Under extensive grazing, a mosaic pattern of frequently defoliated short patches and rarely defoliated tall patches is often formed. The agronomic and ecological consequences of this patch‐grazing pattern strongly depend on its stability between successive years. We assessed patch structure and temporal stability under three intensities of cattle stocking (moderate, lenient and very lenient) in a cattle grazing experiment established in 2002. Aerial images of the whole area taken in 2005, 2010, 2013 and 2015 were classified into short and tall patches using random forest classification. These were complemented by annual sward height measurements (2007‐2017) at 10 permanent plots per paddock, which were classified into sward height classes. The mean proportion (0.72, 0.32, 0.19) and size of short patches decreased with stocking intensity, while size of tall patches increased. Inter‐annual stability depended on patch type and stocking intensity and was particularly high for the respective dominant patch type. Of the short patch area in 2015, 0.62, 0.29 and 0.30 were classified as short in all four aerial images under moderate, lenient and very lenient grazing, respectively; the corresponding proportions for tall patches were 0.10, 0.53 and 0.65. Our results imply that short and tall patches experience persistent differences in local grazing intensity over extended periods. The long‐term effects of this heterogeneity on soil properties and vegetation composition need to be monitored to assess agronomic sustainability and ecological potential of patch‐grazed pastures.

Bioenergy generation by combustion is an alternative utilization of biomass from semi-natural grasslands no longer needed for forage production. Variability of fuel composition affects the suitability of grassland herbage for combustion, in terms of ash-related problems and harmful emissions of N, S and Cl compounds. A field experiment was established at six semi-natural grassland sites in southwest Germany to investigate the importance of botanical composition, harvest date and site effects in influencing fuel composition. The first growth at each site was harvested at five dates from June to October. Concentrations of N, S, K, Ca, Mg and ash were lower in grasses than forbs. Between June and October, K concentrations decreased and Ca concentrations increased in grasses and forbs. Ash concentration increased only in grasses, while yields remained stable. Considerable site effects were also found, particularly for K and Cl. The findings are discussed in relation to knowledge of combustion technology. Fuel composition of the investigated grassland biomass was less suitable for combustion than that of perennial energy grasses, but comparable to that of cereal straw. Most critical parameters were high N concentrations, cause of NO x emissions, and high ash, K and Cl concentrations, responsible for particle emissions, fouling and corrosion. Although combustion of semi-natural grassland biomass for small-scale residential boilers cannot be recommended currently, results of this study suggest that utilization in medium-scale combustion units may offer realistic perspectives, creating synergies between bioenergy production and biodiversity conservation.

1.Maintaining semi-natural open habitats requires biomass removal, which can be achieved by extensive grazing with livestock species. However, implementing this established conservation management strategy in large or access-restricted areas is often not possible. 2.We investigated grazing by wild and free-ranging red deer Cervus elaphus as an alternative conservation management approach on an active military training area in Germany. In grasslands and heathlands protected under the EU Habitats Directive, we quantified above-ground net primary productivity, forage quality and forage removal by red deer over three successive years. To assess synergistic effects between wildlife grazing and additional grassland management measures removing vegetation biomass (i.e. burning, mowing), we conducted our grazing experiment in burnt, mown and untreated grasslands.3. Annual forage removal by red deer amounted to 35%, 44%, 48% and 59% of the above-ground net primary productivity in burnt, mown and untreated grasslands, and untreated heathlands, respectively. Theoretically, a similar annual biomass removal could be obtained by livestock grazing with 0.54 animal units ha −1 in grasslands and 0.45 animal units ha −1 in heathlands. In grasslands, daily rates of forage removal peaked in spring and early summer, whereas in heathlands, forage removal rates were only significant in winter. 4.Forage removal rates in grasslands increased with productivity and forage quality, which were both enhanced in mown grasslands. This suggests mowing can increase grassland attractiveness to red deer. Forage removal rates in heathlands did not relate to productivity or forage quality but to standing biomass. Synthesis and applications.We demonstrate that the quantity of forage removed by wild red deer can be comparable to that of livestock in common conservation grazing systems. The seasonal patterns of forage removal by red deer in grasslands and heathlands coincided with the different grazing requirements of these habitats. Especially in large areas of conservation interest, we therefore encourage attempts to modify current wildlife management strategies to allow red deer to forage in open landscapes, which can contribute to the conservation of seminatural open habitats and also help to reduce damage in forest stands.

Figure S1. Location of the sampling sites in heathlands (10) and grasslands (nine) at Grafenwöhr military training area (GTA) in Bavaria, Germany. Each site comprised four plots in heathlands and six plots in grasslands, respectively. Shaded areas indicate the occurrence of the Natura 2000 habitat types 4030, European dry heaths, and 6510, lowland hay meadows according to the draft of the Natura 2000 management plan (2013/2014) for the Site of Community Importance and Special Area of Conservation US-Truppenübungsplatz Grafenwöhr (DE6336301).

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1. Livestock grazing at low stocking rates is widely recommended to maintain grassland biodiversity. However, empirical evidence of grazing-intensity effects on plant diversity is contradictory. Explicitly considering the small-scale heterogeneity of short, frequently grazed and tall, rarely grazed patches typical of low-input grazing systems may be crucial to the understanding of paddock-scale grazing effects.2. We studied three patch types (short, intermediate, tall) within an unfertilised long-term cattle grazing experiment in Lower Saxony, Germany, comparing three paddock-scale grazing intensities. We analysed soil nutrient concentrations and recorded vegetation composition at a total of 135 plots. We determined species richness, Simpson diversity, Simpson evenness and beta diversity of individual plots (plot scale) and patch types within paddocks (patch scale). To quantify paddock-scale diversity, we resampled plot-scale species composition across a gradient of relative proportions of short and tall patches within a paddock.3. Patch type, not paddock-scale grazing intensity, was the main driver of plant diversity at both plot and patch scale. Short patches were more diverse than tall patches, but the effect was not strongly mediated by the lower soil nutrient concentrations in the short patches. By contrast, both patch type and grazing intensity affected vegetation composition at plot and patch scale. 4. Beta-diversity within and between patch types was independent of grazing intensity; consequently, paddock-scale diversity was determined by the relative proportion of short versus tall patches. Higher alpha diversity of short patches compared to tall patches was more important than beta diversity between the two patch types in shaping paddock-scale diversity. Consequently, with increasing short-patch proportion, paddock-scale diversity increased. Synthesis and applications.Our study identifies the grazing-induced patch structure as the most important driver of plant diversity across different grazing intensities in low-input, that is, unfertilised and continuously stocked, pastures. To optimise grazing management for biodiversity, understanding plant-diversity responses to grazing at the patch scale is indispensable. Our results suggest that, in unfertilised, continuously stocked European pastures, trade-offs between biodiversity and | 1625Journal of Applied Ecology TONN eT al.