About

John Seiler, Ph.D., is a Professor and Tree Physiology Specialist in the Department of Forest Resources and Environmental Conservation at Virginia Tech. He holds a B.S. and M.S. from Penn State and earned his Ph.D. from Virginia Tech. His research interests include environmental stress effects on woody plant physiology, including water and pollutant stresses, physiological responses to silvicultural treatments, and carbon sequestration. Dr. Seiler is involved in characterizing and modeling seasonal gas exchange in fertilized loblolly pine plantations, developing multimedia tutorials for woody plant identification and forest biology, and quantifying carbon efflux rates in managed loblolly pine plantations. His work aims to improve understanding of forest physiological processes and their role in global carbon budgets, contributing to sustainable forest management practices.

Research topics

• Biology
• Horticulture
• Agronomy
• Botany
• Medicine
• Surgery
• Computer Science
• Physical therapy
• Composite material
• Engineering
• Ecology
• Geomorphology
• Geotechnical engineering
• Geology
• Environmental science
• Orthodontics
• Soil science

Selected publications

• Interfragmentary Screws Versus Intramedullary Implants For Proximal Phalanx Fractures: A Biomechanical Study in Matched Hands

  The Journal Of Hand Surgery · 2025-04-06 · 1 citations

  article
  PublisherDOI

• Mechanical site preparation treatment and species effects on carbon pools in 12-year-old American sycamore [Platanus occidentalis L.] and willow oak [Quercus phellos L.] riparian plantations, Virginia Piedmont, USA

  New Forests · 2025-09-26

  articleOpen accessSenior author

  Abstract Restoration of riparian forests can improve water quality and wildlife habitat and also sequester carbon. Unfortunately, failures of riparian restoration efforts are common due to planting mortality. Selection of well-suited species, dense planting and use of mechanical soil site preparations may potentially enhance wetland restoration plantings. Carbon valuation of forestland is increasing and additional research is needed to determine rates and pools of carbon accumulation in riparian areas. We evaluated the effects of four soil mechanical site preparation treatments (bedding, disking, pit and mounding, and ripping) and species selection (American sycamore [ Platanus occidentalis L.] and willow oak, [ Quercus phellos L.] on survival, growth and carbon storage across multiple pools: planted trees, herbaceous vegetation, fine roots, organic soil (litter) horizons, and the mineral soil. At 12 years, species selection was more important to carbon storage than site preparation. American sycamore was well-suited to the site and had better survival than willow oak (64% vs. 42% survival). American sycamore also stored more carbon across all site preparation methods than willow oak. Measured carbon storage averaged 74.8 Mg ha −1 for American sycamore treatments and 63.1 Mg ha −1 for willow oak treatments. The densely planted treatments established forests even in higher mortality willow oak plots. Results indicate that appropriate species planted at high densities may be used to enhance forest stand establishment and carbon storage in similar riparian restorations.

  PublisherOA PDFDOI

• Effect of drought stress on the physiology and early growth of seven Senegalia (Acacia) Senegal (L.) Britton provenances

  New Forests · 2024 · 6 citations

  • Biology
  • Horticulture
  • Botany

  Abstract Decline of Senegalia senegal ( Acacia senegal ) in its natural range has been observed and attributed mainly to harsh environmental conditions such as frequent drought occurrences. The objective of this study is to assess the effect of water stress on growth, biomass allocation and photosynthetic capacity in Senegalia senegal seedlings. Seeds were collected from seven provenances in Senegal and grown under greenhouse conditions in a randomized complete block design with 5 replications. Seedlings were subjected to three cyclic droughts by watering them when average soil moisture content dropped to 4.7%, 2.7%, and 2.1% during the first, second, and third dry down cycles, respectively. With the exception of net photosynthetic rate, stomatal conductance and transpiration at the second and third dry down cycles, no drought by provenance interaction was found for any trait measured. Ngane provenance had a lower root/shoot ratio and allometric analysis revealed that Ngane allocated less biomass to roots than shoots. Ngane developed superior growth traits and biomass production, despite similar net photosynthetic rate with other provenances before treatments started. Overall, drought stress significantly reduced biomass, stem height, diameter and leaf gas exchange. Total biomass was reduced by 28.5%, whereas root/shoot ratio was increased by 25% compared to control. Significant interaction on leaf gas exchanges at the second and third dry down cycles reveals different sensitivity levels to drought among provenances with the Ranerou provenance exhibiting no decline in leaf gas exchange. No significant difference of stomatal limitation among genotypes was found, which is indicative of the complex process of photosynthesis and the need for extended times scales for measurements to better depict physiological sensitivity of Senegalia senegal to drought.

  PublisherOA PDFDOI

• Soil Respiration and Related Abiotic and Remotely Sensed Variables in Different Overstories and Understories in a High-Elevation Southern Appalachian Forest

  Forests · 2023-08-15 · 1 citations

  articleOpen accessCorresponding

  Accurately predicting soil respiration (Rs) has received considerable attention recently due to its importance as a significant carbon flux back to the atmosphere. Even small changes in Rs can have a significant impact on the net ecosystem productivity of forests. Variations in Rs have been related to both spatial and temporal variation due to changes in both abiotic and biotic factors. This study focused on soil temperature and moisture and changes in the species composition of the overstory and understory and how these variables impact Rs. Sample plots consisted of four vegetation types: eastern hemlock (Tsuga canadensis L. Carriere)-dominated overstory, mountain laurel (Kalmia latifolia L.)-dominated understory, hardwood-dominated overstory, and cinnamon fern (Osmundastrum cinnamomeum (L.) C. Presl)-dominated understory, with four replications of each. Remotely sensed data collected for each plot, light detection and ranging, and hyperspectral data, were compiled from the National Ecological Observatory Network (NEON) to determine if they could improve predictions of Rs. Soil temperature and soil moisture explained 82% of the variation in Rs. There were no statistically significant differences between the average annual Rs rates among the vegetation types. However, when looking at monthly Rs, cinnamon fern plots had statistically higher rates in the summer when it was abundant and hemlock had significantly higher rates in the dormant months. At the same soil temperature, the vegetation types’ Rs rates were not statistically different. However, the cinnamon fern plots showed the most sensitivity to soil moisture changes and were the wettest sites. Normalized Difference Lignin Index (NDLI) was the only vegetation index (VI) to vary between the vegetation types. It also correlated with Rs for the months of August and September. Photochemical reflectance index (PRI), normalized difference vegetation index (NDVI), and normalized difference nitrogen index (NDNI) also correlated with September’s Rs. In the future, further research into the accuracy and the spatial scale of VIs could provide us with more information on the capability of VIs to estimate Rs at these fine scales. The differences we found in monthly Rs rates among the vegetation types might have been driven by varying litter quality and quantity, litter decomposition rates, and root respiration rates. Future efforts to understand carbon dynamics on a broader scale should consider the temporal and finer-scale differences we observed.

  PublisherOA PDFDOI

• Effect of Drought Stress on the Physiology and Early Growth of Seven Senegalia senegal (L.) Britton Provenances

  Research Square (Research Square) · 2023

  • Biology
  • Horticulture
  • Agronomy

  Abstract Decline of Senegalia senegal in its natural range has been observed and attributed mainly to harsh environmental conditions such as frequent drought occurrences. The objective of this study is to assess the effect of water stress on growth, biomass allocation and photosynthetic capacity in Senegalia senegal seedlings. Seeds were collected from seven provenances in Senegal and grown under greenhouse conditions in a randomized complete block design with 5 replications. Seedlings were subjected to three cyclic droughts by watering them when average soil moisture content dropped to 4.7%, 2.7%, and 2.1% during the first, second, and third dry-down cycles, respectively. With the exception of net photosynthetic rate, stomatal conductance and transpiration at the second and third dry down cycles, no drought by provenance interaction was found for any trait measured. Ngane provenance had a lower root/shoot ratio and allometric analysis revealed that Ngane seemed to allocate less biomass to roots than shoots. Ngane developed superior growth traits and biomass production, despite similar net photosynthetic rate with other provenances before treatments started. Overall, drought stress significantly reduced biomass, stem height, diameter and leaf gas exchange. Total biomass was reduced by 28.5%, whereas root/shoot ratio was increased by 25% compared to control. Significant interaction on leaf gas exchanges at the second and third dry down cycles reveals different sensitivity levels to drought among provenances with the Ranerou provenance exhibiting no decline in leaf gas exchange. No significant difference of stomatal limitation among genotypes was found, which is indicative of the complex process of photosynthesis and the need for extended times scales for measurements to better depict physiological sensitivity of Senegalia senegal under drought.

  PublisherOA PDFDOI

• The Impact of Predation of Laricobius nigrinus (Coleoptera: Derodontidae) on Adelges tsugae (Hemiptera: Adelgidae) and Tsuga canadensis (Pinales: Pinaceae) Tree Health

  Forests · 2023-03-29 · 5 citations

  articleOpen access

  The hemlock woolly adelgid (HWA), Adelges tsugae, has threatened the sustainable management of Tsuga canadensis in the eastern United States. Biological control efforts have led to the establishment of Laricobius nigrinus, a specialist predator of HWA. Although L. nigrinus has a significant impact on HWA populations, its effect on the health of HWA’s host is unknown. In 2020, 14 eastern hemlocks at one site in Virginia were selected to determine whether predation of L. nigrinus at different densities on HWA populations had an effect on tree health. Laricobius nigrinus predation significantly impacted the HWA sistens generation, resulting in significantly more new shoots produced on treatment branches with the greatest density of L. nigrinus adults. Final HWA density was lowest on treatment branches with L. nigrinus, followed by the negative control, and the treatment without L. nigrinus. In June, the photosynthetic rate was significantly greater for the negative control, followed by L. nigrinus treatments. There were no statistical differences among measured tree physiological parameters in July and October, indicating a temporary effect from L. nigrinus predation on hemlock tree physiology.

  PublisherOA PDFDOI

• Root reinforcement and extracellular products reduce streambank fluvial erosion

  The Science of The Total Environment · 2023-06-29 · 6 citations

  article
  PublisherDOI

• Effects of Hemlock Woolly Adelgid Control Using Imidacloprid on Leaf-Level Physiology of Eastern Hemlock

  Forests · 2023-06-14 · 2 citations

  articleOpen accessCorresponding

  Widespread mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) has been occurring due to the introduction of hemlock woolly adelgid (Adelges tsugae Annand) (HWA), threatening millions of hectares of hemlock-dominated forests in the eastern United States. HWA feeds at the base of needles and removes stored carbohydrates, which can impact leaf-level physiology, contributing to the decline of the tree. However, these physiological mechanisms in HWA-infested hemlocks are still not clearly understood. We investigated hemlock leaf physiology year-round at three forested sites with various degrees of infestation. At each site, half the trees were treated with imidacloprid (Merit® 2 F, Bayer, Kansas City, MO, USA) while the rest were left untreated. Imidacloprid is widely used to control HWA but can itself have phytotoxic effects. After one growing season, there was an increase in photosynthetic rates (7.5%, p = 0.0163) and stomatal conductance (7.1%, p = 0.0163) across sites in the trees treated with imidacloprid. After two years, the imidacloprid treatment also increased bud break from 22.5% to 88.7% at Fishburn (the most severely impacted site) and from 22.7% to 58.9% at Mountain Lake (the least impacted site), and slightly increased chlorophyll fluorescence for treated trees at Fishburn. Chemical treatment also slightly increased water use efficiency at Mountain Lake. These results suggest that HWA is causing tree mortality largely through a reduction in leaf area caused by decreasing bud break and also by a slight, but significant, reduction in leaf-level photosynthesis and stomatal conductance.

  PublisherOA PDFDOI

• Estimating heat tolerance of buds in southeastern US trees in fire-prone forests

  Fire Ecology · 2022-12-19 · 4 citations

  articleOpen access

  Abstract Background Traits of mature trees, such as bark thickness and texture, have been documented to promote resistance or resilience to heating in fire-prone forests. These traits often assist managers as they plan and promote prescribed fire management to accomplish specific land management objectives. Species are often grouped together as pyrophobes or pyrophytes as a result of these features. Nonetheless, little is known about species-specific traits of other structures, such as bud diameter, length, mass, moisture content, and surface area, that might be related to heat tolerance. Many prescribed fires are utilized in the eastern United States to control regeneration of less desired species, which could apply a more mechanistic understanding of energy doses that result in topkilling mid-story stems. In this study, we investigated potential relationships between terminal bud mortality from lateral branches of midstory stems and species-specific bud features of six eastern US deciduous trees. Characterized at maturity as either pyrophytes or pyrophobes, each was exposed to different heat dosages in a laboratory setting. Results Bud diameter, length, mass, moisture content, and surface area differed by species. Bud percent mortality at the first heat flux density (0.255–0.891MJm −2 ) was highest for two pyrophobes, chestnut oak ( Quercus montana Willd.) and scarlet oak ( Quercus coccinea Münchh). For the second heat flux density (1.275–1.485MJm −2 ), bud percent mortality was highest for these species and red maple ( Acer rubrum L.). Principal component analysis suggested that bud surface area and length differentiated species. Red maple, chestnut oak, and scarlet oak produced clusters of buds, which may explain their more pronounced bud mortality. Yellow-poplar ( Liriodendron tulipifera L.) was also present in that cluster, suggesting that its unique bud architecture of pre-emergent leaves may have elicited responses most similar to those of the clustered buds. Conclusions Contrary to expectations, lateral buds of species regarded as pyrophytes at maturity displayed some of the highest values of bud percent mortality when heated at two heat flux densities generated in a laboratory. Their responses may be related to clustering of their lateral buds. Testing of additional species using these methods in a laboratory setting, and perhaps additional methodologies in the field, is warranted.

  PublisherOA PDFDOI

• Supplementary material 1 from: Lakoba VT, Welbaum GE, Seiler JR, Barney JN (2021) A perennial invader's seed and rhizome differ in cold tolerance and apparent local adaptation. NeoBiota 70: 1-21. https://doi.org/10.3897/neobiota.70.64614

  Zenodo (CERN European Organization for Nuclear Research) · 2021-11-24

  paratextOpen access

  Extreme cold plays a key role in the range boundaries of plants. Winter survival is central to their persistence, but not all structures are equally susceptible to frost kill and, therefore, limiting to distributions. Furthermore, we expect intraspecific variation in cold tolerance both within and among tissue types. In a laboratory setting, we determined freezing tolerances of two overwintering propagule types – seeds and rhizomes – of the globally invasive Johnsongrass (Sorghum halepense), testing apparent emergence and electrolyte leakage as a proxy for cell death. We used 18 genotypes from agricultural and non-agricultural habitats spanning the climatic extremes occupied by Johnsongrass in the US. Single node rhizome fragments had an average LT90 of -5.1 °C with no significant variation based on home climate or ecotype. Seeds frozen at -85 °C suffered a decline in germinability to 10% from 25% at 22 °C. Population origin did not affect seed response to any temperature. However, non-agricultural seeds germinated more and faster than agricultural seeds from the coldest climates, with a reversed relationship among warmest origin seeds. Regardless of ecotype, seeds from the cold/dry and wet/warm sectors of Johnsongrass’s range germinated more and faster. Drastic differences in cold tolerance between seeds and rhizome and evidence for seeds’ local adaptation to land use and climate suggest that its spread is likely limited by winter rhizome survival, as well as adaptability of germination behavior to longer winters. These findings shed light on Johnsongrass’ dispersal dynamics and help identify future avenues for mechanistically understanding its range limitation.

  PublisherDOI

Frequent coauthors

• Richard H. Gelberman

  36 shared

• Brian D. Strahm

  North Carolina State University

  22 shared

• Kurt H. Johnsen

  US Forest Service

  21 shared

• Frank D. Ellis

  18 shared

• Peter C. Amadio

  Mayo Clinic

  18 shared

• Shepard M. Zedaker

  Virginia Tech

  17 shared

• Michael C. Tyree

  16 shared

• Eric B. Sucre

  Weyerhaeuser (United States)

  16 shared

Awards & honors

• Ernest L. Boyer International Award for Excellence on Teachi…
• Forestry and Wildlife Resources Curriculum Clubs' Outstandin…
• University Certificate of Teaching Excellence, 1994-95
• University W.E. Wine Award for Excellence in Teaching, 1997
• Carl Alwin Schenck Award for Outstanding Performance in Fore…