Treesearch

Thinning is commonly used in managing loblolly pine (Pinus taeda L.) plantations in the Western Gulf Region. While long-term loblolly pine growth responses to thinning have been well documented, understanding of the response in the first couple of years after thinning is limited. Data were collected for a loblolly pine thinning study from 16 sites across east Texas and western Louisiana over the first four growing seasons following thinning. Three thinning intensities, with residual stockings of 150, 225, and 300 trees per acre after thinning, and an un-thinned control were implemented...

Loblolly pine (Pinus taeda L.) plantation forestry continues to incorporate silvicultural advances that increase individual tree growth. These faster-growing trees may have different stem characteristics than their slower-growing predecessors, with unknown effects on wood quality. We examined fertilizer and thinning effects on individual tree taper and wood properties of loblolly pine in the Piedmont of Virginia, United States. Treatments included two levels of thinning (500 (unthinned) and 200 trees per acre residual density) and two levels of fertilization after thinning (none and 200...

Carbon storage and maintaining forest complexity have been important objectives in developing forest management strategies to address global climate change. Although maintaining complexity and carbon stores are inherently interrelated, the effect of management strategies on these objectives have generally been examined independently. Moreover, little is known about the effect of management on carbon stock and distribution in structurally and compositionally complex forests. This study examines the effect of selective, partial harvests on carbon stock and distribution in natural-origin, 80-...

The World Health Organization (2016) states that air pollution is the largest environmental risk factor to human health, accounting for about one in nine deaths annually. The problems associated with air pollution and higher air temperatures in cities have been known for over a century, but so have the impacts of trees and forests on improving air quality and regulating air temperatures. Trees, through their interaction with the atmosphere, affect air quality and consequently human health, particularly when in close association with people (e.g., in cities).

Peatlands are among the largest natural sources of atmospheric methane (CH4) worldwide. Peatland emissions are projected to increase under climate change, as rising temperatures and shifting precipitation accelerate microbial metabolic pathways favorable for CH4 production. However, how these changing environmental factors will impact peatland emissions over the long term remains unknown. Here, we investigate a novel data set spanning an exceptionally long 11 years to analyze the influence of soil temperature and water table elevation on peatland CH4 emissions. We show that higher water...

The chloroplast DNA (cpDNA) is paternally inherited in pine species (Pinus spp.), hence potentially useful in developing genetic markers for four common southern pine species [longleaf pine (P. palustris Mill.), loblolly pine (P. taeda L.), shortleaf pine (P. echinata Mill.), and slash pine (P. elliottii Engelm.)]. In this study, we (a) developed a simple DNA tool to accurately distinguish pure longleaf pine seeds or seedlings from other pine species, a critically important aspect of any longleaf pine restoration effort, and (b) validated the accuracy of identified genetic marker/specific...

In 2009, 6.5 acres on the University of Tennessee’s Cumberland Forest in Morgan County, TN, were identified for hardwood afforestation. Twenty-seven plots were planted in one of three species of hardwoods: yellow-poplar (Liriodendron tulipifera), black cherry (Prunus serotina), and sweetgum (Liquidambar styraciflua) at three spacings. Cherrybark oak (Quercus pagoda) was intermixed in these plantings such that each oak was completely surrounded by a competitor species. These unique, species-specific neighborhoods act on oak growth and development particular to variations in competitor crown...

In the mid-1970s, four oak (Quercus spp.) species adapted to bottomland sites, cherrybark oak (Q. pagoda), Nuttall oak (Q. texana), swamp chestnut oak (Q. michauxii), and water oak (Q. nigra), were planted in monocultures at several spacings to evaluate species and spacing effects on stand dynamics. The present investigation extends this study out to the fifth decade by comparing the oak monocultures planted at the two widest spacings (8 by 8 feet and 12 by 12 feet). A thinning in March 1996 provided an opportunity to assess potential effects of a single tending treatment. Results suggest...

Five cherrybark oak (Quercus pagoda) plantations outside its native range spanning 10 to 50 years in age were studied to determine survival, growth rates, and projected yields. The plantations were located from southern Indiana to eastern Tennessee on former agricultural fields or cleared areas adjacent to minor drainages. Soils of these plantations were evaluated to determine if they had similar characteristics to common soils within the cherrybark oak range using the Baker and Broadfoot (1979) site evaluation guide. Plantations were wellstocked with present volumes of 8,000 to 14,000...

In upland oak (Quercus spp.) forests of the Eastern United States, shade-intolerant, fire-tolerant oaks are being replaced by shade-tolerant, fire-sensitive species due to changes in forest management and fire regimes. In these mixed-species forests, rainwater redistribution by the forest canopy is determined by tree species traits as well as canopy position. To better understand how shifting forest composition could impact rainwater partitioning, we quantified differences in canopy structure and the resultant net flux of water to forest soils in a series of experiments across the Southeast...