Evans Jonathan P, Meckstroth Shelby, Garai Julie
Department of Biology, University of the South, Sewanee, TN 37383, USA.
Department of Mathematics and Computer Science, University of the South, Sewanee, TN 37383, USA.
Plants (Basel). 2023 Feb 6;12(4):724. doi: 10.3390/plants12040724.
Rhizomatous growth and associated physiological integration can allow a clonal dune species to potentially compensate for the selective removal of leaves associated with herbivory. is a rhizomatous clonal plant species that is abundant in the coastal dune environments of the southeastern United States that are inhabited by large feral horse populations. has been shown to integrate resources among ramets within extensive clones as an adaptation to resource heterogeneity in sandy soils. In this study, we hypothesized that clonal integration is a mechanism that promotes persistence in these communities, despite high levels of herbivory by feral horses. In a field experiment, we used exclosures to test for herbivory in over a four-month period. We found that feral horses utilized as a food species, and that while grazing will suppress clonal biomass, is able to maintain populations in a high grazing regime with and without competition present. We then conducted an experiment in which portions of clones were clipped to simulate different levels of grazing. Half of the clones were severed to eliminate the possibility of integration. We found that after 12 weeks, the mean number of leaves and ramets increased as the grazing level increased, for integrated clones. Integrated clones had significantly increased biomass production compared to the severed equivalents. Our research suggests that rhizomatous growth and physiological integration are traits that allow clonal plant species to maintain populations and to tolerate grazing in coastal dune environments.
根状茎生长及相关的生理整合能使一种克隆性沙丘物种有可能补偿因食草作用导致的叶片选择性去除。[物种名称]是一种根状茎克隆植物物种，在美国东南部沿海沙丘环境中大量存在，那里有大量野生马群栖息。研究表明，[物种名称]能在广泛的克隆体内的分株间整合资源，以适应沙质土壤中的资源异质性。在本研究中，我们假设克隆整合是一种机制，能促进[物种名称]在这些群落中持续存在，尽管野生马的食草水平很高。在一项田间试验中，我们使用围栏在四个月的时间里测试了[物种名称]的食草情况。我们发现野生马将[物种名称]作为食物来源，并且虽然放牧会抑制克隆生物量，但[物种名称]在有或没有竞争的高放牧强度下都能够维持种群数量。然后我们进行了一项实验，在实验中对[物种名称]克隆体的部分进行修剪以模拟不同程度的放牧。一半的克隆体被切断以消除整合的可能性。我们发现12周后，对于整合的克隆体，随着放牧水平的增加，叶片和分株的平均数量增加。与切断的克隆体相比，整合的克隆体生物量产量显著增加。我们的研究表明，根状茎生长和生理整合是使克隆植物物种在沿海沙丘环境中维持种群数量并耐受放牧的特性。
