Periodic Reporting for period 1 - PlantSoilAdapt (Eco-evolutionary dynamics in plant-soil interactions during land use transition: consequences for soil functioning and resilience to drought)
Reporting period: 2022-09-01 to 2025-02-28
Human activity is having a huge impact on natural world, and we need to understand the limits of what different species can endure and what can be done to improve their chances of survival and persistence under changing climate. European grasslands have been shaped by millennia of low-intensity management and are unique cultural and biodiversity hotspots providing critical ecosystem services. However, the area of traditionally-managed grassland has declined dramatically during the last century, with land-use intensification on productive soil and abandonment of unfertile land both causing species loss and deterioration of ecosystem services. Recent evidence suggests that land-use change also leads to genetic changes in plant populations. How such changes cascade to ecosystem functions and affect adaptive potential to future perturbations is entirely unknown. Filling this knowledge gap is urgent as grasslands face additional pressure from climate change, particularly an increasing frequency of droughts. PlantSoilAdapt project aims to reveal the consequences of land use change for grassland plants with particular focus on plant characteristic that shape the movement of carbon and nutrients within ecosystems. Conversion of grasslands to arable land, fertilisation of grasslands with mineral fertilisers, and tree and shrub encroachment in abandoned grasslands, can disrupt co-evolved mutualistic plant-microbial interactions, with cascading effects on essential ecosystem services provided by soils and their resilience to droughts. This project uses a range of study systems across Europe, representing different histories and contrasting management regimes, to reveal the pressures imposed on plant-soil systems by human land use and will inform future policies for sustainable land management and maintenance of adaptive potential in the face of climate change.
To assess functional and adaptive potential of grassland plants across different land management histories, we have collected grass genotypes from a range of traditionally managed grasslands and those that have been fertilized or abandoned for several decades, grass populations from grasslands of different age (ancient grasslands and those that were ploughed for arable production and then re-established as grasslands), and populations from five long-term fertilization experiments across Europe (two in UK, Netherlands, Austria and Germany). This resulted in a unique, extensive collection of grass genotypes across many populations with long history of distinct land use. This collection of genetic material now allows us to tackle many questions regarding how plant characteristics evolve in response to land use, what happens with plant functional diversity when land use changes, and how these changes in plants cascade to affect overall ecosystem processes such as productivity, carbon and nutrient flow and microbial activity in soil. Several experiments are now underway to link plant functional traits and their diversity to grassland resilience to drought and feedbacks between plant productivity and soil microbial communities and activity.
Investigation of changes in plant characteristics in response to grazing abandonment revealed that plant populations undergo evolutionary shifts that can potentially affect ecosystem functions and resilience to stress. These changes can only be detected in laboratory conditions but will be entirely masked if we only rely only on simple habitat surveys. This is crucial information for nature conservation and restoration of habitats highlighting the urgent need for more rigorous biodiversity monitoring. Secondly, we found that ancient grassland soils provide higher drought resistance to plants and promote more positive plant-microbial interactions only when plant and soil are locally adapted to each other. This is an important finding highlighting the value of preserving remaining undisturbed habitats as these will be more resilient to climate change impacts. It also highlights that restored habitats may be less resilient to climate change as long time is needed for plants and soil microbiomes to co-adapt. These findings are relevant for the ambitious goal set by the European Union to restore biodiversity and enhance resilience to climate change.