You will recall this planning tool from Unit One. The Matrix supplies information about the physical site requirements for plants that have potential as forest crops. The Nut Crop section of the matrix provides information about xx varieties of nut trees that might be candidates for your site. The Fruit Crop section identifies site requirements for xx varieties of fruits trees and shrubs.
Candidate crops are listed across the top of the matrix, as column headings. Down the left hand side of the matrix are site descriptors. The cells provide information about the range of tolerance of that particular plant for each site characteristic. For example, in looking at the Nut Crop section of the matrix we see that Black Walnut has a soil pH tolerance range of xx to xx. To make use of this information, you will want to measure the pH of the soils, in areas of your forest where you might consider planting Black Walnut trees, to see if the pH level there is within range of what this plant is likely to tolerate.
In looking at the Fruit Crop section of the matrix we see that Black Currant has a shade tolerance of medium. This is a less precise measure than our pH measure for Black Walnut. Two reasons for this are important to appreciate as you use the matrix for selecting candidate fruit and nut crops.
First, considerably less is known about Black Currant as a forest crop, as there is little experience with it. Black Walnut on the other hand is an established forest crop whose timber has long had commercial value, which helps account for its better scientific knowledge base. Second, measures of light intensity are more costly and difficult to develop than measures of soil pH. Therefore, relatively more qualitative assessments of this site characteristic are inevitable. For the time being, in other words, there is more “guesswork” in assessing light requirement, or shade tolerance characteristics, than in assessing some of the other factors that will affect the performance of forest crops.