The current mode of global food production is characterized by negative impacts on both human and planetary health (Haddad et al., 2016; Pinstrup-Andersen, 2013; Whitmee et al., 2015; Chapter 2). Fifty years after the Green Revolution, the world still faces multiple forms of malnutrition while much of the agricultural expansion related to achieving global food security often occurs at the expense of natural systems, including forests (Gibbs et al., 2010; Leblois et al., 2017).
The environmental toll of unsustainable agriculture threatens to undermine progress toward achieving global food security (Gordon et al., 2017). Climate change, to which agriculture is a major contributing factor, threatens crop production around the world (Kent et al., 2017; Martinich et al., 2017). At the same time, loss of fertility, desertification, loss of ecosystem services, and natural habitats undermine the long-term stability of the global food system (Haddad et al., 2016). Thus, the major questions facing global sustainable production are: (1) How do we increase production on existing agricultural land while reducing environmental degradation? (2) How do we reduce the environmental degradation and loss of ecosystem services as well as important sources of wild food and income resulting from agricultural expansion into natural habitats? (3) How do we restore degraded, unproductive, and abandoned agricultural land and natural habitats?
Forests and trees are an essential part of the solution to all three questions. Trees in agricultural landscapes can simultaneously increase production and mitigate against environmental degradation. Judicious landscape-scale land use planning that incorporates trees and forests into productive landscapes can simultaneously conserve forests and protect the ecosystem services upon which agricultural production depends (Baudron and Giller, 2014; Reed et al., 2016). At the same time, reforestation and regeneration of forests can restore degraded land and provide new productive landscapes on abandoned or degraded land.
Here, we divide the roles and functions of forests into three categories. First, is the provisioning function of forests; that is, the direct provision of food and income from forests and agroforestry. Second, forests have a protective function, a term referring to the oft-neglected contributions of ecosystem service provision, and the potential of forest regeneration to reclaim degraded land and increase agricultural production and mitigate climate change. The third function relates to the restorative capacity of forests that can be leveraged through increasing the availability of trees and forests in agricultural landscapes. Such contributions include climate change mitigation via sequestration and the restoration of degraded agricultural land. The latter can occur either through secondary forest succession or deliberate planting and restoration.
This chapter begins with a brief overview and outlook on the link between agriculture, deforestation, and climate change. In the next section, we explore the direct contributions forests make to food security through the provision of food and income and as a safety net for poor and vulnerable people. In Section 6.4, we examine the protective function of forests in terms of often-neglected ecosystem services upon which current agricultural production depends. The restorative function of forests and the potential of forest and tree-based agricultural systems to provide sustainable alternatives to contemporary industrial agriculture and mitigate climate change are discussed in Section 6.5. Finally, we discuss the governance and landscape management challenges and opportunities of incorporating forests and trees into agricultural landscapes.