Can we emulate early seral forest through silviculture? Klaus J. Puettmann Edmund Hayes Professor in Siviculture Alternatives Adrian Ares Research Associate Oregon State University

Background –Structure –Composition –Legacies Management of vegetation –after stand replacing disturbances –after partial disturbances o - Thinning o - Gaps Outline

Early seral forest conditions after a disturbance that removes overstory Background

Structure: Open growing space; allowing for establishment of vegetation and associated insects, animals, etc. –Shift towards tall canopy layers Composition: dominance of early successional species –Shifts towards late seral species (within and among canopy layers) Legacies from pre-disturbance vegetation Background

Legacies Important for ecosystems processes and function Influence development of early and late seral conditions –Sprouting –Seed source –Cover that prevents establishment of early seral species Background

Suislaw NFWillamette NF From Yang et al Structural development of plantations Conifer cover

20 years 6 years 13 years Management – Stand replacing disturbances ODF land OR Coast Range

Dave Powell, USDA Forest Service, Bugwood.org Management – Stand replacing disturbances Arrested stand development Ceanothus after wildfire, Umatilla NF

P. Anderson, USFS L. Kayes 2 nd growing season 3 rd growing season Management – Stand replacing disturbances Impacts of legacies – Sprouts Timbered Rock, BLM

P. Anderson, USFS Management – Stand replacing disturbances Shrub removal No treatment Hardwood control initially maintains open structure

T. Harrington USFS Management – Stand replacing disturbances Intensive hardwood control accelerates dominance of conifers

Unmanaged 125 snags/ha (range ) Management – Stand replacing disturbances

Natural regeneration (no salvage logging or planting) suggest longer early seral phase Management – Stand replacing disturbances # dominant seedlings established

Conifer size distribution M. J. Lopez 2008 Management (salvage, fuel treatment, planting, release) speeds up conifer dominance * Spatial evenness (!!) Management – Stand replacing disturbances

> 15 feet = gap How many gaps are in ODF plantations? Management – Stand replacing disturbances Low density Gap Road Measurement line

YEAR planted % area in gap Puettmann and Berger 2005 Management – Stand replacing disturbances Gaps contain early seral vegetation, but disappear as stands develop

Spatial scale and variability Timber production Structural Diversity Management – Stand replacing disturbances

No management Management – keep gaps open Gap - scale Management – stand replacing disturbances Ongoing studies:

6% of plantation in gaps Does wildlife notice the difference? Gap and stand scale Management – Stand replacing disturbances Ongoing studies:

YSTDS - Christy Flats Management – Partial disturbances Thinning and gaps = managing for early seral legacies in mature forests

Control High Moderate Variable density Modified from Berryman, unpubl. Management – Partial disturbances

Structural development: Herbs take advantage of disturbance Tall shrubs recover slow Study Results From Ares et al Management – Partial disturbances

Harvesting layout to protect shrubs (legacies) Management – Partial disturbances

From Ares et al Management – Partial disturbances Early seral herbs are responsive: structure and composition C = Control LC = Low complexity thinning MC = Moderate complexity thinning HC = High complexity thinning

Management – Partial disturbances Shrub layer slow to recover and dominated by legacies C = Control LC = Low complexity thinning MC = Moderate complexity thinning HC = High complexity thinning

Early seral vegetation 11-years after thinning Management – Partial disturbances Long-term impact C = Control HD = High density MD = Moderate density VD = Variable density

Lindh and Muir 2004 Management – Partial disturbances

Gap influence Encourages early seral vegetation Limited to gap Early seral species –Physical disturbance –Competition for light (large gaps only) Fahey and Puettmann, FEM 2008 Competitor Management – Partial disturbances

Conclusion –Distinction between structure and composition –Slow vegetation development - Short-term versus medium term impacts of management practices - Choice of legacies –Repeated disturbances Thinning and gap creation –Attention to scale allows early seral legacies in mature forests

Acknowledgements: L. Kayes, P. Anderson, T. Harrington, M. Lopez, J. Shatford, D. Hibbs and all people involved in the various thinning studies Questions and comments?