title: Occurrence of stomatal patchiness and its spatial scale in leaves from various sizes of trees distributed in a South-east Asian tropical rainforest in Peninsular Malaysia.
abstract: In this study, we demonstrated the occurrence of stomatal patchiness and its spatial scale in leaves from various sizes of trees grown in a lowland dipterocarp forest in Peninsular Malaysia. To evaluate the patterns of stomatal behavior, we used three techniques simultaneously to analyze heterobaric or homobaric leaves from five tree species ranging from 0.6 to 31 m in height: (i) diurnal changes in chlorophyll fluorescence imaging, (ii) observation and simulation of leaf gas-exchange rates and (iii) a pressure-infiltration method. Measurements were performed in situ with 1000 or 500 μmol m(-2) s(-1) photosynthetic photon flux density. Diurnal patterns in the spatial distribution of photosynthetic electron transport rate (J) mapped from chlorophyll fluorescence images, a comparison of observed and simulated leaf gas-exchange rates, and the spatial distribution of stomatal apertures obtained from the acid-fuchsin-infiltrated area showed that patchy stomatal closure coupled with severe midday depression of photosynthesis occurred in Neobalanocarpus heimii (King) Ashton, a higher canopy tree with heterobaric leaves due to the higher leaf temperature and vapor pressure deficit. However, subcanopy or understory trees showed uniform stomatal behavior throughout the day, although they also have heterobaric leaves. These results suggest that the occurrence of stomatal patchiness is determined by tree size and/or environmental conditions. The analysis of spatial scale by chlorophyll fluorescence imaging showed that several adjacent anatomical patches (lamina areas bounded by bundle-sheath extensions within the lamina) may co-operate for the distributed patterns of J and stomatal apertures.
authors.affiliation: Laboratory of Forest Hydrology, Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan m.kamakura1192@gmail.com.
authors.forename: Mai
authors.initials: M
authors.lastname: Kamakura
authors.affiliation: Laboratory of Forest Hydrology, Division of Environmental Science and Technology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kosugi
authors.affiliation: Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Takanashi
authors.affiliation: Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo 062-8516, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Uemura
authors.affiliation: Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Utsugi
authors.affiliation: Forest Research Institute Malaysia, Kepong, Selangor 52109, Malaysia.
authors.forename: Abd Rahman
authors.initials: AR
authors.lastname: Kassim
mesh_terms: D002734:Chlorophyll / Q000737:chemistry; D053958:Dipterocarpaceae / Q000033:anatomy & histology / Q000502:physiology; D019665:Euphorbiaceae / Q000033:anatomy & histology / Q000502:physiology; D008296:Malaysia; D017440:Photoperiod; D010788:Photosynthesis; D018515:Plant Leaves / Q000033:anatomy & histology / Q000502:physiology; D054046:Plant Stomata / Q000033:anatomy & histology* / Q000502:physiology; D065947:Rainforest; D019666:Rubiaceae / Q000033:anatomy & histology / Q000502:physiology; D014197:Trees / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D002734:Chlorophyll
keywords: chlorophyll fluorescence imaging; heterobaric and homobaric leaf; midday depression of photosynthesis; patchy stomatal closure; pressure infiltration