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Tree Improvement

Tree improvement is a science exploiting the genetic diversity that exists among forest trees. The aim of tree breeding programmes is to improve the growth and quality of future generations of trees. This entails the improvement and maintenance of the genetic base of the breeding population and the turnover of the generations in order to increase volume growth, tree form, wood quality and disease tolerance. Several biological science disciplines, such as genetics, , plant pathology, , wood science and statistics are combined to breed superior trees.

KLF focuses mainly on applied research, while basic research is contracted out or done in collaboration with other institutes and organizations such as the Institute for Commercial Forestry Research (ICFR) and the Forest and Agriculture Biotechnology Institute (FABI). Current breeding programmes include species such as Pinus patula, P. elliottii, P. elliottii x, P. caribaea, P. patula x P. tecunumanii, Eucalyptus grandis and E. grandis-based hybrids, as well as a number of minor species that have already shown potential as alternative species for possible future afforestation.

The breeding of trees is a lengthy process, taking up to 20 years in pines and 8 years in eucalypts to turn over a generation. The first generation population consists of trees that are selected from unimproved stands of trees or commercial plantations. The progeny of these selected trees are then planted in trials from which the best trees are selected from the best families (family and within family selection). These trees represent the second generation and seed produced by the best trees selected from this generation are used to raise trees to represent the third generation of genetically improved trees, and so forth.
Most of the pine species that are worked with are in their second generation and in some instances there are third generation selections. The company already has fourth generation progeny trials for E. grandis as the breeding cycle for this species is much faster.

As eucalypts are relatively easy to regenerate vegetatively, the use of clones are playing an increasingly important role in tree breeding, as well as in clonal forestry. A clone can be defined as a group of genetically identical trees asexually propagated from a single ancestor. The best clones for commercial production are selected from clonal trials. Clonal plantations improve the uniformity and quality of the forests and have many benefits for the users.

Currently KLF manages a number of species, provenance, progeny and clonal trials, which are used to evaluate the genetic potential of the material under specific environmental conditions. This broad genetic base ensures that KLF will always have the best quality trees in the field.