Source height and contact with terrestrial soil drive transplanted epiphyte performance
Source height and contact with terrestrial soil drive transplanted epiphyte performance
复制标题
DOI：
10.1111/1365-2745.14187
复制
发表时间：
2023-09
影响因子：
5.5
通讯作者：
M. Spicer;Josué Ortega
中科院分区：
文献类型：
--
作者：
M. Spicer;Josué Ortega
附生植物的特征是它们在没有与地面的根连接的情况下存活的能力，但这种独特的空中生长习性的许多基本生活史特征和生态权衡在很大程度上仍未确定。死亡原因尚不清楚，但从寄主树上坠落已被认为是真菌死亡和群落动态的主要原因。几乎没有经验证据来解释为什么附生植物在被迫变成陆地时不能存活，也没有什么研究将附生植物移植到高森林和低森林地层之间，以测试在树冠环境中茁壮成长和在森林林下生存之间的权衡。在这里，我们通过实验测试了两个关于巴拿马中部云雾森林中真菌死亡的驱动因素的假设。我们测试了与陆地土壤的简单接触是否对附生植物有害，初步测试了附生植物敌人逃逸假说，并检验了垂直生态位分化假说，即附生植物专门适应垂直森林地层中的微生境。通过对270株移栽附生植物的存活、落叶和健康状况进行一年半的监测，我们准确地确定了土壤接触和起源高度对附生植物表现的影响程度。我们发现，与陆地土壤本身的接触对原位附生植物是有害的，提供了一些第一批经验数据，解释了为什么坠落到地面上，而不是落入林下，对附生植物特别致命。然而，我们也发现，不同的分类群和最初来自不同高度地层的附生植物之间的死亡率有很大的差异。综合。适应树冠的植物在与陆地土壤接触时会经历更高的死亡率。后续研究应该探索陆地土壤微生物的作用和生理限制，作为降低地面附生植物存活率的潜在驱动因素。
Epiphytes are characterized by their ability to survive without a root connection to the ground, but many basic life‐history traits and ecological trade‐offs of this unique aerial growth habit remain largely uncharacterized. Mortality causes are still not well understood, but falling from the host tree has been suggested as a leading cause of epiphyte mortality and community dynamics. Little empirical evidence exists for why epiphytes do not survive when forced to become terrestrial, and few studies exist that transplant epiphytes between high‐ and low‐forest strata to test trade‐offs between thriving in canopy environments and survival in the forest understorey. Here, we experimentally test two hypotheses regarding the drivers of epiphyte mortality in a cloud forest of central Panama. We test whether simple contact with terrestrial soil is deleterious to epiphytes, preliminarily testing the epiphyte enemy escape hypothesis, and test the vertical niche differentiation hypothesis, wherein epiphytes are specifically adapted for microsites throughout the vertical forest strata. By monitoring survival, leaf loss and health status of 270 transplanted epiphytes for a year and a half, we pinpoint the extent to which soil contact and height of origin regulate epiphyte performance. We found that contact with terrestrial soil itself was detrimental to epiphytes in situ, providing some of the first empirical data to explain why falling onto the ground, versus falling into the understorey, is particularly fatal to epiphytes. However, we also found that mortality rates vary substantially among taxonomic groups and among epiphytes that originally came from different height strata. Synthesis. Plants that are adapted for the canopy experience a trade‐off with higher mortality when in contact with terrestrial soil. Follow‐up studies should explore the role of terrestrial soil microbes and physiological constraints as potential drivers of decreased grounded epiphyte survival.