Biophysical Modeling of Mangrove Seedling Establishment and Survival Across an Elevation Gradient With Forest Zones

Mangrove forest development critically depends on the establishment and survival of seedlings. Mechanistic insights into how water levels, waves and bed level dynamics influence the establishment process of individual mangrove seedlings are increasing. However, little is known about how spatial and temporal changes in water levels, waves and bed level dynamics across elevation gradients in mangrove forests facilitate/limit seedling dynamics. For this study, a new seedling establishment and growth model was integrated into a process-based hydrodynamic and morphodynamic numerical model. This biophysical model was applied to a fringing mangrove forest located in the southern Firth of Thames, Aotearoa, New Zealand. This study quantifies the increasing establishment density and survival probability of mangrove seedlings from the lower-elevated unvegetated intertidal flat toward the higher-elevated mature mangrove forest. Three cross-shore zones with distinctive seedling dynamics were identified: (a) a zone with daily tidal inundation where seedling dynamics are episodic and limited by the dispersal of individual propagules that rapidly anchor to the substrate by root growth, (b) a zone with daily to bi-weekly tidal inundation where seedling dynamics respond to variations in spring-neap tidal cycles and, (c) a zone with less than bi-weekly inundation where seedling dynamics are governed by high propagule supply and seedling survival probability. The seedling establishment density and survival probability are dominated by annual extremes in tidal hydroperiod and bed shear stresses, respectively. The obtained parameterizations can be used to incorporate seedling dynamics in decadal-timescale mangrove forest development models that are instrumental for mangrove management and restoration

Designing digital vertigo experiences

Many people enjoy “vertigo” sensations caused by intense playful bodily activities; examples of such activities include spinning in circles, riding fairground rides, and driving fast cars. Game scholar Caillois calls the associated experiences “vertigo play”, elucidating that these enjoyable activities are a result of confusion between sensory channels. In Human-Computer Interaction (HCI), designers often attempt to avoid causing sensory confusion as it can be associated with a negative user experience. I believe this has led to a lack of understanding surrounding how to transition and extend Caillois' thinking from analogue games and play to the digital realm. However, with more digital games focusing on the body through technologies such as motion sensors and head mounted displays, an opportunity to understand how to design digital vertigo games has arisen. Understanding this will allow designers to create novel and intriguing digital bodily experiences inspired by traditional vertigo play activities. This thesis explores this opportunity by answering the research question: “How do we design digital vertigo experiences?” I developed and studied three different experiences to answer this research question. The first game, “Inner Disturbance”, is a single player game where sensory confusion is facilitated by manipulating a player's vestibular sense of balance through Galvanic Vestibular Stimulation (GVS). The second game, “Balance Ninja”, uses GVS to extend sensory confusion across two players through a feedback loop, whereby the lateral movements of each player affects the GVS system of the opposing player. In the final game, “AR Fighter”, Head Mounted Displays confuse players’ visual sense as a result of the opposing player's movements. Studies of the player experience of the three games led to the development of the Digital Vertigo Experience Framework. This framework, which presents designers with the first understanding of how to design digital vertigo experiences, contains two axes: amount of surrendered body agency, and extent of facilitated sensory confusion. The framework is split into four digital vertigo user experience areas: more daring, more overwhelming, more predictable, and more nauseating. Designers are encouraged to stay within these areas to avoid causing one of four possible risks to players: risk of physical injury, sensory overload, boredom, and nausea. With this work, I aim to bring the excitement of traditional vertigo play experiences to the digital world, guiding designers in their creation. Offering an increased understanding of digital vertigo play experiences will allow designers to create more engaging and exciting body-based games, and provide players with more possibilities to enjoy novel and exciting bodily-play experiences

Designing interactive technology for skateboarding

Interactive technology is increasingly used to support physical activities. However, there is limited knowledge about how interactive technology should be designed to support trick-focused experiences such as skateboarding. We developed Copy Paste Skate, a novel multimodal feedback system, and studied its use by 21 avid skateboarders to explore the design of interactive technology for skateboarding. Based on observations and interviews we articulate two key design dimensions that highlight how designing for skateboarding means supporting execution quality of tricks as well as supporting the trick originality. We also present 4 design strategies to help designers support both dimensions in one integrated design. Our work extends designers' knowledge about how to design interactive technology for skateboarding, ultimately extending our understanding of how interactive technology can support people being physically active