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Old Tree Responses


1. Evaluate the 15-year-post-treatment growth response, damage and mortality of mature Jeffrey and ponderosa pine following individual tree (radial) thinning, stand level thinning and in adjacent untreated stands.

2. Use results to improve retention guidelines for individual mature Jeffrey and ponderosa pines and enhance silvicultural prescriptions used in ecological restoration projects.

Ecological restoration of fire-adapted forest systems often focuses on density reduction with the retention of mature fire resistant pines to increase stand resiliency. However, there is disagreement about the ability of mature and old pines to respond to increased growing space, duration of the treatment effect and/or the treatment scale and intensity required to achieve a positive growth response. Variables such as drought, low live crown ratio, mechanical damage, and/or dwarf mistletoe infections can also limit the response in growth and vigor of mature pine to reductions in stand density. This project will determine to what degree thinning treatments affect 15 year growth rates of mature, 200+ year old ponderosa and Jeffrey pine. This is essential knowledge for developing treatment prescriptions, as old trees are scarce on the landscape and often a high priority for retention.

Photo: Stand level treatment to restore old-growth pine forests and improve vigor of old trees.

Stand level treatment to restore old-growth pine forests and improve vigor of old trees.

Modified: Oct 10, 2019

Select Publications & Products

Hood, S. M., D. R. Cluck, B. Jones, and S. Pinnell. 2018. Radial and stand-level thinning treatments: 15-year growth response of legacy ponderosa and Jeffrey pine trees. Restoration Ecology 26:813-819.

Doughnuts don’t make trees fatter. 2019. RMRS Science Spotlight.