Tree Diversity and Ecosystem Functioning in Forests

Tree diversity underpins the vitality and resilience of forest ecosystems by enhancing productivity, stabilising carbon sequestration and buffering environmental stresses. Diverse assemblages of tree species optimise resource use through complementary rooting depths, varied phenologies and a range of leaf and wood traits. This complementarity drives overyielding, whereby mixed communities exceed the biomass or growth rates of monocultures. Diversity also promotes asynchronous responses to climatic variability, ensuring that declines in one species are offset by the performance of others and thus maintaining overall ecosystem functioning. Interactions among neighbouring trees – whether competitive or facilitative – shape local microclimates, soil moisture dynamics and nutrient cycling, with cascading effects on broader ecosystem services such as water regulation and habitat provision. At a global scale, mixed-species forests contribute to climate mitigation and biodiversity conservation, while offering practical advantages for restoration and sustainable forestry. Understanding the mechanisms linking tree diversity to ecosystem processes is essential for designing resilient plantations and informing policy on forest landscape restoration.

Research from Nature Portfolio

Recent experimental work has demonstrated that local neighbourhood interactions are a key regulator of community productivity. In mixed-species plots, individual tree growth increases with the richness of nearby species, indicating that diversity at the micro-scale drives overyielding at the stand scale. Another line of enquiry has examined resilience to extreme climatic events in tropical planted forests, showing that mixtures with higher species richness maintain growth and exhibit lower mortality during prolonged droughts. These findings emphasise that positive interactions among co-occurring species can buffer ecosystems against environmental stress and enhance the stability of forest functioning over time.

Research from all publishers

Studies across a variety of biomes have clarified who benefits from diversity and why. Work on tree–mycorrhiza associations has revealed that combining species reliant on different fungal partners can substantially boost productivity, as arbuscular and ectomycorrhizal trees exploit soil nutrients in complementary ways. Large-scale experiments have shown that increased species richness stabilises productivity through asynchronous growth responses and variation in drought-tolerance traits, thereby mitigating the impacts of climate variability. Trait-based neighbourhood analyses have further demonstrated that local mixtures can alleviate drought-induced growth declines by partitioning soil water among species with different cavitation resistance thresholds. Collectively, these advances highlight the interplay between species interactions, functional traits and ecosystem resilience.

Tree Diversity and Ecosystem Functioning in Forests publication trend

The graph below shows the total number of articles in tree diversity and ecosystem functioning in forests across all publications each year (not limited to Nature Index journals).

Technical terms

Species richness: The number of distinct tree species within a defined area.

Functional diversity: The range and value distribution of species’ traits influencing ecosystem processes.

Complementarity effect: The gain in ecosystem performance arising from niche differentiation among species.

Overyielding: When mixed-species assemblages produce greater biomass or productivity than monocultures.

Asynchrony: Temporal mismatch in species’ growth or phenological responses that stabilises community productivity.

Mycorrhizal association: A symbiotic relationship between tree roots and soil fungi, enhancing nutrient and water uptake.

References

1. Mycorrhizal associations modify tree diversity−productivity relationships across experimental tree plantations. New Phytologist (2024).
2. Biodiversity and ecosystem services in forest ecosystems: a research agenda for applied forest ecology. Journal of Applied Ecology (2016).
3. Contributions of a global network of tree diversity experiments to sustainable forest plantations. Ambio (2015).
4. For the sake of resilience and multifunctionality, let's diversify planted forests!. Conservation Letters (2021).
5. Species richness stabilizes productivity via asynchrony and drought-tolerance diversity in a large-scale tree biodiversity experiment. Science Advances (2021).
6. Neighbourhood interactions drive overyielding in mixed-species tree communities. Nature Communications (2018).
7. Effect of diversity on growth, mortality, and loss of resilience to extreme climate events in a tropical planted forest experiment. Scientific Reports (2018).
8. Neighbourhood diversity mitigates drought impacts on tree growth. Journal of Ecology (2020).
9. The significance of tree-tree interactions for forest ecosystem functioning. Basic and Applied Ecology (2021).