Treesearch

Moist mixed-conifer forests of the northern Rocky Mountains often contain thousands of stems per acre following stand-replacing disturbance. Many of these trees are shade tolerant species such as grand fir and western hemlock, even though current management objectives aim to increase density of early seral species such as western larch. Managers are faced with questions on how best to manage these overstocked stands and thinning is often a proposed solution. Knowledge on changes in stand structure over long periods of time following thinning are limited in these forests. This study applied...

Widespread failure of oak regeneration and subsequent loss of the oak component has been reported across Eurasia and the Americas. The oak regeneration issue has been linked to changing disturbance regimes, including the lack of fire. Burning used in combination with stand thinning creates conditions that should be conducive to oak regeneration establishment and recruitment, including increased understory light and decreased woody plant competition.

In eastern woodlands, frequent, low-intensity disturbances are needed to achieve desired woodland management objectives: an abundant and diverse ground flora, rich with herbaceous and graminoids species and minimal or isolated-dense patches of woody mid-story cover. These traits are integral to the structure and function of woodland communities. Prescribed burns are commonly used to meet these objectives; however, prescribed fire use can be limited by many constraints (e.g., risk, smoke, limited seasonality, legality), especially at the wildland-urban interface. Targeted goat browsing may...

Silvicultural establishment practices can influence survival and growth of the succeeding stand, including effects on stand productivity and plant community composition. Vegetation control and logging-debris manipulation are two common practices that influence reforestation success, but their effectiveness is likely to vary with soil quality and its influence on plant resource supply. We established an experimental manipulation of logging debris (removed, retained, or piled) and vegetation control (initial site preparation or annual herbicide application for 5 years) at two sites that...

White oak regeneration is both disturbance dependent and advanced growth dependent (Clatterbuck 2019). “The answer to the question of how to ensure oak regeneration … is not the development of some radically new method of cutting, but recognition that all cutting operations in a stand, from the very first, should have as some of their objectives the creation of an environment, largely light conditions, favorable for oak regeneration … and furthermore … ensure that cuttings occur frequently enough to maintain growth of oak regeneration” (Hodges 1989).

Red maple was once a minor component of eastern deciduous forests. It is now the most abundant and widespread tree species in the eastern United States (Oswalt et al. 2019). The increase in red maple is attributed to its adaptability to a wide range of environments and the current management policy of forest fire suppression (Abrams 1992). On most sites, red maple seedlings tend to outgrow the regeneration of more desirable species, especially oaks.

Despite growing interest in restoring and managing oak woodlands and savannas, few silvicultural guidelines and tools are available, particularly for evaluating or adjusting woodland or savanna stand density and overall structure. Gingrich’s Stocking Guide has been used for managing oak-hickory forests for several decades, but important density thresholds are intended for use in forests where maintaining full growing space occupancy is the goal during thinning.

Montane and subalpine forests in the Northern Rocky Mountains produce wood fiber for products, store water in the snowpack, sequester carbon, and provide wildlife habitat, including for threatened Canada lynx and their primary prey, the snowshoe hare. Use of precommercial thinning (PCT) in potential lynx habitat is restricted on federal lands due to short-term reduction of forage and hiding cover for hares. However, dense young forests are slow to develop multiple canopy layers (fig. 1) - habitat preferred by hares and lynx - yet silvicultural thinning can accelerate development of...

Timber management in Sitka spruce / western hemlock temperate rainforests is increasingly focused on secondary even-aged stands that re-established after primary forest removal during the 20th century. After clear-cut harvest, abundant natural regeneration fosters rapid stand initiation forming dense, close canopy forests. Understory vegetation declines rapidly after canopy closure and is nearly absent during the prolonged stem exclusion phase of stand development. Productive understory vegetation is important for wildlife habitat and subsistence food resources across the ecoregion....

The Superior National Forest (SNF) is preparing forest ecosystems for the challenges of continued climate change. Covering over 3 million acres in northern Minnesota, the SNF consists of boreal-temperate transition forests including several species expected to decline over the next century, such as jack pine, black spruce, and quaking aspen. As one possible adaptation action, silviculturists on the SNF have been implementing small-scale pilot projects to test assisted migration of tree species, including reforesting with new seed sources of existing species as well as introducing novel...