The effect of substrate abundance in the vertical stratification of bromeliad epiphytes in a tropical dry forest (Mexico)
The effect of substrate abundance in the vertical stratification of bromeliad epiphytes in a tropical dry forest (Mexico)
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DOI：
10.1016/j.flora.2014.06.003
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发表时间：
2014-01-01
期刊：
影响因子：
1.9
通讯作者：
Flores-Palacios, Alejandro
中科院分区：
文献类型：
--
作者：
Pablo Ruiz-Cordova, Juan;Hugo Toledo-Hernandez, Victor;Flores-Palacios, Alejandro
附生植物的多样性与生态位分区，通过垂直层和主机的喜好。然而，丰富的主机提供的基板之间的垂直地层不同，误导，如果附生植物喜欢一个层或随机分布。在墨西哥中部的圣安德烈斯德拉卡尔莫雷洛斯的热带干燥森林中，我们测试了零假设，即附生植物遵循丰富的基板，而不是表现出偏好的一个特定的垂直层，并测试是否小气候变量，种子萌发和幼苗存活与观察到的附生植物分布相匹配。我们的数据表明，附生植物可以随机分布在一些主机内，但在一些主机物种，某些结构提出了无论是赤字或过剩的所有，大气，或坦克附生植物。在寄主树中，附生植物的分布偏向于上层，而下层则缺乏。在多花山椒、山乌桕和少花牵牛中，附生植物的分布偏向下层。垂直梯度的光，种子萌发和幼苗存活一般不匹配的附生植物分布，并不支持的概念，即小气候梯度管辖的附生植物的垂直分布。我们的数据表明，垂直分布的附生植物在这样的热带干旱森林主要是由分布的结构，这显然影响种子的分散和分支机构的寿命，这使得浓度的附生植物在地层中，优化种子捕获和附生植物的克隆生长。(C)2014 Elsevier GmbH. All rights reserved.
Diversity of epiphytes is associated with niche partitioning, through vertical strata and host preferences. However, abundance of substrate offered by hosts differs between vertical strata, misleading if epiphytes prefer a stratum or are randomly distributed. In a tropical dry forest of San Andres de la Cal Morelos, central Mexico, we tested the null hypothesis, that epiphytes follow the abundance of the substrate, rather than showing preference for a particular vertical stratum, and tested whether microclimatic variables, seed germination and seedling survival match with observed epiphyte distribution. Our data show that epiphytes could be randomly distributed inside some host; but in some host species, certain structures presented either a deficit or an excess of all, atmospheric, or tank epiphytes. In the hosts Bursera copallifera and Bursera glabrifolia, distribution of epiphytes was biased towards the upper strata, with a deficit of epiphytes in the lower strata. In Conzattia multiflora, Sapium macrocarpum and Ipomoea pauciflora, epiphyte distribution was biased towards the lower strata. Vertical gradation of light, seed germination and seedling survival did not generally match with epiphyte distribution and did not support the notion that the microclimatic gradient governs the vertical distribution of epiphytes. Our data indicate that vertical distribution of epiphytes in such tropical dry forests is mainly driven by the distribution of the structures, which apparently influence dispersion of the seeds and by the lifespan of branches, which allow the concentration of epiphytes in the stratum that optimizes seed capture and the clonal growth of epiphytes. (C) 2014 Elsevier GmbH. All rights reserved.