The influence of soil age on ecosystem structure and function across biomes

The importance of soil age as an ecosystem driver across biomes remains largely unresolved. By combining a cross-biome global field survey, including data for 32 soil, plant, and microbial properties in 16 soil chronosequences, with a global meta-analysis, we show that soil age is a significant ecosystem driver, but only accounts for a relatively small proportion of the cross-biome variation in multiple ecosystem properties. Parent material, climate, vegetation and topography predict, collectively, 24 times more variation in ecosystem properties than soil age alone. Soil age is an important local-scale ecosystem driver; however, environmental context, rather than soil age, determines the rates and trajectories of ecosystem development in structure and function across biomes. Our work provides insights into the natural history of terrestrial ecosystems. We propose that, regardless of soil age, changes in the environmental context, such as those associated with global climatic and land-use changes, will have important long-term impacts on the structure and function of terrestrial ecosystems across biomes.


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October 2018
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The importance of soil age as an ecosystem driver across global biomes remains largely undetermined. To fill this knowledge gap, here, we combined a new field survey including data for 32 soil, plant, and microbial properties across 16 globally distributed soil chronosequences, with a global meta-analysis.
Vegetation information and soil samples coming from 16 globally distributed soil chronosequences. We complemented this information with a data synthesis from the literature including 48 additional comparable soil chronosequences. Detailed information on the investigated 16 chronosequences can be found in the method section, Fig. 1 and Supplementary Table 1. We also collected data from 48 global soil chronosequences. Information on these locations can be found in the method section, Fig. 3 Soil and vegetation data were collected using standardized protocols between 2016 and 2017 from 16 soil chronosequences located in nine countries and six continents. Field surveys were conducted according to a standardized sampling protocol. We surveyed a 50 m × 50 m plot within each chronosequence stage, and within each quadrat, collected five composite surface soil samples from the surface 10 cm soil under the dominant vegetation types (e.g., trees, shrubs, grasses etc). Within each 50x50m plot, three 50-m parallel transects were established, spaced 25 m apart. These transects were used in our vegetation surveys. The replication numbers were comparable to those in most publications within the field of knowledge.
We collected an extensive amount of new field data from 16 soil chronosequences across global biomes (Fig. 1), and collected information for 32 topsoil, plant and microbial ecosystem properties. Detailed information about the methods used to obtain this information can be found in the Method section and in Supplementary Methods 1. Detailed information on the investigated 16 chronosequences can be found in the method section, Fig. 1  Soil and vegetation data were collected using standardized protocols between 2016 and 2017 from 16 soil chronosequences located in nine countries and six continents ( Fig. 1 and Supplementary Table 1) No data were excluded from analyses.
Information about the sampled locations and methods used in this paper are included in our material and methods Field-based samples were collected, a priori, for sites of known soil age and data analysed using these a priori classes. Therefore there was no allocation of data to classes a posteriori.

N/A
We conducted a field survey in 16 globally distributed soil chronosequences. These chronosequences were selected to include a wide range of climates (tropical, temperate, continental, polar and arid) and vegetation types (including grasslands, shrublands, forests, and forblands).
We conducted a global field survey in 16 soil chronosequences from nine countries and six continents. Detailed information on these locations can be found in the method section, Fig. 1  Samples were collected by all authors in their respective locations and using local permits.
This study did not cause any environmental disturbance