensive agriculture. Reducing the intensity of management under agrienvironment schemes has often failed to increase botanical diversity. We investigated biotic and abiotic constraints on diversification by manipulating seed and microsite availability, soil fertility, resource competition, herbivory and deficiencies in the soil microbial community. 2. The effectiveness of 13 restoration treatments was investigated over 4 years in a randomized block experiment established in two productive grasslands in central-east and south-west England. 3. Severe disturbance involving turf removal followed by seed addition was the most effective and reliable means of increasing grassland diversity. Disturbance by multiple harrowing was moderately effective but was enhanced by molluscicide application to reduce seedling herbivory and by sowing the hemiparasite Rhinanthus to reduce competition from grasses. 4. Low-level disturbance by grazing or slot-seeding was ineffective in increasing diversity. Inoculation with soil microbial communities from species-rich grasslands had no effect on botanical diversity. Nitrogen and potassium fertilizer addition accelerated off-take of phosphorus in cut herbage but did not cause a reduction in soil phosphorus or increase botanical diversity. 5. Different grazing management regimes had little impact on diversity. This may reflect the constraining effect of the July hay cut on species dispersal and colonization. 6. Synthesis and applications. Three alternative approaches to grassland diversification, with different outcomes, are recommended. (i) High intervention deturfing, which would create patches with low competitive conditions for rapid and reliable establishment of the target community. For reasons of cost and practicality this can only be done over small areas but will form source populations for subsequent spread. (ii) Moderate intervention (harrowing or slot-seeding) over large areas, which would establish a limited number of desirable, generalist species that perform well in restoration. This method is low cost and rapid but the increases in biodiversity are less predictable. (iii) Phased restoration, which would complement the above approaches. Productivity and competition are reduced over 3-5 years using Rhinanthus or fertilizers to accelerate phosphorus off-take. After this time harrowing and seeding should allow a wide range of more specialist species to establish. However, further research is required to determine the long-term effectiveness of these approaches.

Summary 1.Effects of high nutrient input on the longevity and viability of buried seed are examined. Seeds of 17 fen-meadow species were buried in nylon mesh bags at four sites in the Netherlands and one site in Great Britain in plots to which N, P, K fertilizers are applied. Prior to burial germination tests were conducted on the seeds of each species. This paper describes the results of the viability tests on the seeds that were exhumed after one and 2 years of burial. 2. The percentage of seeds that germinated after 1 year of burial was significantly lower than the pre-burial percentage for the majority of the species. After 2 years of burial the germination percentage further decreased. A few species, such as the Carex species, did, however, show an increase in germination percentage indicating that the burial conditions allowed dormancy controls to be broken. 3. Differences in the edaphic conditions between the sites appeared to affect germination percentages after 1 year of burial. A difference in germination response between sites was observed for Carex acutiformis, Filipendula ulmaria and Lychnis flos-cuculi. 4. A significantly higher germination percentage was found at the Great Britain site for F. ulmaria in the phosphate treatment compared with the potassium treatment and the control after 1 year of burial. In contrast to many literature assessments no significant effects of fertilizer application was found after 2 years. 5. For all sites, except one in the Netherlands, the total number of seeds that germinated was lower in 1996 than in 1995.

Pywell, R. F., Hayes, M. J., Tallowin, J. B., Walker, K. J., Meek, W. R., Carvell, C., Warman, L. A., Bullock, J. M. (2010). Minimizing environmental impacts of grassland weed management: can Cirsium arvense be controlled without herbicides? Grass and Forage Science, 65 (2), 159-174. IMPF: 01.10Invasion by undesirable plants, such as Cirsium arvense, can constrain attempts to conserve and restore biodiversity in extensively managed temperate grasslands, but control with herbicides can cause environmental harm. We contrasted herbicides with more environmentally sustainable weed control strategies. Six-year, large-scale randomized block experiments were established to determine optimum combinations of grazing management and mechanical or herbicide treatments to control thistles within lowland and upland grazing systems. Factorial combinations of tight vs. lenient grazing in spring and autumn with additional treatments of winter grazing were compared. Thistle control methods were applied in sub-treatments for the first 2 years: cutting twice yearly, herbicide wiping, and cutting followed by herbicide application. Thistle abundance decreased under lenient grazing in spring, autumn and winter at the lowland site, under lenient spring and winter grazing in the uplands and under cattle compared with sheep grazing. Herbicide wiping was the most effective control measure and cutting the least, but effects of all weed control sub-treatments were lost rapidly, so lenient grazing was sufficient to give long-term thistle control. Lenient grazing and herbicide wiping also caused small declines in non-target forb diversity. Control of creeping thistle can therefore be achieved without herbicides because lenient grazing in spring and autumn can decrease thistle populations to sufficiently low levels. Severe infestations can be more rapidly controlled using herbicides, but are better avoided at botanically diverse sites. Ecologically-based weed control strategies have great potential, but require well designed field experiments, which run for sufficiently long periods to allow community-level impacts to develop.Peer reviewe

The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Methods: We set up a 4-yr experiment using a split-plot design to combine pre-sowing 29 disturbance treatments at sub-plot-level (undisturbed control, glyphosate spraying, harrowing, 30 and creation of ridge-and-furrow features) with three post-establishment management regimes 31 applied at main-plot level in years 2-4, involving either summer cutting or summer cattle 32 grazing, and presence or absence of spring sheep grazing, along with autumn cattle grazing in all 33 regimes. After disturbance application, we sowed a seed mixture containing ten specialist species 34 of calcareous grassland. Using quadrat-based methods, we monitored first-year establishment 35 and subsequent dynamics, including reproductive status of species at quadrat level. Initial 36 establishment and subsequent dynamics were analysed separately using linear mixed models. 37Results: Initial establishment of sown species was promoted both by harrowing and by ridge-38 and-furrow creation. While some species were about equally promoted by both, several other 39 species benefited more strongly or exclusively from ridge-and-furrow creation. Effects of 40 disturbance largely persisted in subsequent years, but for some species, different dynamics were 41 observed for harrowed and ridge-and-furrow treatments. Thymus pulegioides and Hippocrepis 42 comosa gradually achieved higher abundances in the ridge-and-furrow treatment, in which 43 notable levels of bare ground persisted for much longer than in the harrowed treatment. In 44 contrast, Filipendula vulgaris and Pimpinella saxifraga achieved higher abundance in the 45 harrowed treatment. Sown species tended to reach reproductive stage faster in the ridge-and-46 3 furrow treatment than in the harrowed treatment. By the end of the study, management regimes 47 had resulted in few effects on species dynamics. 48Conclusions: Establishment of specialist species of calcareous grassland crucially depended on 49 bare-ground creation prior to sowing. Ridge-and-furrow creation resulted in more persistent 50 reduction of competition than the standard practice of harrowing, provided more suitable 51 conditions for low-statured specialist species, and generally enabled faster transition of 52 introduced specialist species to reproductive stage. Our results thus illustrate potential benefits of 53 using more severe disturbance when introducing specialist species of calcareous grassland at 54 restored sites. 55 56

Land use change from intensive arable production to extensively managed grasslands is encouraged through subsidy payments to farmers under the European Union's Common Agricultural Policy. Created grasslands are sown with a species-rich seed mix and receive limited or no fertiliser application with the aim of increasing the provision of non-production ecosystem services. In the UK these agri-environment schemes are funded for periods of 5, 7 or 10 years. This study compared the plant diversity and soil properties of paired intensively managed (IM) arable and recently created (3, 5, 8 and 9 years) extensively managed speciesrich grasslands (SRG) at 4 sites in the Scottish Borders. Botanical surveys of the newly created grassland plots showed limited establishment of the species-rich seed mixes and the dominance of grasses that favour more nutrient-rich environments. Soil properties at 0-10 and 30-40 cm depths were measured over 2 consecutive years. Total and available soil nitrogen, phosphorus and soil organic carbon were not significantly different between paired plots. This study indicates that in order to create edaphic conditions for species-rich grassland communities to develop within a 10 year timespan on former intensively managed arable land, radical changes in soil properties are required, which current de-intensification managements are not achieving.