"Agroforestry isn't a 'no man's land' between forestry and agriculture and should receive specific policy support," FAO Deputy Director General for Climate and Natural Resources, Maria Helena Semedo said in an opening address to the 4th World Agroforestry Congress.
"Agroforestry can help diversify and sustain (food) production and provide vital social, economic and environmental benefits for land users at all scales," Semedo underlined.
The term refers to land-use systems and technologies where woody perennials - trees, shrubs, palms, bamboos and the like - are deliberately used in the same plots as agricultural crops or livestock to foster ecological synergies.
The approach is gaining in interest due to its ability to sequester carbon and mitigate climate change and to broaden the social, economic and environmental sustainability of rural development, according to Fao.
FAO promotes the potential multiple roles of agroforestry, Semedo said.
Agroforestry projects undertaken in areas of Nepal which local people are migrating from, initiatives to boost soil health and water conservation in drought-prone regions of Guatemala and Honduras and to introduce fruit trees in timber plantations in the Kyrgyztan were examples given by Semedo.
The deliberate use of trees in mixed-use agricultural land systems can also make substantial contributions to the conservation of biodiversity, Semedo noted.
"Traditional agroforestry systems contain between 50 and 80 per cent of the plant species diversity found in comparable natural forests," Semedo stated.
Trees also benefit pollinating insects, leading to farm productivity gains of as much as 24 per cent, said Semedo.
"FAO stands ready to support efforts by (UN) member states to guarantee the real integration of agroforestry in their agriculture policy frameworks with an eye to achieving the Sustainable Development Goals," she said.
As trees often take years to mature, secure land tenure is especially crucial in promoting agroforestry, Semedo warned.
She cited a project in Uganda where farmers were paid the market value of timber for not felling trees, leading to a decline in local deforestation rates. The project is one of several case studies provided in agroforestry guidelines for policymakers, programme managers and farmers which FAO issued at the summit.
In some traditional systems in sub-Saharan Africa, trees can be planted to claim land, which can lead to abuses of power and also stop some smallholders from planting trees in order to avoid conflict. Another constraint on smallholder investment can be different people holding rights to the tree's bark, fruit and timber, which can act as a deterrent or prompt planting of unsuitable types of trees, Fao said.
Up to 70 percent of the land in many developing countries is administered through complex customary rules that often disadvantage women, who may face cultural taboos on cultivating certain types of trees or be banned from planting any if doing so entails an ownership claim, said FAO.
The Montpellier summit is being attended by more than 1,200 practitioners, researchers, students and business and civic leaders from more than 100 countries.