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High student achievement across East Asia is often explained as an outcome of highly competitive, stress‐inducing college entrance exams across the region. This ‘exam hell’ drives students to study longer and harder than their peers worldwide, a race that leads—unsurprisingly—to higher marks in international comparisons such as the Programme for International Student Assessment (PISA). Yet, the race comes at a considerable cost: psychological pressure, forfeited childhoods, regimes of rote memorisation, lack of creativity and private outlays for cram schools. In this article, we seek to refute this outdated narrative by focusing on changes in Japanese education over the past three decades. We first analyse quantitative data for learning time based on three longitudinal surveys conducted by researchers in Japan to show that learning time for Japanese upper secondary students declined during 1980–2000 (Study 1). We then turn to analyse PISA 2015 data to show that now Japanese students study less than their peers in major Anglo‐American countries: the USA, the UK and Australia (Study 2). These findings run counter to well‐worn images frequently rehearsed in both the academic and popular literature. In helping to remove one of the most persistent stereotypes about East Asian education, we seek to help make visible other explanations for East Asian student achievement. [ABSTRACT FROM AUTHOR]

Bamboo forests have been expanding rapidly in Asian countries for the past 50 years. Whether natural or artificial, this expansion involves the replacement of other vegetation types by bamboo, which could impact the local water cycle. Previous studies in Japan have reported that bamboo forests have higher transpiration than coniferous forests under temperate climates, but it is unknown whether this finding applies to subtropical climates. Thus, we examined whether a Moso bamboo ( Phyllostachys pubescens) forest exhibits higher transpiration in a subtropical climate. We used the sap-flux method to estimate the stand transpiration ( E) of Moso bamboo and Japanese cedar ( Cryptomeria japonica) forests in Taiwan. As was observed in the Japanese studies, annual E for bamboo (478 mm) was higher than that for cedar (122 mm), although we found a difference in the seasonality of E between the Taiwanese and Japanese sites. Canopy conductance ( Gc) for bamboo was higher than that for cedar in Taiwan, which was reported previously for Japan. Gc for bamboo in Taiwan was comparable to that in Japan, despite a difference in the leaf area index (LAI). Gc for cedar in Taiwan was lower than that in Japan. This difference in Gc between Taiwan and Japan corresponded to differences in the sapwood area and LAI. These findings suggest a significant change in E and, therefore, the terrestrial water and carbon cycle, regardless of different climates, when Japanese cedar forests are replaced by Moso bamboo forests. [ABSTRACT FROM AUTHOR]

Lianas (woody climbers) have a greater amount of leaves relative to basal area or standing biomass than trees, and very wide vessels that permit efficient water transport. These features suggest that lianas possibly consume proportionally more water through transpiration than trees. Despite their potential importance, researchers have made only limited attempts to evaluate effects of lianas on forest water dynamics., We conducted sap flow measurements for 1 year using a thermal dissipation method for four species each of lianas and trees in a liana-rich, warm-temperate forest in Japan and estimated the contribution of lianas to stand canopy transpiration., Based on a calibration measuring water uptake rates from cut-stem ends, the actual sap flux ( Fd) in liana stems was several times greater than those estimated from the original calibration provided for the method. In the field, lianas showed an average of 2-4 times greater Fd than trees throughout the year. Except for this difference, diurnal and seasonal patterns of relative changes of Fd were similar in both groups. The whole-plant transpiration ( Qt) of sample plants was exponentially related to basal diameter for both lianas and trees; Qt of lianas increased more steeply with basal diameter than that of trees. By extrapolating the relationships between Qt and basal diameter to the inventory data of the study plot, we estimated that lianas contributed 12·8% to the annual stand canopy transpiration while comprising 2·3% of stand basal area, which probably reflected the top-heavy architecture of lianas., Our results indicate that the contribution of lianas to forest water dynamics may be several times greater than their contribution to forest basal area. This implies that a slight increase of liana abundance might have greater effects on water dynamics and, through competitions with trees for limited water, the carbon sequestration capacity of forests than expected from the increase in basal area. This study underlines the necessity of evaluating the relative importance of lianas to forest water dynamics in forests world-wide., A is available for this article. [ABSTRACT FROM AUTHOR]

This study investigated the difference in stand transpiration ( E) between upper (UP) and lower (LP) slope plots of a Japanese cypress ( Chamaecyparis obtusa) watershed to obtain catchment-scale E estimates. Sap flux-based stand-scale E estimates were conducted on the UP and LP, which had contrasting stand structures (diameter at breast height and tree height) despite being the same age. The plant area index was similar in the UP and LP, while the total sapwood area ( AS_stand) and the mean sap flux density ( JS) in the UP were 23% and ~30% lower, respectively, than those of the LP. Stand-scale E is the product of the AS_stand and JS in a stand. As a result, E in the UP was ~50% lower than that in the LP. This ratio was relatively constant throughout the year, which was supported by a similar decline in E, which resulted from soil water decline in the UP and LP. Canopy conductance ( GC) in the UP was ~50% smaller than that of the LP. In contrast to previous studies that showed a consistent JS along a slope, the differences in E between the UP and LP were caused by differences in AS_stand and JS, probably because the UP exhibited a lower GC per unit leaf area than the LP. Additionally, evapotranspiration ( ET), the sum of sap flux-scaled E plus rainfall interception, was 8-14% lower than the catchment water balance ET (precipitation minus runoff), which suggests the feasibility of calculating sap flux-scaled E for the two slope positions. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Stand transpiration ( E) estimated using the sap-flux method includes uncertainty induced by variations in sap flux ( F) within a tree (i.e. radial and azimuthal variations) and those between trees. Unlike radial variations, azimuthal variations are not particularly systematic (i.e. higher/lower F is not always recorded for a specific direction). Here, we present a theoretical framework to address the question on how to allocate a limited number of sensors to minimize uncertainty in E estimates. Specifically, we compare uncertainty in E estimates for two cases: (1) measuring F for two or more directions to cover azimuthal variations in F and (2) measuring F for one direction to cover between-tree variations in F. The framework formulates the variation in the probability density function for E ( σE) based on F recorded in m different azimuthal directions (e.g. north, east, south and west). This formula allows us to determine the m value that minimizes σE. This study applied the framework to F data recorded for a 55-year-old Cryptomeria japonica stand. σE for m = 1 was found to be less than the values for m = 2, 3 and 4. Our results suggest that measuring F for one azimuthal direction provides more reliable E estimates than measuring F for two or more azimuthal directions for this stand, given a limited number of sensors. Application of this framework to other datasets helps us decide how to allocate sensors most effectively. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Forest management (thinning and clearcutting) can reduce evapotranspiration and increase catchment runoff. By summarizing data on the increase in annual runoff (ΔQ) due to forest management at various sites and analysing data using linear regression, traditional studies have reported large unexplained variability among data for different sites. To improve the predictability of ΔQ, it might be useful to model ΔQ for specific species and regions while considering underlying processes. This study performed such modelling for Japanese cedar and cypress plantations in Japan. Model 1 predicts ΔQ assuming that ΔQ equals the decrease in canopy interception loss (ΔEi), which was further modelled by stem density using 46 data for interception loss. Model 2 predicts the potential maximum of ΔQ (ΔQmax) assuming that ΔQmax equals the sum of ΔEi and the decrease in canopy transpiration (ΔEt). Here, ΔEt was calculated using a model developed in our previous study. ΔQ predicted using Model 1 approximated ΔQ observed for seven catchments, and the errors in prediction were less than those derived from traditional linear-regression analysis. ΔQmax predicted using Model 2 was greater than the observed ΔQ for all catchments. Thus, Models 1 and 2 would be respectively useful in assessing the effectiveness and limitations of managing Japanese cedar and cypress plantations to secure water resources, which have been controversial in Japan. Furthermore, the concept of the models gives implications for studies on other species and regions, because the models have demonstrated how to improve predictability of ΔQ considering underlying processes with the input of commonly available data. [ABSTRACT FROM AUTHOR]

This study offers an unprecedented opportunity to estimate total sapwood area over an entire catchment (Ascat/Ag) using small-footprint light detection and ranging technology with a minimal amount of labour in field. Forty-two-year-old plantations of Japanese cypress (Hinoki; Chamaecyparis obtusa Sieb. et Zucc.) and Japanese cedar (Sugi; Cryptomeria japonica D. Don) vegetated the 2.98 ha experimental catchment. Field observations identified diameter at breast height (DBH) of all trees and produced the relationship between DBH and tree sapwood area (Astre). The sum of Astre generated actual values of Ascat/Ag. For light detection and ranging data analyses, local maximum filtering revealed height of tree apices (H) and tree number (N) with 9% omission errors. A novel process was developed to identify tree species by their apices based on height of the apices and canopy roughness. Four methods were tested. In Methods A-C, H was converted to Astre directly or via DBH, then, the sum of Astre created Ascat/Ag. H-Astre or H-DBH relationships were varied irrespective of labour-intensive measurements, and Ascat/Ag was underestimated up to 85% of actual value because of the smaller N. On the other hand, in Method D, ready-made stand density management diagrams (SDMDs) overestimated mean DBH. However, a product of overestimated mean Astre and the underestimated N was almost identical to the actual Ascat/Ag. The estimates were 84% and 95% of the true Ascat/Ag in Hinoki and Sugi, respectively, and the former will be more precise if the SDMD is suitable for the site as indicated through sensitivity analysis. [ABSTRACT FROM AUTHOR]

The large-scale expansion of Moso bamboo forests in Japan raises concerns about how vegetation will affect the hydrological cycle and local water resources. However, information on transpiration (E) is limited to study on a single bamboo stand with low culm density (4 000 ha-1). The present study conducted a year-round measurement of E in a high-density (11 000 ha-1) stand using sap-flow measurements, and additional measurements were made during summer in the previously studied low-density stand and a neighbouring Japanese cedar stand for comparison. Annual E of the high-density stand was estimated at 455 mm. Although the value was greater than those reported for neighbouring coniferous forests (250-370 mm), it was lower than previous measurements made in the low-density stand (567 mm). The daytime sap flux density of the high-density stand was generally less than half that in the low-density stand, resulting in similar daily maximum E values in those stands. In addition, E typically peaked before midday in the high-density stand followed by a rapid decline; the midday suppression of E led to decreased total E in the stand. Based on present and previous measurements of E, combined with the lower rainfall interception (I) reported for bamboo stands, water loss through evapotranspiration would be comparable between bamboo and coniferous forests. Present results also suggest that the E of bamboo stands does not have strong positive relationships with stand structural parameters (e.g., culm density and sapwood area) but possibly depends more on the sites' microenvironments (e.g., solar radiation). [ABSTRACT FROM AUTHOR]

Although changes in rainfall characteristics have been noted across the world, few studies have reported those in mountainous areas. This study was undertaken to clarify spatial and temporal variations in rainfall characteristics such as annual rainfall amount ( Pr), mean daily rainfall intensity ( η), and ratio of rain days ( λ) in mountainous and lowland areas in Taiwan. To this aim, we examined spatial and year-to-year variations and marginal long-term trends in Pr, η, and λ, based on rainfall data from 120 stations during the period 1978-2008. The period mean rainfall ( [ABSTRACT FROM AUTHOR]

In recent years, Moso bamboo ( Phyllostachys pubescens) forests have rapidly expanded in Japan by replacing surrounding coniferous and/or broadleaved forests. To evaluate the change in water yield from forested areas because of this replacement, it is necessary to examine evapotranspiration for Moso bamboo forests. However, canopy interception loss, one of the major components of evapotranspiration in forested areas, has been observed in only two Moso bamboo forests in Japan with relatively high stem density (~7000 stems/ha). There are, in fact, many Moso bamboo forests with much lower stem density. Thus, we made precipitation ( Pr), throughfall ( Tf) and stemflow ( Sf) observations for 1 year in a Moso bamboo forest with stem density of 3611 stems/ha and quantified canopy interception loss ( Ic). Pr and Ic for the experimental period were 1636 and 166 mm, respectively, and Ic/ Pr was 10%. The value was approximately the same as values for the other two Moso bamboo forests and lower than values for coniferous and broadleaved forests. On the other hand, Tf/ Pr and Sf/ Pr for our forest (86% and 4%, respectively) were approximately 10% of Pr larger and smaller than values for the other two Moso bamboo forests. These results suggest that the difference in stem density greatly affects precipitation partitioning (i.e. Tf/ Pr and Sf/ Pr) but does not greatly change Ic/ Pr. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In a deciduous larch forest in eastern Siberia, the mean and standard deviation of the total evapotranspiration ( E) during May to September (day of year (DOY) = 121-274) for 2003-2006 were 181.5 and 26.4 mm, respectively. The interannual variation (IAV) in the total E was caused by the IAV in E for the canopy-foliated period (DOY = 164-253), not by the IAV in the dates of leaf expansion and leaf fall. For the years with higher total E, E in the canopy-foliated period was consistently higher, which corresponded to the higher soil water content in these years. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

According to widely held belief, annual evapotranspiration (ET) for broadleaf forests is less than that for coniferous forests, resulting in higher annual runoff for broadleaf forests. We processed 82 catchment runoff and 126 interception loss data from temperate regions and found that although the belief is valid under conditions of broadleaf deciduous forests and high winter precipitation (e.g. the United States), it is invalid under conditions of broadleaf evergreen forests (e.g. New Zealand) or low winter precipitation (e.g. Japan). Thus, forest management policies based on this belief should be reconsidered on the basis of our results for regions with broadleaf evergreen forests or low winter precipitation. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article explores spatial and temporal variations in summer precipitation between 1976 and 2007 in mountain areas in Japan. It notes that positive correlations between the amount of precipitation and the mean depth of precipitation were collected from 28 stations. It mentions that a temporal distribution pattern, based on the data collected, contributed to the determination of hydrological cycles in Japanese mountain areas.

The article looks at a model that estimates monthly forest evapotranspiration (E) from monthly temperature in Japan. It mentions that the model's accuracy was tested using monthly E data derived using micrometeorological methods and short-term water balance for 15 Japan forest sites. It notes that the model overestimated monthly E, and could only be reduced by considering the effect of precipitation of E.

The article presents a study on the effects of bamboo forest expansion on water resources. Spatial and seasonal variations in throughfall (Tf) and canopy structure (Rf) were observed. Results of the study indicate that the change in leaf area index (LAI) has little impact on Tf and that Rf is a critical factor. The study suggests a sampling design for Tf measurements and the effects of forest expansion to evapotranspiration.

The article presents a study which examines the wet-canopy evaporation process within the forest canopy. It states that this process has been applied on eleven individual tress of various heights, ranging from two to fifty meters in Bornean tropical rainforests. It notes the area and structure of the forest, the sap flow and the meteorological measure. It also presents that the length of the canopy drying time after rainfall appears to be strongly related to meteorological conditions above and within the canopy.

Surface conductance Gs is a significant parameter for indicating the evaporative and photosynthetic properties of a vegetated surface. When comparing Gs values between different observation sites, some studies have used Gsmax and others have used Ĝsmax (where Gsmax is the maximum Gs value measured during the measurement period, and Ĝsmax is the maximum Gs value obtained with a vapour pressure deficit (VPD) of ≥ 1.0 kPa during the measurement period). In this study, we demonstrate a clear justification for using Gsmax instead of Gsmax when comparing Gs values between different sites. We examined whether both Ĝsmax and Gsmax lead to the same conclusions in classifying vegetated sites. Komatsu (2003b) [Hydrological Processes 17: 2503-2512] reported a clear relationship between canopy height h and Ĝsmax for coniferous forests with a projected leaf area index (LAI) of ≥ 3.0. We examined not only the relationship between h and Ĝsmax butalso the relationship between h and Gsmax for coniferous forests with a projected LAI of ≥ 3.0. Both Ĝsmax and Gsmax decreased with increasing h. However, the relationship between h and Gsmax was less well defined than the relationship between h and Ĝsmax because of biased Gsmax data. Consequently, we conclude that Ĝsmax is a more appropriate index than Gsmax to represent Gs for sites with different vegetation. [ABSTRACT FROM AUTHOR]

To our knowledge, no one has examined the canopy conductance of a Cryptomeria japonica plantation, although such forests are very common in Japan. We plan to examine the canopy conductance of a Cryptomeria japonica plantation (canopy height 8 m) based on 1-year sap-flow data using the simplified Penman-Monteith equation. This study examines the effect of the aerodynamic control of transpiration before calculating canopy conductance using the simplified Penman-Monteith equation, because the equation assumes that the effect of aerodynamic control is negligible. To examine the effect of aerodynamic control, we examined the dependency of the relationship between the vapour pressure deficit (VPD) and transpiration on wind speed, when solar radiation, air temperature, and soil water content do not limit transpiration greatly. The relationship between VPD and the heat pulse velocity measured 11 m above the ground was dependent on wind speed only when the wind speed was < 0.7 m s-1. This suggests that the effect of aerodynamic control was negligible when the wind speed was < 0.7 m s-1, but that the effect was not negligible when the wind speed was < 0.7 m s-1. Therefore, we should use data from when the wind speed was ≥ 0.7 m s-1 for calculating canopy conductance Gc, based on the simplified Penman-Monteith equation. Although this criterion is site specific, the methods used to develop it are applicable to other sites. [ABSTRACT FROM AUTHOR]

To our knowledge, there is no information on the canopy conductance of Cryptomeria japonica plantations, although such forests are very common in Japan. We examined the canopy conductance Gc of a C. japonica plantation based on 1-year sap-flow data using the simplified Penman-Monteith equation. After selecting data based on the criterion proposed in part 1 of this study (Komatsu et al., 2006. Hydrological Processes 20: this issue), we now examine Gc responses to meteorological factors. Gc was expressed using functions of solar radiation S (W m-2), the vapour pressure deficit D (kPa), and air temperature T (°C). The resulting functions were f1(S) = [(1000 + 30)S]/[1000(S + 30)], f2(D) = exp(-0.54D)/exp(-0.54), and f3(T) = {[(30 - 5) + 14](T - 5)}/{(30 - 5)[(T - 5) + 14]), where f1(S), f2(D), and f3(T) are functions expressing the Gc responses to S, D, and T respectively. The functions were characterized by comparing general functions for coniferous forests, which showed that it was necessary to consider f3(T) to reproduce the 1-year transpiration at the site, and that f1(S) and f2(D) determined here were not very different from the general functions. This paper is the first to determine Gc responses to meteorological factors for a C. japonica plantation. When predicting transpiration from a C. japonica plantation using hydrological or ecological models, the functions determined here should be used instead of the default functions of the models. [ABSTRACT FROM AUTHOR]

Previous studies reported relationships between stem diameter at breast height (DBH) and whole‐tree transpiration (Qt) across a variety of species and locations. It might be possible to develop a relationship between DBH and Qt with smaller variations when we focused on a single species. We attempted to develop such a relationship for Japanese cypress (Chamaecyparis obtusa), which is one of the major plantation species in Japan. We collated Qt for 51 Japanese cypress trees from nine different‐sized and different‐aged stands using the sap flux method. We found a strong linear correlation between DBH and the reference value of Qt at a vapour pressure deficit of 1 kPa (R = .883). This was a consequence of a strong correlation between DBH and sapwood area (AS_tree; R = .973) and the absence of a correlation between DBH and sap flux density (R = −.043). We confirmed that using the relationship between DBH and AS_tree, while assuming typical responses of sap flux density to meteorological factors, provides reasonable Qt estimates. This study also demonstrated how the DBH–Qt relationship can be applied to estimate changes in EC with changing forest management. [ABSTRACT FROM AUTHOR]