John Lhotka

John Lhotka
University of Kentucky | UKY · Department of Forestry

Doctor of Philosophy

About

50
Publications
4,613
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593
Citations
Citations since 2017
16 Research Items
389 Citations
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20172018201920202021202220230204060
20172018201920202021202220230204060
20172018201920202021202220230204060
Introduction
John Lhotka has been a faculty member at the University of Kentucky since June 2007. His silvicultural research program addresses the following emphasis areas: 1) regeneration practices for oak-dominated forests, 2) modeling forest structure, growth, and mortality in a silvicultural context, 3) development of gap-based silvicultural systems, and 4) forest restoration following surface mining disturbance. Other primary research interests include: irregular silviculture, linkages between canopy structure and understory light environments, climate and biophysical effects on tree growth, and stand density relationships.

Publications

Publications (50)
Article
Full-text available
Urban forests provide critical ecosystem services in an increasingly urbanized global landscape. The reforestation of undeveloped parcels and serially mowed grasslands can increase urban forest cover, but plant community development in planted urban forests is poorly understood. We conducted a study to elucidate the roles of time since tree plantin...
Article
Crop tree release (CTR) can be an effective intermediate silvicultural treatment for culturing high-value stems in mixed hardwood stands. The lengthy rotation of hardwoods requires long-term evaluations if silvicultural treatment effectiveness is to be fully evaluated. Our study provides a 35-year evaluation of individual-tree and stand response to...
Article
Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has chang...
Article
We assessed short-term light and regeneration dynamics following silvicultural gap creation in intermediately productive oak (Quercus)-dominated stands of the Northern Cumberland Plateau, USA. We established 12 experimental units comprising a harvest gap (30-m radius) and a matrix zone extending 30 m beyond the circumference of the gap. Midstory re...
Article
Full-text available
Urbanization causes a variety of negative ecological impacts, impairing forests, streams, and other ecosystems. While urban forests are the subject of increasing research attention, planted urban forests are less well-understood than remnant forests; however, these systems may be distinct in terms of ecosystem structure and function. The current st...
Article
Full-text available
Surface mining for coal has contributed to widespread deforestation and soil loss in coal mining regions around the world, and particularly in Appalachia, USA. Mined land reforestation is of interest in this and other regions where forests are the dominant pre-mining land use. This study evaluated mine soil development on surface-mined sites refore...
Article
Full-text available
Rising mineral and fossil fuel demand have accelerated the global prevalence of surface mining, resulting in adverse impacts to many forest ecosystems. Post-mining reclamation techniques, specifically spoil preparation methods, can influence reforestation success and the trajectory of future stand dynamics. Compaction is a common post-mining spoil...
Article
A growing concern exists over the decreasing proportion of Scots pine (Pinus sylvestris L.) trees in mixed Trojan fir (Abies nordmanniana subsp. equi-trojani [Asch. & Sint. Ex Boiss] Coode & Cullen)-Scots pine forests in northern Turkey. Given the changes in mean annual temperature and annual precipitation for the last forty years in the region, un...
Article
Full-text available
Unmanaged forests may exhibit a higher degree of biodiversity compared to managed forests. We examined and compared the stand structure, density, and volume of deadwood components of managed and unmanaged mixed forests of Trojan fir (Abies nordmanniana subsp. equi-trojani [Asch. & Sint. ex Boiss] Coode & Cullen)–Scots pine (Pinus sylvestris L.) in...
Article
This study examined the influence of midstory removal applied 9 years prior to a shelterwood establishment cut on survival, growth, and competitive status of black oak (Quercus velutina Lam.), white oak (Quercus alba L.), and an oak competitor, red maple (Acer rubrum L.), immediately before and at 6 years following shelterwood cutting on intermedia...
Article
Boreal forests store a large proportion of the global terrestrial carbon (C), while wildfire plays a crucial role in determining their C storage and dynamics. The aboveground C (AC) pool is an important component of forest C stocks. To quantify the turning point (transforming from C source to C sink) and recovery time of postfire AC, and assess how...
Article
This manuscript seeks to further the understanding of how silvicultural gap size affects stand development and growth patterns among species. The authors studied an experiment established more than 50 years ago in oak (Quercus spp.) dominated stands that tested three gap sizes, 0.02 ha, 0.16 ha and 0.46 ha. Statistical analysis addressed stand-leve...
Article
Because of the dramatic decline in longleaf pine (Pinus palustris Mill.) acreage, concern about restoration and management of these ecosystems has increased in recent years and created a need for effective silvicultural management tools. Stocking charts are useful quantitative tools to allocate tree area to meet specific silvicultural objectives in...
Article
Full-text available
Conventional Appalachian surface-mine reclamation techniques repress natural forest regeneration, and tree plantings are often necessary for reforestation. Reclaimed Appalachian surface mines harbor a suite of mammal herbivores that forage on recently planted seedlings. Anecdotal reports across Appalachia have implicated herbivory in the hindrance...
Article
Context. Terrestrial reptiles require varied thermal environments to promote optimal physiological performance, growth, reproduction, and survival. Aims. Our study was designed to determine whether gap-based silvicultural practices offer suitable thermal environments for eastern box turtles (Terrapene carolina) by examining environmental temperatur...
Article
This manuscript seeks to further the understanding of growth patterns in Quercus forests, thereby informing the development of appropriate thinning practice. The author leveraged a network of thinning experiments established by the US Forest Service more than 50 years ago. Individual-tree diameter growth and survival models were developed along wit...
Article
Full-text available
We studied an upland forest located within the Grand Prairie region of Illinois and utilized tree-ring analysis to document tree cohort development and radial growth in relation to stand disturbance and climate. The overstory within the Humiston Woods Nature Center (Livingston County, Illinois) study area was dominated by oak (Quercus spp.), hickor...
Article
Full-text available
This study used a spatially-explicit model to identify the amount and spatial distribution of economically feasible sites for establishing dedicated energy crops under various market and policy scenarios. A sensitivity analysis was performed for a biomass market with different discount rates and biomass prices as well as policy scenarios including...
Article
This study investigates the combined impact of carbon and bioenergy markets on upland oak dominated mixed hardwood forests in the Central Hardwood Forest Region (CHFR) of United States. A modification of the Hartman model was used for the economic analysis of carbon sequestration and using wood-based biomass for bioenergy. A life-cycle assessment w...
Article
Key messageIndividual-tree seeding height growth models developed using tree inventory data were comparable to those requiring the unique observation of point-based canopy structure data at each seedling.ContextQuantitative approaches describing the relationship between canopy structure and seedling growth can inform silvicultural decision making r...
Article
This study evaluated the effect of midstory removal on the survival, growth, and competitiveness of natural advance reproduction and underplanted white oak (Quercus alba L.), northern red oak (Quercus rubra L.), and black oak (Quercus velutina Lam.). The response of the predominant shade-tolerant competitor, red maple (Acer rubrum L.), was also eva...
Poster
Background/Question/Methods Savanna communities are strongly influenced by disturbance regimes that affect plant composition and structure. It has been hypothesized that after the precipitous post-1500 decline in Native American populations and use of fire as a habitat management tool, the now globally endangered Kentucky Bluegrass savanna-woodla...
Article
Wood-based bioenergy or energywood has been suggested as an alternative to various fossil-fuel-based energy sources. While a variety of studies have investigated some economic aspects of forest-based bioenergy throughout the United States, none have yet examined the profitability of forest-based bioenergy from a landowner perspective in the Central...
Article
This paper explores the influence of forest edge on the development of tree reproduction and the use of edge as a silvicultural tool for manipulating regeneration outcomes. Oak (Quercus spp.) reproduction was sampled 9 years following edge establishment along transects extending from 8 m into clearcut openings to 40 m into the adjacent intact fores...
Article
In this research, we evaluated the intent of engaged private forest landowners to supply woody biomass for bioenergy production. The study was conducted in a U.S. state (Kentucky) where private individuals own a majority (78%) of the state's forest resources. Intent of family forest owners was measured using a mail-based survey. We used the Theory...
Article
Soil scarification has been shown to increase oak (Quercus spp.) seedling establishment on sites with gently sloping topography that provide ideal operational conditions for soil scarification equipment. However, oaks are also an important component of forests occupying physiographic regions where topography can be highly dissected and steeply slop...
Poster
Background/Question/Methods Historical floristic surveys and anecdotal evidence suggest that the dominant habitat of the Inner Bluegrass Region of Kentucky was a savanna-woodland community. However, since the time of European settlement 99% of this community has been converted to agricultural or urban land uses and remaining savannas have been exp...
Article
We evaluate the effect of four midstory removal (no removal, 1/3 removal, 1/2 removal, and complete removal) and two understory removal (no removal, complete removal) intensities on underplanted seeding size and survival after seven growing seasons. The study was conducted in a mixed-hardwood riparian forest. The underplanted species were cherrybar...
Article
A hybrid Strengths, Weaknesses, Opportunities and Threats–Analytic Network Process (SWOT-ANP) framework was used to assess further development of biomass-based energy production in Kentucky. SWOT-ANP analyses were conducted with a focus group of forest policy experts in a statewide symposium on bioenergy development. Results show that participants...
Article
Midstory removal can enhance the development of oak advance reproduction on higher quality sites; however, the long-term response of oak species common to intermediate quality sites is relatively unknown. Within the western edge of the Northern Cumberland Plateau, we investigated the 7-year response of natural and underplanted black oak (Quercus ve...
Article
Full-text available
Although double sampling has been shown to be an effective method to estimate timber volume in forest inventories, only a limited body of research has tested the effectiveness of double sampling on forest biomass estimation. From forest biomass inventories collected over 9,683 ha using systematic point sampling, we examined how a double sampling sc...
Conference Paper
Background/Question/Methods Plant communities emerge from two main forces, resource competition (for water, light, and/or nutrients) and disturbance (e.g., herbivory and/or fire). Savanna systems are particularly interesting as they represent assemblages of contrasting life forms (grasses and trees) and a delicate balance between competition and...
Article
This paper is an assessment of the effect of gap size on stand structure and species composition 48 years following treatment in a mixed broadleaf upland forest. Established in 1960, the study tests three circular openings, 15.2 m (0.02 ha), 45.7 m (0.16 ha), and 76.2 m (0.46 ha). Forty-eight years following treatment (2008) basal area, top height,...
Article
This report presents height-diameter equations for five hardwood species commonly associated with sweetgum (Liquidambar styraciflua L.) stands within the Piedmont and Coastal Plain regions of Alabama, Georgia, and South Carolina. Mixed-effects regression and the Chapman-Richards function were used to fit height-diameter equations for each species....
Article
The Nelder (Biometrics 18:283–307, 1962) wheel design allows a researcher to test multiple tree densities in a single plot. Because spatial relationships among planted trees are fundamental to a Nelder wheel, a researcher needs a specific set of layout parameters to establish a Nelder plot. While Nelder (Biometrics 18:283–307, 1962) provides calcul...
Article
Short rotation woody biofuel plantations on reclaimed surface mines in Appalachia can diversify domestic energy supplies and facilitate the reforestation of these disturbed lands. This study examined growth, survival, biomass accumulation and allocation, and nitrogen concentrations following two growing seasons in American sycamore (Platanus occide...
Article
The Pioneer Forest encompasses more than 60,000 ha in the Ozark Highlands of Missouri, USA and has been managed using single-tree selection since the early 1950s. This paper quantifies the influence of tree size and competitive position, stand density, species composition, and site quality on ten-year (1992–2002) diameter increment within oak (Quer...
Article
This study evaluates the effects of four midstory removal intensities on residual stand structure, understory light availability, and the 2-year growth and survival of underplanted cherrybark oak (Quercus pagoda Raf.) seedlings. It also examines whether survival and growth were affected by the removal of competing understory vegetation <1.4 m tall....
Article
Full-text available
There are some options on how to help oaks regenerate and this is by implementing some practices. These include both soil scarification and underplanting. Soil scarification is a silvicultural treatment that may increase both germination rates and oak seedling establishment which only requires limited labor and readily available equipment. Underpla...
Article
A comparison is made among the size-density relationships of sugar maple (Acer saccharum Marsh.), European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst), lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.), eastern white pine (Pinus strobus L.), Scots pine (Pinus sylvestris L.), loblolly pine (Pinus taeda L.)...
Article
This study explores the indirect relationship between forest structural measures and initial seedling survival and growth along a structural gradient between 64% to 92% canopy closure. The gradient was created by applying various levels of midstory removal to fifty 0.05ha areas located within a mixed-hardwood riparian forest corridor. Twelve yellow...
Article
Full-text available
We present a weighted, individual-tree relative density approach whose reference conditions have the same distribution of crown areas and species as a subject stand. An initial evaluation of the method's efficacy was performed within an even-aged loblolly pine (Pinus taeda L.) plantation. Species-specific reference density equations were developed...
Article
Understanding the effect of canopy structure on the understory light environment is useful in the design of silvicultural strategies that facilitate sustainable tree recruitment. To address this need, a study was designed to quantify the relationship between forest structure and light along a gradient of 50–100% canopy cover. The gradient was creat...
Poster
Socially acceptable forest management at the wildland-urban interface (WUI) is often limited to individual tree removal by arborists or other landscape professionals as trees succumb to overcrowding, insects and disease, or old age. Perhaps, the reason that a more proactive approach to managing forest health is rarely attempted lies in the fact tha...
Article
We report on the density and height of seedling reproduction established with and without soil scarification in a mixed-oak two-stage shelterwood after overstory removal. In 1993, shallow soil scarification was conducted to bury recently disseminated northern red oak (Quercus rubra L.) acorns collected from another site and disrupt red maple (Acer...
Article
This study investigated whether soil scarification during the presence of oak mast could increase oak seedling establishment and decrease poison ivy cover in two mixed-oak bottomland stands that lacked adequate advanced oak reproduction. Study sites were located along the Saline River in southern Illinois and designated as Cherrybark Bottoms, with...
Article
This study investigated whether soil scarification during the presence of abundant white oak (Quercus alba L.) acorns and other mast could be used to increase the density of oak reproduction and reduce competitive midstory species in a mid-successional mixed-oak upland forest. The study was conducted in a 7.3 ha forest with a mature oak overstory a...
Article
Full-text available
poison ivy decreased from 36 percent to12 percent in the scarified plots. These results suggest that, in the presence of abundant acorns, scarification increased the likelihood of oak germination in a stand that lacked advanced oak regeneration prior to the treatment. Finally, because scarification increased the density of oak seedlings, it will in...
Article
Full-text available
With the current emphasis and interest in riparian forest management, it is necessary to develop management strategies that enhance and regenerate bottomland hardwoods in these biologically important areas. However, the regeneration of bottomland oaks has been problematic across much of the eastern United States. Two ongoing studies presented in th...

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