Half to two-thirds of global terrestrial biodiversity is found in forests (Raven, 1988), the majority in tropical forests (which contains 50–90 percent of the world's species, WRI, 1992). Biodiversity underpins forest environmental services, productivity and resilience. Ecological processes such as tree growth, carbon sequestration, pollination, seed dispersal and nutrient recycling depend on biodiversity, which is also fundamental to food security and nutrition. Maintaining the resilience of forest ecosystems is therefore a critical element in planning and implementing SFM independently from the type of forestry that is practised.

Forest biodiversity is decreasing in some areas due to forest loss, degradation and fragmentation. It is necessary to reduce pressures on forests, restore ecosystems, use biological resources sustainably, and share the benefits arising from the use of genetic resources in a fair and equitable manner. Only a relatively small part of the biodiversity of tropical forests is known, which is a constraint on conservation efforts.

Biodiversity conservation should be practiced in all types of forests, whether they are managed for production, protection or other purposes. There is a need to ensure that adequate areas of forest representing the full suite of forest types are managed specifically for biodiversity conservation (“protection forest”); such management is part of the suite of SFM approaches. In areas in which wood harvesting may take place (“production forest”), SFM should ensure that genetic resources, including vulnerable, threatened and endangered species, as well as the diversity of ecosystems, are maintained. An adaptive management with controlled disturbances also benefit wild pollinators, which depend heavily on forest habitats and play a vital role in the reproduction process of most flowering plants.