Treesearch

Competition for water among multiple tree rooting systems is investigated using a soil–plant model that accounts for soil moisture dynamics and root water uptake (RWU), whole plant transpiration, and leaflevel photosynthesis. The model is based on a numerical solution to the 3D Richards equation modified to account for a 3D RWU, trunk xylem, and stomatal conductances. The stomatal conductance is determined by combining a conventional biochemical demand formulation for photosynthesis with an optimization hypothesis that selects stomatal aperture so as to maximize carbon gain for a given...

El Inventario Forestal Nacional de Colombia (IFN) incluye un programa de Aseguramiento de Calidad (AC) para garantizar la confiabilidad de todos los datos recogidos y generados en la etapa de muestreo. El objetivo de este programa; es proporcionar un marco que asegure que la información compilada acerca de los bosques es completa, exacta, imparcial y de calidad conocida. La existencia de este programa aumentará la credibilidad y solidez del inventario forestal nacional de Colombia. El alcance del programa de calidad abarca todo el proceso de inventario, incluyendo la preparación para la...

The role of competition in structuring biotic communities at fine spatial scales is well known from detailed process-based studies. Our understanding of competition’s importance at broader scales is less resolved and mainly based on static species distribution maps. Here, we bridge this gap by examining the joint occupancy dynamics of an invading species (Barred Owl, Strix varia) and a resident species (Northern Spotted Owl, Strix occidentalis caurina) in a 1000-km2 study area over a 22-year period. Past studies of these competitors have focused on the dynamics of one species at a time,...

American chestnut [Castanea dentata Marsh. (Borkh.)] is an iconic species with important ecological and utilitarian values, but was decimated by the mid-20th century by exotic fungal species fromAsia. Successful restoration will require sustainable silvicultural methods to maximize survival and afford chestnut a competitive advantage over natural vegetation. The study examined effects of prescribed burning and commercial tree harvesting on survival and height growth of planted American chestnut on the mid-Cumberland Plateau in Tennessee. American chestnuts grew best in patch clearcuts...

Lodgepole pine (Pinus contorta) forests are widely distributed throughout North America and are subject to mountain pine beetle (Dendroctonus ponderosae) epidemics, which have caused mortality over millions of hectares of mature trees in recent decades. Mountain pine beetle is known to influence stand structure, and has the ability to impact many forest processes. Dwarf mistletoe (Arceuthobium americanum) also influences stand structure and occurs frequently in postmountain pine beetle epidemic lodgepole pine forests. Few studies have incorporated both disturbances simultaneously although...

Under the multiple-use paradigm, conflicts may arise when protection of an endangered species must compete with other management objectives. To resolve such a conflict in the Critical Habitat of the endangered Hawaiian honeycreeper, palila (Loxioides bailleui), federal courts ordered the eradication of introduced ungulates responsible for damaging the mâmane (Sophora chrysophylla) forest on which palila depend. During 1980-2011, a total of 18,130 sheep (Ovis aries and O. gmelini musimon) and 310 goats (Capra hircus) were removed from Palila Critical Habitat (PCH) primarily by public...

The goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), is an invasive species that has colonized oak woodlands in southern California. To better define its seasonal flight activity, assist with forest and integrated pest management activities, and define the current distribution in California, an effective monitoring technique for A. auroguttatus is necessary. We assessed the efficacy of two colors of flight-intercept prism traps, the placement of these traps at three heights, and several commercially available lures [Manuka oil, Phoebe oil, and a green leaf...

A principal challenge to restoring tree-invaded grasslands is the removal of woody biomass. Burning of slash piles to reduce woody residues from forest restoration practices generates intense, prolonged heating, with adverse effects on soils and vegetation. In this study, we examined vegetation responses to pile burning following tree removal from conifer-invaded grasslands of the Oregon Cascades. We quantified the longevity and magnitude of fire effects by comparing ground conditions and the cover and richness of plant species in burn-scar centers (higher-intensity fire) and edges...

While air pollution control devices and programs are the primary method of reducing emissions, urban air pollution can be further mitigated through planning and design strategies, including vegetation preservation and planting, building design and development, installing roadside and near-source structures, and modifying surrounding terrain features.

Technology transfer has been an important part of the research program at Bent Creek Experimental Forest (Bent Creek) since its establishment in 1925. Our stated mission is to develop and disseminate knowledge and strategies for restoring, managing, sustaining, and enhancing the vegetation and wildlife of upland hardwood-dominated forest ecosystems of the Southern Appalachian Mountains. Over the years, disseminating knowledge has taken many forms to address the needs of many different user groups. The diversity of user groups make disseminating knowledge challenging. Groups range from...