# Influences of Extreme Weather Conditions on the Carbon Cycles of Bamboo and Tea Ecosystems
## 1 Introduction  
Tea is the second most consumed beverage in the world and is one of the \"business cards\" of Chinese culture. Driven by economic development and the rise in living standards, tea plantations have expanded rapidly over the past several decades in China. China currently has the largest area of tea plantations and produces the most tea in the world, accounting for approximately 60% and 50% of the world's plantations and production in 2016, respectively [1]. The area of plantations in China is currently around 30,000 km\({}^{2}\), which increased by 143% from 2000 to 2014, representing the most rapid increase worldwide [1]. Moreover, tea production is predicted to increase by 55% from 2013 to 2023 [2]. This rapid expansion in tea plantations must be achieved by reducing the area of other land types, in most cases causing deforestation, because tea is usually planted in hilly areas in China. However, few studies have investigated the influences of tea plantations and corresponding land use changes on the terrestrial carbon (C) cycle. Climate change and extreme weather and climate events (EWCEs) have increased the complexity of the influences of tea plantations on the terrestrial C cycle. EWCEs occur frequently in the middle and lower reaches of the Yangtze River (MLRYR), where water resources are plentiful and the monsoon climate is dominant. For example, the entire Yangtze River experienced the second largest recorded flood in the 20 th century in 1998. Meanwhile, the MLRYR suffered from a drought with a return period of 50 years during the spring of 2011 [3] and experienced another severe flood in 2016 accompanied by rainfall from June 19 to July 20 equivalent to twice the multi-year average (600 mm) [4; 5]. Increasing frequencies of extreme rainfall events [6; 7; 8; 9] and extreme droughs [10; 11; 12; 13] have been projected with increasing global air temperature. Tea plantations located in the southern region of the MLRYR produce more than two-thirds of the tea in China [14] and are frequently affected by EWCEs; however, no studies have assessed the influences of EWCEs on the C cycle in tea plantations. Bamboo is another plant with special meaning in Chinese culture; for example, a man of complete virtue is often compared to bamboo in China. Bamboo forests account for 2.97% of the total forest area in China [15] and have a similar spatial distribution as that of tea in China (e.g., in Zhejiang, Fujian Province) [16]. As a result, tea plantations are often developed at the expense of bamboo forest (e.g., at the present study site). Currently, the area of tea plantation is approximately half that of bamboo forest [15]. In recent years, bamboo has received attention for its high capacity to store C and potential for C farming and trading [16; 17]. Therefore, the influence of replacing natural bamboo forest with tea plantations on the C cycle must be investigated in depth. The tea plant can be categorized as a shrub (shorter varieties) or tree (taller stages or varieties), and fertilization is required to increase production. However, most land surface models do not have an option or module for fertilized shrubs or trees in agroforestry, including the most widely used land surface model in climate change studies, the Community Land Model (CLM). Meanwhile, bamboo is biologically classified as a giant grass [18], although its height, stem, and other characteristics are tree-like. To our knowledge, no studies have assessed the performance of the CLM in modeling bamboo. In this study, we monitored meteorological indexes and soil water content and measured soil respiration (SR) at a reference bamboo plot and a green tea plot in Taihu Basin, MLRYR. Then, we constructed and validated mathematical models based on the field observations and data from the literature.