Nitrogen fertilisation is a common form of agricultural intensification, aimed at increasing biomass, which can affect plant species diversity and ecosystem functioning. Using a systematic review and meta-analysis of nitrogen fertilisation studies in European permanent grasslands, we asked: (i) what relationship form exists between nitrogen application rate and change in plant diversity, compared to zero fertilisation controls; and (ii) how grassland, management and study characteristics affect this relationship. Meta-analysis of 34 control-treatment effects from 14 studies conducted across nine European countries revealed a negative linear relationship between nitrogen fertilisation rate and change in plant species richness, equivalent to approximately 1.5 species/m2 lost for every 100 Kg ha−1 yr−1 of nitrogen added. Fertilisation induced reductions in plant species richness were greater when defoliation rates were lower. We found some evidence that grasslands with a higher baseline plant diversity lost more species when fertilised compared to more species poor grasslands, although uncertainty was high. Due to the diverse grassland types included in the analysis, the variability in fertilisation-driven changes in plant diversity was high. We identified several remaining limitations to our understanding, including uncertainty about non-linear effects, which could aid efforts to optimise the trade-off of plant diversity and increasing grassland yields.
Despite their importance for biodiversity and other ecosystem services, many semi-natural grasslands deteriorate or have even disappeared due to insufficient grazing and neglect. Preservation of grassland habitats depends on a good understanding of sustainable grazing management as well as effective agricultural policy measures that ensure long-term economic sustainability for the farmer. Through meta-evaluation and synthesis of previous investigations and discussion of scientific literature, we aimed to evaluate factors that determine the extent to which cattle and sheep in Sweden graze semi-natural grasslands instead of more productive land and what this means for biodiversity and sustainability. We also aimed to propose which practises and policy measures may be the most cost-effective to promote habitat quality and the sustainable use of grasslands. Results from a nationwide survey of Swedish farmers’ attitudes towards agri-environmental payment schemes are discussed in relation to farm characteristics and other factors influencing the use of cattle and sheep for sustainable grazing. This study supports recommendations by environmental economists that payments should be targeted more strongly at the most valuable grasslands, emphasising the need for a more detailed and nuanced framework for classifying grasslands in Europe. A comparison with independent estimates of the area of agricultural land from nation-wide, sample-based monitoring shows that the data from official statistics normally used for nationwide evaluations are partly biased and of insufficient quality, underscoring the need for more sophisticated and precise methods for monitoring both overall trends and detailed environmental effects related to the preservation of semi-natural grasslands.
A major task for decision makers is deciding how to consider monetary, cultural and conservation values of biodiversity explicitly when planning sustainable land use. Thus, there is a great need to understand just what “valuing” biodiversity or species really means, e.g. regarding how many and which species are important in providing ecosystem services or other values. Constructing ecosystem-level indices, however, requires weighting the relative contribution of species to the different values. Using farmland birds, we illustrate how species contribute to different biodiversity values, namely utilitarian (pest seed predation potential), cultural (species occurrence in poetry), conservational (declines and rarity) and inherent (all species equal) value. Major contributions to each value are often made by a subset of the community and different species are important for different values, leading to no correlations or, in some cases, negative correlations between species’ relative contributions to different values. Our results and methods using relative contributions of species to biodiversity values can aid decisions when weighing different values in policies and strategies for natural resource management. We conclude that acknowledging the importance of the range of biodiversity values that are apparent from different perspectives is critical if the full value of biodiversity to society is to be realised.
Conflicts between different goals can obstruct progress in sustainability, but interests may also coincide. We evaluated relationships between environmental quality and animal welfare on Swedish farms with grazing livestock, using publicly available databases. Data were collected from 8700 official animal welfare inspections on 5808 cattle farms and 2823 inspections on 2280 sheep farms in 2012–2017. Compliance with three animal-based checkpoints was modeled using logistic regression, including a random farm effect to account for repeated inspections. Compliance was regressed on semi-natural grassland area, participation in the National Meadow and Pasture Inventory, Agri-Environmental Scheme (AES) grassland payments, presence of indicator plant species, and the presence of Natura 2000 habitats. Cattle farms complied more often if they received AES payments for grasslands of special values compared with if they did not apply for them (OR = 1.55–1.65; p ≤ 0.0001) and there was a similar tendency for cattle farms that applied for but were denied such payments (OR = 1.29; p = 0.074). There was also a strong tendency for Natura 2000 habitats on cattle farms to be associated with higher compliance (OR = 1.36; p = 0.059). These results suggest a direct or indirect causal effect of biodiversity on cattle welfare. The same associations could not be shown in sheep.