As trees grow older, they become more vulnerable to all sorts of maladies – some simply the consequences of age, others because of changes to the environment in which they’re living.
To prevent the spread of invasive pests and diseases, pay particular attention to older trees that may be more susceptible to disease.
Resist big number campaigns
It’s surprising how often this is overlooked — but trees of similar ages and/or species are likely to fail and die at about the same time. Organize your “big number” tree planting campaign wisely. [It can be done. ] Or your community may one day face a huge surge in expenses and a simultaneous deficit in ecosystem services.
How to manage a multi-generational forest
- Consider potential liability risks and take care to compare costs and benefits of maintaining old trees against planting new trees.
- Over the long haul, strive for a tapestry of trees of different ages and species. Uneven age distribution is important for sustainability because it spreads out the timing of all management activities – planting, maintenance, removal, and replacement – so they won’t all come due at once.
- Uneven-aged forest stands also help pace the delivery of ecosystem services, or tree benefits, so there will be a steady supply at all times. A newly-planted tree needs decades of growth before it can provide the same level of benefits as its elders.