Year-to-Year Differences in Sap Flow and Crown-Level Stomatal Conductance of Two Species in a Lowland Evergreen Forest, Central Cambodia

Japan Agricultural Research Quarterly
ISSN 00213551
NII recode ID (NCID) AA0068709X
Full text
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Although information about the hydrologic and ecological features of lowland evergreen forests in central Cambodia has been collected since the beginning of the 21st century, measurements of the transpiration process remain very limited. This paper describes the differences detected in transpiration (q) and crown-level stomatal conductance (GS) between Calophyllum inophyllum (which undergoes successive leaf exchange) and Drypetes sp. (which performs irregular leaf exchange) (hereafter referred to as Calophyllum and Drypetes, respectively), and the analysis of these differences in consideration of their contrasting leaf phenologies. We evaluated q using sap flow measurements and obtained daily GS values. Calophyllum and Drypetes had high and low periods between which q and GS differed significantly. Within high/low periods, smaller scatter in the plot of GS versus vapour pressure deficit (D) was found in Calophyllum compared to Drypetes. For a given value of D, q in high periods was 1.3 and 1.9 times larger than in low periods for Calophyllum and Drypetes, respectively. The smaller scatter for Calophyllum was the result of relatively constant physiological activity that was maintained by successive leaf fall. For both species, high periods were recorded after remarkable leaf-fall events; thus, our current data implied that leaf phenology is one of the most important factors affecting transpiration.

Date of issued
Creator IIDA Shin'ichi ITO Eriko SHIMIZU Akira NOBUHIRO Tatsuhiko SHIMIZU Takanori KABEYA Naoki TAMAI Koji ARAKI Makoto CHANN Sophal KETH Nang
Subject

leaf phenology

riparian zone

sap flux density

transpiration

vapour pressure deficit

Publisher Japan International Research Center for Agricultural Sciences
Available Online
NII resource type vocabulary Journal Article
Volume 47
Issue 3
spage 319
epage 327
DOI 10.6090/jarq.47.319
Rights Japan International Research Center for Agricultural Sciences
Language eng

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