Changes in C : N : Р Ratios in Plant Biomass, Soil and Soil Microbial Biomass Due to the Warming and Dessication Effect of Flaring

Abstract

Climate warming results in significant changes in the structure and functioning of terrestrial ecosystems. The ecosystems situated near oil-well gas flares may be used as model ones for studying warming effect on soil and vegetation. By contrast to regular manipulation experiments where ecopysiological factors are modified or controlled artificially, we used anthropogenically affected condi-tions caused by the gas flaring. Our research was aimed to assess the warming and desiccation effect on the stoichiometric ratios of the principle nutrients (C : N : P) in pine phytomass, soil and soil microbial biomass. Soil organic matter (SOM) and dying microbial biomass were found to be exposed to the increased rate of mineralization under conditions of the abiotic stress. In addition, the de-crease of relative С content in sustainable SOM pools occured along with the increase of C content in the most labile water-soluble pools. Accelerated SOM mineralization decreasing C : N with respect to phosphorus ratio in soil and soil microbial biomass was sufficiently intensified by the decrease in C : N : P in pine needles. Thus, studying changes in stoichiometric ratios of biophylic ele-ments as affected by abiotic factors seems to be prospective and promising methodological approach for predicting terrestrial ecosystem transformations under global climate changes.

Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health

“…They also suggest that low soil N and P concentrations tend to be associated with higher temperatures along natural long‐term climatic gradients, but the reverse occurs for phenotypic responses of species to N in short‐term field studies with climatic manipulation (Yuan et al, ). Several studies have indeed reported decreases in aboveground plant N:P ratios under warming that were attributed to the greater allocation of P to stems and/or to greater plant growth capacity (Dudareva, Kvitkina, Yusupov, & Yevdokimov, ; Wang, Ciais, et al, ; Wang, Liu, et al, ). The effects of warmer temperatures on plant and soil C:N:P ratios along natural gradients are not easy to distinguish from those of precipitation, radiation, or atmospheric N deposition, which frequently correlate with the geographical temperature gradient (Jiao et al, ).…”

Recent advances and future research in ecological stoichiometry

“…A meta-analysis of 86 studies that did not differentiate among plant organs found an overall increase in N:P ratios along natural temperature gradients, but not in field experiments with controlled warming conditions (Yuan and Chen, 2015). Several studies have reported a decrease in aboveground plant N:P ratios under warming, which were attributed to a greater allocation of P to stems and/or to a greater capacity for plant growth (Dudareva et al, 2018;Wang et al 2018e, 2019b. A meta-analysis of data from 76 warming manipulation field studies reported an overall increase in plant N:P ratios under warming (Yue et al, 2017).…”