Climatic warming is predicted to affect high-latitude habitats, such as boreal peatlands, at a larger magnitude than the global average. The controls on the breakdown of organic matter in peatlands are complex; it’s unclear how climatic warming will affect the stability of the large carbon pool that’s currently stored in peatlands. To investigate this, we collected soil cores from three boreal habitats along a hydrological transect (Bog, Intermediate, and Upland Forest) in Finland, and incubated ex-situ for 140 days. Each soil horizon was incubated in three temperatures (0°C, 4°C, 20°C). Here, we found the Intermediate site had the largest CO2 production considering the entirety of the soil column (per gram dry weight). Statistical analysis found that sample C content was the most indicative independent variable to predict sample CO2 production. Each soil horizon displayed a different magnitude of response to the temperature incubations (Q10s ranged from 0.60-2.33), and through microbial relative abundance analysis we found that the microbial community structure had significant differences between both habitat and depth of sample origin. Coupling these methods, and the fine scale of the both vertical (soil column horizons) and horizontal (along a hydrological gradient through distinct habitats) transects gives us a novel perspective on the controls of microbial respiration rates. Our results stress that large scale modeling efforts of carbon dynamics should prioritize both soil carbon quantity and quality.

An estimated 8.7 million eukaryotic species exist on our planet. However, recent tools for taxonomic classification of eukaryotes only dispose of 734 reference genomes. As most Eukaryotic genomes are yet to be sequenced, the mechanisms underlying their contribution to different ecosystem processes remain untapped. Although approaches to recover Prokaryotic genomes have become common in genome biology, few studies have tackled the recovery of Eukaryotic genomes from metagenomes. This study assessed the reconstruction of Eukaryotic genomes using 215 metagenomes from diverse environments using the EukRep pipeline. We obtained 447 eukaryotic bins from 15 classes (e.g., Saccharomycetes, Sordariomycetes, and Mamiellophyceae) and 16 orders (e.g., Mamiellales, Saccharomycetales, and Hypocreales). More than 73% of the obtained eukaryotic bins were recovered from samples whose biomes were classified as host-associated, aquatic and anthropogenic terrestrial. However, only 93 bins showed taxonomic classification to (9 unique) genera and 17 bins to (6 unique) species. A total of 193 bins contained completeness and contamination measures. Average completeness and contamination were 44.64% (σ=27.41%) and 3.97% (σ=6.53%), respectively. Micromonas commoda was the most frequent taxa found while Saccharomyces cerevisiae presented the highest completeness, possibly resulting from a more significant number of reference genomes. However, mapping eukaryotic bins to the chromosomes of the reference genomes suggests that completeness measures should consider both single-copy genes and chromosome coverage. Recovering eukaryotic genomes will benefit significantly from long-read sequencing, intron removal after assembly, and improved reference genomes databases.