Data from: Root community traits along a land use gradient: evidence of a community-level economics spectrum

1. There is a fundamental trade-off between leaf traits associated with either resource acquisition or resource conservation. This gradient of trait variation, called the economics spectrum also applies to fine roots but whether it is consistent for coarse roots or at the plant community level remains untested. 2. We measured a set of morphological and chemical root traits at a community level (functional parameters; FP) in 20 plant communities located along land-use intensity gradients and across 3 climatic zones (Tropical, Mediterranean and Montane). We hypothesized (i) the existence of a root economics spectrum in plant communities consistent within root types (fine, < 2 mm; coarse, 2-5 mm) but that ii) variations in root traits occur with soil depths (top 20 cm of soil and 100-150 cm deep) and iii) along land use gradients thus leading to variation in root FP. 3. Root FP co-varied, in line with the resource acquisition-conservation trade-off, from communities with root FP syndromes associated to resource acquisition (e.g. high specific root length, SRL; thin diameters and low root dry matter contents, RDMC) to root FP syndromes associated with resource conservation (e.g. low SRL, thick diameters and high RDMC). This pattern was consistent for both fine and coarse roots indicating a strong consistency of a trade-off between resource acquisition and conservation for plant roots. 4. Roots had different suites of traits at different depths, suggesting a disparity in root function and exploitation capacities. Shallow, fine roots were thinner, richer in nitrogen and with lower lignin concentrations associated to greater exploitation capacities compared to deep, fine roots. However, shallow coarse roots were richer in nitrogen, carbon and soluble concentrations than deep, coarse roots. 5. Fine root parameters of highly disturbed, herbaceous dominated plant communities in poorer soils were associated to foraging strategies, i.e. greater SRL and lower lignin and RDMC than those from less disturbed communities. Coarse roots however, were less sensitive to the land use gradient. 6. Synthesis This study demonstrates the existence of a general trade-off in root construction at a community level, which operates within all root types suggesting that all plant tissues are controlled by the trade-off between resource acquisition and conservation