Phosphorus Dynamics in Forest Ecosystems

Phosphorus (P) is a vital macronutrient that governs primary productivity, biodiversity and carbon sequestration in forest ecosystems. Unlike nitrogen, which can be fixed from the atmosphere, P is derived solely from weathering of parent material and recycling within the soil–plant–microbe continuum. In mineral soils, P occurs in diverse pools, including readily available inorganic phosphate, adsorbed P bound to aluminium and iron oxides, organically bound P within humic substances and largely inaccessible occluded forms. Plants and their mycorrhizal symbionts mobilise P through root exudation of organic acids and extracellular phosphatases, tapping into both inorganic and organic pools. Soil microbial communities compete for soluble phosphate, further modulating P availability through mineralisation and immobilisation processes. Fine‐root architecture, litter turnover and microbial biomass form tightly coupled feedbacks that control P retention and loss. In P‐poor forests, tight internal recycling and specialised mycorrhizal associations enhance P use efficiency, whereas in P‐rich sites slower turnover and accumulation in mineral horizons may prevail. Geogenic inputs from rock weathering or dust deposition can partially offset losses by erosion and leaching, but the rate of replenishment is often orders of magnitude slower than demand. Anthropogenic influences such as acid deposition, nitrogen enrichment and land‐use change alter soil chemistry, microbial community structure and P cycling dynamics, with implications for forest health and resilience under global change.

Research from Nature Portfolio

Advanced spectroscopic and spectrometric mapping at the micrometre scale has revealed that phosphorus distribution within soil aggregates is highly heterogeneous and controlled by substrate mineralogy and depth. In high‐P clay soils, P co‐locates primarily with aluminium and iron oxides, whereas in sandy, low‐P topsoils organic P dominates. Such microscale patterns determine bioavailability by influencing diffusion distances and phosphate sorption–desorption kinetics. This mechanistic insight challenges bulk‐scale assumptions of uniform P pools and highlights the need for spatially resolved soil characterisation to predict plant‐accessible P under changing environmental conditions.

Phosphorus Dynamics in Forest Ecosystems publication trend

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

Technical terms

Labile P: The pool of inorganic phosphate in soil solution or weakly adsorbed forms readily taken up by plants and microbes.

Occluded P: Phosphate bound within sesquioxide or mineral matrices, largely inaccessible under normal soil conditions.

Phosphatase: An enzyme secreted by roots or microbes that hydrolyses organic P compounds, releasing inorganic phosphate.

Geogenic nutrient pathway: The gradual release of nutrients, including P, from the weathering of parent rock material at depth.

Mycorrhizal efficiency: The capacity of fungal symbionts to acquire and transfer phosphorus to host plants relative to microbial or abiotic competitors.

References

1. Soil phosphorus supply controls P nutrition strategies of beech forest ecosystems in Central Europe. Biogeochemistry (2017).
2. From soil to plant, the journey of P through trophic relationships and ectomycorrhizal association. Frontiers in Plant Science (2014).
3. Micro-scale heterogeneity of soil phosphorus depends on soil substrate and depth. Scientific Reports (2017).
4. How Slow Rock Weathering Balances Nutrient Loss During Fast Forest Floor Turnover in Montane, Temperate Forest Ecosystems. Frontiers in Earth Science (2019).
5. Carbon, nitrogen, and phosphorus stoichiometry of organic matter in Swedish forest soils and its relationship with climate, tree species, and soil texture. Biogeosciences (2022).
6. Mycorrhizal Phosphorus Efficiencies and Microbial Competition Drive Root P Uptake. Frontiers in Forests and Global Change (2020).