Temperature and carbon dioxide interactively drive shifts in the compositional and functional structure of peatland protist communities

Microbes affect the global carbon cycle that influences climate change and are in turn influenced by environmental change. Here, we use data from a long-term whole-ecosystem warming experiment at a boreal peatland to answer how temperature and CO2 jointly influence communities of abundant, diverse, yet poorly understood, non-fungi microbial Eukaryotes (protists). These microbes influence ecosystem function directly through photosynthesis and respiration, and indirectly, through predation on decomposers (bacteria, fungi). Using a combination of high-throughput fluid imaging and 18S amplicon sequencing, we report large climate-induced, community-wide shifts in the community functional composition of these microbes (size, shape, metabolism) that could alter overall function in peatlands. Importantly, we demonstrate a taxonomic convergence but a functional divergence in response to warming and elevated CO2 with most environmental responses being contingent on organismal size: warming effect..., , , # Data from: Temperature and carbon dioxide interactively drive shifts in the compositional and functional structure of peatland protist communities

## General Information

**Date of data collection:** June and September 2019

**Geographic location of data collection:** S1-Bog of the Marcell Experimental Forest (47° 30.4760′ N, 93° 27.1620′ W; 418 m above mean sea level), Minnesota, USA

## Study Description

This dataset contains protist trait measurements, abundance data, and taxonomic composition data from the SPRUCE (Spruce and Peatland Responses Under Changing Environments) long-term whole-ecosystem warming experiment. Samples were collected from experimental enclosures with factorial temperature (+0, +2.25, +4.5, +6.75, +9°C above ambient) and CO2 treatments (ambient 450 ppm and elevated 900 ppm). Protist communities were analyzed using fluid imaging (FlowCAM) and 18S rRNA gene amplicon sequencing.

## File Descriptions

### 1. SPRUCE_2019.csv

**Description:** Raw protist trait ...,