Ruetz W F
Botanisches Institut II der Universität Würzburg, Wurzburg, Germany.
Bayerische Landesanstalt für Forstliche Saat- und Pflanzenzucht, Forstamtsplatz, D-8221, Teisendorf, Federal Republic of Germany.
Oecologia. 1973 Sep;13(3):247-269. doi: 10.1007/BF00360515.
Completely climatized cuvettes were used to follow the CO gas exchange of red fescue (Festuca rubra L.), growing on a fertilized and an unfertilized plot, during a growing season from May through October. Objective of the study was to determine the effect of environmental factors on the seasonal CO gas exchange.Gas exchange rates were calculated on the basis of leaf dry weight, surface area and chlorophyll content. Photosynthetic rates differed between the fertilized and unfertilized plants when based on leaf dry weight or leaf surface area but were similar when based on chlorophyll.Multiple regression analysis was used to related photosynthetic rates to radiation, temperature, water vapor concentration difference, chlorophyll content and time. A cubic regression equation based on daily radiation alone explained 85% of the variation for the fertilized plants and 87% of the variation for the unfertilized plants.During the growing season the unfertilized plants had a continual decline in their photosynthetic rates. The fertilized plants had high photosynthetic rates in the spring and in the fall.Light response curves indicated greater photosynthetic rates at light saturation as well as in the light limited portion of the light response curve for the fertilized plants. Photosynthetic rates of the fertilized plants were generally depressed during periods of warm temperature and high light intensity in June and July.Photosynthetic rates declined at temperatures above 24°C. The decline was greater for the more mesomorphic fertilized plants. A similar response was noted to increasing water vapor difference, although it was difficult to separate from the temperature effect. Maximum photosynthetic rates were found between 14°C and 22°C, although there was considerable variation in the maximum rates.The effects of cutting (mowing) on the gas exchange were difficult to determine due to the interaction of the environmental factors.Chlorophyll content showed significant correlation with photosynthetic rates.
在5月至10月的生长季节，使用完全控温的比色皿跟踪生长在施肥地块和未施肥地块上的紫羊茅（Festuca rubra L.）的一氧化碳气体交换情况。该研究的目的是确定环境因素对季节性一氧化碳气体交换的影响。气体交换率是根据叶片干重、表面积和叶绿素含量计算得出的。基于叶片干重或叶片表面积时，施肥和未施肥植株的光合速率有所不同，但基于叶绿素时则相似。采用多元回归分析将光合速率与辐射、温度、水汽浓度差、叶绿素含量和时间联系起来。仅基于每日辐射的三次回归方程解释了施肥植株85%的变异和未施肥植株87%的变异。在生长季节，未施肥植株的光合速率持续下降。施肥植株在春季和秋季具有较高的光合速率。光响应曲线表明，施肥植株在光饱和以及光响应曲线的光限制部分具有更高的光合速率。施肥植株的光合速率在6月和7月温暖温度和高光强时期通常会受到抑制。光合速率在温度高于24°C时下降。对于更中生的施肥植株，下降幅度更大。尽管难以将其与温度效应区分开来，但对增加的水汽差异也观察到了类似的响应。最大光合速率出现在14°C至22°C之间，尽管最大速率存在相当大的差异。由于环境因素的相互作用，切割（修剪）对气体交换的影响难以确定。叶绿素含量与光合速率显示出显著相关性。
