Soil Phosphorus Dynamics in Terrestrial Ecosystems

Soil phosphorus (P) underpins ecosystem productivity by mediating plant growth, microbial activity and carbon sequestration. Terrestrial P occurs in organic and inorganic forms across a continuum from readily exchangeable to occluded pools. Processes such as mineralisation, sorption and desorption regulate the release of phosphate into soil solution, while interactions among plant roots, microorganisms and mineral surfaces determine the fate of this nutrient. Climatic factors, soil age and parent material shape P availability by influencing weathering, biotic cycling and sorption capacity. In P-limited systems, microbial immobilisation and sorption can constrain plant access, with consequences for efficiency of fertiliser use, forest management and global carbon budgets.

Advances in spectroscopic, isotopic and modelling approaches have elucidated the turnover times of different P pools and refined Earth system models by coupling P dynamics with carbon and nitrogen cycles. Improved spatial mapping of soil P forms informs process-based models and guides land management, highlighting the importance of P cycling in predicting ecosystem responses under climate change and rising atmospheric CO2. In many regions, particularly tropical and highly weathered soils, P limitation curtails the CO2 fertilisation effect on plant biomass and alters nutrient stoichiometry. Practical applications range from optimising fertiliser regimes in agriculture to enhancing reforestation practices and improving water quality by managing P leaching.

Research from Nature Portfolio

Recent studies have demonstrated that microbial competition for phosphate can limit forest responses to elevated CO2 by sequestering mineralised P before plant uptake, thereby constraining additional carbon capture into biomass. In a long-term soil warming experiment, sustained +4 °C warming has been shown to decrease total P pools and increase sorption to recalcitrant fractions, leading to declines in bioavailable P and microbial biomass phosphorus despite elevated phosphatase activity. These findings reveal how warming alters both biotic and abiotic controls on P cycling, potentially exacerbating nutrient constraints on tree growth and soil microbial communities. Together, this work refines mechanistic understanding of P feedbacks under climate change and informs Earth system models by quantifying shifts in P pool distributions.

Soil Phosphorus Dynamics in Terrestrial Ecosystems publication trend

The graph below shows the total number of articles in soil phosphorus dynamics in terrestrial ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Bioavailable phosphorus: The pool of inorganic phosphate in soil solution readily taken up by plants and microbes.

Mineralisation: Microbial or enzymatic conversion of organic P compounds into inorganic phosphate.

Sorption: Abiotic binding of phosphate ions onto soil mineral surfaces, reducing their mobility.

Occluded phosphorus: Phosphate trapped within mineral structures or secondary minerals, largely inaccessible to biota.

Rhizosphere: The zone of soil influenced by root exudates and microbial activity around plant roots.

Phosphatase: Enzyme produced by organisms to hydrolyse organic P compounds, releasing inorganic phosphate.

References

1. Microbial competition for phosphorus limits the CO2 response of a mature forest. Nature (2024).
2. Long-term soil warming decreases microbial phosphorus utilization by increasing abiotic phosphorus sorption and phosphorus losses. Nature Communications (2023).
3. Terrestrial Phosphorus Cycling: Responses to Climatic Change. Annual Review of Ecology Evolution and Systematics (2023).
4. Reference maps of soil phosphorus for the pan-Amazon region. Earth System Science Data (2024).
5. Global meta-analysis shows pervasive phosphorus limitation of aboveground plant production in natural terrestrial ecosystems. Nature Communications (2020).
6. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere. Biogeosciences (2010).
7. Phosphorus transformations as a function of pedogenesis: A synthesis of soil phosphorus data using Hedley fractionation method. Biogeosciences (2011).
8. The distribution of soil phosphorus for global biogeochemical modeling. Biogeosciences (2013).
9. Combining spectroscopic and isotopic techniques gives a dynamic view of phosphorus cycling in soil. Nature Communications (2018).