Data from: Trait-based selection of nurse plants to restore ecosystem functions in mine tailings

1.Metal mining in drylands generates waste tailings with high toxicity,
physical instability, as well as water and thermal stresses, that hamper
their biological colonisation. This limits the restoration of ecosystem
functions that are essential to re-integrate these artificial
micro-deserts within the landscape matrix. 2.We assessed the functional
role of local nurse plant species and their traits to restore ecosystem
functions related to soil fertility, soil microbial productivity and the
reduction of abiotic stress. We sampled 30 metalliferous tailings in a
mining district from semiarid Spain to detect nurse plant species and
quantify their ability to promote essential functions from their
establishment on the barren substrate up to the adult stage. 3.We found 11
plant species acting as nurses out of 102 species able to colonise barren
soils. Ten nurses further triggered a cascade of effects increasing soil
fertility and microbial productivity and/or lowering soil abiotic stress.
4.Plant species with larger life forms and longer periods of establishment
since tailing abandonment contributed the most to the promotion of
ecosystem functions. C4 plant species developing root systems with lower
intensivity and depth: laterality ratios, as well as leaves with lower
carbon: nitrogen ratios (C:N) induced a faster recovery of ecosystem
functions. 5.Synthesis and applications. We propose a protocol for
selecting key species to be used in restoration programs based on their
ability to restore ecosystem functions under extremely stressful
conditions. We encourage combination of multiple target species with
complementary traits in order to reinforce the rehabilitation of ecosystem
functions.