SIVICULTURE OPERATIONS IN OUR PINE PLANTATIONS

Pinus Radiata compartment before thinning and pruning

​Strawberry Hill Farm has always had a small but active sawmill which utilises the pine plantations on the property. Most of the property is being returned to indigenous vegetation but we maintain a small area of Pinus Radiata. We recently added a certified forester to our team (Ndukwenhle) who will assist in revitalizing our pine plantations. With Ndu on the team, our pines will undoubtedly be healthier, better managed, and more attractive to visitors. He is currently assisting with silviculture operations on the farm.

---

​The project is divided into two silvicultural operations: thinning and pruning. Both of these operations need to first include field surveys and the consideration of management objectives for the plantations.
The first operation is thinning. The aim of a thinning regime for pine is to keep the stand in a steady growing cycle, such that good diameter growth can occur and the best trees can be selected for the final harvest. Thinning eliminates rivalry, allowing the remaining trees to grow faster. Thinning is also a good way to generate intermediate income as thinned pines can be sold. The operation involves a sequential process to spray paint trees with irregularities and limited diameter. The pine species grown on Strawberry hill farm are generally not self-pruning. However, on the positive side, Pinus Radiata is a hardy, fast-growing softwood with a medium density that can be used for a variety of purposes.

Thinning on a constant basis also helps to improve genetics as it kills trees that are inferior, diseased, or have an unattractive appearance, which is often due to poor genetics. Thinning will help to reduce the number of trees with undesirable characteristics in a stand and to harvest those trees early, prior to forest regeneration. Thinning also changes the forest's climate for the better, by allowing light to penetrate the soil, raising the temperature and increasing moisture and nutrient supply.

A 3 meter pruned, naturally regenerated pine compartment.

​The second silvicultural activity is pruning. There are several reasons why pruning is important. Firstly, for fire protection as research has shown that trees with lower branches start fire sooner and so the lower branches are removed. Secondly, pruning is also done to limit the formation of large dead knots. Finally, pruning aids in getting rid of damaged wood containing pests and helps provide a more desirable shape for the tree. 

A tractor-winch extracting a thinned log to the depot

​ 
One may ask what happens to the thinned pines and side branches that are cut? For extraction of thinned log, a primary transport is used to extract the logs to a central place. They are then transported to our sawmill. This ensures that our sawmill team has enough timber to work with. The pruned side branches are not removed but stacked neatly, so that they break down, adding organic matter into the soil.

These operations are important to ensure good and healthy pines that can be harvested when the trees reach a suitable size. They also make the plantation safer in times of fire management and more attractive to visitors.