Nature and ecosystems provide a number of benefits to humans through ecosystem processes, i.e. water infiltration in soils or nutrient uptake by plant roots. This set of benefits are what we call Ecosystem Services. However, not all ecosystem services occur together in the same location and time. On the other hand, certain ecosystem services repeatedly appear together in time and/or space. These groups of ES are known as bundles. The ES that form a bundle can interact together, leading to synergies and trade-offs, when the interaction is positive or negative respectively.
We talk about synergies when the use of one ES would increase the benefits supplied by another service or group of services. The implications of this type of interaction are of high importance for planning and management strategies. For example, maintaining a high number of perennial grassland species in semi-natural grasslands both supports habitats but also attracts a high number of pollinators: bees, butterflies and bumblebees. By enhancing the population of pollinators, we also increase the pollination rate in nearby cultivars, highlighting the fact that the synergies can happen also at different locations.
The term trade-offs refers to an interaction in which some ecosystem services are provided at the expense of others. This means that an increase in the production of a service would decrease the production and benefits of other service. A clear example in the context of grasslands is the tradeoff between biomass production and biodiversity and habitats: Increasing grasslands productivity usually requires a certain degree of intensification through fertilization, ploughing and reseeding with a mix of selected species. These intensification practices in turn simplify grasslands’ structure and decrease the number of grassland species, leading to a loss of habitats for birds and arthropods.
Within LIFE Vivagrass project, 3 bundles have been identified in the study areas, namely:
- Production synergy: This synergy is formed by 3 ecosystem services closely related to the productivity of ecosystems: Reared animals and their outputs, fodder and biomass for energy. In this particular synergy, the underlying ecosystem function that drives the production of the three ES is the net primary production, or biomass production. Therefore, the increase in one of the services in this bundle usually means an increase in the other two services. However, biomass for energy not only depends on the productivity of grasslands, but also on the calorific potential of grassland species.
- Habitats synergy: 4 ecosystem services interact in this bundle: Herbs for medicine, pollination, maintaining habitats and global climate regulation. The increase in one of the services in this bundle usually means an increase in the other two services. For example, in species rich grasslands, we are also likely to find a wide range of herbs with a medicinal value. Moreover, grassland management practices that aim to increase biodiversity, such us the reduction or complete elimination of plowing, and fertilization, also increase the carbon sequestration capacity of soils, which is a key service for the regulation of climate.
- Soil synergy: The 3 ecosystem services that form this bundle are related with the role of soil functions in ecosystem processes: Bio-remediation, filtration/storage/accumulation and chemical condition of fresh waters. The increase in one of the services in this bundle usually means an increase in the other two services.
A fourth interaction between ES was identified as a trade-off between production and habitat bundles: As explained before, management strategies that aim at increasing the productivity of ecosystems also lead to a decrease in the number of grassland species and consequently a decrease in pollination services.