TREE MORTALITY ANALYSIS OF GIANT SEQUOIA GROVES IN SEQUOIA AND KINGS CANYON NATIONAL PARK

Abstract

California has been in a drought since the year 2000 and is now considered to be in a “megadrought” (Borunda, 2021). Dead and weak trees are susceptible to native bark beetles and as the drought continues to create more vulnerable trees, the bark beetle population has been increasing, causing more tree mortality (Rosner, 2020). Giant sequoia trees are the largest trees on Earth and live for thousands of years (“Giant Sequoias”, 2021). Scientist have seen not a severe increase in sequoia tree mortality due to the drought but have seen a “die-back” in their foliage and canopy loss caused by low water stress (“Leaf to Landscape”, 2016). Fire is an important part to the life cycle of giant sequoia trees, and they have been known to survive through many fires throughout their existence (“Giant Sequoias and Fire”, n.d.). However, with an increase in forest fire fuel from the drought, rising temperatures causing dryer tinder and many years of fire suppression, fires are getting unnaturally hotter and stronger, putting sequoia trees at risk (Fox, 2021). When scientists noticed their dying foliage and canopy loss, the Leaf to Landscape Project was created through partnership with multiple federal agencies and universities to study the giant sequoia trees health (“Leaf to Landscape”, 2016). The project collected tree data by flying an aircraft over Sequoia and Kings Canyon National Park using LiDAR technology (Nydick, 2018). My project utilizes the LiDAR data to analyze dead tree clusters and their proximity to giant sequoia groves using a variety of cluster finding techniques using ArcGIS Pro. Locating dead tree clusters will help assist with future fire planning for the protection of sequoia trees.