Data from: Variations in root functional traits facilitate the adaptation of pioneer plants to rare earth element mine tailings

The trade-offs in plant root traits significantly influence the adaptation
and community dynamics in heterogeneous habitats. However, the role of
inter- and intraspecific root trait variation in the adaptation of pioneer
plants in stressed mine tailings is poorly understood. We assessed root
morphological and chemical traits of 16 dominant species from unexploited
forest sites adjacent to rare earth elements (REEs) mine tailings, and
three pioneer species (Miscanthus sinensis, Dicranopteris linearis, Pinus
massoniana) across a gradient of soil stress—including REEs toxicity,
nutrient deficiency, and compaction—from forest to REEs tailings. In the
two-dimensional root economics space (RES), the contents of cellulose,
hemicellulose, and silicon were coaxial with the collaboration gradients
(“do-it-yourself” – “outsourcing”) and inversely related to fine root
diameter. Meanwhile, root REEs content aligned with conservation gradients
(“fast” – “slow”), indicating a slow strategy. Interspecific variations
did not show a distinct strategy preference for pioneer species compared
to non-pioneer plants. However, notable intraspecific variations were
observed, particularly in stress-related traits such as root N content, C:
N ratio, and REEs content, which exceeded interspecific variations. All
three pioneer species exhibited a shift toward “slow” strategies, while P.
massoniana also transitioned toward “do-it-yourself” strategies, driven by
increased soil bulk density, elevated bioavailable REEs content, and
reduced soil carbon and nutrient levels in the tailings. Our findings
highlight the pivotal role of root chemical traits and intraspecific
plasticity in facilitating the adaptation of pioneer plants to extreme REE
tailing environments. The observed shifts toward stress-tolerant “slow”
strategies and “do-it-yourself” nutrient acquisition provide a trait-based
framework for advancing phytoremediation in the ecological restoration of
degraded mine tailings, such as informing plant species selection.