Treesearch

A solution to the growing problem of catastrophic wildfires in Greece will require a more holistic fuel management strategy that focuses more broadly on landscape fire behavior and risk in relation to suppression tactics and ignition prevention. Current fire protection planning is either non‐existent or narrowly focused on reducing fuels in proximity to roads and communities where ignitions are most likely. A more effective strategy would expand the treatment footprint to landscape scales to reduce fire intensity and increase the likelihood of safe and efficient suppression activities....

Forest inventories are traditionally designed to produce estimates of merchantable timber volume but are increasingly used to estimate stand-level biomass or carbon. Since inventory is volume-focused, it is common practice to tally stems 5 inches and greater in diameter (at breast height; d.b.h.). When estimating carbon or biomass, practitioners may be concerned about the effect of omitting smaller stems from the inventory. We present summaries to provide indicators of when smaller diameters may be less important for an accurate estimate to assist those foresters considering adding carbon...

Wildland fire and bark beetle outbreaks are both large disturbances in North American forests with the potential to interact over spatial and temporal scales (Hicke et al. 2016; Raffa et al. 2008). The order of the disturbances, fire before bark beetles or fire after bark beetles, influences the outcome of the interaction. Fire and bark beetles are similar in that both can cause massive amounts of tree mortality, alter nutrient cycling, and alter forest structure and species composition, but these disturbances, in isolation and together, also have distinct effects on ecosystems. Several...

Here we compare the environmental niche of a highly polyphagous forest Lepidoptera species, the winter moth (Operophtera brumata), in its native and invaded range. During the last 90 years, this European tree folivore has invaded North America in at least three regions and exhibited eruptive population behavior in both its native and invaded range. Despite its importance as both a forest and agricultural pest, neither the potential extent of this species’ invaded range nor the geographic source of invading populations from its native range are known. Here we fit a climatic niche model,...

Ice storms can have profound and lasting effects on the structure and function of forest ecosystems in regions that experience freezing conditions. Current models suggest that the frequency and intensity of ice storms could increase over the coming decades in response to changes in climate, heightening interest in understanding their impacts. Because of the stochastic nature of ice storms and difficulties in predicting when and where they will occur, most past investigations of the ecological effects of ice storms have been based on case studies following major storms. Since intense ice...

In 1994, a large-tree harvest standard known as the “21-inch rule” was applied to land and resource management plans of national forests in eastern Oregon and Washington (hereafter, the “east side”) to halt the loss of large, old, live, and dead trees and old forest patches. These trees and forest patches have distinct ecological, economic, and social values, as reflected in widespread fish and wildlife use, public support for protecting them, and commercial interest in harvesting them, thus they have been the topic of much discussion and debate. At the request of regional Forest Service...

Sprouting by woody plants can increase species resilience to disturbance and foster regeneration during periods with little recruitment from seed. Though sprouting often plays a critical role in oak forest regeneration, there is little information available on sprouting capacity and sprout physiology at the seedling stage, particularly for new germinants. This study compared sprouting capacity and sprout photosynthesis of shoot-clipped germinants of two temperate oaks established in contrasting light environments. We studied the North American Quercus alba and the European Q. robur, both...

Conifer removal in interior woodland ecosystems of the western US is a common management treatment used to decrease fire hazard and shift woodlands to more historical states. Woody material is frequently removed by skidding material off site and via slash pile burning. Assessing the long-term outcomes of seeding treatments after such ground disturbing activities is critical for informing future management and treatment strategies. Using two designed experiments from a central Oregon juniper woodland, we resampled slash piles and skid trails 8 years after seeding. Our objectives were to...

Multiple introductions in California of Phytophthora cinnamomi are severely threatening its native ecosystems. However, little is known about the consequences of outbreaks caused by different genotypes on endemic hosts. Virulence of 10 genotypes representative of the California and worldwide genetic variability of P. cinnamomi was studied on roots and stems of four native California plant hosts. Hosts differed in type of response and susceptibility level, and individual pathogen genotypes differed in virulence. Pathogen variability was clear when testing hosts of moderate susceptibility...

Bark beetles are important disturbance agents in coniferous forests, and spruce beetle, Dendroctonus rufipennis(Kirby) (Coleoptera: Curculionidae), is one of the more notable species causing landscape-level tree mortality in western North America. We evaluated the efficacy of bole injections of emamectin benzoate (TREE-äge®; Arborjet Inc., Woburn, MA) alone and combined with propiconazole (Alamo®; Syngenta Crop Protection Inc., Wilmington, DE) for protecting Engelmann spruce, Picea engelmanniiParry ex Engelmann (Pinales: Pinaceae), from mortality attributed to colonization byD. rufipennis....