Forest Diversification

This project aims to improve our understanding of how woodland biodiversity and related ecosystem functioning is influenced by woodland management practices that seek to ‘diversify’ forest stands. ‘Diversification’ of a forest stand can be achieved by increasing its compositional (e.g. multiple tree species), structural (e.g. mixed tree heights in mixed age stands), and/or genotypic complexity (e.g. multiple provenances).

Research objectives

To compare woodland biodiversity and related ecosystem functioning in single-aged monocultures compared with ‘diversified’ (i.e. mixed species, mixed aged, mixed provenance) forest stands

To gain a better understanding of the current practical experience of conversion of conifer plantation monocultures to more structurally complex native woodland in Britain and reported influences on forest biodiversity

To investigate survival, growth, phenology and associated biodiversity of single provenance, single species stands compared with mixed provenance, mixed species stands in experimental planting trials

Results so far

Species diversity has been assessed in 42 mixed and monoculture stands of oak (Quercus robur) and Scots pine (Pinus sylvestris) in three regions. The regions include Thetford Forest, Norfolk, the New Forest, Hampshire and across Ireland. Species sampled were ground vegetation, invertebrates of the forest floor and ground vegetation layers and ectomycorrhiza.

A literature review has been completed reviewing the impacts on biodiversity of conversion of non-native conifer plantation monocultures to more structurally complex, native woodland. A report has also been finalised providing the results of questionnaires circulated to woodland owners in Britain to better understand prevailing attitudes to the conversion of non-native to native woodland, the extent of conversion taking place and how this is achieved.

Assessments of oak, cherry, sweet chestnut and ash survival, growth, phenology and associated biodiversity are conducted annually at planting trials in Kent and the Midlands where these species are planted in single provenance and single species blocks but also in mixed provenance, mixed species blocks.


The project started in July 2009 until 2015.


Dr Nadia Barsoum

Funders and partners

Management of multifunctional forests (MULTIFOR)

FC Programme entitled : Habitat management, protected species, biodiversity, genetic conservation and forest reproductive materials

Forestry Commission policy

Biodiversity conservation is an integral part of sustainable forestry, the Government's approach to which is detailed in The UK Forestry Standard and supporting Guidelines. The aim is to enhance the nature conservation value of all our forests and safeguard special habitats.


Barsoum, N., Fuller, L, Ashwood, F., Reed, K., Bonnet-Lebrun, A.-S. and Leung, F (2014) Ground-dwelling spider (Araneae) and carabid beetle (Coleoptera: Carabidae) community assemblages in mixed and monoculture stands of oak (Quercus robur L./Quercus petraea (Matt.) Liebl.) and Scots pine (Pinus sylvestris L.). Forest Ecology and Management. 321: 29–41.

Barsoum, N. and Henderson, L. (2014) Conversion of woodland from non-native to native tree species: Results of questionnaires put to forest managers on current practice. Report to the Forestry Commission.

Barsoum, N. (2012) ‘Conversion of conifer plantation monocultures to native woodland: Current practical experience and reported influences on forest biodiversity’. Report to the Forestry Commission.

N. Barsoum, A-S. Bonnet-Lebrun, J. Brunt, A. Eycott, S. Kallow, A. Kiewitt, and M. Bidartondo. (2012) ‘Multitaxon responses to a ‘diversification’ in the composition of forest stands as an adaptation measure to global environmental change’ Conference Proceedings ‘Tackling climate change: contribution of forest scientific knowledge’ Tours, France.

Barsoum, N., McCartan, S., Wilkinson, M., Morison, J., Cottrell, J., Hubert, J. and Ray, D. (2011). Increasing the adaptation potential of native tree species to climate change. Conference Proceedings Joint BES - Natural England Meeting ‘Adapting Conservation to a Changing Climate’ 11-12 January 2011, Charles Darwin House, London.

Barsoum, N., D. Williams, N. Straw, M. Jukes, R. Johnson, M. Bidartondo, A. Kiewitt and R. Ibrahim (2009). Consequences of increased stand structural complexity for floral diversity and the prevalence of insect pests in Sitka spruce (Picea sitchensis) stands. Conference Proceedings ‘Adapting Forest Management to Maintain the Environmental Services: Carbon Sequestration, Biodiversity, Water’. Koli National Park, Finland 21.9.-24.9.2009.