Patterns of plant carbon, nitrogen, and phosphorus concentration in relation to productivity in China’s terrestrial ecosystems

Abstract

Plant nitrogen (N) and phosphorus (P) content regulate productivity and carbon (C) sequestration in terrestrial ecosystems. Estimates of the allocation of N and P content in plant tissues and the relationship between nutrient content and photosynthetic capacity are critical to predicting future ecosystem C sequestration under global change. In this study, by investigating the nutrient concentrations of plant leaves, stems, and roots across China's terrestrial biomes, we document large-scale patterns of community-level concentrations of C, N, and P. We also examine the possible correlation between nutrient content and plant production as indicated by vegetation gross primary productivity (GPP). The nationally averaged community concentrations of C, N, and P were 436.8, 14.14, and 1.11 mg·g for leaves; 448.3, 3.04 and 0.31 mg·g for stems; and 418.2, 4.85, and 0.47 mg·g for roots, respectively. The nationally averaged leaf N and P productivity was 249.5 g C GPP·g N·y and 3,157.9 g C GPP·g P·y, respectively. The N and P concentrations in stems and roots were generally more sensitive to the abiotic environment than those in leaves. There were strong power-law relationships between N (or P) content in different tissues for all biomes, which were closely coupled with vegetation GPP. These findings not only provide key parameters to develop empirical models to scale the responses of plants to global change from a single tissue to the whole community but also offer large-scale evidence of biome-dependent regulation of C sequestration by nutrients.

Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent

“…These results show that there is no canonical numerical value for the N vs. P scaling exponent, and that the analysis of pooled data for this scaling relationship may hide biologically and ecologically significant variation. Our findings have important implications for predicting plant growth rate and ultimately vegetation productivity, helping parameterize vegetation climate models [13,17,21], and increasing our understanding of plant adaptation and evolution [22]. Our results also suggest that we need to incorporate specific exponents into scaling leaf N to P in plant growth and ecosystem functioning models according to specific functional groups, biogeographic regions and ecosystem nutrient availabilities.…”

“…Nitrogen (N) and phosphorus (P), especially the N in Rubisco that drives photosynthesis and the P in ribosomal RNA that drives the generation and maintenance of proteins, are essential nutrients [3][4][5][6] that are consequently tightly linked and important parameters in stoichiometric growth models [7][8][9]. Therefore, the leaf N and P stoichiometric patterns including N and P concentrations and N:P ratios are largely explored both at regional and global levels [10][11][12][13], which are important bridges linking elemental compositions or allocations with organismal metabolic processes, and even energy flow in the whole ecosystem [9]. In particular, the strong correlation between leaf N and P concentrations can be quantified via a stoichiometric scaling relationship described by a power function as N = βP α , where α and β indicate the slope (i.e.…”

The Central Amazon Biomass Sink Under Current and Future Atmospheric CO2: Predictions From Big‐Leaf and Demographic Vegetation Models

“…Even though CLM5 predicted a weaker increase in woody NPP compared to the VDMs, it still projected a large increase in absolute biomass, very similar to the VDMs (Figure ). This larger biomass response in CLM5 could be a result of higher vegetation C:N ratio (Tang et al, ), compared to the other big‐leaf model (inverse of vegetation N:C; Figure d) or warrants further investigation. ED2 predicted the lowest LAI (~4 m 2 m −2 ), yet simulated the highest NPP and biomass sink, suggesting that assimilated and stored C was connected to processes other than phenology.…”

Nutrient addition affects scaling relationship of leaf nitrogen to phosphorus in Arabidopsis thaliana

“…Our findings highlight that the capacities of nutrient utilization and competition among different individuals are subject to global nutrient changes at population (or community) level, which could further affect the population (or community) structures and functioning. This study also provides important implications for the parameterization in modelling stoichiometric growth and nutrient cycles in terrestrial ecosystems (Niklas et al, ; Peñuelas et al, ; Tang et al, ; Wright et al, ), and for understanding plant adaptation and evolution under varying nutrient environments (Kerkhoff et al, ). Moreover, our results consolidate one recent finding that there is no universal N‐P scaling exponent (Tian et al, ).…”

“…The general 0.667‐power law of leaf N versus P scaling (Reich et al, ) may be counterintuitive when considering the role of nutrient changes. However, plant stoichiometry and scaling relationships at community level contain information of species composition and interactions, and directly mirror the responses of vegetation structures and functions to the varying environment (Tang et al, ). Whether our observed patterns in A. thaliana could be extended to those at community level warrants further studies and more validations.…”