In recent years,thediscussionontheenvironmental sustainabilityof commercial plantations has intensified.Inparticular, some peoplebelievethat theymightbe affecting biodiversity, water flows, and soil quality. However, according to Cossalter (2003), in most cases this reasoning is often misguided, and the problems are usually related to specific plantations and a poor planning and execution process.
Regarding biodiversity, the direction of the impact is a function of the type of ecosystem it replaces. If natural forests are replaced in the process, the effect on biodiversity will be negative. However, if plantations are establishedon degraded land, the effect will be positive and environmental sustainability will be achieved.
The relationship with water flows requires a more difficult understanding. Erroneous conclusions and generalizations are usually made, even in formal literature. For instance, it is necessary to analyze eachplantation separately, since different variables interact with each other to define thedirection and magnitude of the impact on water flows. Some examples of these variables are:the type of soil, and its capacity to absorb water, the species used, the type of habitat replacedby the plantation, the climateconditions of the region, and the precipitation level in the area.
Finally, the effect on the soilsis usually correlated with the rotation ageof the forests. On the one hand, erosion tends to intensify in early stages of plantations. During this time periodland preparation tends to leave plantationsexposed to environmental conditions; incases of very short rotationsages, they might not have time enough to fully stabilize their erosion levels. However,again, the magnitude and direction of the impactonsoil qualityis correlated with the specific characteristics of each plantation. With proper planning and management it is possible to mitigate most of these effects completelyand ensure the environmental sustainability of the plantations. Nevertheless, if the time period between tree planting and rotation ageis expected to be very short, it is possible to increase the amount of fertilizers used, preventing any type of inconvenience with the soil. It should be noted that most commercial plantations tend to negatively affect soil quality to a lesser extent than many of the traditional agricultural crops. According to an FAO study (2017), a cereal crop decreases the amount of nitrogen in the soil 2.5 times more than aneucalyptus plantation.
27 Nov