By Jim Tule¹
International Forest Company grows some of the most Genetically Diverse Loblolly pine (Pinus taeda L.) containerized seedlings in the Southwestern United States. It is through their membership and association with the Western Gulf Forest Tree Improvement Program (WGFTIP) that this Genetic Diversity is expressed. Genetic Diversity is important to all forest users and it has both economic and ecological value. Loblolly pine contains a high level of natural genetic diversity and tree improvement programs are committed to maintaining genetic diversity in trees for the future.
What is Genetic Diversity?
- Genetic diversity separates species
- Genetic diversity makes individuals within a species different, even when the effects of the environment are constant
- Genetic diversity within a species exists between geographic regions, stands within regions and trees within stands
Why is Genetic Diversity Important?
- Genetic diversity is important to the health of a species
- Genetic diversity allows a species to adapt to change in the environment
- Loblolly pine is one of the widest-ranging and most economically important conifers in the Southern United States, harvested for both pulpwood and solid wood products
- Loblolly pine is not threatened or endangered, because new stands are planted or naturally regenerated on millions of acres each year
- Conserving genetic diversity is an important aspect of sound species management
How do Tree Improvement Programs Affect Genetic Diversity?
- Genetic diversity is the raw material for tree improvement programs
- Tree improvement programs work with a sample of the genetic variability present in the natural population
- Breeding populations are managed to enhance variation, which can result in genetic combinations not seen in the natural population
- Breed populations are often subdivided. This avoids inbreeding in the production populations and ensures a high level of genetic diversity in the breeding population
- Tree improvement programs are careful not to rely on only one or a few genotypes
The Western Gulf Tree Improvement Program is a cooperative tree improvement project founded in 1969 with the objective of providing the best genetic quality seed for use in forest regeneration programs in the Western Gulf Region of the United States. There are currently 13 members represented by 4 state agencies and 9 industrial and private land owners. Genetic variation is the natural resource on which all breeding and genetic improvement programs are based and therefore conservation of genetic diversity is considered good natural resource stewardship, a prerequisite for evolutionary change and an obligation to future human generations. The cooperative is conserving and improving populations of five Southern Pine species and several hardwood species (Loblolly pine, Slash pine, Shortleaf pine, Longleaf pine, Virginia pine, Cherrybark oak, Water/Willow Oak and Nuttall oak).
IFCO continues to be a member of the WGFTIP. It is through this membership along with other cooperative ventures that IFCO is a steward of a genetically diverse forest. IFCO is committed to the breeding and testing programs of the WGFTIP and has completed 3 generations of tree breeding resulting in significant genetic gains in volume growth. Along with volume growth, wood quality characteristics such as stem straightness, wood specific gravity and microfibril angle are also considered as important selection criterion in their breeding populations.
The seed utilized in IFCO’s regeneration efforts are collected from Seed Orchards derived from these extensive breeding and testing efforts over the past 44 years. These breeding efforts have resulted in the deployment of genetically improved seedlings from certified seed orchards throughout the South. Much of the seed that the Evans Nursery Complex will utilize in 2014 comes from IFCO’s Seed Orchards in Louisiana. Loblolly pine seed is collected and stored for future use from this Seed Orchard annually. Seed and seedling deployment is based on the breeding and testing completed by the cooperative over the past 44 years along with the correlation of the soil mapping that was completed through past land ownership. These correlations have led to the deployment of the best genetically improved seedlings being matched to the soils that show superior growth characteristics. These characteristics are then matched to plant hardiness zones resulting in superior growth. It is through this process that IFCO assists landowners in the deployment of their seedlings to regenerate their forests and deploy seedlings to regenerate their Forests.
The deployment of seedlings in the Western Gulf Region along with IFCO’s other Nursery operations is based on their original provenance, their growth and yield characteristic based on years of genetic breeding and testing, along with the soil characteristics of the tracts that are to be regenerated and the silvicultural practices to be employed for their tracts. All of the being considered has resulted in a superior genetically diverse sustainable forest for the landowner.