Publications [#356964] of A. Brad Murray
Papers Published
- Dong, X; Murray, AB; Heffernan, JB, Competition Among Limestone Depressions Leads to Self-Organized Regular Patterning on a Flat Landscape,
Journal of Geophysical Research: Earth Surface, vol. 126 no. 5
(May, 2021) [doi]
(last updated on 2023/06/01)Abstract:
Self-organized pattern formation is widespread and functionally significant. Scale-dependent feedback in space (short-distance positive feedback coupled with long-distance negative feedback) has been embraced as an arguably universal mechanism of ecological self-organization. Recently, intraspecific territorial competition has been proposed as a complementary mechanism contributing to spatial self-organization in ecology. In geomorphology, regular patterning is also widespread and has often been attributed to competition among geomorphic features. This mechanism has never been integrated into the framework of ecological pattern formation. Using the regularly patterned landscape of Big Cypress National Preserve in South Florida as a case study, we formalize a third mechanism of spatial self-organization: competition among pattern elements of finite amplitude stabilized by scale-dependent feedback in time. Depressions first accelerate their expansion rate via the positive feedback between depression volume and weathering rate. Later negative feedbacks become stronger, and eventually stabilize the size of depressions. While scale-dependent feedback in time provides a mechanism to stabilize individual depressions, it is the competition among depressions that induces spatial regularity. A relatively smaller depression could have a greater expansion rate than larger ones in its development. Higher weathering rate on the side of a divide toward the smaller depression causes migration of the divide to the larger depression. Consequently, the smaller depression expands its catchment area while the catchment area of the neighboring larger depression contracts, resulting in depressions achieving similar size and distance from each other. The diversity of regular patterns dictates the need to integrate perspectives from multiple disciplines.