Forest Biodiversity

Forests harbour the majority of terrestrial species richness, spanning distinct biomes—from hyperdiverse tropical rainforests through subtropical woodlands and temperate broadleaf forests to vast boreal taiga. Each biome supports characteristic assemblages of trees, understory plants, invertebrates, fungi and vertebrates, many adapted to long-undisturbed conditions. Forest biodiversity underpins essential processes such as nutrient cycling, carbon sequestration, pollination and pest regulation, and provides cultural, material and health-related benefits. Yet global change pressures—clear-fell logging, agricultural expansion, selective harvesting, hunting and invasive species—have fragmented and degraded vast tracts of forest. Fragmentation increases edge effects, reduces core habitat and impairs dispersal of specialist species. Selective removal of large old trees and deadwood diminishes microhabitat diversity and disrupts life cycles of cavity nesters, wood-dependent fungi and saproxylic invertebrates. Climate change introduces further stress by altering disturbance regimes, shortening snow cover, shifting species ranges and increasing drought and fire frequency. Conservation of intact old-growth remnants, restoration of degraded stands and adoption of biodiversity-sensitive management are therefore critical to maintain forest resilience and retain multifunctional ecosystems for future generations.

Research from Nature Portfolio

Recent studies have revealed that plantation of non-native timber species such as Eucalyptus supports dramatically fewer specialist wood-boring insects and true bugs than native pine forests, with communities in exotic wood dominated by generalist fungivores and predators, underlining the importance of host-tree identity and microclimatic context for deadwood-dwelling biodiversity.

Analyses of saproxylic beetle assemblages collected via emergence and flight traps show that tree hollows, although less species-rich than canopy microhabitats, harbour a broader functional trait spectrum and reduced redundancy, emphasising the disproportionately high functional value of large-tree cavities for maintaining invertebrate diversity.

Research from all publishers

Longitudinal work in boreal mixedwood stands demonstrates that variable retention harvesting—leaving dispersed and aggregated patches of live trees—accelerates the recovery of ground-dwelling invertebrate communities, with rove beetle assemblages converging on those in mature, fire-origin forests within two decades, highlighting retention design as a key tool for biodiversity conservation.

Field experiments in western North American Douglas-fir forests show that partial retention of mature overstory trees preserves mycorrhizal inoculum potential and soil resources, while fostering seedling recruitment and sustaining understory plant and fungal diversity, illustrating how legacy structures support both regeneration and ecological complexity.

Forest Biodiversity publication trend

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

Technical terms

Canopy closure: The percentage of the forest floor covered by the vertical projection of tree crowns, indicating degree of light limitation.

Saproxylic: Describing organisms that depend on dead or decaying wood for at least part of their life cycle.

Variable retention: A harvest system that deliberately retains specified proportions and patterns of live trees and deadwood to emulate natural disturbance legacies.

Mycorrhizal inoculum potential: The capacity of soil and root fragments to supply fungal propagules for symbiotic colonisation of regenerating seedlings.

Edge effect: Ecological changes in abundance and composition of species at the boundary between forest and non-forest habitats.

References

1. Effects of Eucalyptus wood and leaf litter on saproxylic insects in the southeastern United States. Scientific Reports (2024).
2. Contrasting functional structure of saproxylic beetle assemblages associated to different microhabitats. Scientific Reports (2020).
3. Rapid recovery of boreal rove beetle (Staphylinidae) assemblages 16 years after variable retention harvest. Ecography (2022).
4. Partial Retention of Legacy Trees Protect Mycorrhizal Inoculum Potential, Biodiversity, and Soil Resources While Promoting Natural Regeneration of Interior Douglas-Fir. Frontiers in Forests and Global Change (2021).