Foliar water uptake by coastal wetland plants: A novel water acquisition mechanism in arid and humid subtropical mangroves
Foliar water uptake by coastal wetland plants: A novel water acquisition mechanism in arid and humid subtropical mangroves
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DOI：
10.1111/1365-2745.13398
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发表时间：
2020-05-15
影响因子：
5.5
通讯作者：
Cavanaugh, Kyle C.
中科院分区：
文献类型：
--
作者：
Hayes, Matthew A.;Chapman, Samantha;Cavanaugh, Kyle C.
气候变化改变了许多生态系统中的淡水可用性，导致许多植物的分布发生变化。尽管红树林只生活在潮间带的盐水环境中，但它依靠非盐水来维持植物的生产力。然而，若干红树林物种在干旱环境中持续存在，因为来自雨水和地下水源的非盐水有限。在这些条件下，叶片从雾和薄雾中吸收水分可能是一种重要的水分获取策略。我们在墨西哥干旱的南下加利福尼亚进行了田间试验，沿着进行了受控雾室试验（使用来自美国佛罗里达湿润亚热带地区的幼苗）表明，新热带区的三种共存的红树林物种，即白骨壤、总状兔尾草和红树林，干旱和湿润环境下生长的紫茎泽兰叶片都能吸收凝结在叶片上的水分，紫茎泽兰叶片吸水量最大。germinans和R. mangle，可能反映了与物种特定的水平衡策略相关的叶性状。在田间喷雾试验中，刺槐叶片吸水的贡献较大。germinans（32 ± 2%）比L. racemosa（26 ± 2%）和R. mangle（16 +/- 1%）。叶片吸水量也因地而异。racemosa和R. mangle，在南下加利福尼亚两个物种的北方范围限制吸收下降，这表明干旱区红树林的分布格局可能受到物种特定的空间变异叶用水。在物种内，叶面水的使用是可比的跨领域和控制实验，无论源人口（南下加利福尼亚与佛罗里达），这表明叶面水的吸收不是干旱区的适应，而是作为一种补充水平衡策略，在干旱和潮湿的新热带红树林。我们的研究结果表明，红树林有可能通过它们的叶子获得大气水分，如雨水，露水和海雾，以弥补土壤水分不足。在这三个新热带红树林物种的叶面水分利用的变化可能会影响红树林物种分布在干旱区和假干旱（高盐）的环境，与红树林对气候变化的反应的影响。
Climate change alters freshwater availability in many ecosystems leading to shifts in distributions for many plants. Despite living exclusively in intertidal, saline environments, mangroves rely on non-saline water to maintain plant productivity. However, several mangrove species persist in arid environments where non-saline water from rain and groundwater sources are limited. Under these conditions, foliar water uptake from fog and mist may be an important water acquisition strategy.We conducted a field experiment in arid Baja California Sur, Mexico along with a controlled mist chamber experiment (using seedlings sourced from humid subtropical region, Florida, USA) to show that three co-occurring, neotropical mangrove species, Avicennia germinans, Laguncularia racemosa and Rhizophora mangle, growing in both arid and humid environments can access water condensed on their leaves.Foliar water uptake was greatest in A. germinans and lowest in R. mangle, possibly reflecting leaf traits associated with species-specific water balance strategies. In our field misting experiment, the contribution of foliar water uptake was higher in A. germinans (32 +/- 2%) than L. racemosa (26 +/- 2%) and R. mangle (16 +/- 1%). Foliar water uptake also varied across locations for L. racemosa and R. mangle, with declining uptake towards both species' northern range limits in Baja California Sur, suggesting the distribution patterns of arid-zone mangroves may be affected by species-specific spatial variation in foliar water use. Within species, foliar water use was comparable across field and controlled experiments irrespective of source population (Baja California Sur vs. Florida), suggesting foliar water uptake is not an arid-zone adaptation, and is instead used as a supplemental water balance strategy in arid and humid neotropical mangroves.Synthesis. Our findings indicate mangroves have the potential to access atmospheric water, such as rain, dew and sea fog, through their leaves to offset soil water deficits. Variation in foliar water use across these three neotropical mangrove species may influence mangrove species distributions across arid-zone and pseudo-drought (highly saline) environments, with implications for mangrove response to climate change.