PRETATERRA Answers: How Do You Implement an Agroforest Where There Is Already a Forest?

We got a question from Carlos, from Manaus, who would like to plant an agroforest on 32 hectares, in an area that is already forest. He wants to plant cocoa, açaí and a tree component using native species such as cumaru, Brazil nut and andiroba. Carlos also says he plans to carry out forest management to harvest some trees for commercial use (timber) and, after that, move on to establishing the agroforest across the 32 hectares, with the goal of enriching the area and earning an economic return.

"My big question is how to manage these 32 hectares to establish the agroforest, since it is an area of advanced forest. It generates a lot of material and takes a lot of labor to organize the area. Do I really have to put all the material on the ground to trigger the growth pulse, or is a partial management that opens up light for each plot enough to trigger the pulse?"

Hi Carlos, thank you for your question. Since it is a complex situation, we will answer it in parts:

First point: forest management in native areas

To carry out forest management, you need to submit a management plan to your state's environmental agency, including a species inventory, that is, a list of which species occur, an estimate of their quantities and the volume of timber to be harvested. Once this Management Plan is finalized and approved by the agency, before harvesting the species of interest, you will need to carry out a census: a 100% survey of the area identifying which trees will be removed, the measurements and volume of each individual, and the specific spots where they will be harvested. Both the Management Plan and its execution are costly, technically (since they involve hiring professionals for technical supervision, writing the plan and doing the inventories) and operationally. Once this first management is done to harvest species for commercial use, especially timber, it will create some opening for light. An important note is that at the end of this process, only a few trees per hectare may be removed. In any case, when trees are removed through sustainable forest management, vines and climbers must be cleared or cut at least a year beforehand, and you need to identify the surrounding trees and plan how each tree will fall so as to open the smallest possible gap. It is neither a simple nor an easy process and needs very good technical guidance.

Second point: converting the area into an agroforest

Since it is a forest area, you will also need a Management Plan submitted to your state's environmental enforcement agency, and its authorization before starting the conversion. The Management Plan will describe what actions will be taken, the area, species, and so on. After approval, a first step can be to identify which species can be removed to open up light, for example pioneer species that are already senescent.

Third point: do you need to put all the material on the ground to trigger the pulse?

You need to weigh the cost-benefit of pulsing, because while it is good for the pruned material, chopped as finely as possible, to be in contact with the soil to decompose and feed soil life, it is also a very costly operation. One solution would be partial management: for example, thin branches, leaves and vine stems can be left on the ground. Thicker branches can be removed for firewood or similar uses, or even burned on site very carefully in isolated piles. This opening, removing pioneer or shorter-cycle individuals and malformed or diseased ones, lets in some light and allows us to bring in secondary species such as cocoa, cumaru, or even Brazil nut and andiroba. This can be done in rows, for example, to make it easier to keep track of the number of plants per hectare. Ideally, this forest enrichment should be done systematically to make operations easier, and also so that, based on the number of plants per hectare, the expected production can be estimated.