## 4 Experimental Results and Analysis
### Dynamic Monitoring Results and Analysis  
As the number and height detection meet the accuracy requirements, a variety of dynamic data can be monitored according to the needs of bamboo cultivation management. Potential variables of interest that can be measured using this method include changes in the number of bamboo shoots at monitoring sites at different time intervals, the height growth rate of each moso bamboo shoot, and the height growth trend of selected moso bamboo shoots; the method can also be used to discover degraded shoots [40]. Figure 11 shows the daily growth rate monitoring results of the experimental bamboo forest in Jing County. The selected images were taken at 17:00 PM each day from 13-18 April 2019, which differs from the period of the model training data set. The daily growth rate indicates the difference between the height on a given day and that on the previous day at the same time divided by the height of the previous day, in percent (%). Negative values indicate errors in the height detection results for the corresponding moso bamboo shoots or shoot tilt due to external factors. There are 29 bamboo shoots in Figure 11. The height  
Figure 10: Box plot of relative error: (a) number relative error; (b) height relative error. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**No.** & **Xmin** & **Xmax** & **Ymin** & **Ymax** & **H\({}^{\prime}\)** & **H** & \(\alpha\) \\ \hline  
(-\)3.26\% \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Detection results for each moso bamboo shoot in Figure 9(b) (all values are given in pixels). growth rate of moso bamboo shoots showed a normally distributed pattern, in which most of the moso bamboo shoots had their fastest daily growth rates on April 16, and each moso bamboo shoot had its slowest daily growth rate on 18 April. Shoots 4 and 23 were new moso bamboo shoots, with no corresponding daily growth rate data on 14 April. Table 6 shows the weekly growth monitoring data for the moso bamboo shoots at the monitoring site of Mufu Mountain. The selected images were taken at 12:00 noon each day from 29 March to 15 April 2021. The weekly growth rate is the difference between the height on a given day, and that on the same day and time in the previous week, divided by the height of the previous week, in percentage (%). The blank cell indicates that there was no data at the corresponding time one week previously, as there were no corresponding moso bamboo shoots. According to Table 6, shoot Nos. 1, 2, 5, 6, and 17 were new moso bamboo shoots. The emergence time of new moso bamboo shoots and the height change in each moso bamboo shoot in the monitoring area can be obtained through analysis of the data of each line. The number of moso bamboo shoots at the corresponding time one week previously and the height growth rate of each moso bamboo shoot in the monitoring were obtained through analysis of the data of each column. The analysis shows that there were 26 moso bamboo shoots in this area at the end, of which shoot Nos. 2, 5, and 17 had relatively similar emergence times, whereas shoot No. 1 emerged at the latest time point, and there were no newly emerged moso bamboo shoots in the final three days of monitoring. The system can monitor the number and height changes of all moso bamboo shoots in the area, as well as the growth trends of certain moso bamboo shoots. Figure 12 shows the height growth trend of four selected moso bamboo shoots. The figure shows the height growth rates of moso bamboo shoot Nos. 4, 7, 16, and 19 from 30 March to 15 April compared with those on 29 March. Moso bamboo shoot Nos. 7 and 19 grew more vigorously, whereas moso bamboo shoot Nos. 4 and 16 grew more slowly. From the monitoring results, it can be concluded that most of the height growth of the moso bamboo shoots was concentrated on 3-5 April. During the growth stage of moso bamboo shoots, some moso bamboo shoots recede, i.e., the shoots stop growing or die back.