Chinese Tallow Invasion in Maritime Forests: Understand Invasion Mechanism and Develop Ecologically-Based Management

Invasion by highly aggressive, non-native, invasive plants is a significant threat to management and conservation priorities as these plants can transform ecosystem functions and processes. In this study, I investigated the non-native, invasive tree, Chinese tallow (Triadica sebifera (L.) Small) in the maritime forests of Parris Island, South Carolina. I studied the role of land-use history and modern forest disturbance in facilitating the invasion of Chinese tallow. I found that stands previously cleared for agriculture and reforested with slash pine (Pinus elliottii Englem.) since the 1970s had significantly more Chinese tallow stems than stands that remained forested since 1939 and conclude that past and contemporary land-use practices facilitated the invasion of Chinese tallow in disturbed stands by allowing a window of opportunity for establishment, followed by further spread with increased propagule supply. I investigated the potential of white-tailed deer (Odocoileus virginianus) as a highly abundant, non-native seed disperser, particularly its role in dispersing Chinese tallow seeds within forest stands. I found that while white-tailed deer did not disperse the seeds of Chinese tallow in this study, they were dispersing the seeds of other small-seeded non-native plants. To determine the most effective management option for the control of Chinese tallow and the restoration of the native community, I tested several integrated management options: herbicide (H); herbicide and fire (HF); mastication and herbicide (MH); and mastication, herbicide, and fire combined (MHF). Overall, I found that MHF was the most effective at reducing Chinese tallow density, without having a significant increase in Chinese tallow regeneration, when compared to all other treatment types. MHF also resulted in a positive response from the community by reducing midstory density of yaupon (Ilex vomitoria Aiton), and southern waxmyrtle (Morella cerifera (L.) Small), promoting desired oak (Quercus sp.) species, and increasing ground flora richness. Results from my work show that while land-use history and modern forestry practices increase the establishment of Chinese tallow, an ecologically-based integrated management approach aimed to restore the historic stand structure and fire regime may effectively control Chinese tallow and increase community resistance