1. Ecosystem productivity is largely dependent on soil nutrient cycling which, in turn, is driven by decomposition rates governed by locally-adapted belowground microbial and invertebrate communities. How climate change will impact soil biota and the correlated ecosystem functioning, however, remains largely an open question.
2. To address this challenge, we first characterized the functional identity of soil microbial and nematode communities originated from the foothills or in the sub-alpine soils of the Alps, and then, using a full-factorial reciprocal transplant common garden experiment at two elevations, we asked whether soil biota from low elevation were more prone in generating nutrient cycling than high elevation soil biota. Specifically, we separately transplanted soil microbial and nematode to community from low and high elevation in their home or opposite elevation in pots added with a common plant community. 
3. We found evidence for ecotypic and functional differentiation of the microbial and nematode communities growing in. We also observed a decrease in microbial diversity and activity at high elevation, and additionally, through nematodes’ functional characterization, we found increased fungal-dominated energy channels at high elevation.
4. Moreover, while we found little effect of soil biodiversity change based on elevation of origin on plant productivity, soils inoculated with microbes originating from low elevation respired more than those originating at high elevation. This observation correlates well with the observed faster carbon degradation rates by the low-elevation microbial communities.
5. Climate change can reshuffle soil invertebrate communities depending on organism-specific variation in range expansion, ultimately affecting soil fertility and vegetation productivity.

To measure ecotypic differentiation, and the relative contribution of soil microbes and nematodes from low and high elevations on soil productivity and respiration, we performed a full-factorial soil biota reciprocal transplant experiment in the Swiss Prealps. The soils and soil organisms were collected across three elevation transects, belonging to three different bioclimatic regions of Switzerland; the Vaud transect in the Northern Alps, the Valais transect in the Western Alps, and the Ticino transect in the Southern Alps, and at both low and high elevation ranging from 440m above sea level (asl) up to 1850m asl. Soil microbes and nematodes were extracted from high and low elevation soils, and reciprocally re-inoculated on soils from both elevations at the same transect location. The treatments consisted in inoculating about 1.5 L of the collected, autoclaved (2 cycles of autoclave at 121 °C) soils with high- or low-elevation soil biota (nematodes or microorganisms, separately). Soils were sieved at 2 cm prior autoclaving. The soil biota was added to the soils belonging to the same transects. All the soil-filled pots were then divided equally in two batches and placed at both common garden sites (N = 4 replicates * 2 common garden sites * 2 soil biota treatments * 2 elevations of origin for soil biota * 2 elevations of origin for the soils * 3 transects = 192 pots).

Each data set in ".xls" format is composed of two tabs, the first tab contains the data, and the second tab called "metadata" includes the details and legends of the data tab.

The available data sets are as follows:

• Explanation of experimental design with inoculum & soil details, see "ReciprocalTranspl.Inoculum_data.xls"
• Fungi data, see "Fungal_Merged_taxa_aboundance_ITS.xls" 
• Bacterial data, see "Bacterial_Merged_taxa_aboundance_ITS" 
• Microbial community analysis, see "MicrobialCommunityAnalysis_EcoPlates_data.xls"
• Plant community data, see "ReciprocalTransplant_Plant_data.xls"
• Nematode community analysis, see "Nematode_NIJA_data.xls"
• Soil physicochemical propreties, see "SoilProperites_data.xls"

If any questions, contact the corresponding authors