Land use intensification results in abrupt transitions between
contrasting grassland states
Abstract
Understanding whether land use intensification causes regime shifts is
of key importance for management, particularly if these shifts are
associated with thresholds separating different ecosystem states and
with hysteretic dynamics. Here we use a unique, long-term grassland
database to identify thresholds in the response of 16 ecosystem
functions and the diversities of 21 taxa to land use intensity. We show
that aboveground diversity (5 of 10 taxa), shoot biomass and soil N
retention showed threshold responses to land use intensity, i.e., abrupt
changes between extensively and intensively managed grasslands.
Time-series analysis revealed that ecosystem functions showed hysteresis
around the threshold, while diversity did not. Shifting back to the
functioning seen in extensively managed grasslands may therefore require
larger reductions in land use intensity than shifting to the high
intensity state. Identifying such thresholds along land use gradients is
critical to prevent ecosystem degradation and conserve biodiversity and
ecosystem functions.