Diversity and Productivity in Mixed-Species Forests

Mixed-species forests combine two or more tree species within the same stand, often yielding higher productivity, stability and resilience than single-species plantations. Enhanced biomass production arises through niche complementarity and facilitation, whereby species differ in root depth, nutrient uptake or phenology, reducing competition and optimising resource use. Diverse stands also buffer against pests, pathogens and climate extremes, improving carbon storage and ecosystem service provision. Global experiments and long-term observations highlight that mixed forests can adapt more readily to changing conditions, offering a sustainable pathway for forestry that balances timber yield, biodiversity conservation and climate mitigation.

Research from Nature Portfolio

Foundational analyses across Europe have revealed that the benefits of species mixing depend critically on individual tree size and climatic context. In colder, energy-limited regions, small trees achieve greater growth increments when surrounded by functionally dissimilar neighbours, whereas in warmer areas larger trees derive stronger complementarity effects. This size-dependent response to functional dissimilarity underscores the need to consider stand structure dynamics in predicting diversity-productivity relationships under variable environmental gradients.

Diversity and Productivity in Mixed-Species Forests publication trend

The graph below shows the total number of articles in diversity and productivity in mixed-species forests across all publications each year (not limited to Nature Index journals).

Technical terms

Mixed-species stand: A forest unit in which two or more tree species coexist and interact to share resources.

Monoculture: A forest stand composed of a single tree species, often associated with uniform growth but lower resilience.

Niche complementarity: The process by which coexisting species exploit different resources or occupy distinct ecological niches, enhancing overall productivity.

Overyielding: The phenomenon in which a mixed stand produces more biomass or growth than the sum of its species’ yields in separate monocultures.

Resilience: The capacity of a forest to recover its structure and function following disturbance, stress or environmental change.

References

1. Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe. Scientific Reports (2016).
2. Allometry and biomass dynamics in temperate mixed and monospecific stands: Contrasting response of Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea (Matt.) Liebl.). The Science of The Total Environment (2024).
3. Tree species growth response to climate in mixtures of Quercus robur/Quercus petraea and Pinus sylvestris across Europe - a dynamic, sensitive equilibrium. Forest Ecology and Management (2023).
4. The greater resilience of mixed forests to drought mainly depends on their composition: Analysis along a climate gradient across Europe. Forest Ecology and Management (2021).