Agroecosystems, are defined as communities of plants and animals interacting with their physical and chemical environments that have been modified by people to produce food, fibre, fuel and other products for human consumption and processing (Maes, 2018). They are composed by cropland and grassland, and cover about 47 % of the EU’s land area. To a very large degree these are managed ecosystems, only some grassland habitats exist in fact under a natural state. The history of agriculture spans for several millennia, a sufficient time to have specific species and habitats coevolving together with human management. The latter is key to maintain agroecosystems in good condition. But what is a good condition for a managed ecosystem, therefore in an ecosystem that exists to a great extent for the benefit of humans? The approach taken in this report is that a good condition requires balance: in the use of natural resources while maintaining biodiversity, in the supply of a set of ecosystems services, in the necessity to fulfil the needs of current as well as of future generations.
Agroecosystems host some of the most species-rich habitats in the EU (Wilson et al, 2012) and it is estimated that ca. 50% of all species in Europe rely on agricultural habitats at least to some extent (Halada et al., 2011; Lomba et al., 2015). Moreover, agrobiodiversity and in particular genetic resources for food and agriculture (wild crop relatives, plant varieties, landraces etc.) represent an insurance for the future, guaranteeing the capacity to respond to crises (climatic, economic etc.) contributing thus to food security.
50% of all species in Europe rely on agricultural habitats some extent
The report can be read in detail: here
Extent and change:
The extent of agroecosystems according to CORINE Land Cover (all eleven level-3 classes 2.x, of which ten are assigned to cropland ecosystems, and one -class 2.3.1 “Pastures”- assigned to grassland ecosystems) corresponds to almost 48% (2018) of total EU land area. The total area covered by agroecosystems has decreased by over 12 000 km² since 2000.A key driver for this was urbanisation, with 4 200 km² of agroecosystems irreversibly lost in a decade.
Drivers and pressures:
The assessment of pressures on agroecosystems focuses on three categories of pressures, deriving from: climate change, land conversion, pollution and nutrient enrichment.
The relation of agroecosystems with climate is twofold: farming activities shaping agroecosystems depend directly on climatic conditions (e.g. planting and sowing dates, water availability and irrigation, choice of species varieties better adapted to climate extremes etc.). Moreover, changing climatic conditions affect plant community traits and composition, leading to species range shifts e.g. in grassland habitats (Tardella et al, 2016; Choler P., 2018), and change in their usage (e.g. duration and intensity of grazing season) driving therefore a whole range of impacts on biodiversity. The perspective adopted in this assessment is that climate change creates a disturbance, leading to changes in the physiological responses of ecosystems, their time responses (e.g. phenology), and spatial distribution (Bellard et al. 2012). Therefore, even though some beneficial effects for some ecosystems are possible, e.g. in terms of increased primary productivity at the regional scale, significant changes are overall considered major cross-ecosystem drivers of degradation including agroecosystems . Generally, EU climate goes in the direction of having higher temperatures, longer warm periods, and milder winters.
Depositions of pollutants (nitrogen and sulphur) causing acidification and eutrophication on agroecosystems have decreased both in the short term and since 2000 (long-term trend). High deposition levels can in fact impact grassland structure and function, in particular by inducing changes in plant species composition, eutrophication and soil acidification (Henry and Aherne, 2014). The improvement is significant, 47% decrease per decade for the acidification component, 20% decrease for the eutrophication component.
Convergence of evidence
According to the results, 22% of the agroecosystems area shows improvement in at least three indicators (Figure 3.2.16), most of these are concentrated in the Northern part of the EU (Figure 3.2.15). Conversely, 27% of the agroecosystems area shows degradation in at least three indicators (Figure 3.2.18), mostly concentrated in the Southern part of the EU (Figure 3.2.17). In 28% of agroecosystems area five indicators show no change (Figures 3.2.19 and 3.2.20).
While pressures on agroecosystems have largely remained unchanged or even increased throughout the 2010-2020 decade, two thirds of condition indicators show either stable or declining trends.
The European Court of Auditors (ECA) in its 2020 assessment on the contribution made by the CAP to maintaining and enhancing biodiversity (ECA, 2020), found that the CAP has so far been insufficient to counteract declining biodiversity on farmland. The ECA recommendations to the European Commission are to:
1. improve coordination and design for the post-2020 EU biodiversity strategy – to this end also tracking expenditure more accurately;
2. enhance the contribution of direct payments to farmland biodiversity;
3. increase the contribution of rural development to farmland biodiversity;
4. develop reliable indicators to assess the impact of the CAP on farmland biodiversity.
The assessment presented in this report is based on trends calculated on the basis of available data, and therefore may overlook factors that would describe in a more complete way the dynamics of agroecosystem condition. Nevertheless, many relevant variables are considered and the main conclusion is that the degradation trend of agroecosystems was not halted in the 2010-2020 decade. Such trend departs from a condition of agroecosystems that had already been suffering long-term degradation and important biodiversity losses, while pressure levels are to a large degree unchanged or increasing. These are the same pressures that contributed in the past decades to biodiversity loss, which is still ongoing, as clearly shown by available biodiversity indicators. Therefore, when increasing pressures from a changing climate are added to the picture, there is no evidence that reversal of biodiversity trends and improvement of ecosystem condition will take place, if appropriate actions are not taken.