文献类型：期刊文献

英文题名：Prediction of sap flux of elm (Ulmus pumila var. sabulosa) by solar induced fluorescence in a temperate savanna, China

作者：Cong, Weiwei[1] Yang, Kaijie[2] Lu, Sen[3] Zhao, Tianhong[1] Wang, Feng[2] Lu, Qi[2]

第一作者：Cong, Weiwei

通信作者：Wang, F[1]

机构：[1]Shenyang Agr Univ, Coll Agron, Shenyang 110161, Peoples R China;[2]Chinese Acad Forestry, Inst Ecol Conservat & Restorat, Beijing 100091, Peoples R China;[3]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Efficient Prod Forest Resources, Beijing 100091, Peoples R China

年份：2025

卷号：36

期号：1

外文期刊名：JOURNAL OF FORESTRY RESEARCH

收录：;EI(收录号：20252618688345);Scopus(收录号：2-s2.0-105009068825);WOS:【SCI-EXPANDED(收录号:WOS:001518511200002)】；

语种：英文

外文关键词：Temperate savanna; Ulmus pumila.; Far-red SIF; Sap flux relationships; Environmental factors

摘要：Tracking the sap flux of woody plants in savannas is essential for understanding their response to climate change and human management. Solar-induced fluorescence (SIF) has potential to predict transpiration yet its applicability for estimating savanna sap flux is unclear. Using three years of tower-based far-red SIF observations and ground-based sap flow monitoring in a temperate savanna of Otindag Sandy Land, China, we investigated the relationship between far-red SIF and sap flux density and developed linear and random forest models for estimating. The results show a variable correlation between SIF and sap flux density for Ulmus pumila var. sabulosa (J.H. Xin) G.H. Zhu & D.H. Bian (U. pumila.) at an hourly scale. The strongest correlations were during the mid- growth period July and August when considering the time lag between SIF and sap flux (0-0.5 h). Photosynthetically active radiation was the primary factor driving the SIF and sap flux density relationship. Soil moisture, vapor pressure deficit, and air temperature also influenced this relationship on daily and monthly scales. Compared to SIF-based linear regression models, the SIF-based random forest model performed better in tracking the seasonal sap flux density. The results suggest the feasibility of accurately monitoring vegetation sap flux using SIF, woody fractional vegetation cover, and environmental factors in a temperate savanna. This method could also be used in modeling land surface processes in savanna-type ecosystems.