Performing Department
Ecology, Evolution & Natural Resources
Non Technical Summary
The project investigates and develops models to link urban tree trunk diameter to canopy volume and then link those findings to growth curves established from tree core rind counts. It will build on existing program efforts to better describe urban tree growth and age estimators to improve urban tree management models and professional practice in the interpretation and management of both urban tree canopy and in specific tree evaluation.Additionally, we will investigate leaf area index to link leaf surface to canopy volume estimators. We will work to develop a linkage of these models to related research in urban forest community inventory and demography, and finally we will look to develop further information linking tree water use to canopy volume/leaf surface area.
Animal Health Component
0%
Research Effort Categories
Basic
15%
Applied
85%
Developmental
(N/A)
Goals / Objectives
Goals:Develop and augment files on urban trees to better link growth models in urban trees to link diameter at breast height (DBH) to age, with consideration to design space provided as a soil resource.Develop allometric relationships on the urban tree form to link both DBH and growth models to canopy volumes over time.Develop Leaf Area Index (LAI) in several contexts to better relate urban canopy form to leaf area in environmental serviceDevelop linkages of growth and service potentials to inventory development/demography to link services and growth expectation to urban tree community stocking and community structure.Develop data in tree water use expectation scaling from small leaf gas exchange to tree canopy and community environmental service.
Project Methods
We will link existing tree ring analyses to tree dimensions for canopy and whole-tree allometric algorithm development. We also link the dimensional relationships to Leaf Area Index measures to enable empirical observations to satellite imagery and a better modelling context for water use budgeting. We will contribute to field data collections to better understand over-all community structures. Finally, we will develop student training to measure leaf-level water use efficiency and gas exchange on trees with repeated measures to provide context to any scaling of the growth/allometric data into water budgeting models for use in environmental service models.Track I: The first track uses an organized image collection of street and park trees to enable a tree silhouette form analysis of a species from installation size to maturity in common landscape planting situations. Tree images of 10 targeted species will be collected in four common landscape design forms: tree pits, narrow linear strips parallel to a road, wide linear strips and lawns/park situations to link to the trunk growth analysis outcomes. Working on a protocol developed by the PI and project doctoral student, undergraduate and graduate student summer interns will be trained for the field data collection campaign. A target will be affixed to the tree at 4.5 feet above grade where DBH is measured in the same plane by a caliper. Images of the entire tree will be taken and then calibrated to the target using the direct measure of DBH in the imaging plane. Trunk size will establish a link between previous and currently ongoing DBH-based age and growth analysis. Once calibrated, pixel counts will develop estimates for height and canopy. Thus, we'll have a linkage from empirical data in tree size in DBH to canopy dimension growth pattern, and better modelling foundations for canopy volume and tree size, scaled to the urban context. We are initially targeting 100-125 trees in each species/ planting space category, spanning sizes of 2-inch trunk diameter to maximum expected size as established in prior analysis (Sanders et al. 2013). Replicate counts will be adjusted pending observation of variability and availability (as some species are not always found in all design situations). Modelling algorithms in Reduced Major Axis Regression and/or Bayesian analysis will be useful for other benefit modelling programs. Anticipated allometric algorithms include growth pattern of DBH and canopy area, expanded to a volume as a uniform form from the image view. Years 1 and 2 will be dedicated to base data description and library development. Years 3,4 will be focused on analysis and publication/outreach product development. Research manuscripts will be developed for traditional publication avenues, coupled with technical documents for use by NJ forestry practitioners. Our goal is to move toward machine learning methods to provide a streamlined guidance for expansion and replication of study outcomes on same species in other regions or other species in general. We can then test for design influence on tree service provision rather than simply using a single growth trajectory for a given species. All data will be shared with USDA FS and NJ DEP Forestry personnel to advance common goals of model refinement in common canopy and tree environmental service and biomass yield tools. Track II: To augment the information available in environmental service modelling, we will train undergraduate forestry student interns to use a LI-COR 2200-C Leaf Canopy Analyzer. A plot sample program in rural forests and urban forests will be developed to dovetail in both urban forestry research and on-going silvicultural research, with the aim of validating remotely-sensed canopy water use (Bernard Isaacson Doctoral Dissertation). Data about rural forest canopy thickness and water use will be linked to landscape-scale water resource management. Additional field measures will be used to compare with existing literature on urban trees, and then used for water use and transpiration demand as a linkage to NJ State programs on Low Impact Development and stormwater management programming, in line and in support of collaborative efforts with NJAES and the NJ DEP. Under the guidance of a doctoral student and the PI, students will train or verify competency of undergraduate students (2 students in a team for two, 12-week summer field campaigns) on the use of field measurement protocol in a range of forest densities and under different forest management activities. This will be coupled with a series of urbanized transects of common street tree species to develop modelling data baselines in Basal Area and other basic field measures to couple with in-field LAI. Student measurement protocols of seasonal canopy development from May through August will be developed, with phenology notes for senescence in deciduous species common to the urban landscape. Advanced students may opt to develop technical reports and literature supports under the guidance of the PI and Graduate students as a capstone project or Honors thesis on a species or forest type increment basis.Protocol and sampling plot location development will be defined over the dormant season during the academic year of year 1. The literature basis and review to be established along with student training plan will also be developed in the first academic year. Sumer of year 1 and year 2 will be used to collect field data. Analysis will be developed in years 2,3 by the graduate student, mentoring advanced undergraduate students as needed. Track III: Students will be trained in basic inventory skills and join in with the research teams based in Philadelphia, PA and New York City with the USDA FS Urban Field Stations. We are collaboratively developing teams to track tree community structures in the effort to create demographic models which also include growth expectation over time. Our other tracks can directly inform those models. We take advantage of existing permanent plots which develop a supplemental data stream of deeper observation which can inform and augment the Urban FIA data being developed in Philadelphia, New York City and New Jersey. Track IV: We seek to use undergraduate student research effort in years 3 and 4 to develop field assessments of transpiration rates of common urban street trees. While we have the ability to lean in on the literature to provide guidance on transpiration rate estimates, field data in urban situations is limited. We have evidences from previous research observation that rates can vary substantially and likely relate to soil volumes provided in urban designs over time (Salisbury and Grabosky 2019, Ryan 2017). As water status translates to tree growth vigor, we can use this work to objectively test questions of design impact on water budget as a foundational aspect for differential growth rate species. Programs across the US are looking to better explain urban tree longevity and propose varied definitions and approaches to an urban site index. We specifically develop a more formal and traditional construct for what is deemed Site Index in forestry within an urban context. The fourth track establishes the most likely and salient aspect to the biotic capacity of the designed site; water access as a function of soil volume available to tree root colonization. This compliments our earlier and proposed research as differences in a lawn versus a soil trench or tree pit in pavement.