Ecophysiological performance of the rare terrestrial orchid Platanthera integrilabia across contrasting habitats
Ecophysiological performance of the rare terrestrial orchid Platanthera integrilabia across contrasting habitats
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DOI：
10.1007/s11258-016-0653-2
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发表时间：
2016-10-01
期刊：
影响因子：
1.7
通讯作者：
Pistrang, Mark J.
中科院分区：
文献类型：
--
作者：
Boyd, Jennifer N.;Raymond, Gregory A.;Pistrang, Mark J.
Platanthera integrilabia是一种罕见的陆生兰花，通常与美国东南部的半开放森林湿地有关。有人认为，可整合假单胞菌对非生物资源的需求具有限制性；然而，尽管这些要求在物种保护中具有潜在的应用价值，但尚未得到深入的研究。研究了光照和土壤水分对景观尺度和局地尺度上的可积蓬的影响，以及不同冠层开度对可积蓬种群和生物水平的影响。我们还评估了叶片对光和土壤湿度的生理反应，以反映生境适宜性和影响性能的潜力。在景观尺度上，光照和土壤水分与可积假的密度和个体大小无关。在不同地点，光合光响应和水分利用效率的测量表明，在不同的光和土壤湿度环境下，可整合草的光合效率和能量增益最大化。这些措施与站点内的非生物变化之间的最小关联表明，在小空间和/或时间尺度上进行调整的能力可能有限。保护与可存活的可整合木相关的现有栖息地是有必要的，但该物种的叶级生态生理表明，其栖息地适宜性也可能包括更开阔和更干燥的地方。对于在最近受到干扰的生境中经历下降的可积木种群，我们建议对冠层覆盖度进行良好管理的修改可能是有益的。
Platanthera integrilabia is a rare terrestrial orchid species generally associated with semiopen forested wetlands in the southeastern US. It has been suggested that P. integrilabia has restrictive abiotic resource requirements; however, these requirements have not been implicitly studied despite their potential application to species conservation. We investigated the influence of light and soil moisture on P. integrilabia at landscape and local scales and population and organismal levels across and within four occurrences with contrasting canopy openness. We also evaluated the potential for leaf-level physiological responses to light and soil moisture to reflect habitat suitability and influence performance. At landscape scales, light and soil moisture were not associated with P. integrilabia density or individual size. Across sites, measures of photosynthetic light response and water-use efficiency indicated that P. integrilabia can maximize photosynthetic efficiency and energy gain in contrasting light and soil moisture environments. Minimal associations of these measures with abiotic variations within sites suggested that the capacity for adjustments across small spatial and/or temporal scales may be limited. Preservation of existing habitats associated with viable P. integrilabia occurrences is warranted, but the leaf-level ecophysiology of this species indicates that its habitat suitability also could include more open and drier sites. For populations of P. integrilabia experiencing declines in habitats with recent disturbance, we suggest the possibility that well-managed modifications to canopy cover may be beneficial.