Patterns of nitrogen and phosphorus pools in terrestrial ecosystems in China

Abstract

Abstract. Recent increases in atmospheric carbon dioxide (CO2) and temperature relieve their limitations on terrestrial ecosystem productivity, while nutrient availability constrains the increasing plant photosynthesis more intensively. Nitrogen (N) and phosphorus (P) are critical for plant physiological activities and consequently regulate ecosystem productivity. Here, for the first time, we mapped N and P densities and concentrations of leaves, woody stems, roots, litter, and soil in forest, shrubland, and grassland ecosystems across China based on an intensive investigation at 4868 sites, covering species composition, biomass, and nutrient concentrations of different tissues of living plants, litter, and soil. Forest, shrubland, and grassland ecosystems in China stored 6803.6 Tg N, with 6635.2 Tg N (97.5 %) fixed in soil (to a depth of 1 m) and 27.7 (0.4 %), 57.8 (0.8 %), 71.2 (1 %), and 11.7 Tg N (0.2 %) in leaves, stems, roots, and litter, respectively. The forest, shrubland, and grassland ecosystems in China stored 2806.0 Tg P, with 2786.1 Tg P (99.3 %) fixed in soil (to a depth of 1 m) and 2.7 (0.1 %), 9.4 (0.3 %), 6.7 (0.2 %), and 1.0 Tg P (< 0.1 %) in leaves, stems, roots, and litter, respectively. Our estimation showed that N pools were low in northern China, except in the Changbai Mountains, Mount Tianshan, and Mount Alta, while relatively higher values existed in the eastern Qinghai–Tibetan Plateau and Yunnan. P densities in vegetation were higher towards the southern and north-eastern part of China, while soil P density was higher towards the northern and western part of China. The estimated N and P density and concentration datasets, “Patterns of nitrogen and phosphorus pools in terrestrial ecosystems in China” (https://doi.org/10.5061/dryad.6hdr7sqzx), are available from the Dryad digital repository (Zhang et al., 2021). These patterns of N and P densities could potentially improve existing earth system models and large-scale research on ecosystem nutrients.

Saturation response of enhanced vegetation productivity attributes to intricate interactions

“…This model-calculated dataset was provided in a spatial resolution of 0.5° × 0.5° (van den Dool et al, 2003). Nitrogen (N) and phosphorus (P) density and concentration datasets with a spatial resolution of 1 km can be obtained from the Dryad digital repository (Zhang et al, 2021). Nutrient concentrations (i.e., N and P) of 0-10, 10-20, 20-30, 30-50, and 50-100 cm soil layers, soil N:P ratio, leaf nutrient concentrations (i.e., N and P), and leaf N:P ratio were extracted from this dataset (https://doi.org/10.5061/dryad.6hdr7 sqzx).…”

Climate and forest attributes influence above‐ground biomass of deciduous broadleaf forests in China

“…To accurately assess forest carbon stock in China, Zhou et al (2018) reconstructed allometric equations according to 900 sets of allometric equations from published literature on forest ecosystems in China. These allometric equations have been widely applied to evaluate forest biomass (Tang, Xu, et al, 2018;Tang, Zhao, et al, 2018;Zhang, Guo, et al, 2021). In this study, AGB of each plot was calculated for all living individuals with DBH ≥3 cm using diameter-tobiomass allometric equations obtained from Zhou et al (2018).…”

“…The community-level H max was calculated using relative basal area (percentage of species to total basal area) as the weighting variable (Aponte et al, 2020). The community-level leaf N and P concentrations were obtained from (Zhang, Guo, et al (2021). We quantified stand structures for each plot by calculating the coefficient of variation of DBH (DBH CoV) and tree height (H CoV), indicating tree size inequality.…”

Global patterns and drivers of phosphorus pools in natural soils

“…For example, soil P availability imposes a major constraint on plant productivity in terrestrial ecosystems worldwide (Augusto et al, 2017;Ellsworth et al, 2022;Elser et al, 2007;Hou et al, 2020;Hou et al, 2021) and affects modeled projections of terrestrial carbon cycle responses to climate change and increasing atmospheric carbon dioxide concentrations (Cunha et al, 2022;Fleischer et al, 2019;Goll et al, 2012). The size of soil P stocks is large compared to annual plant P requirements (Wang et al, 2018) and the amount of P stored in vegetation (Wang et al, 2018;Zhang et al, 2021). However, only a small proportion of soil P can be directly taken up by plants (Morel et al, 2014), with most P tightly sorbed to soil minerals, organic compounds, or organo-mineral complexes with a turnover time of centuries to millennia or longer (Helfenstein et al, 2020;Vitousek et al, 2010).…”