Photosynthesis and Respiration of Forest and Alpine Populations of Polytrichum juniperinum
Photosynthesis and Respiration of Forest and Alpine Populations of Polytrichum juniperinum
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森林和高山杜松种群的光合作用和呼吸作用
DOI：
10.2307/3241495
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
R. Jagels
中科院分区：
文献类型：
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作者：
F. Bazzaz;D. Paolillo;R. Jagels
测定了高寒和森林种群的表观光合作用随光照强度、温度和CO浓度的变化规律。森林种群在较低光强下表现出光饱和，在较高温度下维持表观光合作用，对CO浓度升高的响应大于高山种群。高山植物的叶绿叶边缘比森林植物的叶绿叶边缘大得不成比例。生理和形态上的差异可以解释为对高山种群和森林种群各自栖息地的适应。苔藓Polytrichum iuniperinum Hedw。是一种在北美广泛分布的物种。它占据了不同的栖息地，从高山地带，例如在新英格兰山脉，到相当干燥的沙质土壤上的灌木橡树林。如此广泛的物种可能由生态上不同的种族组成，这些种族在遗传上适应了它们的环境，或者它们可能具有广泛的耐受性限制，使它们能够在各种环境条件下茁壮成长。在显像上，这两种情况都会发生，并且有很好的记录。在苔藓植物中，对生态型分化的研究是有限的。Tallis（1959）报道lanuginosum的形态随地点的变化而变化，生长速率随海拔的变化而变化，80 m处最高，720 m处最低。Forman（1964）发现，透明四叶的叶片形态随温度的变化而变化，在较低的温度下，叶片相对于长度的宽度更宽。在另一项研究中（福尔曼，1968年），他发现苔藓的热值与它们生长的海拔高度成反比。来自华盛顿山高寒地区的刺柏多毛（Polytrichum juniperinum）在研究的高山苔藓中值最低（3951 cal）。还有其他报告表明，一些苔藓植物由于其广泛的耐受性而能够占据不同的栖息地。例如，Rastorfer和Higinbotham（1968）表明，在很宽的温度和光强范围内，桑氏Bryum sandbergii具有净光合作用的能力。根据其广泛的耐受性，他们解释了它在太平洋西北山间地区所有植被带中的存在。Szweykowski和Vogel（1966）发现，在两个完全不同的地点采集的地萼（Geocalyx graveolens）种群。这项研究是在伊利诺伊大学厄巴纳分校植物系进行的。这项工作的部分支持由NSF GB-6520提供。我们也感谢J. S. Boyer博士，他提供了供我们使用的气体分析仪。2伊利诺伊大学植物系，伊利诺伊厄巴纳61801；3康奈尔大学遗传、发育和生理学部，纽约伊萨卡14850。4佛蒙特大学植物系，佛蒙特州伯灵顿05401；在相同的环境条件下，苔藓学家[卷73]的栖息地没有明显的形态差异。本文研究了两个不同生境的刺柏种群，测量了它们在不同温度、光照强度和二氧化碳浓度下的CO2交换模式。此外，还研究了叶片形态和膨胀运动，以阐明与环境的可能关系
Apparent photosynthesis was measured as a function of light intensity, temperature, and CO, concentration in alpine and forest populations of Polytrichum juniperinum Hedw. The forest population showed light saturation at lower light intensities, sustained apparent photosynthesis at higher temperatures, and showed a greater response to elevated CO, concentration than did the alpine population. The achlorophyllous margins of the leaves in the alpine plants are disproportionately large compared to those in forest plants. The differences in physiology and morphology can be interpreted as adaptations to the respective habitats of alpine and forest populations. The moss Polytrichum iuniperinum Hedw. is a widely distributed species in North America. It occupies diverse habitats ranging from the alpine zone, e.g. in the New England mountains, to fairly dry scrub oak forests on sandy soils. Species of such a wide range may consist of ecologically distinct races genetically adapted to their environments or they may possess wide tolerance limits that allow them to thrive under various environmental conditions. In phanerogams both conditions occur and are very well documented. In the bryophytes, studies on ecotypic differentiation are limited. Tallis (1959) reported that Rhacoamitrium lanuginosum has variable morphology according to the site variation, and that growth rates vary with altitude, being highest at 80 m and lowest at 720 m. Forman (1964) found that leaf morphology of Tetraphis pellucida varies with temperature, being wider relative to its length at lower temperatures. In another study (Forman, 1968) he found that there was an inverse correlation in caloric values of mosses with the altitudes at which they grow. Polytrichum juniperinum from the alpine zone of Mt. Washington gave the lowest value (3951 cal) of the alpine mosses studied. There are other reports indicating that some bryophytes are able to occupy diverse habitats because of their wide tolerances. For example, Rastorfer and Higinbotham (1968) showed that Bryum sandbergii has the capacity of net photosynthesis over a wide range of temperatures and light intensities. They explain its presence in all vegetation zones of the Pacific Northwest intermountain area on the basis of its wide tolerances. Szweykowski and Vogel (1966) found that populations of Geocalyx graveolens collected at two totally different 1 This study was performed at the Department of Botany, University of Illinois, Urbana. Support for the work was furnished in part by NSF GB-6520. We also acknowledge Dr. J. S. Boyer, who furnished the gas analyzer for our use. 2 Department of Botany, University of Illinois, Urbana, Illinois 61801. 3 Section of Genetics, Development, and Physiology, Cornell University, Ithaca, New York 14850. 4 Department of Botany, University of Vermont, Burlington, Vermont 05401. This content downloaded from 157.55.39.177 on Sat, 19 Nov 2016 04:38:54 UTC All use subject to http://about.jstor.org/terms 580 THE BRYOLOGIST [Volume 73 habitats showed no significant morphological differences when grown under the same environmental conditions. For this paper we studied two populations of P. juniperinum from contrasting habitats, measuring their patterns of CO2 exchange at various temperatures, light intensities, and carbon dioxide concentrations. In addition leaf morphology and turgor movements were studied to elucidate possible relationships with the environ-