Researchers Tony D'Amato from the University of Vermont, and Paul Catanzaro and Lena Fletcher from the University of Massachusetts teamed up to investigate techniques to help develop old-growth characteristics in second-growth northern forests thanks to funding from the MA Chapter of The Nature Conservancy.
Historically, old growth forests dominated the New England landscape. Our land use history of agriculture has led to relatively younger forests which don't include all the characteristics that old-growth forests once did. While old-growth forest cannot be re-created, old-growth characteristics missing from today's forests can be encouraged through not only a passive approach, but also active forest management. Characteristics, such as a diversity of tree ages and sizes, gaps in the forest canopy, and large amounts of standing and fallen dead trees, can increase the habitat value of the forest and the amount of carbon being sequestered.
This new research tested if it was possible to use patch selection, cutting everything within a 1/3 acre gap, to develop old-growth characteristics while also regenerating shade intolerant and midtolerant tree species such as white pine, white ash, and black cherry. The treatments being tested included some patches in which legacy trees were left standing in the patch (see the picture above). Legacy trees are those trees that are left in a forest to grow old, large and eventually turn into a snag and downed, dead log.
The results of the study suggest that 1/3 acre patch selection does indeed help the develpment of old-growth characterstics in our second growth forests. However, the retention of even a few legacy trees in the patch to increase old-growth structure did negatively affect the amount of shade intolerant and midtolerant species regenerated in the patch. Thus, a trade off decision must be made on where the relative management emphasis should be placed on forest structure or species composition.
This new knowledge and insight on how old-growth characteristics can be introduced into a forest is important in the face of climate change and as many landowners and foresters manage for dynamic and resilient stands.