奥巴马总统is in Africa本周讨论发展，投资，健康以及notably, food security. The trip comes on the heels of thepresident’s groundbreaking announcementof a U.S. Climate Action Plan. So it’s a fitting time for Obama and other global leaders to take notice of a strategy that addresses both climate change and food security in Africa—re-greening.

Re-greening- 非洲农民管理和保护在农场上生长的树木而不是削减树木的过程，已经开始改变非洲大陆的旱地。支持和扩大低技术的过程不仅可以增加易于干旱地区的农作物产量，还可以减轻气候变化并减少农村贫困。必威官网是真的吗

非洲旱地重新绿化的历史

在2007年，非洲重新绿化在2007年首次引起了国际关注纽约时报published a front page article entitled “在尼日尔，树木和农作物有助于倒退沙漠。”那时，纽约时代的西非局局长莉迪亚·波格林（Lydia Polgreen）访问了尼日尔，并报告“至少有740万新建树木覆盖的英亩”。NYT文章显示，这种大规模的重新绿化不是由于昂贵的树木植树项目，而是农民保护和管理在其耕地上再生的幼树的结果。

This re-greening did not happen everywhere. It was observed in particular in dryland regions with high population densities. Life in dryland areas presents many challenges, and farmers and decision makers are continuously searching for ways to restore their resilience and agricultural productivity.Since 2007, re-greening has slowly expanded throughout Africa’s drylands.Gray Tappan美国地质调查局的EROS数据中心的遥感专家，2009年报道说，尼日尔人口稠密地区农民重新估计的地区不是740万英亩，而是1200万英亩。尼日尔的农民受到保护和管理至少2亿棵新树over the past two decades.

Farmers in other parts of the Sahel have also begun to invest in on-farm trees. For instance, on Mali’s Seno Plains, on-farm tree densities have increased on more than one million acres. Increasing numbers of farmers in Burkina Faso, Ethiopia, and Senegal are also beginning to adopt re-greening practices. Many more examples of on-farm re-greening in the Sahel can be read on the非洲重新绿化计划博客.

农民管理的重新绿化的好处

整个非洲农业景观中有数亿棵其他树木隔离了大量二氧化碳。通过增加农场树木的数量，尼日尔和其他国家的农民正在帮助减轻气候变化。必威官网是真的吗

At the same time, increased tree density on farms helps farmersadapt to the effectsof climate change and提高粮食安全. On-farm trees reduce wind speed and produce shade for crops, reducing loss of water through evaporation. The added leaf litter also helps replenish organic matter in the soil and increase moisture-holding capacity, boosting soil fertility and crop yields. Niger, for example, faced a significant national grain deficit in 2012 due to erratic rainfall in 2011. Meanwhile, Niger researchers found that a district with high on-farm tree densities had produced a grain surplus of almost 14,000 tons in 2011.

农民还倾向于保护特定的树木，这些树木可提供耕地以外的好处。这些树木可以生产用于牲畜的饲料，以及用于烹饪，房屋建设和在当地市场出售的木材。将树木融入农业系统中，有助于农业生产的可持续加强和多样化，以及家庭收入的增加和对气候变化的韧性。必威官网是真的吗

Scaling Up Re-greening in Africa

Much has been done to boost re-greening in the Sahel, but much more remains to be done. There is ample opportunity for increasing the number of on-farm trees as well as the diversity of trees throughout Africa’s drylands.

A major challenge is devising policies and legislation that stimulate tens of millions of farmers to invest in protecting and managing on-farm trees. Working with farmers to increase the number of on-farm trees can be one of the most cost-effective ways to boost crop production and to scale up“climate smart” agricultural practices这直接有助于提高非洲小农户的粮食和生计安全。世界资源必威官网手机版研究所及其合作伙伴现在正在制定一项策略，以根据已经在萨赫勒和其他地区获得的经验来扩展重新终止成功。

But really growing Africa’s re-greening requires cooperation from multiple stakeholders. Global leaders like President Obama, ministers of agriculture and forestry, NGOs supporting rural and agricultural development, and other decision makers can engage with African farmers to identify key interventions and scale up successes. President Obama and his team, for example, have developed“养活未来”，一项全球反狩猎和粮食安全计划。如果该策略支持另一种绿色革命的发展，则可以更快，成本地实现其目标，这可以帮助农民增加农业系统中的树木数量并恢复退化土地的生产力。

Agroforestry是改善粮食安全和刺激气候变化缓解和适应的关键机会。必威官网是真的吗埃塞俄比亚Tigray的农民告诉我和其他人“树木是我们的骨干”。他们是对的。在世界各地的许多旱地，没有增加农场树木数量的农业没有未来。