A substantial body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of... Show moreA substantial body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of biodiversity underlying the diversity-stability relationship remains unclear. Here we use data from 39 grassland biodiversity experiments and structural equation modelling to investigate the roles of species richness, phylogenetic diversity and both the diversity and community-weighted mean of functional traits representing the 'fast-slow' leaf economics spectrum in driving the diversity-stability relationship. We found that high species richness and phylogenetic diversity stabilize biomass production via enhanced asynchrony in the performance of co-occurring species. Contrary to expectations, low phylogenetic diversity enhances ecosystem stability directly, albeit weakly. While the diversity of fast-slow functional traits has a weak effect on ecosystem stability, communities dominated by slow species enhance ecosystem stability by increasing mean biomass production relative to the standard deviation of biomass over time. Our in-depth, integrative assessment of factors influencing the diversity-stability relationship demonstrates a more multicausal relationship than has been previously acknowledged. Show less
Kuiper, M.W.; Ottens, H.J.; Ruijven, J. van; Koks, B.J.; Snoo, G.R. de; Berendse, F. 2015
Field margin management is a common measure employed in Europe to support farmland bird populations. In this study we found and analysed 237 nests of the Skylark Alauda arvensis in the Netherlands... Show moreField margin management is a common measure employed in Europe to support farmland bird populations. In this study we found and analysed 237 nests of the Skylark Alauda arvensis in the Netherlands over a period of 6 years to determine the effects of arable field margins and breeding crop on nest-level reproductive success. Additionally, the effect of field margins on predation was investigated and food availability in crops and field margins was compared. Neither clutch size, nest survival nor nestling body weight were improved by field margin availability, irrespective of the breeding crop used. However, the choice of breeding crop had important effects. Nestling weight was significantly lower in cereals than in grassland and lucerne, corresponding with the low prey densities present in cereals. Nest survival was lowest in grassland due to frequent silage cutting. Predation rates were highest in cereals but were not affected by field margin proximity. The highest reproductive success was achieved in lucerne, which was mown twice a year and retained a suitable height for breeding throughout the breeding season. We conclude that field margins are not sufficient to maintain a Skylark population in this intensively farmed area. The presumably more subtle effects of increased food availability cannot compensate for the high nest failure rates resulting from agricultural operations and predation. In this and similar areas, the provisioning of safe nesting habitat throughout the breeding season is essential to improve breeding performance. Our research suggests that this can be achieved by reducing the frequency of silage cutting on grassland and by increasing the surface area of lucerne. Show less
Isbell, F.; Craven, D.; Connolly, J.; Loreau, M.; Schmid, B.; Beierkuhnlein, C.; ... ; Eisenhauer, N. 2015
Agricultural intensification in grasslands has led to the decline of meadow bird populations in The Netherlands in the last 60 years. Habitat for meadow bird chicks has declined in quality and... Show moreAgricultural intensification in grasslands has led to the decline of meadow bird populations in The Netherlands in the last 60 years. Habitat for meadow bird chicks has declined in quality and quantity, thereby reducing food availability. Agri-environment schemes (AES) to halt the decline in meadow bird numbers have thus far been insufficient. These AES are on the level of entire fields, but recent research suggests that margins of fields may be more suitable chick habitat than centres of fields. Therefore, it could be productive to specifically target grass field margins as part of meadow bird AES. Our study examined the differences in food availability for meadow bird families in different portions of a grass field. Invertebrates were sampled in different locations on the field and results were compared to known dietary preferences of four species of meadow bird chicks. We show strong differences in food availability within fields, depending on meadow bird species. The preferred prey species of chicks of Black-tailed Godwit Limosa limosa and Redshank Tringa totanuspredominantly occurred in field margins, whereas those of Oystercatcher Haematopus ostraleguschicks were found mostly in the main part of the field. The prey species of Northern LapwingVanellus vanellus chicks showed no clear pattern within fields. We conclude that food availability within a field differs spatially between meadow bird species. Particularly for Black-tailed Godwit and Redshank, grass field margins constitute an important part of the field. Therefore, specific management to further enhance food availability in these margins may constitute an important addition to the existing mosaic approach. Show less
