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Agri‐environment schemes (AES) are the primary policy mechanism for addressing farmland biodiversity declines across Europe. Despite previous studies on the impacts of AES on biodiversity, there is little empirical evidence on the scale of provision required to reverse declines.Across three regions of lowland England with contrasting farm systems (arable, pastoral, mixed), we estimated avian population growth rates (PGRs) on farmland with high AES provision ('higher‐tier': average bird‐friendly option cover = 7.4%), low AES provision ('lower‐tier': 2.3%) and no bird‐friendly AES ('no AES'). Ten‐year PGRs were derived for 24 species and three multi‐species groups comprising farmland‐associated species ('farmland birds'), species of conservation concern ('priority birds') and species restricted to farmland ('specialist birds'). We used PGRs to simulate the proportion of the regional farmland landscape that would have to be assigned to higher‐ and lower‐tier agreements to stabilise or increase populations.In the arable and pastoral regions, 13/23 and 13/22 species, respectively, had more positive PGRs under higher‐tier AES than on no AES farmland (none had more negative PGRs), compared to 4/22 (positive) and 1/22 (negative) in the mixed region. Only two to four species per region exhibited more positive PGRs under lower‐tier AES compared to no AES farmland.Multi‐species PGRs in the arable and pastoral regions increased from no AES (strong decline), to lower‐tier (decline or stability) to higher‐tier (moderate or strong increase). There was no overall AES effect in the mixed region.To increase regional farmland bird populations by 10% over 10 years, 47% and 26% of the farmed landscape would need to be devoted to higher‐tier agreements in arable and pastoral landscapes respectively. This falls to 34% and 17% when higher‐tier is targeted at localities supporting higher abundances of target species, and to 29% and 10% when 30% of the farmed landscape is also devoted to lower‐tier. Priority and specialist birds require higher provision levels.Policy implications. Where farmland bird recovery is an AES objective, farms should prioritise higher‐tier agreement delivery over lower‐tier. Farmland bird responses to AES provision are likely to vary regionally, but careful targeting will reduce the amount needed in the landscape. [ABSTRACT FROM AUTHOR]

Abstract: Agri‐environment schemes (AES) are the main policy mechanism available for reversing the widespread declines of European farmland biodiversity. We assessed the impact of AES land management on the abundance of bird species whose populations have declined as a consequence of agricultural intensification. The AES involved the deployment of a whole‐farm package of wildlife‐friendly land management options covering an average of 7% of the farmed area. The study was conducted across three English regions and focused on species of conservation concern and on a wider suite of farmland birds comprising the UK Government's Farmland Bird Indicator (FBI). Changes in avian abundance on AES farms were compared with those measured across the wider farmed landscape as part of a national bird monitoring scheme. Twelve out of 17 priority species, and the FBI, showed more positive changes in abundance on AES farms in at least one region. Eight species exhibited sustained responses to AES management in at least one region, and eight species exhibited a temporary enhancement in abundance in at least one region. Temporary responses to AES management followed a large scale failure of key AES options to establish during successive wet and cold summers, and involved species known to depend on the habitats provided by these options. In order to offset ongoing declines of FBI species in the wider farmed countryside of 2.3–4.1% per annum, we estimate 26–33% of FBI populations would need to be subject to AES‐type management. This study demonstrates the potential for AES land management to substantially enhance the abundance of priority farmland birds and highlights the need for option packages that are resilient to the impacts of variable weather conditions. [ABSTRACT FROM AUTHOR]

Researchers and policy-makers have become increasingly interested in re-designing agri-environmental policy to improve both economic efficiency and ecological effectiveness. One idea within this debate has been payments for results (outcomes) rather than payment for actions. Payment for result policies have been argued to have some important advantages, but two key disadvantages are the higher risks faced by landowners, leading to low participation rates; and the potentially high costs of monitoring outcomes. Bartkowski et al. (2021) propose an alternative of payment for modelled results, which claims to avoid these two problems. Our paper provides the first application of this approach to spatially realistic patterns of ecological and economic heterogeneity for farmland biodiversity in England. We compare payment for modelled results findings with approximately equivalent payment for actions schemes intended to deliver increases in the same biodiversity indicators. Key insights are that payment for modelled results delivers superior predicted ecological outcomes for the same budgetary cost as payment for actions, whilst economic surpluses to farmers are also higher. • We simulate the ecological and economic outcomes of alternatives Agri-Environment Schemes. • Payment for modelled results is compared to payment for actions. • Payment for modelled results leads to better biodiversity outcomes and higher surpluses for farmers. • Big spatial variation in where land is converted to conservation land use is predicted. [ABSTRACT FROM AUTHOR]

1. There has been a surge of interest in the effects of modern agriculture on biodiversity but studies of farmland flora have lacked continuity and historical context. Here we present the results of 38 years of annual monitoring of the weed flora of cereal crops on the Sussex Downs. 2. This study investigates the long-term changes in abundance of 214 weed species, two subspecies and one forma found in the cereal fields of a 62-km2 area of the Sussex Downs. Species occurrence and weed abundance were recorded annually in June from 1970 to 2005 inclusive. Stubbles were surveyed in 1968, 1971, 2004 and 2005. 3. Annual archaeophytes and perennial natives predominated and the community belonged to the Papaver rhoeas– Silene noctiflora association (OV16) of the UK National Vegetation Classification. 4. Overall, 97% of fields were treated with herbicides prior to sampling, reducing dicotyledonous weed abundance by 64% and taxon occurrence by 52%. From 1970 to 2005 there was no trend in overall abundance of dicotyledons, although monocotyledons decreased by 13% relative to the early 1970s. 5. Of 66 taxa monitored from 1970 to 2005, 18 increased, 38 rose and fell (or vice versa) and 10 showed no trend. Annuals increased until the early 1980s, when many were not susceptible to herbicides, before levelling off or declining slightly as the efficacy of herbicides expanded. 6. Perennial dicotyledons increased steadily throughout the study. This latter change was due to the loss of traditional leys, not to changes in herbicide efficacy. 7. Ninety-two species of dicotyledons were found on stubbles, with no significant overall change in occurrence from 1968–1971 to 2004–2005. In both stubbles and crops, species uncommon at the start have tended to increase whereas common species have tended to decrease. 8. Combining this study with earlier records, we estimate that 16 weed species have been lost from the study area and 15 gained. Before 1970, the loss rate of archaeophytes and the gain rate of neophytes were both higher than for other species. Most species lost were historically uncommon whereas many of the species gained are now common. 9. Synthesis and applications. The soil seed bank remains sufficient to enable a rapid restoration of the pre-herbicide flora where needed for wildlife conservation purposes, without ‘enhancement’, i.e. seeding. The means to do this are available through the UK’s agri-environment ‘in-field measures’, but these are very unpopular with farmers. Incentives need to be much improved to ensure the future conservation of the traditional arable flora. [ABSTRACT FROM AUTHOR]

• Many farmland songbirds are associated with woody networks of hedgerows and trees. • We tested bird associations with a lidar model of a complete linear woody network. • Songbirds had greater positive associations with farmland type than with hedgerow type. • Most songbirds had negative associations with grassland-dominated farmland. • Diversifying grassland agricultural landscapes may benefit farmland songbirds. Farmland birds have declined throughout Europe over recent decades. Many farmland songbirds are associated with linear woody features on field boundaries, such as hedgerows and tree lines. Previous studies have assessed songbird associations with specific hedgerow and tree characteristics, and their landscape context, but large-scale assessments have been limited by difficulties in mapping linear woody networks over large extents, particularly their height structure. We used a high-resolution lidar model of the complete network of linear woody features in southwest England (9424 km2), summarising linear feature lengths by height class. Associations were tested between heights of linear woody features and the abundance of 22 farmland birds, using bird survey data summarised for 1446 near-contiguous tetrads, and a weighted version of the phi coefficient of association. Land cover mapping defined tetrads as grassland, mixed or arable farmland. Results showed that the linear woody network was dominated by features corresponding to managed hedgerows (1.5–2.9 m tall, 42−47% of the network by land cover type), followed by tree lines (≥ 6.0 m, 28–35 %). All songbird species had statistically significant, but weak, associations with combinations of land cover and height class of linear woody features, although land cover appeared to be the dominant factor. Many species showed more positive associations with linear woody features on arable farmland than on grassland, particularly for taller hedgerows and tree lines. The results suggest that land-use diversification may benefit some farmland songbirds, such as introducing pockets of arable farming in landscapes dominated by intensively managed grassland. Diverse heights in the linear woody network, incorporating tall hedgerows and trees, would also likely benefit a range of songbird species. The study demonstrates the significant potential of lidar in characterising the structure of linear woody features at the landscape scale, facilitating detailed analyses of wildlife habitat associations and landscape ecology. [ABSTRACT FROM AUTHOR]