Treesearch

Wood specific gravity (SG) has long been used by foresters as an index for wood properties. More recently, SG has been widely used by ecologists as a plant functional trait and as a key variable in estimates of biomass. However, sampling wood to determine SG can be problematic; at present, the most common method is sampling with an increment borer to extract a bark-to-pith core—a difficult task requiring considerable physical effort and sometimes repeated borings to hit the pith, with potential to damage the trunk of small trees. Here, we test a novel sampling method that reduces the...

Using natural cellulosic fibers as fillers for biodegradable polymers can result in fully biodegradable composites. Biodegradable composites were prepared using nanofibrillated cellulose (NFC) as the reinforcement and poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) as the polymer matrix. The objective of this study was to determine how various additives (i.e., blending PHBV with chain extender (CE) and/or Ecovio—a commercially available PLA/PBAT blend) affect the mechanical properties of injection molded PHBV/NFC nanocomposites. Tensile test bars of PHBV/NFC nanocomposites were...

Use of environmental variables as predictors of vegetation distribution patterns has long been a focus of ecology. However, the effect of edaphic factors on vegetation pattern is often measured using surrogates such as topography, because accurate measures of soil fertility and nutrients are unavailable or rare (Marage and Gégout 2009). Kalmia latifolia and Rosa multiflora exhibit contrasting regional vegetation patterns in which K. latifolia is more abundant in north central Pennsylvania and eastern West Virginia than in western West Virginia and eastern Ohio. In contrast, R. multiflora...

Limber pine (Pinus flexilis James) is an ecologically and culturally important, yet little studied, tree species within the Western United States. Its distribution extends from Alberta and southeastern British Colombia to New Mexico, Arizona, and southeastern California with isolated populations in North Dakota, South Dakota, Nebraska, eastern Oregon, and southwestern California (Burns and Honkala 1990). Limber pine has a very wide elevational distribution as well, ranging from 2,850 feet in North Dakota to 12,500 feet in Colorado (Burns and Honkala 1990). Limber pines serve many important...

Bark beetles (Coleoptera: Scolytinae) are important biotic agents of conifer mortality in forests of western North America (Furniss and Carolin 1977) and play an important role in the disturbance ecology of these ecosystems (Fettig and others 2007). Bark beetle outbreaks affect subsequent fire behavior in part by influencing the spatial distribution and state of fuels [see review by Jenkins and others (2008)]. Crown fire hazard following a bark beetle outbreak likely varies as a function of time (Romme and others 2006) with increased risk of crown fire initiation immediately following...

Analysis of crown condition data for the 2006 national technical report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, exposed clusters of phase 3 plots (by the Forest Inventory and Analysis [FIA] Program of the Forest Service) with northern white-cedar (Thuja occidentalis L.) crown dieback averages of 10 percent or more in Maine and northern Michigan (Randolph 2009). Such elevated levels of dieback were of concern because unlike hardwood trees, conifers often do not exhibit crown dieback unless the tree, and in particular its root...

As development introduces competing land uses into forest and grassland landscapes, the public concerns for landscape patterns are expressed through headline issues such as urban sprawl and forest fragmentation. The task for resource managers is to maintain an appropriate balance of biodiversity, water quality, recreation experience, and other amenities in forest and grassland ecosystems. A prerequisite for informed actions at local, regional, and national scales is reliable information about landscape patterns at those scales. National assessments document the status and trends of...

Criterion 3, Indicator 15, of the Montréal Process identifies the impact that biotic processes and agents have on forests (Montréal Process Working Group 2007). Where change due to these agents and processes occurs beyond a critical threshold, forest ecosystem health and vitality may be significantly altered and a forest’s ability to recover could be reduced or lost. Monitoring and measuring the effects of these processes provides information helpful in the formulation of management strategies to mitigate risk. A variety of detection and monitoring surveys are conducted annually by Forest...

Criterion 3, Indicator 16, of the Montréal Process Criteria and Indicators for the Conservation and Sustainable Management of Temperate and Boreal Forests was designed to assess the impact of abiotic agents upon forests (Montréal Process Working Group 2007). Various abiotic agents, both natural and human-induced, can change forest structure and species composition. Where such change goes beyond a critical threshold, forest ecosystem health may be significantly altered and its ability to recover from disturbance reduced or lost, often meaning a reduction or loss of benefits associated with...

An increase in dieback and mortality of thinleaf alder (Alnus incana ssp. tenuifolia) raised concern in southern Wyoming and Colorado two decades ago. In 1990, there was concern over extensive mortality of thinleaf alder along Big Laramie River near Jelm, WY, as well as in multiple locations in Colorado.2 Trees of all ages were affected and Cytospora canker was associated with the mortality. In 1996, records of the Sulphur Ranger District, Arapaho National Forest indicated that a grazing allotment had severe dieback and mortality of alder (fig. 11.1). In 2005, damage was continuing,...