DOI: 10.5061/dryad.wpzgmsbnb
title: Win some, lose some: mesocosm communities maintain community productivity despite lower phosphorus availability because of increased species diversity

description: Aims The restoration of degraded ecosystems typically focuses on
 establishing assemblages of target species, but successful recovery should
 also be evaluated by the ecosystem’s functioning to guarantee long-term
 persistence. We investigated how the processes underlying community
 assembly (i.e. species loss, species gain and changes in abundance of
 resident species) influenced ecosystem functioning in experimental
 grassland communities in different restoration states. Location A
 greenhouse experiment in Northern Flanders, Belgium. Methods We set up a
 mesocosm experiment with communities of nineteen planted species, ranging
 from slow-growing species from poorly productive Nardus grasslands to
 fast-growing species from highly productive Lolium perenne grasslands. We
 categorized the mesocosms into different grassland restoration states
 based on known abiotic and biotic restoration barriers for semi-natural
 grassland restoration: soil phosphorus levels and soil biota communities.
 After two growing seasons, we used the CAFE approach, an ecological
 application of the Price equation, to partition the effects of plant
 community assembly on ecosystem functioning (here community productivity)
 for the different restoration states. Results Adding soil biota
 communities sampled from reference Nardus grasslands versus more
 intensively managed grasslands did not have a significant effect on either
 plant species richness or biomass productivity. Lower soil phosphorus
 concentrations (i.e. abiotic restoration) resulted in a higher plant
 species richness. However, the net effect on productivity was close to
 zero. The increase in productivity caused by species gains was compensated
 through decreases in productivity caused by species loss and by decreases
 in the abundance or functioning of species that are present in both
 abiotically degraded and abiotically restored states. Conclusions Not only
 species richness but also species identity resulted in changes in
 ecosystem functioning (i.e. productivity), even though the net functional
 effects were close to zero. More specifically, we found that species
 richness-driven increases in productivity were counterbalanced by
 resource-driven and species identity-driven reductions in productivity.
description: In June
 2017, the harvested biomass was sorted per species, dried for 48 h at
 70°C, and weighed. Summing the biomass across species gave the total
 community biomass, which we used as measure for the aboveground
 productivity. Immediately after biomass harvest, the 0-5 cm mineral soil
 layer of each mesocosm was sampled (n=3) with a 1 cm diameter auger.
 Analysis of bioavailable phosphorus (P<sub>Olsen</sub>) was
 done on the dried soil samples (48h, 40°C) with an extraction with sodium
 bicarbonate according to Olsen <i>et al.</i> (1954) and
 colorimetric measurement with the malachite green procedure of Lajtha
 <i>et al.</i> (1999).
description: The readme file ('DeCock_AVS_Readme.txt') contains an
 explanation of each of the variables in the dataset, its measurement
 units, and the allowed range as well as information on the
 measurements.