Large old trees are critical organisms and ecological structures in forests, woodlands, savannas, and agricultural and urban environments. They play many essential ecological roles ranging from the storage of large amounts of carbon to the provision of key habitats for wildlife. Some of these roles cannot be replaced by other structures.
Large old trees are disproportionately vulnerable to loss in many ecosystems worldwide as a result of accelerated rates of mortality, impaired recruitment, or both. Drivers of loss, such as the combined impacts of fire and browsing by domestic or native herbivores, chemical spray drift in agricultural environments, and post-disturbance salvage logging, are often unique to large old trees but also represent ecosystem-specific threats.
David Lindenmayer and colleagues argue in a new paper in Conservation Letters that new policies and practices are urgently needed to conserve existing large old trees and restore ecologically effective and viable populations of such trees by managing trees and forests on much longer time scales than is currently practiced. They also recommend we need to do more to protect places where old trees are most likely to develop. Without these steps, large old trees will vanish from many ecosystems, and associated biota and ecosystem functions will be severely diminished or lost.
Lindenmayer DB, WF Laurance, JF Franklin, GE Likens, SC Banks, W Blanchard, P Gibbons, K Ikin, D Blair, L McBurney, AD Manning & JAR Stein (2014). New Policies for Old Trees: Averting a Global Crisis in a Keystone Ecological Structure. Conservation Letters, 7: 61–69.