Spring Leafing Phenology Favors Younger Culms of Moso Bamboo: Aspects From Water Use Relations

Abstract

As the most widely distributed giant running bamboo species in China, Moso bamboo (Phyllostachys edulis) can accomplish both development of newly sprouted culms and leaf renewal of odd-year-old culms within a few months in spring. The two phenological events in spring may together change water distribution among culms in different age categories within a stand, which may differ from our conventional understanding of the negative age effect on bamboo water use. Therefore, to explore the effect of spring shooting and leaf phenology on age-specific water use of Moso bamboo and potential water redistribution, we monitored water use of four culm age categories (newly sprouted, 1-, 2-, and 3-year-old; namely A0, A1, A2, A3) in spring from March to June 2018. For newly sprouting culms, the spring phenological period was classified into five stages (incubation, culm-elongation, branch-development, leafing, established). Over these phenological stages, age-specific accumulated sap flux density showed different patterns. The oldest culms, A3, were not influenced by leaf renewal and kept nearly constant and less water use than the other aged culms. However, A2, which did not renew their leaves, had the most water use at the two initial stages (incubation, culm-elongation) but consumed less water than A0 and A1 after the fourth stage (leafing). At the end of June, water use of the four age categories sorted in order of A0 > A1 > A2 > A3, which confirms the conventional thought and observations, i.e., a negative age effect. The results indicate that new leaf flushing may benefit younger culms (A1 and A0) more than older culms (A2 and A3), i.e., increasing their transpiration response to radiation and share of the stand transpiration. With the underground connected rhizome system, the bamboo stand as an integration seems to balance its water use among culms of different ages to support the water use of freshly sprouted culms during their developing period.

Shoot Phenology in Bambusoideae: A Review

“…The influence of ramet age, phenology, and drought on the transpiration of moso bamboo was studied in Guilin Botanical Garden in Southern China, which has a subtropical monsoon climate [34]. The mean annual air temperature of the site was 19.3 • C. The study showed that the daily maximum sap flux density was higher, which lead to an increasing transpiration rate in less than >3-year-old ramets, results which are similar to those reported by [32]. The above results showed that the transpiration of moso bamboo was influenced by culm age, phenological stages, and soil moisture content.…”

“…It can be summarized that the leaf phenology can be altered to grow according to the environmental conditions under which they will survive. With regards to physiological processes related to bamboo phenology, water use in moso bamboo (P. edulis) was examined [32] according to spring leafing phenology with four different culm ages, which were newly sprouted, at 1, 2, and 3 years old, at Zhejiang A&F University, Hangzhou, China. The mean annual temperature of the study site from 2008 to 2017 was 17.6 ± 0.4 • C. The tested 3-year-old culms were found to have the least water utilization compared to other age culms during the experimental period from March to June 2018.…”

Age effects of Moso bamboo on leaf isoprene emission characteristics

“…This study included three age categories of culms: newly sprouted culms less than 1-year-old (the leaf formation was completed in June 2021), 2 or 4 years old (the leaf formation was completed in June 2020), and 6 or 8 years old (the leaf formation was completed in June 2020), referred to as young, mature, and old, respectively. The age of the selected culms was determined according to Mei et al (2020). The crowns of the selected bamboo culms were intact, unbroken, and unaffected by visible diseases or pests.…”

Non-structural carbohydrate and water dynamics of Moso bamboo during its explosive growth period

“…The study site locates in the Pingshan experimental base of the Zhejiang A&F University, Lin an, Zhejiang Province of China. Zhejiang Province is located in southeast China and belongs to a typical subtropical monsoon climate zone with an average temperature of 17.6 ± 0.4 • C and an average annual rainfall of 1,579.7 ± 263.5 mm from 2008 to 2017 (data obtained from the National Meteorological Information Center; http:// data.cma.cn/site/index.html) (Mei et al, 2020;Tong et al, 2021).…”