# Shoot Phenology in _Bambusoideae_: A Review
## 1 Introduction  
Phenology is the study of the changes in the seasonal timing of budburst, shooting, leaf flushing, leaf fall, flowering, dormancy [1, 2]. Vegetation phenology is defined as changes in plant growth and development such as germination, branching, leaf spreading, flowering, and fruiting influenced by the changes in a seasonal climate [3]. Phenology is also described as the scientific study of plant life cycles (such as vegetative and generative phases) and of how the seasonal and interannual variations can influence those life cycles [4]. Vegetation phenology plays an important role in the monitoring of climate change [5]. Phenology in plants is affected by numerous factors, such as short-term environmental factors that can cause phenological patterns (called proximate cause), while the evolutionary force that can lead to those phenological patterns is called the ultimate cause [6]. Therefore, it can be said that environmental factors, biotic (organisms such as viruses, fungi, bacteria, insects, and plants) and abiotic factors (sunlight, wind, temperature, water, and soil), directly correlate to the plant's physiological development. Both biotic stress (viruses, bacteria, fungi, nematodes, insects, arachnids and weeds) and abiotic stress (oxidative stress, salt stress, water deficit, extreme temperature stress, and flooding stress) hugely impact the plant's physiological development. Plants tend to adjust their developmental stages and metabolism in order to survive under a stressed environment, so phenological changes might occur due to the stress conditions during their life cycles. The timing and scale of response are governed by the severity and duration of the stress [7]. The annual study of plant phenology is important in the monitoring of climate change. Climate change can alter plant phenology because, primarily, temperature determines the timing of plant developmental stages, often alone, but sometimes in interaction with other factors, such as the photoperiod [8,9]. The study of changes in plant phenology is also important for agronomy and agro-meteorology to document the plant response to unpredictable climate change, which often leads to loss in agricultural productivity. The increment of atmospheric (CO\({}_{2}\)) is the main factor of changes in temperature and precipitation, and it can also affect changes in phenology directly [5,10]. The effect of elevated (CO\({}_{2}\)) on the vegetative and reproductive growth of _Xanthium strumarium_ was studied, and it was found that the vegetative growth increased with an extension of the flowering period when the plants were exposed to elevated CO\({}_{2}\)[11]. Phenological responses to environmental changes are always species-specific [9]. Plant phenology at a species-specific level involves two opposing factors. The first one is the characteristics of the individual plant (such as genome, age, and evolution within a plant community) that are affected by biotic potential, photosynthetic activity, nutrient absorption, constructive metabolism, etc. The other one is the environmental component, which is representative of the limited resources, stress, respiration, photosynthesis, transpiration, aging factors, etc. [4]. The timing shift of plant phenological events is primarily affected by temperature and photoperiod [12]. Daily temperature fluctuation also influences the changes in the phenology of plants and insects [13]. Some environmental factors that drive plant phenological changes have been studied [4,14], and a model was developed to analyze the date of leaf unfolding for 18 North American temperate tree species, including 11 genera at three different locations and collected annual leaf unfolding dates over the 20 th century with daily temperature data. They found that the date of leaf unfolding of most species changed from the 20 th century to the 21 st century because of the impact of temperature on the phenology of the leaf.