ausblenden:
Schlagwörter:
silicate weathering, ecosystem nutrition
Zusammenfassung:
With this data, we expand the data set characterizing the Critical Zone geochemistry along the Chilean Coastal Cordillera provided by Oeser et al. (2018). This data set completes the results of bulk geochemical analysis of bedrock and regolith with those of bulk analysis of major plants and those of the bio-available fraction in saprolite and soil (determined using a modified sequential extraction method on bulk regolith samples after Arunachalam et al., 1996; He et al., 1995; Tessier et al., 1979). For all those compartments of the Earth’s Critical Zone, we further present 87Sr/86Sr isotope ratios. A detailed graphical presentation and discussion of this data as well as method description is given in Oeser and von Blanckenburg (2020), Decoupling primary productivity from silicate weathering – how ecosystems regulate nutrient uptake along a climate and vegetation gradient.
Using this data, we were thus, able to determine weathering rates and nutrient uptake along the “EarthShape” climate and vegetation gradient in the Chilean Coastal Cordillera and to identify the sources of mineral nutrients to plants. Ultimately, we were able to budget inventories, gains and losses of nutritive elements in and out of these ecosystems and to quantify nutrient recycling. We found that the weathering rate does not increase from north to south along the climate gradient. Instead, the increase in biomass growth rate is accommodated by faster nutrient recycling. The absence of an increase in weathering rate in spite of a five-fold increase in precipitation led us to hypothesize that the presence of plants even negatively impacts weathering through reducing the water flow, inducing secondary-mineral formation, and fostering a microbial community specializing on nutrient-recycling rather than nutrient-acquisition through weathering.
All samples are assigned with International Geo Sample Numbers (IGSN), a globally unique and persistent Identifier for physical samples. The IGSNs are provided in the data tables and link to a comprehensive sample description in the internet.
