This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
A Dynamic Succession-Based Life-Cycle Simulation Model for Projecting Carbon Source–Sink Transitions in Urban Plant Communities
1
School of Human Settlements, North China University of Water Resources and Electric Power, Zhengzhou 450046, China
2
School of Architecture, Tianjin University, Tianjin 300072, China
3
College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China
*
Author to whom correspondence should be addressed.
Biology 2026, 15(13), 1072; https://doi.org/10.3390/biology15131072 (registering DOI)
Submission received: 31 May 2026
/
Revised: 27 June 2026
/
Accepted: 2 July 2026
/
Published: 4 July 2026
(This article belongs to the Section Ecology)
Simple Summary
Urban green spaces are widely assumed to absorb carbon and help cities address climate change, but planting and maintaining vegetation also generate emissions through construction, irrigation, fertilization, and pesticide use. We developed a simulation model tracking how 150 urban plant communities in Tianjin, China, grow and are managed over 50 years. Most communities began as net carbon emitters but shifted to net carbon absorbers as plants matured, with 86.1% projected to achieve a positive modeled carbon balance by year 50 under the baseline scenario. Communities with multiple vegetation layers, greater species diversity, and locally adapted species performed best. These findings offer practical guidance for designing urban green spaces that deliver genuine long-term climate benefits.
Abstract
Urban plant communities are widely regarded as important nature-based solutions for climate mitigation, yet their actual carbon benefits remain uncertain: vegetation growth is accompanied by carbon emissions from construction and long-term maintenance, and existing assessments rarely integrate community succession, interspecific competition, and maintenance-related emissions within a consistent life-cycle framework. To address these limitations, this study developed a dynamic succession-based life-cycle simulation model to project the 50-year carbon source–sink transitions of 150 typical urban plant communities in Tianjin, China. The model updates plant structural attributes—diameter at breast height, crown width, and tree height—iteratively by linking individual plant growth to environmental suitability and neighborhood competition through a Plant Health Index. Simulated structural trajectories were coupled with biomass equations and carbon content coefficients to estimate aboveground carbon sequestration, while construction and maintenance emissions were quantified using life cycle assessment, enabling evaluation of modeled net carbon balance rather than gross carbon sequestration alone. Under the modeled 50-year scenario, most communities were projected to act as carbon sources during the early stage but gradually shifted toward carbon sinks as biomass accumulated; 86.1% of the communities were projected to become net carbon sinks after 50 years (a scenario-based projection under specified growth, maintenance, and emission assumptions). The highest modeled net carbon balance reached 3186.08 kg C ha−1, whereas the weakest community remained a slight carbon source at −81.21 kg C ha−1. Vertical structural complexity and species richness were the strongest positive predictors of modeled net carbon balance, followed by three-dimensional green quantity and canopy closure. Among maintenance processes, fertilization was the dominant emission source, followed by pesticide application and irrigation; comparative scenario analysis showed that resource-saving maintenance consistently improved projected net carbon balance relative to high-maintenance management. These results suggest that low-carbon planting design should prioritize locally adapted species, multi-layered vertical structures, and adaptive maintenance over simply maximizing planting density or minimizing inputs. The results represent scenario-based projections of aboveground vegetation carbon balance; belowground biomass, soil carbon, litter carbon, dead organic matter, and parameter uncertainty were not fully incorporated, and future studies should address these limitations to improve the robustness and transferability of the proposed framework.
