DOI: 10.5061/dryad.83bk3j9wj
title: Temperature drives the coordination between aboveground nutrient conservation and belowground nutrient acquisition in alpine coniferous forests

description: Aboveground nutrient conservation via resorption processes and belowground
 nutrient acquisition from soils are two important mechanisms for plants to
 maintain nutrition and ecosystem functions. However, the mechanism by
 which plants coordinate these two nutrient strategies, especially for
 ectomycorrhizal (ECM)-dominated conifers in alpine forests, remains
 unclear. We investigated the relationships between aboveground nutrient
 conservation and belowground nutrient acquisition and their environmental
 drivers by measuring leaf nutrient (i.e., nitrogen [N] and phosphorous
 [P]) resorption efficiency, resource foraging- and uptake-related root
 morphological (root diameter [RD], specific root length [SRL]/area [SRA])
 and physiological (root tissue density [RTD], root N and P concentration)
 traits, mycorrhizal colonization rate (MCR), rhizosphere effect on soil N
 and P cycling, and environmental factors of 40 ECM coniferous populations
 on the eastern Tibetan Plateau, China. Our results show that with
 increasing leaf nutrient (N and P) resorption efficiency, conifers shifted
 from depending on the ‘outsourcing’ strategy by mycorrhizal fungi (high
 MCR) to relying on the ‘do-it-yourself’ strategy of root mining (high
 rhizosphere effect on N- and P-mining-related enzyme activities) rather
 than on root foraging (high SRL and SRA) and preferred more conservative
 roots (high RTD and low root N and P concentrations). Temperature was the
 main factor driving a negative relationship of ECM fungi foraging, root
 uptake and a positive relationship of root mining with leaf nutrient
 resorption, while precipitation resulted in a decoupled relationship
 between root foraging and leaf nutrient resorption. Our findings
 demonstrate temperature-driven and diverse collaborations (e.g., tradeoff
 or synergy) between belowground nutrient acquisition and aboveground
 nutrient conservation strategies in alpine ECM conifers and highlight that
 the preference for belowground nutrient acquisition strategies could
 influence the aboveground nutrient utilization strategy. This is
 insightful for a holistic understanding of the adaptation and responses of
 alpine forests to climatic change.
description: This data set was
 collected in the alpine region of the eastern Tibetan
 Plateau, which spans a wide geographic range, from latitude 27.37 to
 35.27° N, longitude 94.55 to 103.31° E, and with an altitude of
 2562.0-4351.0 m a.s.l. Forty pure forest stands were selected for leaf,
 root, and soil collection in July and August 2017-2018. Specifically, we first set up three to five 30 m × 40 m
 experimental plots in each stand; then, in each plot, at least three
 mature and healthy individuals of a target conifer species were randomly
 selected for leaf and
 root collections. For each
 individual, three representative twigs from sun-exposed, first-order
 branches were collected from the mid to upper canopy using pole pruners,
 and then the fully expanded, current-year needles of each cohort were
 immediately detached from the twigs. Accordingly, freshly fallen leaf
 litter was collected under the canopy of the same individual in a similar
 position to that of the green leaves. Here, only the terminal two orders of a root
 branch were sampled because of their highest absorptive activity and
 mycorrhizal colonization in the root branch (Guo et al.,
 2008). Once collected, the
 leaf, root, and soil samples in each plot were separately combined to make
 one composite sample to minimize any heterogeneity caused by sampling
 positions and immediately placed on ice, transported to the laboratory,
 and kept at -20 °C prior to further analyses.
description: Column, Entry, Description, Unit * A, Site, Sample site, * B, MAT, mean
 annual temperature, ℃ * C, MAP, mean annual precipitation, mm * D, pH,
 Soil pH, wet and dry * E, STC, Soil total carbon, g/kg * F, STN, Soil
 total nitrogen, g/kg * G, STP, Soil total phosphorus, g/kg * H, NRE, Leaf
 N resorption efficiency, % * I, PRE, Leaf P resorption efficiency, % * J,
 RD, Root diameter, mm * K, SRL, Specific root length, m/g * L, SRA,
 Specific root area, cm<sup>2</sup>/g * M, RTD, Root tissue
 density, g/cm<sup>3</sup> * N, RNC, Root nitrogen
 concentration, g/kg * O, RPC, Root phosphorus concentration, g/kg * P,
 MCR, Mycorrhizal colonization rate, % * Q, RE(NAG+LAP), "Rhizosphere
 effect on N-mining related enzyme activity (i.e.,
 β‐1,4‐N‐acetylglucosaminidase and leucine aminopeptidase)", % * R,
 REAP, "Rhizosphere effect on P-mining related enzyme activity (i.e.,
 acid phosphatase)", %