Data from: Grassland restoration drives strong multitrophic biodiversity recovery, but climate extremes jeopardize drought-sensitive species

Semi-natural grasslands, Europe’s most biodiverse ecosystems, are rapidly
declining due to agricultural intensification, abandonment, and
afforestation, leading to biodiversity loss and reduced ecosystem
function. Despite their ecological value, grasslands are often overlooked,
while afforestation, for instance, is prioritized for climate mitigation.
This study assessed the effects of grassland abandonment, afforestation,
and ecological restoration on multitrophic species richness and soil
conditions. We used Estonian semi-natural calcareous grasslands (alvars)
as a model system. We surveyed different taxa in proximity to a fixed,
permanently marked point, which was chosen to be reflective of the average
subsite condition. Results showed that historical overgrown and afforested
grasslands recover fast and rapidly become species-rich after woody plant
removal and low-intensity grazing reinstatement. These grasslands also
serve as stable carbon sinks, storing soil carbon at levels comparable to
afforested grassland areas, with restoration having no negative impact on
carbon storage. Multitrophic species richness responded to restoration in
three main ways: fast responders (plants, pollinators, birds) recovered
relatively quickly, slow responders (lichens, bryophytes, soil fungi)
showed little to no short-term change, and drought-sensitive species
(ground-dwelling arthropods) declined due to prolonged drought, which also
potentially overshadowed the impact of restoration. Grassland restoration
is vital for biodiversity, sustainable supply of ecosystem services, and
climate resilience, with long-term monitoring needed to track recovery.