Overstory Response to Alternative Thinning Treatments in Young Douglas-fir Forests of Western Oregon

Davis, Liane R.; Puettmann, Klaus J.; Tucker, Gabriel

doi:10.3955/0029-344x-81.1.1

Cited by 47 publications

(49 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As expected, the lower post-treatment densities resulted in increased average tree diameter growth [15,29]. Closer inspection showed that the smaller trees had the highest diameter growth increase.…”

Section: Tree and Stand Growth Responsesmentioning

confidence: 85%

“…Closer inspection showed that the smaller trees had the highest diameter growth increase. In contrast, diameter growth of larger trees was still higher than those of smaller trees, but increased less or not at all after thinning, unless densities surrounding the trees were very open [15,29]. The spatial variability created, e.g., by including gaps, was also reflected in diameter growth responses, with trees adjacent to gaps showing higher increases in growth [15,30].…”

Section: Tree and Stand Growth Responsesmentioning

confidence: 92%

“…Restoration goals in such settings often include opening canopies sufficiently to provide a niche for regenerating tree seedlings and to maintain the full suite of early and late-seral plant species and associated habitats [38]. Although restoration treatments applied in the YSTDS and DMS resulted in large reduction e.g., from around 80% in controls down to 40% canopy cover [29,39,40], the response was transient and the remaining trees responded to increased space and resources with crown expansion. The associated recovery rate of approximately 1.5% to 2% per year indicated that the canopy closes fairly quickly and benefits of canopy openings will not last.…”

Section: Canopy and Crown Size And Structurementioning

confidence: 99%

“…As suggested by Wilson and Oliver [41], these trends are not quickly reversed. However, the variable density thinning does suspend the process of crown lift and lead to the retention of lower crowns and live crown ratios [29,42]. The impact of additional growing space on increasing branch sizes has been well documented [43].…”

Section: Canopy and Crown Size And Structurementioning

confidence: 99%

“…This problem can be overcome or mediated by designating untreated leave islands or skips in treatments. However, as indicated above, these areas left at higher densities and associated high competition levels exhibited mostly competition related mortality of the smaller trees, i.e., most new snags were from the smaller end of the diameter distributions [15,29]. As an alternative, we modified our restoration treatments to accelerate snag provision and downed wood by intentionally creating snags [36] and downed wood.…”

Section: Tree Mortalitymentioning

confidence: 99%

See 4 more Smart Citations

Forest Restoration Using Variable Density Thinning: Lessons from Douglas-Fir Stands in Western Oregon

Puettmann

Ares

Burton

et al. 2016

Forests

View full text Add to dashboard Cite

A large research effort was initiated in the 1990s in western United States and Canada to investigate how the development of old-growth structures can be accelerated in young even-aged stands that regenerated following clearcut harvests, while also providing income and ecosystem services. Large-scale experiments were established to compare effects of thinning arrangements (e.g., spatial variability) and residual densities (including leave islands and gaps of various sizes). Treatment effects were context dependent, varying with initial conditions and spatial and temporal scales of measurement. The general trends were highly predictable, but most responses were spatially variable. Thus, accounting for initial conditions at neighborhood scales appears to be critical for efficient restoration. Different components of stand structure and composition responded uniquely to restoration thinnings. Achieving a wide range of structures and composition therefore requires the full suite of silvicultural treatments, from leave islands to variable density thinnings and creation of large gaps. Trade-offs among ecosystem services occurred as result of these contrasting responses, suggesting that foresters set priorities where and when different vegetation structures are most desirable within a stand or landscape. Finally, the results suggested that foresters should develop restoration approaches that include multiple treatments.

show abstract

Section: Tree and Stand Growth Responsesmentioning

confidence: 85%

Section: Tree and Stand Growth Responsesmentioning

confidence: 92%

Section: Canopy and Crown Size And Structurementioning

confidence: 99%

Section: Canopy and Crown Size And Structurementioning

confidence: 99%

Section: Tree Mortalitymentioning

confidence: 99%

See 3 more Smart Citations

Forest Restoration Using Variable Density Thinning: Lessons from Douglas-Fir Stands in Western Oregon

Puettmann

Ares

Burton

et al. 2016

Forests

View full text Add to dashboard Cite

show abstract

Exceptional variability in historical fire regimes across a western Cascades landscape, Oregon, USA

Johnston,

Schmidt,

Merschel

et al. 2023

Ecosphere

View full text Add to dashboard Cite

Detailed information about the historical range of variability in wildfire activity informs adaptation to future climate and disturbance regimes. Here, we describe one of the first annually resolved reconstructions of historical (1500–1900 ce) fire occurrence in coast Douglas‐fir dominated forests of the west slope of the Cascade Range in western Oregon. Mean fire return intervals (MFRIs) across 16 sites within our study area ranged from 6 to 165 years. Variability in MFRIs was strongly associated with average maximum summer vapor pressure deficit. Fire occurred infrequently in Douglas‐fir forest stands seral to mountain hemlock or silver fir, but fire frequency was much shorter than predicted by theory in other forest types. MFRIs within Douglas‐fir stands seral to western hemlock or grand fir ranged from 19 to 45 years, and MFRIs in stands seral to Douglas‐fir ranged from 6 to 11 years. There was little synchrony in fire occurrence or tree establishment across 16 sites separated by 4 km. The lack of synchrony in fire suggests that large, wind‐driven fire events that are often considered to be characteristic of coast Douglas‐fir forests were not an important driver of succession in our study area during the last ~400–500 years. Climate was more arid than normal during fire years in most forest types, but historical fire in stands seral to Douglas‐fir was strongly associated with antecedent moisture and less strongly associated with drought. We interpret the extraordinary tempo of fire we observed in stands seral to Douglas‐fir and the unique climate pattern associated with fire in these stands to be indicative of Indigenous fire stewardship. This study provides evidence of far more frequent historical fire in coast Douglas‐fir forests than assumed by managers or scientists—including some of the most frequent fire return intervals documented in the Pacific Northwest. We recommend additional research across the western Cascades to create a comprehensive account of historical fire in highly productive forests with significant cultural, economic, and ecological importance.

show abstract

Variable-density thinning promotes differential recruitment and development of shade tolerant conifer species after 17 years

2020

View full text Add to dashboard Cite

Overstory Response to Alternative Thinning Treatments in Young Douglas-fir Forests of Western Oregon

Cited by 47 publications

References 30 publications

Forest Restoration Using Variable Density Thinning: Lessons from Douglas-Fir Stands in Western Oregon

Forest Restoration Using Variable Density Thinning: Lessons from Douglas-Fir Stands in Western Oregon

Exceptional variability in historical fire regimes across a western Cascades landscape, Oregon, USA

Variable-density thinning promotes differential recruitment and development of shade tolerant conifer species after 17 years

Contact Info

Product

Resources

About