Differences in seasonality and temperature dependency of stand transpiration and canopy conductance between Japanese cypress (Hinoki) and Japanese cedar (Sugi) in a plantation          下载免费PDF全文

Takami Saito  Tomo'omi Kumagai  Makiko Tateishi  Nakako Kobayashi  Kyoichi Otsuki  Thomas W. Giambelluca 《水文研究》2017,31(10):1952-1965

In this paper, we present an investigation of interspecies differences in transpiration of the 2 most common plantation forest tree species in Japan, both in the family Cupressaceae with different northern limits of native distribution, Japanese cypress (Hinoki; Chamaecyparis obtusa Sieb. et Zucc.) and Japanese cedar (Sugi; Cryptomeria japonica D. Don). The stem sap flow rate was measured in 2 nearby stands of similar leaf area index in a 42‐year‐old plantation. Single‐tree and stand‐scale transpiration rates (E_tre and E_sta, respectively) were observed during an ideal autumn environment. At the stand scale, mean sap flux density of Hinoki was greater than that of Sugi, whereas total sapwood area per ground area was smaller in Hinoki than Sugi. Because the 2 variables had counterbalancing effects on transpiration, E_sta of Hinoki was similar to (94% of) that of Sugi. This offset was also found between the mean E_tre of the 2 species. E_sta was similar between the stands from May to October, whereas E_sta of Sugi was notably greater than that of Hinoki from February to April. During these 3 months, the difference in cumulative E_sta was 21.7 mm, which accounted for 79% of the difference in annual E_sta between Hinoki and Sugi (192 and 219 mm/year, respectively). We found that canopy conductance (G_c) and its sensitivity to the mean vapour pressure deficit during daylight hours in Sugi were particularly high in early spring, whereas those in Hinoki shifted gradually throughout the growing season. This difference was related to the optimal temperature of G_c in Sugi, which was approximately 10 °C lower than that in Hinoki. Our results suggest that plantations of water‐conserving species such as Hinoki produce timber slowly but yield water resources generously. Moreover, for plantations of trees sensitive to high temperature, such as Sugi, managers should be concerned about possible future decline caused by anticipated global warming.  相似文献   

Deforestation‐induced reduction in rainfall     

Tomo'omi Kumagai  Hironari Kanamori  Tetsuzo Yasunari 《水文研究》2013,27(25):3811-3814

  相似文献   

Are measurements from excised leaves suitable for modeling diurnal patterns of gas exchange of intact leaves?     

Yoshiyuki Miyazawa  Makiko Tateishi  Hikaru Komatsu  Tomo'omi Kumagai  Kyoichi Otsuki 《水文研究》2011,25(18):2924-2930

To examine the feasibility of using ecophysiological data from excised leaves for a meteorological simulation model of gas exchange, we compared the obtained gas exchange rates and the modelled ones using excised leaves and those using intact leaves. Instantaneous gas exchange rates of excised leaves and stomatal control in response to environmental conditions were not significantly different from those of attached leaves. Modelled gas exchange rates based on excised leaf data showed a good fit to the diurnal patterns of in situ measurements. This suggests that use of excised leaf data to predict gas exchange of intact leaves is permissible as long as the effects of excision are pre‐screened as described in this paper. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Estimation of vertical profiles of leaf drying times after daytime rainfall within a Bornean tropical rainforest     

Tomonori Kume  Odair J Manfroi  Masakazu Suzuki  Katsunori Tanaka  Koichiro Kuraji  Michiko Nakagawa  Hikaru Komatsu  Tomo'omi Kumagai 《水文研究》2008,22(18):3689-3696

South‐east Asian Bornean tropical rainforests have large and complex canopy structures. To clarify how forest structure affects wet‐canopy evaporation, it is necessary to consider wet‐canopy evaporation processes within the forest canopy, such as vertical profiles of canopy drying time. In a previous study a method was proposed that utilizes sap flow measurements to estimate canopy drying time after rainfall (CDTobs) during daytime. In this present study, the method was applied to estimations of the vertical variations in CDTobs in 11 individual trees of various heights, ranging from 2·7 m to 53 m. The study derived vertical profiles and showed that the lengths of CDTobs in lower canopy trees were 2–4 h longer than those in the upper canopy trees. The new method for CDTobs profiles presented in this study, which is available for validation of multi‐layer biosphere‐atmospheric models, is a useful illustration for clarifying wet‐canopy evaporation processes in tropical rainforests. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Interpretation of El Niño–Southern Oscillation‐related precipitation anomalies in north‐western Borneo using isotopic tracers          下载免费PDF全文

Naoyuki Kurita  Mayumi Horikawa  Hironari Kanamori  Hatsuki Fujinami  Tomo'omi Kumagai  Tetsuzo Yasunari 《水文研究》2018,32(14):2176-2186

We examined rainfall anomalies associated with the El Niño–Southern Oscillation (ENSO) in northern Sarawak, Malaysia, using the oxygen isotopic composition of rainfall. Two precipitation‐sampling campaigns were conducted for isotope analysis: (a) at the Lambir Hill National Park (4.2° N, 114.0° E) from July 2004 to October 2006 and (b) at the Gunung Mulu National Park (3.9° N, 114.8° E) from January 2006 to July 2008. The records from these campaigns were merged with a previously published rainfall isotope dataset from Gunung Mulu site to create a 7‐year‐long record of the oxygen isotopic composition of Sarawak rainfall. The record exhibits clear intraseasonal variations (ISVs) with periods ranging from 10 to 70 days. The ISVs of 10‐ to 90‐day band‐pass filtered oxygen isotopic composition are linked to the synoptic‐scale precipitation anomalies over the southern South China Sea (SCS). The lead–lag correlation map of precipitation with the filtered oxygen isotope anomalies shows that an anomalous wet condition responsible for the decrease in oxygen isotopic composition appears over the SCS in association with the passage of north‐eastward propagation of the boreal summer intraseasonal oscillation (BSISO) in the summer monsoon season. The anomalous wet condition in spring is connected with eastward‐propagating Madden–Julian oscillation (MJO), whereas the sustained wet condition in winter is responsible for the occurrence of the Borneo vortex (BV) over the SCS. ENSO modulates the frequency of these synoptic conditions on a seasonal and longer time scale, showing a strong correlation between the seasonal isotopic anomalies and the Southern Oscillation index. We therefore discern, from the significant correlation between the isotope anomalies and area‐averaged Sarawak rainfall anomalies (R = ?0.65, p < 0.01), that ENSO‐related precipitation anomalies are linked to the seasonal modulation of the BSISO and MJO activity and BV genesis.  相似文献   

Estimation of sub-annual inter-catchment groundwater flow using short-term water balance method     

Tomohiro Egusa  Tomoki Oda  Takanori Sato  Tomo'omi Kumagai 《水文研究》2021,35(9):e14368

Predicting inter-catchment groundwater flow (IGF) is essential because IGF greatly affects stream water discharge and water chemistry. However, methods for estimating sub-annual IGF and clarifying its mechanisms using minimal data are limited. Thus, we quantified the sub-annual IGF and elucidated its driving factors using the short-term water balance method (STWB) for three forest headwater catchments in Japan (named here catchment A, B and As). Our previous study using the chloride mass balance indicated that annual IGF of catchment A (49.0 ha) can be negligible. Therefore, we calculated the daily evapotranspiration (ET) rate using the Priestley–Taylor expression and the 5-year water balance in catchment A (2010–2014). The sub-annual IGF of the three catchments was then calculated by subtracting the ET rate from the difference between rainfall and stream discharge during the sub-annual water balance periods selected using the STWB. The IGF rates of catchment B (7.0 ha), which is adjacent to catchment A, were positive in most cases, indicating that more groundwater flowed out of the catchment than into it, and exhibited positive linear relationships with rainfall and stream discharge. This suggested that as the catchments became wetter, more groundwater flowed out of catchment B. Conversely, the IGF rates of catchment As (5.3 ha), included in catchment A, were negative in most cases, indicating that more groundwater flowed into the catchment than out from it, and exhibited negative linear relationships with rainfall and stream discharge. Given the topography of the catchments studied, infiltration into the bedrock was the probable reason for the IGF outflow from catchment B. We hypothesized that in catchment As, the discrepancy between the actual hydrological boundary and the surface topographic boundary could have caused an IGF inflow. This study provides a useful tool for determining an IGF model structure to be incorporated into rainfall-runoff models.  相似文献   

Large-scale managed retreat and structural protection following the 2011 Japan tsunami     

Pinter  Nicholas  Ishiwateri  Mikio  Nonoguchi  Atsuko  Tanaka  Yumiko  Casagrande  David  Durden  Susan  Rees  James 《Natural Hazards》2019,96(3):1429-1436

Natural Hazards - On March 11, 2011, a magnitude MW 9.0 thrust earthquake ruptured the Japan Trench along the northwest coast of Honshu and generated a tsunami that killed 15,894 people, left 2585...  相似文献   

Improvement Of The Mellor–Yamada Turbulence Closure Model Based On Large-Eddy Simulation Data     

Mikio Nakanish 《Boundary-Layer Meteorology》2001,99(3):349-378

On the basis of data constructed with large-eddy simulation (LES), an attempt is made to improve the Mellor–Yamada (M–Y) turbulence closure model. Firstly, stably-stratified and convective planetary boundary layers without moisture are simulated by a LES model to obtain a database for the improvement. Secondly, based on the LES data, closure constants are re-evaluated and a new diagnostic equation for the master length scale L is proposed. The new equation is characterized by allowing L in the surface layer to vary with stability instead of constant kz, where k is the von Kármán constant, and z is height.The non-dimensional eddy-diffusivity coefficients calculated from the modifiedM–Y model are in satisfactory agreement with those from the LES data. It isfound that the modified M–Y model improves the original one largely, and thatthe improvement is achieved by considering buoyancy effects on the pressurecovariances andby using the newly proposed equation for L.  相似文献   

Source process of a long-period event at Kilauea volcano, Hawaii   总被引：1，自引：0，他引：1  

Hiroyuki Kumagai  Bernard A. Chouet  Phillip B. Dawson 《Geophysical Journal International》2005,161(1):243-254

  相似文献   

Rifting and basin inversion in the eastern margin of the Japan Sea     

Yukinobu  Okamura  Mahito  Watanabe  Rie  Morijiri Mikio  Satoh 《Island Arc》1995,4(3):166-181

Abstract Extensional basin formation and subsequent basin inversion in the southern area of the eastern margin of the Japan Sea were studied on the basis of the interpretation of seismic profiles (total length approximately 15 000 km) and the fossil analyses of 77 sea-bottom samples. Rift (Early to Early Middle Miocene), post-rift (Middle to Late Miocene), pre-inversion (Late Miocene to Pliocene) and inversion stages (Pliocene to Quaternary) were differentiated by the extension and contraction of the crust. Many small-scale rifts were formed in the Sado Ridge and the Mogami Trough during the rift stage, simultaneous with back-are spreading of the Japan Sea. Most of the rifts were east- or southeast-facing, rotational half-grabens bounded by west-dipping normal faults at their eastern boundaries. The syn-rift sequence can be divided into lower and upper units by an erosional surface. The sequences are presumed to be composed mainly of fining-upward sediments. The trend of most rifts is north-northeast with the remainder being of east-northeast-bias. The north-northeast trending rifts are distributed widely in the Sado Ridge and Mogami Trough and do not show an en échelon arrangement, suggesting that they were formed mainly by pure extension nearly perpendicular to the arc. The east-northeast trending rifts are presumed to have been developed by a north-northwest extension in the late rift stage, which may have accompanied a right-lateral movement in the eastern margin of the Japan Sea. During the post-rift stage, the rifts and adjacent horsts subsided and became covered by the post-rift sequence, characterized by parallel and continuous reflections. This suggested no significant tectonic movements in this period. In the pre-inversion stage many of the rifts subsided again, presumably because of down-warping due to weak compressional stress. The normal faults reactivated as reverse faults during the inversion stage due to an increase in compressional stress. Many of the rifts have been uplifted and transformed into east-vergent asymmetric anticlines. The basin inversion is greatest in the Sado Ridges and in the Dewa Bank Chain, while it is least developed in the Mogami Trough and in the western slope of the Sado Ridge, in which some normal faults have not been reactivated. The increase and decrease of the inversion corresponds to the peak and trough of undulation at an interval of about 50 km trending parallel to the arc.  相似文献