Fruits, leaves, wood and bark provide the vital resources for rural life
Trees can serve as a vital "famine food" to keep drought-hit communities alive when all other food crops fail, according to campaigners.
Food insecurity is a routine fact of life for many of the world's poorest people, Miranda Spitteler, chief executive of Tree Aid told BBC News.
She said the West needed to recognise the important role trees could play in reducing the need for conventional aid.
She also called for support for a local tree-based solution to food shortages.
At this year's G8 summit, hosted by Italy, the leaders of the world's biggest economies recognised the need to improve global food security.
They pledge to spend $20bn over three years in an effort to support food production in developing nations, reducing the need for emergency food aid.
But Ms Spitteler commented: "What is missing from this pledge is any mention of the key role that trees can play."
In an article for the BBC News website's Green Room column, she added: "'Conventional' crops are often not native and require expensive inputs, significant irrigation and land preparation in order to produce a successful harvest.
"Trees, on the other hand, often survive when other crops fail."
Trees provide fruits, nuts, seeds, leaves, flowers, sepals, even sap, which can be used as food.
The leaves of Moringa oleifera, which is cultivated across Africa, India and South America, for example, have more beta-carotene than carrots, more vitamin C than oranges and more calcium than milk, the head of Tree Aid wrote.
She said the fight against hunger, especially in drought-hit times, must target those at the epicentre of of world poverty - smallholder farmers in rural Africa.
Some tree foods can provide much needed energy
"They need support to adopt agro-forestry techniques, which boost soil fertility and provide tree food crops to supplement nutrition."
Ms Spitteler added: "This approach can increase self-sufficiency for both rural communities and national economies. It can increase environmental security, diversify livelihood options and reduce the vulnerability of poor households to climate change and external shocks."
Global food production needs to double over the next 40 years if the world's population is to be fed, according to UN estimates.
Jacques Diouf, director-general of the UN Food and Agriculture Organization (FAO), says the massive challenge will require a global effort.
"For the first time in human history, we have more than one billion hungry people in the world.
"I am therefore happy that most of the leaders of the G8 have said that we need to focus on food production in poor countries and allow them to earn their income by producing food."
President of Tree Aid, Sir Crispin Tickell said: "As a member of the Copenhagen Climate Council, I greatly applaud the G8's initiative and hope that the vital role of trees will be fully recognised at the COP 15 Summit in Copenhagen in December."