# Shoot Phenology in _Bambusoideae_: A Review
## 2 Phenological Studies in Bamboo Species
### Factors Affecting Bamboo Phenology
The daily average temperature during the shooting period was above 10 \({}^{\circ}\)C. Based on their results, it can be observed that the date of shooting was delayed with the higher altitude. The growth characteristics of _Chimonobambusa utilis_ were studied at different altitudes in Dingjing Mountain and Qingba Mountain in Guizhou Province, China where the altitude is between 1000 and 2000 m. Altitude \(\geq\)1300-1450 m was identified as low altitude, \(\geq\)1450-1600 m as low and medium altitude, \(\geq\)1600-1750 as medium and high altitude, and \(\geq\)1750-1900 m as high altitude [30]. The normal shooting period of _C. utilis_ at medium to high altitude was from August to September, while at a low altitude, it was later from September to October; however, from their observations they concluded that the bamboo shooting period was slightly prolonged with increasing altitude, from 21 days to 25 days from low altitude to high altitude. Precipitation and water availability in the soil are also vital factors affecting bamboo phenology, as it was observed in the case of the vegetative phenology and growth of deciduous bamboo _Bambusa armhenica_. The species was observed monthly for 2.5 years in the Australian monsoonal tropical area in lower riparian, upper riparian, and hill sites [31]. The study showed that leaf flushing began shortly before the first rainfall in riparian sites, and it extended for a longer period in 2001; however, it began shortly after the first rainfall and reached maximum over a shorter period in 2002, while in the hill site, leaf flush started 1 month after the first rainfall according to the 3-year study period. The emergence of first-year new culm shoots started earlier during the onset of the rainy season at two riparian sites in 2001, than in other studied years and at the hill site. Leaf flushing on mature culms appeared mostly before culm elongation at the beginning of the wet season. Culms reached about half of their mature length when the flood occurred, then elongation was completed a month after floodwaters decreased in riparian sites. Even though the same species grows in different places, the leaf flushing and culm elongation occurred at different times. 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 \(\pm\) 0.4 \({}^{\circ}\)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. They concluded in their study that leaf phenology of moso bamboo might influence water redistribution in a bamboo stand to temporarily younger ones (newly sprouted culms and 1-year-old culms) more than to other culms which are 2 years old and 3 years old, after finding a dramatic increase in the transpiration response in younger culms. With regards to the interaction of water use and different age culms, they concluded that the negative age effect of water use might be influenced by both the leaf renewal of established culms and the branch development and leafing stages of newly sprouted culms. Moreover, it was explained that the aging culms have thick cell walls with smaller cell cavities so that the water storage ability was decreased [33]. Consequently, the 3-year-old culms had lower moister content than other younger ones. 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].