干旱区生态环境知识资源中心(Arid): Intracanopy adjustment of leaf-level thermal tolerance is associated with microclimatic variation across the canopy of a desert tree (Acacia papyrocarpa)

Arid

DOI	10.1007/s00442-018-4289-x
	Intracanopy adjustment of leaf-level thermal tolerance is associated with microclimatic variation across the canopy of a desert tree (Acacia papyrocarpa)
	Curtis, Ellen M.1; Knight, Charles A.2; Leigh, Andrea 1
通讯作者	Leigh, Andrea
来源期刊	OECOLOGIA
ISSN	0029-8549
EISSN	1432-1939
出版年	2019
卷号	189 期号:1 页码:37-46
英文摘要	Tree crowns are spatially heterogeneous, sometimes resulting in significant variation in microclimate across the canopy, particularly with respect to temperature. Yet it is not known whether such localised temperature variation equates to intracanopy variation in leaf-level physiological thermal tolerance. Here, we studied whether microclimate variation across the canopy of a dominant desert tree equated to localised variation in leaf thermal thresholds (T-50) among four canopy positions: upper south, upper north, lower south, lower north. Principal component analysis was used to generate a composite climatic stress variable (C-STRESS) from canopy temperature, vapour pressure deficit, and relative humidity. We also determined the average number of days that maximum temperatures exceeded the air temperature equating to this species' critical threshold of 49 degrees C (AT(49)). To estimate how closely leaf temperatures track ambient temperature, we predicted the thermal time constant () for leaves at each canopy position. We found that C-STRESS and AT(49) were significantly greater in lower and north-facing positions in the canopy. Differences in wind speed with height resulted in significantly longer predicted for leaves positioned at lower, north-facing positions. Variation in these drivers was correlated with significantly higher T-50 for leaves in these more environmentally stressful canopy positions. Our findings suggest that this species may optimise resources to protect against thermal damage at a whole-plant level. They also indicate that, particularly in desert environments with steep intracanopy microclimatic gradients, whole-plant carbon models could substantially under- or overestimate productivity under heat stress, depending on where in the canopy T-50 is measured.
英文关键词	Canopy microclimate Desert plants Heat stress Leaf plasticity Thermotolerance
类型	Article
语种	英语
国家	Australia ; USA
开放获取类型	Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000455167600004
WOS关键词	PHOTOSYNTHETIC CAPACITY ; TEMPERATURE-DEPENDENCE ; LIGHT GRADIENTS ; PHOTOSYSTEM-II ; ACCLIMATION ; RESPONSES ; STRESS ; SHAPE ; SIZE ; PHOTOINHIBITION
WOS类目	Ecology
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217806
作者单位	1.Univ Technol Sydney, Sch Life Sci, POB 123,Broadway, Sydney, NSW 2007, Australia; 2.Calif Polytech State Univ San Luis Obispo, Dept Biol Sci, San Luis Obispo, CA 93407 USA
推荐引用方式 GB/T 7714	Curtis, Ellen M.,Knight, Charles A.,Leigh, Andrea. Intracanopy adjustment of leaf-level thermal tolerance is associated with microclimatic variation across the canopy of a desert tree (Acacia papyrocarpa)[J],2019,189(1):37-46.
APA	Curtis, Ellen M.,Knight, Charles A.,&Leigh, Andrea.(2019).Intracanopy adjustment of leaf-level thermal tolerance is associated with microclimatic variation across the canopy of a desert tree (Acacia papyrocarpa).OECOLOGIA,189(1),37-46.
MLA	Curtis, Ellen M.,et al."Intracanopy adjustment of leaf-level thermal tolerance is associated with microclimatic variation across the canopy of a desert tree (Acacia papyrocarpa)".OECOLOGIA 189.1(2019):37-46.