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DOI	10.1002/hyp.15162
	Evidence of field-scale shifts in transpiration dynamics following bark beetle infestation: Stomatal conductance responses
	Li, Meijun; Shao, Wei; Su, Ye; Coenders-Gerrits, Miriam; Jarsjoe, Jerker
发表日期	2024
ISSN	0885-6087
EISSN	1099-1085
起始页码	38
结束页码	5
卷号	38 期号:5
英文摘要	Amplified eruptive outbreaks of bark beetles as a consequence of climate change can cause tree mortality that significantly affects terrestrial water and carbon fluxes. However, the lack of field-scale observations of underlying physiological mechanisms currently hampers the expression of such ecosystem disturbances in predictive modelling. Based on a unique flux tower dataset from a subalpine forest located in the Rocky Mountains, mechanisms of stomatal response to an extensive bark beetle outbreak were investigated using various models and parametrizations. The datasets cover a decade, including the periods of pre-infestation, infestation, and post-infestation. Field measurements showed considerable decreases in evapotranspiration (ET), transpiration (T), and leaf area index (LAI) during the two-year infestation period compared to the pre-infestation period. Model interpretations of observed water and carbon fluxes indicated that the overall reductions in T were not solely due to decreased LAI, but also to changes in physiological behaviours. The summer season's canopy-scale stomatal conductance was significantly reduced during the infestation period, from 0.0018 to 0.0011 m s-1. One primary reason for the observed variations is likely that the bark beetle infestation hampers the water transport in the xylem. The damage of xylem has important implications for water use efficiency (WUE), which also significantly influences the parameterization of stomatal conductance. When using stomatal conductance models to forecast ecosystem dynamics, it is crucial to recalibrate the model's parameters to ensure the accurate depiction of stomatal dynamics during various infestation periods. The neglect of the temporal variability of canopy-scale stomatal conductance under ecosystem disturbances (e.g., bark beetle infestations) in current earth system models, therefore, requires specific attention in assessments of large-scale water and carbon balances. By comparing the simulation accuracy of stomatal conductance and transpiration under an evolution-varied parameterization (considering all infestation stages) and a pre-infestation-fixed parameterization (considering undisturbed conditions) of three stomatal conductance models (Ball-Berry, Leuning, and Medlyn model), the impact of bark beetle infestation was identified. The findings highlight that the overall transpiration reduction was not only caused by reduced LAI, but also by changing physiological behaviour, which was neglected by all current models. image
英文关键词	bark beetle infestation; canopy-scale stomatal conductance; carbon and water fluxes; temporal variability; transpiration; vegetation-atmosphere interaction
语种	英语
WOS研究方向	Water Resources
WOS类目	Water Resources
WOS记录号	WOS:001226374400001
来源期刊	HYDROLOGICAL PROCESSES
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/305642
作者单位	Nanjing University of Information Science & Technology; Charles University Prague; Stockholm University; Delft University of Technology
推荐引用方式 GB/T 7714	Li, Meijun,Shao, Wei,Su, Ye,et al. Evidence of field-scale shifts in transpiration dynamics following bark beetle infestation: Stomatal conductance responses[J],2024,38(5).
APA	Li, Meijun,Shao, Wei,Su, Ye,Coenders-Gerrits, Miriam,&Jarsjoe, Jerker.(2024).Evidence of field-scale shifts in transpiration dynamics following bark beetle infestation: Stomatal conductance responses.HYDROLOGICAL PROCESSES,38(5).
MLA	Li, Meijun,et al."Evidence of field-scale shifts in transpiration dynamics following bark beetle infestation: Stomatal conductance responses".HYDROLOGICAL PROCESSES 38.5(2024).