Abstract

The content of chlorophylls (Сhl) a and b and carotenoids (Сar) during the growing season was studied in the leaves of 31 species of steppe and forest plants. In contrast to forest plants, steppe plants possessed less chlorophylls and carotenoids per leaf mass (2 and 1.5 times, respectively), a low Сhl/Сar ratio, a greater (1.5 times) content of carotenoids per leaf area, and a high Сhl a/b ratio. In spite of the low chlorophyll content per leaf mass in steppe plants, their content per leaf area was similar to forest species (3–4 mg/dm²) owing to their thicker and denser leaves. This suggests that the plants of steppe and forest communities have the same potential ability to intercept solar energy in this locality. In the period of active vegetation (mid-June -early August), parameters of the pigment complex were stable both in steppe and forest communities. However, steppe plants demonstrated the modified in content of Car and Сhl b, as well as Сhl/Сar and Chl a/b ratios, in the beginning and at the end of the season that indicated a reorganization of the light-harvesting complex. Intraspecific variation of parameters during the season was two or three times lower than interspecific. High interspecific variation in forest plants were achieved due to the presence of species with thick long-lived leaves. It was concluded that the chlorophyll content per leaf area reflects the adaptation of plants to climatic conditions of the geographic region, whereas pigment contents per leaf mass shows adaptation to local irradiation in plant community (forest or steppe).

中文翻译：

---

物种和群落水平下草原和森林植物叶片中叶绿素和类胡萝卜素含量的季节动态

摘要

在31种草原和森林植物的叶片中，研究了生长期中叶绿素a和b以及类胡萝卜素ar的含量。相比于森林植物，草原植物具有更少的叶绿素和每片叶子质量类胡萝卜素（2倍和1.5倍，分别地），低Сhl/Сar比，单位叶面积的类胡萝卜素的更大（1.5倍）的含量，和高的Сhl一个/ b比率。尽管草原植物每叶质量的叶绿素含量低，但每叶面积的叶绿素含量却与森林物种相似（3-4 mg / dm ²），因为它们的叶子更厚更密。这表明该地区的草原和森林群落植物具有相同的潜在拦截太阳能的能力。在活跃的植被时期（6月中旬至8月上旬），色素复合物的参数在草原和森林群落中均保持稳定。然而，草原植物表现出的修改Car和Сhl的含量b，以及Сhl/Сar和叶绿素一个/ b比率，在季节的开始和结束时表明采光区已重新组织。季节内参数的种内变化比种间低2到3倍。由于存在具有长寿命长叶片的物种，因此在森林植物中实现了较高的种间变异。结论是，每叶面积的叶绿素含量反映了植物对地理区域气候条件的适应性，而每叶质量的色素含量表明对植物群落（森林或草原）的局部辐射适应。