Thomas R. Fox

Thomas R. Fox
Rayonier

PhD

About

163
Publications
41,598
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5,686
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Introduction
Market Driven Precision Silviculture Financial Analysis of Silviculture Investments Deployment of Elite Genetics Decision Support for Site Specific Silviculture Growth Response to Silviculture Treatments Integrated Silviculture Regimes Sustainability and Forest Certification Ecosystem Services - Carbon, Water, Biodiversity Climate Change Analysis Climate Smart Forestry

Publications

Publications (163)
Article
Full-text available
Forest productivity and response to silvicultural treatments are dependent on inherent site resource availability and limitations. Trees have deeper rooting profiles than agronomic crops, so evaluating the impacts of soils, geology, and physiographic province on forest productivity can help guide silvicultural management decisions in southern pine...
Article
Soil health assessments require the establishment of soil indicators that are easy to measure and sensitive to changes in management practices. Despite the global demand for wood products and the intensification of silvicultural practices, very few indicators are currently used to monitor changes in soil properties and processes in managed forest p...
Article
Full-text available
Tree plantations represent an important component of the global carbon (C) cycle and are expected to increase in prevalence during the 21st century. We examined how silvicultural approaches that optimize economic returns in loblolly pine (Pinus taeda L.) plantations affected the accumulation of C in pools of vegetation, detritus, and mineral soil u...
Article
Considering the temporal responses of carbon isotope discrimination (Δ13C) to local water availability in the spatial analysis of Δ13C is essential for evaluating the contribution of environmental and genetic facets of plant Δ13C. Using tree-ring Δ13C from years with contrasting water availability at 76 locations across the natural range of lobloll...
Article
The private forestry sector faces enormous challenges from complex environmental issues concurrent with societal concerns about intensive forest management and application of silvicultural tools. At the same time, research and development spending and the scientific workforce in the forestry sector has declined. However, the forestry sector has a l...
Article
Managed loblolly pine (P. taeda L.) forests comprise a major land-use across the “wood basket” of the southeastern US. Lower coastal plain loblolly pine forests can enhance carbon (C) storage in fast-growing vegetation and soils, representing a significant opportunity to manage these forests for improved soil health through an understanding of soil...
Article
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In 2019, the Forest Productivity Cooperative (FPC) celebrated its 50th anniversary. The mission of the FPC is and has been creating innovative solutions to enhance forest productivity and value through the sustainable management of site resources. This industry-government-university partnership has generated seminal research with sweeping implicati...
Article
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Increased genotypic diversity has been associated with increased biomass production in short-rotation tree species. Increasing the genotypic diversity of loblolly pine (Pinus taeda L.) in an attempt to increase productivity has not been extensively studied nor tested operationally or over long durations (i.e., >7 yr). We used genetically mixed and...
Article
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Losses of fertilizer nitrogen (N) were compared between urea and urea treated with the urease inhibitor N‐(n‐Butyl) thiophosphoric triamide (urea + NBPT) after a surface application in winter at three thinned mid‐rotation (age 15–20 years) loblolly pine plantations in Virginia, South Carolina, and Florida. Treatments were labeled with ¹⁵N and appli...
Article
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We examined crown architecture and within crown leaf area distribution effects on Pinus taeda L. growth in North Carolina (NC), Virginia (VA), and Brazil (BR) to better understand why P. taeda can grow much better in Brazil than in the southeastern United States. The NC, VA, and BR sites were planted in 2009, 2009, and 2011, respectively. At all si...
Article
Drought frequency and intensity are projected to increase throughout the Southeastern USA, the natural range of loblolly pine (Pinus taeda L.), and are expected to have major ecological and economic implications. We analyzed the carbon and oxygen isotopic compositions in tree ring cellulose of loblolly pine in a factorial drought (~30% throughfall...
Article
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Sustainable forest management is hugely dependent on high-quality estimates of forest site productivity, but it is challenging to generate productivity maps over large areas. We present a method for generating site index (a measure of such forest productivity) maps for plantation loblolly pine (Pinus taeda L.) forests over large areas in the southe...
Article
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Leaf area index (LAI) is an important biophysical parameter used to monitor, model, and manage loblolly pine plantations across the southeastern United States. Landsat provides forest scientists and managers the ability to obtain accurate and timely LAI estimates. The objective of this study was to investigate the relationship between loblolly pine...
Conference Paper
Full-text available
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...
Article
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This study presents forest fertilization and carbon sequestered from fertilization in the southeastern United States in the context of newly available silviculture management information. Maximum annual fertilized forest area in the southeastern United States occurred in 1999 when 1.58 million acres were fertilized. Since then, the fertilized area...
Article
Previous work indicates that Pinus taeda L. grows faster and has a higher carrying capacity when grown outside its native range. We were interested in examining the hypotheses that growth, light use efficiency (volume growth and absorbed photosynthetically active radiation relationship, LUE) and volume growth per unit heat sum is the same for nativ...
Article
Silvicultural practices, particularly fertilization, may counteract or accentuate the effects of climate change on carbon cycling in planted pine ecosystems, but few studies have empirically assessed the potential effects. In the southeastern United States, we established a factorial throughfall reduction (D) × fertilization (F) experiment in 2012...
Poster
Full-text available
There are many loblolly pine (Pinus taeda L.) genotypes including clonal varieties being deployed across a wide range of site conditions throughout the southeastern US. Within these genotypes a wide range of aboveground productivity has been reported. How much of this variation in growth is due to belowground traits is not known. For example, diffe...
Article
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Purpose of Review Intensive management of forest plantations has evolved significantly in recent decades because of advances in our understanding of environmental and silvicultural effects on forest productivity combined with improvements in information technologies. Our paper summarizes concepts that provide a basis for making strategic and operat...
Article
Full-text available
We explore the possibility of extending the national forest inventory-based point data of understory presence using region-wide, disparate lidar data for the southeastern USA. For this, we developed a simple inferential model that helps to understand the basic underlying relationships and associations between lidar predictor metrics and forest unde...
Article
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Stand uniformity is a desired trait affecting stand development and productivity. Stand uniformity is expected to increase if plantation forestry moves to varietal stands and continues to increase management intensity. In this study, we evaluated the response of stand uniformity of 4-year-old loblolly pine clonal varieties and families to changes i...
Article
Full-text available
Key message Light plays a minor role in the within-crown acclimation of physiological and morphological parameters in small loblolly pine trees. Abstract Whether the plasticity of foliage within the crown is driven by light or height is still not well known, especially for small trees. The present study was conducted in two loblolly pine (Pinus ta...
Article
Full-text available
The objective of the current study was to develop methods for estimating the height and horizontal coverage of the forest understorey using airborne Lidar data in three managed pine plantation forest typical of the south eastern USA. The current project demonstrates a two-step approach applied automatically across a given study site extent. The fir...
Article
Clonal forestry must be linked with intensive silvicultural practices to increase forest productivity of loblolly pine (Pinus taeda L.) in the southern United States. Although the positive growth responses due to intensive silviculture have been reported extensively, much less is known about the physiological processes that drive these responses. T...
Article
Full-text available
Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model–data fusion...
Article
We installed a thinning and fertilization study at five sites in mid-rotation Pinus taeda L. stands in the southeastern United States to examine treatment effects on diameter growth, basal area production, and volume increment. The treatments were four levels of post-thinning stand density (247, 494, 741 and 1235 stems ha⁻¹) and two levels of ferti...
Article
Full-text available
Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model-data fusion...
Article
Full-text available
Stand uniformity is a desired trait affecting stand development and productivity. Stand uniformity is expected to increase if plantation forestry moves to varietal stands and continues to increase management intensity. In this study, we evaluated the response of stand uniformity of 4-year-old loblolly pine clonal varieties and families to changes i...
Article
Productivity of loblolly pine in the southeastern US is frequently limited by soil nutrient availability. Therefore, fertilization is commonly used to increase nutrient availability and subsequent growth. This study used the soil fertility rating (FR) in the 3-PG model (Landsberg and Waring, 1997) to predict fertilizer growth response of loblolly p...
Article
Full-text available
This study was conducted to determine the efficacy of using enhanced efficiency fertilizer (EEFs) products compared to urea to improve fertilizer nitrogen use efficiency (FNUE) in forest plantations. All fertilizer treatments were labeled with ¹⁵N (0.5 atom percent) and applied to 100 m² circular plots at 12 loblolly pine stands (Pinus taeda L.) ac...
Article
The ecosystem recovery of four nitrogen (N) containing fertilizers (urea and three enhanced efficiency fertilizers [EEFs]) enriched with ¹⁵N were compared at five different sites with single treatment replication per site for both a spring and summer application in mid-rotation loblolly pine (Pinus taeda L.) stands across the southeastern United St...
Article
Pine plantations in the southern US are among the most intensively managed forests in the world and their productivity has tripled over natural pine forests through application of intensive pine plantation establishment and management practices. As we are trying to increase carbon (C) sequestration through further enhancing pine plantation producti...
Article
Ammonia (NH3) volatilization losses following surface application of urea and three enhanced efficiency nitrogen (N) containing fertilizers (EEFs) were compared in six thinned mid-rotation loblolly pine (Pinus taeda L.) stands across the southern United States. All fertilizer treatments were labeled with 15N (∼370‰, 0.5 AP) and applied during two d...
Article
We used published data from nine sites where nutrient and water optimization studies had been installed in a 2 × 2 factorial design to determine maximum biomass production in response to a simple set of treatments. We tested for site and treatment effects on the relationships between stem, aboveground (stem, branches, foliage) and total (abovegroun...
Article
Full-text available
Nitrogen (N) fertilization and soil redox potential influence N cycling processes in forested ecosystems. Gross N transformations are indicators of NH4+ and NO3− production and consumption within soil. Furthermore, dissimilatory nitrate reduction to ammonium (DNRA), a typically overlooked process in terrestrial N cycling, can conserve N within soil...
Article
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The goal of the current study was to develop methods of estimating the height of vertical components within plantation coniferous forest using airborne discrete multiple return lidar. In the summer of 2008, airborne lidar and field data were acquired for Loblolly pine forest locations in North Carolina and Virginia, USA, which comprised a variety o...
Article
Full-text available
Data from 15 sites with loblolly pine (Pinus taeda L.) plantations located in the southeastern United States were used to predict site index (SI) from soil physical and chemical properties from the top 15 cm of the mineral soil. Two modeling approaches were used to predict SI from soil properties. First, the ordinary least-squares method of multipl...
Article
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Mid-rotation responses to fertilization of Pinus radiata D. Don plantations after the first or second thinning have been observed in research experiments in many regions where the species is grown. The practice is not however common in commercial plantations. This is probably because the effects of soil-site conditions on the magnitude and duration...
Article
Leaf area is an important forest structural variable which serves as the primary means of mass and energy exchange within vegetated ecosystems. The objective of the current study was to determine if leaf area index (LAI) could be estimated accurately and consistently in five intensively managed pine plantation forests using two multiple-return airb...
Article
Full-text available
Fertilization of Pinus radiata plantations mid-rotation after thinning can alter soil nitrogen availability. However, the magnitudes and durations of tree and stand growth responses are not well understood across different soils with specific site conditions. Two mid-rotation fertilization trials in Pinus radiata plantations with unexpected sustain...
Article
Full-text available
Airborne discrete-return light detection and ranging (lidar) can be used to estimate leaf area index (LAI) with relatively high accuracy. This capacity was explored with regard to assessing the capability of estimating LAI at different heights at the plot level, in the presence of understorey vegetation, within intensively managed Loblolly pine for...
Article
Full-text available
Soil fertility is an important component of forest ecosystems, yet evaluating soil fertility remains one of the least understood aspects of forest science. We hypothesized that the fertility rating (FR) used in the model 3-PG could be predicted from site index (SI) for loblolly pine in the southeastern US and then developed a method to predict FR f...
Article
Full-text available
A nutrient dose and application frequency study was installed in Eucalyptus grandis stands at six sites in the Colombian Andes to examine three hypotheses: (1) individual sites have different treatment responses (there is a significant site effect); (2) the relationship between volume growth response and applied nitrogen is not linear (there is an...
Article
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We examined three hypotheses in a nutrient dose and application frequency study installed in juvenile (aged 2-6 years old) Pinus stands at 22 sites in the southeastern United States. At each site, eight or nine treatments were installed where nitrogen was applied at different rates (0, 67, 134, 268 kg ha-1) and frequencies (0, 1, 2, 4 and 6 years)...
Article
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The effects of tillage, vegetation control, and fertilizer treatments applied at stand establishment of Pinus radiata D. Don. at three sites (Sand, Clay, and Ash) in Chile were examined 10 years after planting. Selected sites were typical of sites that routinely received tillage as a normal part of site preparation operations in Chile. At each site...
Article
Background: Trends in forest cover and land use intensity Increasing global population and expanding land use mean that an ever greater percentage of human needs for wood products are being met by managed forests (Foley et al., 2005). Currently, about 7% of world’s forests are plantations and 57% are secondary forests recovering from anthropogenic...
Article
Full-text available
The future climate of the southeastern USA is predicted to be warmer, drier and more variable in rainfall, which may increase drought frequency and intensity. Loblolly pine (Pinus taeda) is the most important commercial tree species in the world and is planted on ~11 million ha within its native range in the southeastern USA. A regional study was i...
Article
Concern over rising atmospheric CO2 and other greenhouse gases due to fossil fuel combustion has intensified research into carbon-neutral energy production. Approximately 15.8 million ha of pine plantations exist across the southeastern United States, representing a vast land area advantageous for bioenergy production without significant land-use c...
Article
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While mid-rotation fertilization increases productivity in many southern pine forests, it remains unclear what impact such management may have on stand water use. We examined the impact of nutrient and water availability on stem volume, leaf area, transpiration per unit ground area (E-c and canopy conductance per unit leaf area (G(s)) of a pine pla...
Conference Paper
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This study examined the species composition of 47 paired stands on submesic sites on the Appalachian Plateau of West Virginia. Paired stands consisted of a mature stand adjacent to a young clearcut that was < 20 years old. The species composition in the mature stands was compared to that of the upper canopy (dominant and codominant) in the clearcut...
Article
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We tested the hypotheses that Pinus taeda L. ecosystems (trees plus forest floor plus soil) can retain nitrogen, phosphorus, potassium, calcium, and magnesium applied as fertilizer. We accomplished this by comparing the ecosystem nutrient content in fertilized plots with the content in nonfertilized plots under ambient rainfall and ambient rainfall...
Article
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Volatilization losses following fertilization with urea or ureaform applied at a rate of 448 kg ha(-1) N were measured in a thinned 22-yr-old loblolly pine (Pinus taeda L.) plantation in the Virginia Piedmont. Fertilizer was applied at two different times, winter and summer, and NH3 volatilization was measured for 29 d using a static chamber method...
Article
As biofuel production continues to increase, so will demand for forests to provide sources of biomass feedstocks. Intensively managed loblolly pine (Pinus taeda L.) plantations cover 15.8 million ha of the southeastern United States. Intercropping of switchgrass (Panicum virgatum L.) within loblolly pine stands offers an opportunity to use interbed...
Article
Full-text available
Growth of midrotation pine plantations in the southeast United States tends to be limited by nitrogen (N) and phosphorus (P). Routine applications of urea and diammonium phosphate ameliorate N and P deficiencies; however, questions concerning what other nutrients are likely to be limiting growth are being raised. Consequently, a trial series with 2...
Conference Paper
Nitrogen has been identified as one of the most limiting nutrients to terrestrial ecosystem primary production and therefore has received significant attention. Soil nitrogen (N) cycling and availability is largely driven by the balance between microbially-mediated mineralization-nitrification-immobilization processes. Release of inorganic N via mi...
Article
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Traditional methods (deciduous arborescent hardwood basal area, cover index) of quantifying competing vegetation were not well correlated with pine response to vegetation control in a regional study examining fertilizer and vegetation control response in Pinus taeda L. in the southeastern United States. Given the links between resource availability...
Article
Site-specific constraints on foliage development and leaf area duration were investigated in two-year-old Pinus radiata D. Don. plantations established under a factorial combination of soil tillage (shovel vs. subsoil + bedding + shovel), fertilization (B only vs. N, P, K, and B), and weed control (pre-plant vs. pre-plant + two-year banded) at thre...
Article
Full-text available
Following fertilization of forest plantations, high accumulations of nutrients in the forest floor creates the need to assess rates of forest floor decomposition and nutrient release. The study site was a 25-year old experimental loblolly pine plantation in the North Carolina Sandhills Region. Soluble and insoluble N, P, carbohydrate and phenol-tan...
Article
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Forests are vital to the world's ecological, social, cultural and economic well-being yet sustainable provision of goods and services from forests is increasingly challenged by pressures such as growing demand for wood and other forest products, land conversion and degradation, and climate change. Intensively managed, highly productive forestry inc...
Chapter
Woody biomass for bioenergy can be generated by growing short-rotation woody crops (SRWCs) or by using products of conventional forestry. This chapter focuses on the sustainability of SRWC systems in the United States. It reviews the research conducted on improvements in SRWC yield and any potential negative environmental impacts that arise from th...
Article
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Functions for estimating foliage, branches and nonmerchantable stem tops, merchantable stem, and total aboveground biomass for Appalachian hardwood trees were assembled and incorporated into an existing growth-and-yield simulator for mixed-species Appalachian hardwood forests. With these functions and user-defined stand table and stand characterist...
Article
Full-text available
Clonal forestry is becoming a reality in the southeastern United States owing to recent improvements in somatic embryogenesis for Pinus taeda (L.). Differences in aboveground and belowground carbon allocation between individual genotypes could have significant implications for productivity and carbon sequestration and cycling in clonal plantations....
Article
Fertilization and irrigation may substantially increase productivity of forests by increasing stand leaf area index and the efficiency of converting intercepted light into wood biomass. This stand-level growth response is the summation of individual tree responses, and these tree-level responses are often non-linear, resulting from shifting in the...
Article
Full-text available
The genus Eucalyptus is native to Australia and Indonesia but has been widely planted in many countries. Eucalyptus has proven to be particularly successful in tropical and sub-tropical regions. Several species are also successful in some temperate regions, but problems with sudden and severe frosts pose limitations. Current plantations around the...