Adaptive Carbon Allocation by Plants Enhances the Terrestrial Carbon Sink

Jiangzhou Xia,Quanguo Zhang,Wenping Yuan,Ying-Ping Wang

doi:10.1038/s41598-017-03574-3

Jiangzhou Xia, Quanguo Zhang + Show 2 more

Open Access

https://doi.org/10.1038/s41598-017-03574-3

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Abstract

Carbon allocation is one of the most important physiological processes to optimize the plant growth, which exerts a strong influence on ecosystem structure and function, with potentially large implications for the global carbon budget. However, it remains unclear how the carbon allocation pattern has changed at global scale and impacted terrestrial carbon uptake. Based on the Community Atmosphere Biosphere Land Exchange (CABLE) model, this study shows the increasing partitioning ratios to leaf and wood and reducing ratio to root globally from 1979 to 2014. The results imply the plant optimizes carbon allocation and reaches its maximum growth by allocating more newly acquired photosynthate to leaves and wood tissues. Thus, terrestrial vegetation has absorbed 16% more carbon averagely between 1979 and 2014 through adjusting their carbon allocation process. Compared with the fixed carbon allocation simulation, the trend of terrestrial carbon sink from 1979 to 2014 increased by 34% in the adaptive carbon allocation simulation. Our study highlights carbon allocation, associated with climate change, needs to be mapped and incorporated into terrestrial carbon cycle estimates.

Highlights

Carbon allocation is a critical physiological process where the products of photosynthesis are shifted between respiration and biomass production, ephemeral and long-lived tissues, and aboveground and belowground components
The Community Atmosphere Biosphere Land Exchange (CABLE) with the resource limitation scheme (RES) carbon allocation scheme showed the potential in reproducing the realistic changes of carbon allocation coefficients to leaves, wood and root with environmental changes (Fig. 1 and Table S1)
The CABLE model correctly simulated the effects of the elevated atmospheric CO2 on carbon allocation at Duke site (Fig. 1c)

Summary

Introduction

Carbon allocation is a critical physiological process where the products of photosynthesis are shifted between respiration and biomass production, ephemeral and long-lived tissues, and aboveground and belowground components. In the FIX scheme, a set of constant fractions are used to determine the carbon allocation from net primary productivity to leaves, wood tissues, and roots, where the fractions differ in various phenological phases in deciduous biomes (Table 1)[19]. Carbon allocation for leaf, wood and root and light, water, nitrogen availabilities have no units and vary from 0 to 1.

Results

Conclusion