Mycorrhizal Interactions for Reforestation: Constraints to Dryland Agroforest in Brazil

Reforestation provides restoration of forest ecosystem services including improved soil fertility, which leads to increased productivity and/or sustainability of the system. Trees also increase the average carbon stocks providing wood supply for local communities; however, C sequestration strategies highlight tree plantations without considering their full environmental consequences, such as losses in stream flow. The productivity of a site is a consequence of their physical, chemical, and biological properties, resulting in natural fertile soils or adequate managed soils for improved quality. Thus, it is required to know the variations in the properties of land-use systems for adoptability of agroforestry innovations. The choice of agroforestry tree species (highly mycorrhizal dependent plants should be selected) would have great implications for the manipulation of arbuscular mycorrhizas's species. In dry forest, the inevitable consequence of cutting has been the loss of vegetation cover and insufficient scientific information on the capacity to optimize forest recuperation affects agroforestry adoption. To study the biological properties of soils is now of interest; therefore, this paper reviews the literature that has hitherto been published on mycorrhizal interactions for reforestation and points out the use of mycorrhizal technology as one of the alternatives to improve forest products and environmental quality. 1. Introduction Several reports on reforestation/afforestation have showed that alternatives to current agricultural practices have resulted in an enhanced interest in agroforestry systems; moreover, reforestation provides restoration of forest ecosystem goods and services, including improved soil fertility and soil structure, which often leads to increased productivity and/or sustainability of the systems [1–3]. Deforestation in the tropics allowed the conversion to unsustainable land uses (homogeneous with lower biodiversity and low contribution to its complex ecological functions) [4]. Reforestation of former agricultural and pasturelands also provides opportunities for carbon (C) sequestration and for the restoration of forest ecosystem goods and services [5, 6]. Forestation (referring to a general process in which forest cover increases) also increases the permeability of the soil and emits water vapor into the atmosphere through evaporation and transpiration, further reducing the runoff of rainwater [7]. The climate benefits of reforestation in the tropics are enhanced by positive biophysical changes such as cloud formation, which