R code for the analysis of Lilaeopsis schaffneriana var. recurva drought ecology research.


This repo accompanies a manuscript submitted to PeerJ and PeerJ Preprints on 29 Dec 2016.

Title: Water (or the Lack Thereof), Management, and Conservation of an Endangered Desert Wetland Obligate, Lilaeopsis schaffneriana var. recurva

Abstract: Huachuca water umbel, Lilaeopsis schaffneriana var. recurva, is a federally endangered desert wetland plant restricted to southeastern Arizona, USA, and adjacent portions of Mexico.  Very little is known about the factors that influence the species presence, absence, and abundance, including the effects of wetland drying caused by drought or water withdrawals.  We conducted three lines of research to address the lack of information about the species’ ecology using observational field research and controlled experiments.  First, we examined ecological correlates of the species presence and absence along a perennial stream in Southeast Arizona where the species has been established for over a decade.  Next, we used a full-factorial experiment to examine the species’ drought resistance and drought resilience.  Last, we monitored transplanting efforts of the species along the upper Rio Yaqui.  We found that distance to the nearest water umbel patch centroid—a measure of historical factors—and distance to surface water were the best predictors of the species’ presence and leaf density.  The drought experiments demonstrated that leaf density is an important factor influencing both resistance and resilience: low leaf-density was associated with replicates reaching critical conditions approximately one full day before high leaf-density plants, and high leaf-density plants rebounded at nearly twice the rate of low-density plants when water became available.  Transplants appeared to be most successful in areas where water levels remained relatively constant, herbaceous-layer competitors were rare, and water velocity was low.  These results indicate that protecting existing populations by ensuring stable water sources is the most important action for conserving the species in current locations and future transplant locations.


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jacob-ogre/LilaeopsisDrought documentation built on May 18, 2019, 8 a.m.