Abstract

The demographic structure of 39 coenopopulations of Tulipa suaveolens Roth in the Lower Volga region was studied. It has been shown that they occupy an area from 0.01 to 20 000 ha or more. Small-area populations grow mainly closer to the northern border of the species range. The density of all individuals (1.6–240.7 PCs/m²) and the number of generative plants (0.1–58.2 PCs/m²) at the interpopulation level varied over a wide range, changing significantly over the years mainly in the populations exposed to recreational load or grazing. The percentage of generative individuals ranged from 2 to 96%. In the years 2013–2016 there was a significant negative correlation between the geographical latitude corresponding to the place of growth of a coenopopulation and the proportion of plants of the generative state therein. On the contrary, in the years 2017–2018 in the southern and western parts surveyed of the habitat the plants of the pregenerative period prevailed, while the share of flowering plants significantly decreased. The observed dynamics correlates well with the weather conditions of the growing season of tulips. In the period 2013–2016, in the southern part of the territory studied, arid conditions were formed just in the spring and seedlings fell out at an early stage of their development. The spring periods of 2017 and 2018 were wetter, and seedlings successfully passed through the early stages of ontogenesis. Thus, cyclical fluctuations of weather conditions significantly affect the demographic structure of the T. suaveolens coenopopulations. Accordingly, the contribution of different years to the renewal of populations is different. The populations in the southern regions maintain a high number of individuals and occupy larger areas mainly due to their long life. Rare seasons with favorable weather conditions provide outbreaks of juvenile plants. In the northern regions of the territory studied, more favorable conditions for the development of sprouts of this species are formed, and fluctuations in the demographic structure of coenopopulations are less pronounced.

中文翻译：

---

伏尔加河下游地区的郁金香（ave科，木兰科）共生种群人口结构的动态

摘要

研究了下伏尔加河地区39个郁金香的共生种群的人口结构。已经表明它们占据的面积为0.01至20000公顷或更多。小面积种群主要生长在该物种范围的北部边界附近。所有个体的密度（1.6–240.7 PCs / m ²）和生殖植物的数量（0.1–58.2 PCs / m ²）种群之间的分布范围很广，多年来变化显着，主要是在受到娱乐负荷或放牧的人群中。生殖个体的百分比为2％至96％。在2013-2016年间，与异种种群的生长地点相对应的地理纬度与其中成生状态植物的比例之间存在显着的负相关。相反，在调查的生境的南部和西部地区，2017-2018年间，盛行期的植物盛行，而开花植物的份额显着下降。观察到的动态与郁金香生长期的天气状况密切相关。在2013-2016年期间，在该领土的南部进行了研究，干旱条件仅在春季形成，幼苗在发育的早期就脱落了。2017年和2018年春季更湿润，幼苗成功通过了本体发育的早期阶段。因此，天气条件的周期性波动会极大地影响该地区的人口结构。suaveolens T. coenopopulations。因此，不同年份对人口更新的贡献是不同的。南部地区的人口数量众多，居住面积较大，这主要是由于其寿命长。天气条件有利的稀少季节会爆发幼株。在所研究领土的北部地区，为该物种的新芽的形成提供了更有利的条件，而异种种群的人口结构波动并不那么明显。