Carbon Allocation and Flux in Terrestrial Ecosystem: From Plant Function to Soil Feedback

Terrestrial ecosystems store vast amounts of carbon in plant biomass and soils, yet the pathways through which photosynthetically fixed carbon is partitioned and transferred along the plant–microbe–soil continuum remain poorly constrained. Photosynthetic carbon allocation is a central process linking plant function with terrestrial carbon cycling. Once atmospheric CO2 is fixed, carbon is partitioned among growth, storage, respiration, reproduction, and belowground transfer, where roots and associated microorganisms further determine its fate. These processes are tightly coupled with nutrient acquisition and are strongly regulated by global change and human activities. Yet plant physiological studies, rhizosphere research, and ecosystem carbon-flux studies are often considered separately, limiting our understanding of how carbon moves across biological compartments and scales. A process-based framework that connects carbon acquisition and allocation within plants to belowground transfer, microbial processing, soil respiration, and ecosystem carbon balance is therefore needed across both natural and managed terrestrial ecosystems.This Research Topic aims to advance an integrated understanding of carbon allocation across the plant-soil-microbe continuum, taking plant physiological control of carbon acquisition and partitioning as its entry point and organizing principle, with belowground transfer, microbial processing, respiration, and ecosystem feedbacks treated as its downstream consequences. Rather than asking what determines the size and stability of soil carbon pools, we seek to elucidate how recently fixed carbon is partitioned and transferred among plants, microbes, and soil, and to quantify the fluxes of respiration, nutrient return, and retention at each stage. Measurement is central to this ambition, and we particularly welcome studies that trace and quantify transfer using isotope tracers, flux partitioning, and cross-scale modeling. The collection will bring together research spanning plant physiology, rhizosphere ecology, soil biogeochemistry, microbial ecology, and ecosystem science. Particular attention will be given to responses to climate change, abiotic stress, nutrient availability, fertilization, organic amendments, residue return, intercropping, and other management practices. By bridging scales from plant metabolism to soil ecosystem processes, the Topic seeks to improve mechanistic understanding of carbon-use strategies and their implications for crop production, ecosystem resilience, and terrestrial carbon-climate feedbacks.The themes below follow carbon along a single continuum, from leaf to soil and back, and share an emphasis on measuring and quantifying what is transferred at each stage. We encourage submissions that address the following themes, among others.· Photosynthetic carbon acquisition, source-sink relationships, and allocation among plant organs.· Belowground allocation: root exudation, rhizodeposition, litter inputs, and carbon transfer to rhizosphere and mycorrhizal partners.· Microbial utilization of plant-derived carbon, carbon use efficiency, necromass formation, and nutrient return to plants.· Autotrophic and heterotrophic respiration, rhizosphere carbon turnover, and ecosystem carbon balance.· Effects of drought, warming, elevated CO2, salinity, and nutrient limitation on carbon allocation and transfer.· Effects of fertilization, organic amendments, residue return, and intercropping on plant-soil-microbe carbon processes.· Methodological advances that quantify these fluxes: isotope tracers, flux measurements, multi-omics, and integrated modeling.Original Research, Reviews, Perspectives, and methodological studies are welcome.-------We welcome contributions from researchers across the field, and we are glad to support you as you prepare your submission. If you would like early feedback on whether your planned manuscript fits the scope of this Research Topic, please write to us at plantscience@frontiersin.org before submitting. A quick check at this stage helps confirm your work is a strong fit and can save you time later in the process.To take part, click “Participate in this topic” at the top right of this page, then confirm through the “Participate” link in the follow-up email. This lets us know to expect your contribution, keeps you informed of key deadlines, and gives you access to resources that guide you through submission. We would also be glad to talk with you about possible routes for support with the Article Processing Charge (APC).We look forward to your participation and to building a vibrant, cohesive Research Topic together. Topic editors: Xuechen Yang, Lei Liu, Tianxue Yang, Zhengfeng An, Raúl Ochoa-Hueso Source: https://www.frontiersin.org/research-topics/86047/carbon-allocation-and-flux-in-terrestrial-ecosystem-from-plant-function-to-soil-feedback