The interactive impact of overstory canopy closure, understory brush control, and simulated white-tailed deer (Odocoileus virginianus Zimmermann) herbivory (i.e., clipping) on growth and survival of underplanted white pine (Pinus strobus L.) seedlings was examined. Clipping was conducted in April 1996 and 1997 at three intensities (control, 0% previous year’s growth...
Silvicultural regimes that aim at an increased stand structural diversity typically promote small-scale heterogeneity in horizontal and vertical structures, e.g. through the creation of gaps. We used terrestrial laser scanning (TLS) to investigate impacts of altered growing conditions on trees adjacent to artificial gaps as compared to responses of trees...
Snags and hardwoods contribute to biological, structural, and functional diversity in old-growth forests. In the US Pacific Northwest, only general knowledge about regional patterns is available to determine target density of snags and hardwood trees. To investigate their variability at relevant scales for silviculture, we examined snag and hardwood densities...
We examined the potential of using upslope density management to influence growth and drought tolerance of trees in untreated downslope riparian forests. Increment cores from Douglas-fir trees in three mature stands in western Oregon, USA, were collected and measured. Trees responded to an apparent edge effect up to 15 m...
We evaluated effects of top-soil scarification by heavy machinery on growth of two valuable and shade-intolerant tree species - Nothofagus dombeyi (evergreen and considered very plastic to different soil fertility levels) and Nothofagus alpina (deciduous and considered sensitive to soil fertility) - seedlings underplanted in Nothofagus old-growth forests subjected to...
Mortality from Armillaria root rot is a major concern of forest management. Field experiments were conducted in Minnesota to evaluate interspecific differential susceptibility and to assess whether density or species composition, specifically the proportion of conifers in a plot, influences seedling mortality from Armillaria spp. Seedlings of 10 tree species...
Quantitative associations between animals and vegetation have long been used as a basis for conservation and management, as well as in formulating predictions about the influence of resource management and climate change on populations. A fundamental assumption embedded in the use of such correlations is that they remain relatively consistent...
We examined natural regeneration following operational-scale variable density retention treatments in 40-60 year old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests at seven sites for a decade following treatment. Treatments included residual overstory densities of 300, 200, and 100 trees/ha, with leave islands and gaps of three sizes (0.1, 0.2, and...
Forest understory vegetation is influenced by broad-scale variation in climate, intermediate-scale variation in topography, disturbance and neighborhood interactions. However, little is known about how these multi-scale controls interact to influence observed spatial patterns. We examined relationships between the aggregated cover of understory plant species (%C[subscript U]) and multi-scale controls using...
Because forest ecosystems have the capacity to store large quantities of carbon
(C), there is interest in managing forests to mitigate elevated CO[subscript 2] concentrations and
associated effects on the global climate. However, some mitigation techniques may contrast
with management strategies for other goals, such as maintaining and restoring biodiversity....