Soil microbial communities with greater investment in resource acquisition have lower growth yield

Abstract

Resource acquisition and growth yield are fundamental traits of microorganisms that have consequences for ecosystem functioning. However, there is a lack of empirical observations linking these traits. Using a landscape-scale survey of temperate near-neutral pH soils, we show tradeoffs in key community-level parameters linked to these traits. Increased investment into extracellular enzymes was associated with reduced growth yield; this reduction was linked more to carbon than nitrogen acquisition enzymes suggesting smaller stoichiometric constraints on community metabolism in examined soils.

Using proxies of microbial community‐weighted means traits to explain the cascading effect of management intensity, soil and plant traits on ecosystem resilience in mountain grasslands

“…The SEM revealed that management drives microbial strategies through both soil and plant CWM trait modifications (Figure ). The observed decrease in mass‐specific enzymes activity with soil N content was in line with previous studies conducted along a 120,000‐year‐old soil development chronosequence in New Zealand (Allison et al, ), and across a large land use gradient in Britain (Malik, Puissant, et al, ). These results support the hypothesis that copiotrophs in nutrient‐rich soils invest less in the production of extracellular enzymes to acquire C and other nutrients from complex organic molecules (Fontaine et al, ).…”

“…EEC:EEP, EEC:EEN and EEN:EEP ratios were calculated to represent the balance of C versus P, C versus N and N versus P acquisition respectively (Sinsabaugh et al, ). Thirdly, mass‐specific enzymes activity was calculated as the total extracellular enzyme activities per unit of microbial biomass‐N and considered as a proxy of the average investment in extracellular enzyme production per unit of microbe within the community (Malik, Puissant, Goodall, Allison, & Griffiths, ).…”

“…Leaf N concentration (LNC) and leaf dry matter content (LDMC) were used as indicators of the plant economics spectrum (Reich, ) and its response to soil fertility (Hodgson et al, ), and because these traits also control litter quality (Fortunel et al, ; Quested et al, ). Microbial biomass N:P was used as an indicator of the relative investment between cellular maintenance and resource acquisition versus growth (Arrigo, ; Karpinets et al, ) and mass‐specific extracellular enzymes activity as proxies of the investment in extracellular enzymes (Malik, Puissant, et al, ). Effects of these predictors were tested on initial MBN, MBN resistance and recovery indices with three independent SEM s. Firstly, the full model structures were tested, containing all potential paths of the a priori model (Figure a).…”

Metabolic tradeoffs and heterogeneity in microbial responses to temperature determine the fate of litter carbon in a warmer world

“…Predictions regarding how soil C stocks will respond to climate change are, in turn, highly sensitive to how carbon use efficiency (CUE)-or the fraction of C taken up by a cell and incorporated into biomass rather than being respired--changes with temperature (Allison et al, 2010;Wieder et al, 2013;Allison, 2014;Li et al, 2014;Sistla et al, 2014;Tang and Riley, 2015). As such, quantifying microbial decomposer CUE and its responsiveness to environmental change has been subject to intensive study (Devêvre and Horwáth, 2000;Frey et al, 2013;Blagodatskaya et al, 2014;Lee and Schmidt, 2014;Spohn et al, 2016a, b;Öquist et al, 2017;Malik et al, 2018;Geyer et al, 2019;Malik et al, 2019;Zheng et al, 2019).…”

“…This is because carbon which could otherwise be allocated to growing the cell or generating the energy required to maintain it must instead be spent producing amino acids and expending ATP to link them together (Kaleta et al, 2013;Kafri et al, 2016). As such, extracellular enzyme production is inferred to reduce the carbon use efficiency of soil microbial communities (Allison, 2014;Malik et al, 2019).…”