Changes in nutrient concentrations of leaves and roots in response to global change factors

Abstract: Global change impacts on biogeochemical cycles have been widely studied, but our understanding of whether the responses of plant elemental composition to global change drivers differ between above-and belowground plant organs remains incomplete. We conducted a meta-analysis of 201 reports...

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Bibliographic Details
Published in:Global Change Biology
Main Authors: Sardans, Jordi, Grau, Oriol, Chen, Han Y.H., Janssens, Ivan, Ciais, Philippe, Piao, Shilong, PeƱuelas, Josep
Format: Article in Journal/Newspaper
Language:English
Published: 2017
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Online Access:https://hdl.handle.net/10067/1451520151162165141
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Summary:Abstract: Global change impacts on biogeochemical cycles have been widely studied, but our understanding of whether the responses of plant elemental composition to global change drivers differ between above-and belowground plant organs remains incomplete. We conducted a meta-analysis of 201 reports including 1,687 observations of studies that have analyzed simultaneously N and P concentrations changes in leaves and roots in the same plants in response to drought, elevated [CO2], and N and P fertilization around the world, and contrasted the results within those obtained with a general database (838 reports and 14,772 observations) that analyzed the changes in N and P concentrations in leaves and/or roots of plants submitted to the commented global change drivers. At global level, elevated [CO2] decreased N concentrations in leaves and roots and decreased N: P ratio in roots but no in leaves, but was not related to P concentration changes. However, the response differed among vegetation types. In temperate forests, elevated [CO2] was related with lower N concentrations in leaves but not in roots, whereas in crops, the contrary patterns were observed. Elevated [CO2] decreased N concentrations in leaves and roots in tundra plants, whereas not clear relationships were observed in temperate grasslands. However, when elevated [CO2] and N fertilization coincided, leaves had lower N concentrations, whereas root had higher N concentrations suggesting that more nutrients will be allocated to roots to improve uptake of the soil resources not directly provided by the global change drivers. N fertilization and drought increased foliar and root N concentrations while the effects on P concentrations were less clear. The changes in N and P allocation to leaves and root, especially those occurring in opposite direction between them have the capacity to differentially affect above-and belowground ecosystem functions, such as litter mineralization and above-and belowground food webs.