About

Jason Grabosky is a faculty member in the Department of Ecology, Evolution, and Natural Resources at Rutgers University. His area of expertise includes urban tree management in the development and maintenance of urban landscapes, managing stormwater for urban sustainability using trees and structural soils, and addressing root-pavement conflicts. He is located at 59 Lipman Drive, New Brunswick, NJ, and can be contacted via email at grabosky@sebs.rutgers.edu. His work focuses on enhancing urban environmental quality through sustainable landscape practices and the strategic management of urban trees.

Research topics

• Ecology
• Geography
• Forestry
• Biology
• Computer Science
• Artificial Intelligence
• Environmental science
• Geology
• Economics
• Business
• Natural resource economics
• Archaeology
• Finance
• Data science
• World Wide Web
• Agricultural economics

Selected publications

• Radial Expansion and Flattening in Woody Tree Roots: Assessing the Limits

  Arboriculture & Urban Forestry · 2026-01-20

  articleOpen access

  Abstract Background Tree roots colonize cracks in rock and similarly confining spaces in built environments, contributing to natural weathering processes and urban infrastructure dysfunction. Methods In this study, we assessed the limits of radial expansion in woody Quercus virginiana Mill. and Taxodium distichum (L.) Rich. roots grown in clamps under increasing tension. Results After two growing seasons, a maximum stress threshold for radial growth in mature structural roots was identified and was similar for both species. These thresholds (0.173 MPa to 0.329 MPa) fall within the lower to middle range of values reported in previous studies and are notably lower than those observed in seedling radicles or in other woody species under more acute stress exposure. Conclusions Our findings provide some of the first empirical estimates of pressure thresholds for deformation in mature woody roots, suggesting that structural root flattening can occur at relatively modest stress levels. These results offer important insights for the design of urban infrastructure aimed at minimizing root-related damage while also informing future biomechanical studies of species-specific responses to soil confinement.

  PublisherOA PDFDOI

• Assessment of Root Growth in Root-Soil-Pavement Systems in Urban Environments

  Preprints.org · 2026-01-09

  preprintOpen access

  Trees in urban environments provide essential ecosystem services, but root growth–pavement system conflicts often constrain tree longevity and degrade infrastructure performance. The study presents a conceptual model for green and grey infrastructure alignment to ensure tree longevity while maintaining pavement performance in the urban environment. Drawing on past research where roots were flattened when exposed to confining stresses greater than 0.35 MPa, we developed a series of finite element models in COMSOL Multiphysics to simulate root-induced stresses in concrete pavements under varying pavement thickness, base thickness, and root depth. Parametric analyses showed that an increase in root depth had the largest impact in reducing stress, followed by an increase in pavement thickness, then base thickness. Maximum single-root-induced stresses were approximately 0.55 MPa, below that of normal concrete flexural strength. From these results, design guidance is proposed for tree root accommodation and pavement in existing and new infrastructure, with emphasis on root growth enhancement, pavement durability, and cost-effectiveness measures.

  PublisherOA PDFDOI

• Assessing The Limits of Radial Expansion in Woody Tree Roots

  Preprints.org · 2025-07-04

  preprintOpen access

  Tree roots colonize cracks in rock and similarly confining spaces in built environments, contributing to natural weathering processes and urban infrastructure dysfunction. In this study, we assessed the limits of radial expansion in woody Quercus virginiana L. and Taxodium distichum (L.) Rich. roots grown in clamps under increasing tension. After two growing seasons, a maximum stress threshold for radial growth in mature structural roots was identified and was similar for both species.

  PublisherOA PDFDOI

• Testing a Modified Pipe Model Approach to Predict Cross-Sectional Area of Tree Roots at Specific Distances from the Tree

  Arboriculture & Urban Forestry · 2025-01-01 · 2 citations

  articleOpen access1st authorCorresponding

  Abstract When considering the establishment of tree protection zones in construction, or in assessing relative damage to a tree for risk or penalty, it would be useful to have a method to predict total root area at some distance from the tree. With such a method, the arborist can assess the level of damage in comparison to some estimate of the total rather than from a loss of possible root zone space based on land area. We used a modification of the pipe model approach to estimate the root cross-sectional area at different distances from the tree as defined by the edge and center of the trunk. We discuss two early studies. The first considers root systems excavated from a limited set of 9 trees over 50 years post-establishment across 3 species. Trees were excavated and roots harvested, cataloged, and imaged for measurement at 1, 2 and 3 meters from the trunk edge of the respective tree. The second study considered 29 digitally mapped root systems of Fraxinus pennsylvanica ‘Patmore’ 9 years post-transplant by developing code for a virtual dissection at specific distances from the tree trunk. The second study observed variability across a tightly defined set of trees. There was a weak relationship between root area at set distances by species, and we found 3 m was a useful distance in the first study. We have a long way to go in development before having a method as a tool for practice, but the approach may be useful with additional observation and study.

  PublisherOA PDFDOI

• Flow similarity model predicts allometric relationships among Acer platanoides L. branches

  PLoS ONE · 2025-08-14

  articleOpen accessSenior authorCorresponding

  Using physical models to predict patterns of plant growth has been a long-standing goal for biologists. Most approaches invoke either thermodynamic, biomechanical or hydraulic principles and assume the mechanism of interest applies similarly throughout the plant branching architecture. A recent effort, the flow similarity model, predicts numerous aspects of branching physiology and morphology and argues that the physiological constraints experienced by plants change as a function of branch order and size, with more basal portions satisfying more biomechanical constraints, and more distal portions, hydraulic ones. Distal branches are expected to have a strong influence on allometric relationships within plants due to their numerical abundance. Here we evaluate the predictions of the flow similarity model and a well-known alternative fractal branching model, using data on the dimensions of 3,484 individual stem internodes across four individual Acer platanoides trees. Overall, we find strong agreement between model predictions and the allometric exponents describing tree branch allometry. Further the predicted curvature in allometric relationships is found in all 24 cases examined and the frequency distributions of branch lengths and diameters are consistent with model expectations in 6/8 cases. We also find the area ratios are consistent with the model assumption of area-preserving branching. Collectively, our data and analysis provide strong support for the flow similarity model, and identifies several areas in need of subsequent inquiry.

  PublisherOA PDFDOI

• Flow similarity model predicts allometric relationships among Acer platanoides branches

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-28

  preprintOpen accessSenior author

  Using physical models to predict patterns of plant growth has been a long-standing goal for biologists. Most approaches invoke either biomechanical or hydraulic principles and assume the mechanism of interest applies similarly throughout the plant branching architecture. A recent effort, the flow similarity model, predicts numerous aspects of branching physiology and morphology and argues that the physiological constraints experienced by plants change as a function of branch order and size, with more basal portions satisfying more biomechanical constraints, and more distal portions, hydraulic ones. Distal branches are expected to have a strong influence on allometric relationships within plants due to their numerical abundance. Here we evaluate the predictions of the flow similarity model and a well-known alternative fractal branching model, using data on the dimensions of 3,484 individual stem internodes across four individual Acer platanoides trees. Overall, we find strong agreement between model predictions and the allometric exponents describing tree branch allometry. Further the predicted curvature in allometric relationships is found in all 24 cases examined and the frequency distributions of branch lengths and diameters are consistent with model expectations in 6/8 cases. We also find the area ratios are consistent with the model assumption of area-preserving branching. Collectively, our data and analysis provides strong support for the flow similarity model, and identifies several areas in need of subsequent inquiry.

  PublisherOA PDFDOI

• Linking overstory relative density to light availability and understory plant community composition in disturbance-dependent, Pinus rigida -dominated forests of the mid-Atlantic coastal plain, USA

  Forest Ecology and Management · 2025-02-04

  articleSenior author
  PublisherDOI

• Predictors of street tree survival in Philadelphia: Tree traits, biophysical environment, and socioeconomic context

  Urban forestry & urban greening · 2024-03-11 · 13 citations

  article
  PublisherDOI

• <i>Quercus virginiana</i> Mill. Root Regrowth Following Linear Trenching

  Arboriculture & Urban Forestry · 2024-06-04 · 1 citations

  articleOpen access

  Abstract Background As long-lived organisms, urban trees often encounter development and redevelopment activities during their lifespans. These activities can damage tree roots, often through methods like root severing during trenching or excavation. Methods In 2017, we simulated trenching damage on mature Quercus virginiana Mill. trees at 3 different distances from the base (3, 6, or 12 times the stem diameter). After 5 years, we revisited these trees to assess root regrowth based on the cut root’s cross-sectional area (CSA) and distance from the base. Results We observed regrowth in all but 38 (6.7%) of the 557 cut roots revisited. The lack of regrowth in some roots was not associated with our original treatments, the CSA of the roots at the time of trenching, or distance between the cut root end and the trunk (minimum P -value = 0.841). On average, the observed CSA of the regrowth was 22.2% of the original root’s CSA. Only our initial trenching treatments ( P -value = 0.024) and the distance between the trunk and the cut root end ( P -value = 0.002) significantly predicted the level of regrowth observed 5 years after pruning. Conclusions In summary, our findings indicate that root systems require many years to recover from trenching damage. Increasing the distance between trenching activities and trees may have a minor effect on root regrowth.

  PublisherOA PDFDOI

• Design of an eDNA sampling method for detection of an endophagous forest pest

  NeoBiota · 2024-09-12 · 6 citations

  articleOpen access

  Invasive wood-boring insects are a major economic and ecological concern worldwide as they impact native woody plant populations. These pest species are increasing in prevalence, with devastating impact, as global trade leads to higher rates of introduction and establishment. The emerald ash borer ( Agrilus planipennis ; EAB) is one such species, which has caused widespread damage across much of the United States and is now spreading across Europe. Non-indigenous woodborers such as EAB are difficult to detect at early stages of invasion, which is when management and eradication efforts are most effective and cost efficient. Environmental DNA (eDNA) surveys have demonstrated power in detecting invasive species when rare in the landscape due to their ability to detect trace amounts of DNA and identify to species. Here, we trialled a novel eDNA method for collecting environmental samples within host trees where invasive pest larvae are feeding, using EAB as a case study. We extracted tree cores approximately 1 cm in length using an increment hammer to assess detectability of eDNA from larvae feeding under the bark. In trees visibly infested with EAB, we observed a seasonal peak in EAB DNA detection probability (~ 64%; towards the end of the growing season), indicating a potential impact of ash tree phenology or EAB phenology on detection. When we trialled the method in a site with ash trees of low or uncertain EAB abundance, we did not record positive EAB eDNA detections. This outcome may have resulted from differing EAB phenology at the northern latitude of this survey site or because larval galleries were less numerous causing EAB DNA to be scarcer within the tree. Our results, however, provide preliminary evidence that increment hammer tree cores can be used to detect eDNA of EAB and, perhaps, other wood-boring pests. Further work is needed to clarify false negative survey detections at ash trees showing little to no signs or symptoms of infestation, as well as investigating the deposition, transport and persistence dynamics of EAB eDNA within trees.

  PublisherOA PDFDOI

Frequent coauthors

• Nina Bassuk

  Cornell University

  18 shared

• Edward F. Gilman

  13 shared

• Gregory Dahle

  West Virginia University

  12 shared

• Frank J. Gallagher

  Rutgers, The State University of New Jersey

  8 shared

• Joshua S. Caplan

  Temple University Ambler

  8 shared

• Chris Harchick

  University of Florida

  7 shared

• Edward Gilman

  6 shared

• Bernard N. Isaacson

  Southern Research Station

  5 shared

Education

• PhD, plant biology

  Cornell University

  1999