Treesearch

Trees bursting forth with new leaves signal the arrival of spring. Budburst for most temperate tree species occurs after a tree has been exposed to a sufficient number of chilling and forcing hours over the winter. Waiting until these chilling and forcing hours have accumulated is a survival mechanism. If a tree bursts bud prematurely, delicate tissue may be damaged by a late frost. Conversely, if a tree bursts bud too late in the spring, it will be unable to achieve substantial height growth before summer drought sets in. Although most Northwest tree species require a combination of...

Over the past decade, wood-energy use in Alaska has grown dramatically. Since 2000, several dozen new wood-energy installations have been established, with numerous others in the design or construction phase. This case study report compares two wood-pellet heating systems in Juneau, Alaska. The Tlingit-Haida Regional Housing Authority, a native housing authority that serves more than 27,000 tribal residents in 11 communities in the southeast, recently established a wood-pellet boiler to provide heating to their 10,000-square-foot warehouse. The Sealaska Corporation is an Alaska Native...

This report highlights key findings from the most recent (2001–2010) data collected by the Forest Inventory and Analysis program across all forest land in California, updating previously published findings from data collected from 2001 through 2005 (Christensen et al. 2008). We summarize and interpret basic resource information such as forest area, ownership, volume, biomass, and carbon stocks; forest structure and function topics such as biodiversity, forest age, and dead wood; disturbance information such as tree damage, fire, and invasive plants; and tree growth, mortality, and removals...

This guidebook describes major biological and physical attributes of the 433-ha (1,070-ac) Grayback Glades Research Natural Area. The area supports high- elevation examples of white fir–Shasta red fir (Abies concolor[Gord. + Glend]–Abies magnifica var. shastensis) forest along the crest of the Siskiyou Mountains in southwestern Oregon. High-elevation Sitka alder (Alnus viridis ssp. sinuata) glades are also represented on the site. Drainages support large individuals of Port Orford cedar (Chamaecyparis lawsoniana[A. Murray bis]).

Natural resource vulnerability to climate change can depend on the climatology and ecological conditions at a particular site. Here we present a conceptual framework for incorporating spatial variability in natural resource vulnerability to climate change in a regional-scale assessment. The framework was implemented in the first regional-scale vulnerability assessment conducted by the US Forest Service. During this assessment, five subregional workshops were held to capture variability in vulnerability and to develop adaptation tactics. At each workshop, participants answered a questionnair...

The Chugach and Tongass National Forests are changing, possibly in response to global warming. Forested areas within Alaska's temperate rain forests are creeping into areas that were previously too cold or too wet. These forests are also becoming denser. As biomass increases, the amount of carbon stored in the forest also increases. Tara Barrett, a research forester with the U.S. Forest Service, Pacific Northwest Research Station, recently measured these changes. She and her colleagues compared Forest Inventory and Analysis survey data collected from 1995 to 2003 with follow-up inventories...

A lack of independent, quality-assured data prevents scientists from effectively evaluating predictions and uncertainties in fire models used by land managers. This paper presents a summary of pre-fire and post-fire fuel, fuel moisture and surface cover fraction data that can be used for fire model evaluation and development. The data were collected in the southeastern United States on 14 forest and 14 non-forest sample units associated with 6 small replicate and 10 large operational prescribed fires conducted during 2008, 2011, and 2012 as part of the Prescribed Fire Combustion and...

Terrestrial laser scanning (TLS) was used to collect spatially continuous measurements of fuelbed characteristics across the plots and burn blocks of the 2012 RxCADRE experiments in Florida. Fuelbeds were scanned obliquely from plot/block edges at a height of 20 m above ground. Pre-fire blocks were scanned from six perspectives and four perspectives for post-fire at~2 cmnominal spot spacing. After processing, fuel height models were developed at one meter spatial resolution in burn blocks and compared with field measurements of height. Spatial bias is also examined. The resultant fuel...

Smoke measurements were made during grass and forest understorey prescribed fires as part of a comprehensive programme to understand fire and smoke behaviour. Instruments deployed on the ground, airplane and tethered aerostat platforms characterised the smoke plumes through measurements of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and particulate matter (PM), and measurements of optical properties. Distinctions were observed in aerial and ground-based measurements, with aerial measurements exhibiting smaller particle size distributions and PM emission factors, likely due to...

Understanding the capacity to reduce wildfire risk and restore dry forests on Western national forests is a key part of prioritizing new accelerated restoration programs initiated by the Forest Service. Although a number of social and biophysical factors influence the ability to implement restoration programs, one key driver is the suite of forest plan land designations and associated management directions. These land use designations and conservation reserves, which are intended to provide an array of ecosystem services (recreation, wildlife, water, timber, research, etc.), were created...