Genetic diversity is the foundation of biodiversity, although too often ignored. For three important reasons, we need to better understand it as we manage our native forests:
- For ecosystem services
Our forest ecosystems provide many services we need in most of southcentral Ontario’s diverse climates and sites. Healthy, diverse forests moderate local climate, conserve soil and ground water, enrich soil, and provide economic benefits from logging. There is increasing evidence of their direct links to human health – go to http://www.treesontario.ca/news/index.php/health_publication_launchSpecies diversity gives us trees that are adapted to hot summers versus cold winters; to moist versus dry soils; to heavy shade versus exposed conditions.
In the ice storm of 1998, eastern Ontario’s rich species diversity allowed the forests to continue to exist and thrive, although many trees and even whole species suffered. Compare this to the effect of Emerald Ash Borer in southwest Ontario where there were few forests, with ash as a dominant species, and the result is a fragile forest landscape and reduced services.
- For evolutionary capacity
Genetic diversity within a species means that, barring catastrophic events, some individuals will be adapted to withstand pressures and survive, and therefore the species will survive.For species threatened with exotic diseases and pests, such as chestnut, butternut and now beech and ash, we hope that genetic tolerance can be found to ensure these species’ continued presence in our forests. The Elm Recovery Program at The Arboretum, University of Guelph is working with such tolerance in elm. If we had reduced these species to a few clones on our landscape that were desired for specific products or aesthetics, it is unlikely we would be successful in finding natural tolerance.
- For economic potential
When we conserve the full breadth of native genetic diversity, we have a greater opportunity to select certain trees to breed for traits which will bring economic benefit. It may be sweeter sap for maple syrup production, faster growth in white pine, better nut production in walnut, or stem form and branch angle for windbreak or Christmas trees.