Does long-term soil warming affect microbial element limitation?

A test by short-term assays of microbial growth responses to labile C, N and P additions

verfasst von

Chupei Shi, Carolina Urbina-Malo, Ye Tian, Jakob Heinzle, Steve Kwatcho Kengdo, Erich Inselsbacher, Werner Borken, Andreas Schindlbacher, Wolfgang Wanek

Abstract

Increasing global temperatures have been reported to accelerate soil carbon (C) cycling, but also to promote nitrogen (N) and phosphorus (P) dynamics in terrestrial ecosystems. However, warming can differentially affect ecosystem C, N and P dynamics, potentially intensifying elemental imbalances between soil resources, plants and soil microorganisms. Here, we investigated the effect of long-term soil warming on microbial resource limitation, based on measurements of microbial growth (¹⁸O incorporation into DNA) and respiration after C, N and P amendments. Soil samples were taken from two soil depths (0–10, 10–20 cm) in control and warmed (>14 years warming, +4°C) plots in the Achenkirch soil warming experiment. Soils were amended with combinations of glucose-C, inorganic/organic N and inorganic/organic P in a full factorial design, followed by incubation at their respective mean field temperatures for 24 h. Soil microbes were generally C-limited, exhibiting 1.8-fold to 8.8-fold increases in microbial growth upon C addition. Warming consistently caused soil microorganisms to shift from being predominately C limited to become C-P co-limited. This P limitation possibly was due to increased abiotic P immobilization in warmed soils. Microbes further showed stronger growth stimulation under combined glucose and inorganic nutrient amendments compared to organic nutrient additions. This may be related to a prolonged lag phase in organic N (glucosamine) mineralization and utilization compared to glucose. Soil respiration strongly positively responded to all kinds of glucose-C amendments, while responses of microbial growth were less pronounced in many of these treatments. This highlights that respiration–though easy and cheap to measure—is not a good substitute of growth when assessing microbial element limitation. Overall, we demonstrate a significant shift in microbial element limitation in warmed soils, from C to C-P co-limitation, with strong repercussions on the linkage between soil C, N and P cycles under long-term warming.

Organisationseinheit(en)

Institut für Bodenkunde

Externe Organisation(en)

Universität Wien
Bundesforschungs- und Ausbildungszentrum für Wald, Naturgefahren und Landschaft (BFW)
Universität Bayreuth
University of Natural Resources and Applied Life Sciences
Universiteit van Amsterdam (UvA)

Typ

Artikel

Journal

Global change biology

Band

29

Seiten

2188-2202

Anzahl der Seiten

15

ISSN

1354-1013

Publikationsdatum

04.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Globaler Wandel, Umweltchemie, Ökologie, Umweltwissenschaften (insg.)

Ziele für nachhaltige Entwicklung

SDG 15 – Lebensraum Land

Elektronische Version(en)

https://doi.org/10.1111/gcb.16591 (Zugang: Offen)