Effect of sieving and sample storage on soil respiration and its temperature sensitivity (Q10) in mineral soils from Germany

Abstract

Knowledge about spatial patterns of soil respiration (SR) and its temperature sensitivity (Q10) is of emerging relevance for assessing carbon fluxes across the landscape. Related experiments are often conducted under controlled laboratory conditions and usually rely on soil samples, which are sieved and stored. Here, we investigated the effect of sieving and storage on SR and Q10. We took 14 samples from different land use types and soil textures. Samples were sieved to 2 mm at field-moist conditions and split into four treatments: sieved/no-storage, sieved/freeze-storage (−18°C), sieved/cold-storage (+ 4°C), and sieved/drystorage (+ 40°C). The storage time was 7 weeks. Intact soil cores were used as a control. The SR was not significantly affected by sieving/no-storage, sieving/freeze-storage, and sieving/cold-storage compared with the control. Yet, sieving/dry-storage significantly increased SR but all samples were similarly affected (r = 0.81 for the correlation between SR after sieving/dry-storage and SR in the control). The Q10 of sieving/no-storage (1.94 ± 0.28), sieving/freeze-storage (1.94 ± 0.23), sieving/cold-storage (2.37 ± 0.29), and sieving/dry-storage (2.29 ± 1.35) did not differ significantly from the control (2.12 ± 0.23). All samples responded similar to sieving and storage (r = 0.68-0.73 for the correlation between Q10 in each respective treatment and Q10 in the control), with the exception of sieved/dry-storage (r = 0.09). We conclude that sieving at field-moist conditions and subsequent freeze-or cold-storage is acceptable to derive SR and Q10 for the here reported storage time. Although dry-storage may be acceptable for the comparison of SR between samples, it should be avoided for realistic estimates of SR and for the determination of Q10.

Simulated rhizosphere deposits induce microbial N‐mining that may accelerate shrubification in the subarctic

“…It is possible that the physical disturbance during soil sampling could have impacted measured microbial parameters, reducing our sensitivity to detect differences among the treatments. However, previous studies found no effects of sieving field‐moist soils on microbial respiration (Meyer et al 2019), and only minor effects on PLFA composition, with sieving primarily reducing the concentration of the fungal biomarker (18:2ω6,9), likely due to the filamentous nature of fungi making them more susceptible to the disturbance (Petersen and Klug 1994). Despite this, we found that the fungal biomarker was one of the PLFAs that drove separation in the microbial community structure among the field treatments, indicating that the signal driven by the field treatments remained stronger than that potentially introduced by the sampling disturbance.…”

Relating four‐day soil respiration to corn nitrogen fertilizer needs across 49 U.S. Midwest fields

“…However, accounting for the incubation duration, the soil respiration rates were approximately the same. From this, it can be presumed that sample storage for two years had a minor effect on soil respiration (Meyer, Welp, & Amelung, 2019). Further, the relative differences among sites followed the same trend for both tests, finding that sites with lower respiration measurements prior to storage were still lower following storage.…”

Land‐use drives the temporal stability and magnitude of soil microbial functions and modulates climate effects

“…Although standard sieving and storage/freezing procedures can preserve functions, such as microbial respiration, for up to seven weeks (Meyer et al 2019), modifications and stricter measurement timelines may be necessary to limit confounding effects of storage on other soil functions and their temporal dynamics. In this study, longer storage times prior to Microresp experiments may have influenced functional diversity measurements through driving metabolic shifts toward carboxylic acids and recalcitrant organic matter (Goberna et al 2005).…”