Analysis of canopy phenology in man-made forests using near-earth remote sensing

Plant Methods

Guannan Lei¹  Peng Guan¹  Yili Zheng¹ 

[1] School of Engineering, Beijing Forestry University, Beijing, China;Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Municipal Education Commission, Beijing, China;

关键词: Color index;    Forecast;    Forest phenology;    LSTM model;    Near-earth remote sensing;   

DOI  :  10.1186/s13007-021-00803-9

来源: Springer

【 摘 要 】

BackgroundForest canopies are highly sensitive to their growth, health, and climate change. The study aims to obtain time sequence images in mix foresters using a near-earth remote sensing method to track the seasonal variation in the color index and select the optimal color index. Three different regions of interest (RIOs) were defined and six color indexes (GRVI, HUE, GGR, RCC, GCC, and GEI) were calculated to analyze the microenvironment difference. The key phenological phase was identified using the double logistic model and the derivative method, and the phenology forecast of color indexes was performed based on the long short-term memory (LSTM) model.ResultsThe results showed that the same color index in different RIOs and different color indexes in the same RIO present a slight difference in the days of growth and the days corresponding to the peak value, exhibiting different phenological phases; the mean squared error (MSE), root mean squared error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) of the LSTM model was 0.0016, 0.0405, 0.0334, and 12.55%, respectively, indicating that this model has a good forecast effect.ConclusionsIn different areas of the same forest, differences in the micro-ecological environment in the canopies were prevalent, with their internal growth mechanism being affected by different cultivation ways and the external environment. Besides, the optimal color index also varies with species in phenological response, that is, different color indexes are used for different forests. With the data of color indexes as the training set and forecast set, the feasibility of the LSTM model in phenology forecast is verified.

【 授权许可】

CC BY