Effects of temperature on flowering phenological traits of Populus euphratica Oliv. and Populus pruinosa Schrenk populations, Xinjiang, China

Abstract

The aims of this study were to explore the interspecific differences of Populus euphratica Oliv. and Populus pruinosa Schrenk populations and the intraspecific differences of males and females within the same species in flowering phenological traits, and the effects of temperatures on flowering phenological traits in different growth years (2001-2003 and 2013-2015). The results showed that P. euphratica population flowered earlier than P. pruinosa population. Moreover, flowering phenological period of population, number of days of flowering phenological period per population, number of days of flowering phenological period per plant and average number of days of flowering period per plant of P. euphratica population were less than those of P. pruinosa population. The differences between male and female within the same species indicated that the flowering periods of males P. euphratica and P. pruinosa populations were earlier than those of female plants. For both species, flowering phenological traits were significantly and negatively correlated with the average temperatures in previous ten days, previous one month and previous three months of flowering. Both species are sensitive to temperature changes and adjust to the changes by advancing the start of flowering and prolonging the duration of flowering.

Using Sentinel-2 Images to Map the Populus euphratica Distribution Based on the Spectral Difference Acquired at the Key Phenological Stage

“…A disadvantage of this method is that due to environmental variation (such as accessibility to surface water and the groundwater depth), the phenological timing of Tamarix chinensis varies at a regional scale, decreasing the extraction accuracy of the Populus euphratica distribution [57]. Furthermore, the temperature is the primary factor affecting the Populus euphratica phenology [58]. Therefore, at a larger spatial scale, differences may exist in phenological timing, thereby reducing the availability of the optimal time window.…”

Sex-dependent phenological responses to climate vary across species’ ranges

“…This is because the reproductive investment of males is mainly restricted to flowering, whereas that of females extends to embryo development and dispersal. Given this disparity in reproductive investment, we may expect males of dioecious plants to be more abundant than females and bloom earlier to maximize their chances of successful reproduction ( 94 – 96 ). Females, on the other hand, may be more averse to risk and adapted to flower once i) climatic conditions for reproduction are safely met and ii) pollen availability is not of concern.…”

“…However, the net effect of temporal divergence between sexes and phenophases on pollination efficacy is uncertain. Along these lines, other factors, including flowering duration, pollen viability, intrapopulation phenological variability, and their responses to climate must be considered to ascertain the true reproductive cost of phenological divergence among sexes and phenophases ( 94 ). Further, studies of sexual differences in dioecious plants should also consider resource investment across the entire reproductive season, and not just flowering ( 112 ).…”

Assessment of the current status of the turanga forests in the south-east of Kazakhstan

“…Currently, studies of Turanga forests are conducted mostly in China and are mainly aimed at solving the physiological, phenological aspects of the dominant species, the impact of natural and anthropogenic factors on them [8][9][10][11][12][13][14][15].…”