Opportunities for biodiversity gains under the world's largest reforestation programme

Area of Science:

• Ecological restoration
• Conservation biology
• Environmental policy

Background:

• Deforestation poses significant environmental and social challenges.
• China's Grain-for-Green Program (GFGP) is the world's largest reforestation initiative.
• Understanding the ecological impact of large-scale reforestation is crucial.

Purpose of the Study:

• To conduct the first nationwide assessment of tree composition in GFGP forests.
• To evaluate the biodiversity implications of GFGP using combined ecological and economic analyses.
• To compare the biodiversity outcomes of monocultures versus mixed forests in GFGP.

Main Methods:

• Nationwide analysis of GFGP forest tree composition.
• Ecological assessment of bird and bee diversity in Sichuan Province.
• Economic analysis of reforestation strategies and household impacts.

Main Results:

• GFGP forests are predominantly monocultures or simple mixed forests nationwide.
• Reforestation via monocultures led to bird diversity losses and major bee diversity losses.
• Mixed forests showed modest gains in bird diversity but still fell short of native forest levels.
• All GFGP approaches failed to restore biodiversity comparable to native forests.

Conclusions:

• Promoting mixed forests over monocultures within GFGP can significantly enhance biodiversity.
• Increasing forest diversity in GFGP is unlikely to incur substantial economic costs or risks for households.
• GFGP has the potential for greater biodiversity restoration by prioritizing diverse forest structures.