Treesearch

The role of planting in the restoration of southern pine ecosystems that are underrepresented on the landscape is simple to the point of being rudimentary--when a seed source of the desired species is absent from a stand, planting is the only way to re-establish the desired species in the stand being restored. The advantages are obvious, especially when application of planting is done in a manner that draws on existing knowledge of seed sources, nursery practice, site preparation, and planting methodology in a manner that resembles reforestation after clearcutting. Much headway is being...

Two separate disciplines, hydrology and forestry, together constitute forest hydrology. It is obvious that forestry and forest hydrology disciplines are spatial entities. Forestry is the science that seeks to understand the nature of forests throygh their life cycle and interactions with the surrounding environment. Forest hydrology includes forest soil water, streams and other small waterbodies encompassed by forest cover, and the hydorlogical cycle itself within a forested land cover.

Most of the world's 4030 million ha of forested lands are situated on hilly, mountainous or well-drained upland landscapes where improved drainage is not needed. However, there are millions of hectares of poorly drained forested lands where excessively wet soil conditions limit tree growth and access for harvesting and other management activities. Improved or artificial drainage has been used to improve forest productivity on such lands substantially. Drainage has increased timber growth in natural forests and, applied as a silvicultural practice, enabled harvesting, regeneration and...

Compared with traditional engineering hydrology, forest hydrology has a relatively long history of studying the effects of vegetation in regulating streamflow through evapotranspiration (Hewlett, 1982; Swank and Crossley, 1988; Andreassian, 2004; Brown et al., 2005; Amatya et al., 2011, 2015, 2016; Sun et al., 2011b; Vose et al., 2011). It is estimated that more than half of the solar energy absorbed by land surfaces is used to evaporate water (Trenberth et al., 2009).

The 2011 Richardson wildland mega-fire in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada had large effects on air quality. At a receptor site in the center of the AOSR ambient PM2.5, O3, NO, NO2, SO2, NH3, HONO, HNO3, NH4+ and NO3- were measured during the April–August 2011 period. Concentrations of NH3, HNO3, NO2, SO2 and O3 were also monitored across the AOSR with passive samplers, providing monthly summer and bi-monthly winter average values in 2010, 2011 and 2012. During the fire, hourly PM2.5 concentrations, >450 μg m-3 were measured at the AMS 1 receptor site. The...

Concurrent with fire exclusion, shortleaf pine x
loblolly pine hybrids have increased throughout the southeastern USA and may threaten the genetic integrity of shortleaf pine. Historically, fire favored shortleaf pine over other southern pine species, especially loblolly pine, with which it shares a broad sympatric natural range. Shortleaf pine seedlings have a morphological adaptation (basal crook) that lowers dormant buds to the soil surface where they are presumably protected from fire to facilitate resprouting after topkill. To evaluate this presumption, we tested (1) the functional...

Preliminary results indicate that switchgrass (Panicum virgatum L.), grown as a cellulosic biofuel between managed loblolly pine (Pinus taeda L.) beds on the Atlantic Coastal Plain forests has no significant effect on shallow ground water table and stream outflows. Although management operations (e.g. harvesting, shearing between pine rows, raking, and bedding) implemented for pine and switchgrass establishment can lead to increases of nitrogen export, the magnitude of increases was lower than those usually observed on agricultural drainage waters in the region. Final results of study will...

Fuel treatments in fire-suppressed mixed-conifer forests are designed to moderate potential wildfire behavior and effects. However, the objectives for modifying potential fire effects can vary widely, from improving fire suppression efforts and protecting infrastructure, to reintroducing low-severity fire, to restoring and maintaining variable forest structure and wildlife habitat. In designing a fuel treatment, managers can alter the treatment's prescription, placement, and extent (collectively the "treatment strategy") to optimally meet one objective. However, the potential for trade-offs...

Long-term research at small, gauged, forested watersheds within the USDA Forest Service, Experimental Forest and Range network (USDA-EFR) has contributed substantially to our current understanding of relationships between forests and streamflow (Vose et al., 2014). Many of these watershed studies were established in the early to mid-20th century and have been used to evaluate the effects of forest disturbances such as harvesting, road construction, wild and prescribe fire, invasive species and changes in tree species composition on hydrological responses including stormflows, peak flows,...

The agave snout weevil (AGW) or sisal weevil, Scyphophorus acupunctatus Gyllenhal is here reported for the first time in St. Croix, U.S. Virgin Islands (USVI) where it threatens Agave eggersiana Trel., a USVI endemic and endangered century-plant. We provide molecular, morphological, and behavioral characters to successfully distinguish the two known Scyphophorus species at all developmental stages. We identified seven new larval characters on the mandibles and characters relating to the chaetotaxy of the labrum and labio-maxillary complex as well as new, putatively informative characters...