Date of Award
Doctor of Philosophy (PhD)
College of Science and Mathematics
Earth and Environmental Studies
Thesis Sponsor/Dissertation Chair/Project Chair
Ram Sewak Dubey
Though the impacts of pest infestation on forested ecosystems vary, the natural factors that facilitate outbreaks are of concern across multiple disciplines across the USA, affecting such diverse fields as economics, ecology, hydrology, atmospheric sciences, and pedology. Emerald Ash Borer (EAB) is a typical example of an aggressive invasive forest pest; it has proven difficult to eliminate, resistant to natural predators, and damaging to local flora. EAB has recently proliferated through the northern and mid-western forests of the USA, devastating the native population of ash trees (Fraxinus spp.), and has invaded an estimated 28% of all susceptible trees. In New Jersey alone, approximately 9% of forests are vulnerable to EAB attacks, potentially resulting in more than $2.7 billion in damages. The excessive cost of Fraxinus mortality presents serious implications for the state in the forestry and infrastructure sectors. Managing EAB is difficult, with critical uncertainties in the rates of infestation, mortality, and anthropogenically introduced controls. To address the imprecise future of Fraxinus under EAB predation we developed a set of novel models for exploring the spread of EAB and then further evaluated the potential risks to local electrical distribution infrastructure and ecosystem service provisioning. Through an original project that addresses this urgent, complex, and widespread challenge, utilizing New Jersey as a study area, we have i) developed a unique geospatial-based partial differential equation (PDE) model to predict EAB infestation through the forest system over a heterogeneous 2D landscape and estimate the mortality of both EAB, from introduced and native parasitoids, and Fraxinus, from EAB predation; ii) used an innovative tree fall risk structure to assess potential infrastructure impacts; and iii) examined ecosystem service losses caused by the infestation. We found that controlling the infestation requires early and intense introduction of parasitoids to maintain the forest structure. Failing to do so will lead to millions of dollars of externalities in potential Fraxinus removals to protect critical infrastructure and the potential for increased erosion and sedimentation given the degraded state of the New Jersey Forest understory.
Lyttek, Erik W., "The Fate of Fraxinus spp. in New Jersey : A Physioeconomic Evaluation of the Forest System and Infrastructure Implications" (2023). Theses, Dissertations and Culminating Projects. 1290.
Available for download on Wednesday, May 29, 2024