Heather E. Schneider, Sean A. Carson, Santa Barbara Botanic Garden
Documenting the abundance and distribution of rare plants is a critical first step in the the conservation of wild populations. The methods used to map plants on the landscape have changed dramatically over time. Biologists have progressed from providing locality descriptions and marking plant locations on maps by hand, to using handheld GPS units, to the modern-day use of tablets and smart phones. Depending on the goals of a project, plants may be mapped using points, polygons and lines, or sometimes a combination of features, with varying degrees of accuracy. All of these variables can make it difficult to compare population dynamics over time. How can we determine wither a population really expanded or contracted, versus when it appears that way based on discrepancies in mapping technique or GPS accuracy? In an attempt to standardize rare plant mapping efforts on the Channel Islands, the Santa Barbara Botanic Garden worked with a group of collaborators to adapt and implement mapping protocols developed by Wildlands Conservation Science using ESRI’s Collector Application and a static spatial grid system. In 2019, we mapped the endangered Santa Cruz Island Dudleya (Dudleya nesiotica) using the protocols that we developed. Our results suggest that the abundance and extent of Santa Cruz Island Dudleya has increased since the last mapping effort in 2006, but we also laid the groundwork for more accurate comparisons in the future. The data generated using this method allow surveyors to map rare plants using consistent protocols that will improve the accuracy of comparisons of spatial distribution and abundance over time. While we are still fine-tuning our protocols and perfecting our methodology, this represents a significant step in improving data collection and analysis for rare plant surveys and monitoring.