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Copyright of Comparative Education is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The OECD's PISA exercise has by now been widely critiqued. Whilst we agree with most concerns, we begin with the assumption that PISA will remain an enduring and powerful feature of the global educational landscape. Even if the PISA test itself were discontinued, a similar large-scale quantitative assessment exercise would soon arise to take its place. As such, we focus herein on strategies for rearticulating ILSAs such as PISA: the creative use of data to shift the exercise away from dissemination of one dominant worldview towards the recognition of alternatives. To do this, we discuss the approach and findings from our recent papers, and then suggest future directions. Rather than mere accommodation, re-articulation underscores an approach to critique that is generative for theory and practice, one that extends of the horizon of possibility beyond culturally saturated notions of 'good' education. [ABSTRACT FROM AUTHOR]

Extending recent analyses using PISA data, the current study utilises the OECD's Survey of Adult Skills (PIAAC) to test the central claims of knowledge capital theory. PIAAC has a distinct advantage over PISA in that it more directly tests levels of purported 'knowledge capital' across an entire national workforce, rather than offering approximations based on the performance of 15-year-old students. Findings from our two original studies reported herein further refute the tight linkage between cognitive levels and GDP growth per capita envisaged by proponents of knowledge capital, most notably the OECD and World Bank. These results suggest that knowledge capital theory is now degenerate. If scholars are willing to extend this reporting of results refuting knowledge capital theory, this will likely accelerate the theory's loss of momentum in the coming years. [ABSTRACT FROM AUTHOR]

Educational scholars, particularly those working in comparative education, have largely failed to recognise, let alone discuss, the impending finite-ness of global resources. The field continues to operate on an assumption of infinite resources, an implicit cultural horizon in place since at least the Western Enlightenment. It has missed the epochal shift that is now upon us; unable to contribute to the deep transformation of research and practices that has now become urgent. Herein we discuss how such concerns might be addressed, suggesting an approach that centres ontological alterity through comparative method as means of making the turn towards a sustainable future. [ABSTRACT FROM AUTHOR]

Herein we examine the dominant image of East Asian schools as marked by a darker side of widespread bullying, leading to high rates of youth suicide. First outlining the substantial literature on bullying in the English language, we turn to show how – paradoxically – the rates of bullying and suicide are no higher, or in nearly all cases, lower than both Anglo-American systems (Australia, England, New Zealand, United States) and high PISA performers (Canada, Finland, Estonia). To explain this, we extend a constructivist approach proposed by sociologists of Japanese youth, suggesting that recurrent 'moral panics' such as bullying are determined, at least in part, by underlying differences in self-construal and views of how society functions. This analysis contributes to recent work that has challenged persistent stereotypes of East Asian education, those images blocking deeper engagement with the underlying differences in approach and philosophy these systems represent. [ABSTRACT FROM AUTHOR]

Facing increasing critique that PISA focuses too narrowly on cognitive achievement and human/knowledge capital, the OECD has recently shifted some of its focus to student happiness. The 2017 Students' Well-Being report distinguishes between 'happy schools' and 'unhappy schools', showing that among students who combined high performance and life satisfaction, northern European countries topped the charts. Meanwhile, students in East Asian countries including Japan, China, Taiwan, Hong Kong, and Korea registered the lowest 'life satisfaction' scores among all participating countries. This piece points out some of the problems inherent in the OECD's recent turn to happiness, problematizing the OECD yardstick of life satisfaction. Attempting to keep the critique constructive, we suggest that the OECD may want to consider using alternative metrics, then briefly highlight one developed in East Asia from different first assumptions: the Interdependent Happiness Scale. In conclusion we flag, but cannot answer, some related educational questions concerning policy, pedagogy, and priorities for the future. [ABSTRACT FROM AUTHOR]

Founded on several highly influential quantitative studies, the past decade has witnessed the OECD and World Bank increasingly converge on the view that cognitive levels of students and education quality, as proxied by international large-scale assessments (ILSAs), are the primary determinant of national economic growth worldwide. More recent OECD and World Bank pronouncements have further suggested these dynamics are clearly illustrated in East Asia's education and 'Economic Miracle', in particular the cases of South Korea and Singapore. Herein we utilise the OECD's own data to examine this new development narrative, finding little evidence in support of these claims. [ABSTRACT FROM AUTHOR]

East Asian dominance in international large-scale assessments is widely known. This is often explained as an outcome of highly competitive, exam-oriented education systems in East Asia, wherein students partake in a fierce competition for limited college entrance. Although achievement scores may be comparatively higher, the argument goes, the relative success comes at a steep price, with the emphasis on high-stakes tests heightening student stress and anxiety. In this paper we refute this persistent and out-dated stereotype by focusing on changes in Japanese education over the past several decades. The two original studies we report herein show that not only do Japanese students feel less school-related anxiety and stress than they once did, but these levels are now comparable to students in America, Australia, and the United Kingdom. In showing that stereotypes do not match empirical realities, we seek to open a richer discussion around East Asian student achievement. We conclude by extending the discussion to recent changes in China, Taiwan, and South Korea. We then raise the possibility that fundamentally different outlooks on the learning process explain both differences in achievement and the persistence of the West’s distorted images of Japanese and East Asian education. [ABSTRACT FROM AUTHOR]

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]

Copyright of Comparative Education Review is the property of University of Chicago Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several recent, highly influential comparative studies have made strong statistical claims that improvements on global learning assessments such as PISA will lead to higher GDP growth rates. These claims have provided the primary source of legitimation for policy reforms championed by leading international organisations, most notably the World Bank and OECD. To date there have been several critiques but these have been too limited to challenge the validity of the claims. The consequence is continued utilisation and citation of these strong claims, resulting in a growing aura of scientific truth and concrete policy reforms. In this piece we report findings from two original studies that invalidate these statistical claims. Our intent is to contribute to a more rigorous global discussion on education policy, as well as call attention to the fact that the new global policy regime is founded on flawed statistics. [ABSTRACT FROM PUBLISHER]

There exists a significant incongruity between scientific knowledge and ordinary perceptions concerning the relation between forest and water (e.g. droughts and floods). Traditionally, forest hydrologists interpreted this incongruity using the deficit model, i.e. this incongruity is viewed as one that must be overcome through efforts to disseminate scientific knowledge more widely across society. However, one previous study suggested an alternative interpretation for the incongruity observed in Japan: the incongruity is induced by an enduring conflict between modern science and indigenous culture, one which purportedly promotes an “emotional” outlook to nature. This review attempts to clarify this alternative interpretation by utilizing a diverse range of disciplinary perspectives. We first clarify, using psychology and philosophy, that the “emotional” outlook of Japanese is rooted in a notion of self which is interdependent. Reviewing historical studies, we then find that the interdependent self was replaced by the notion of the independent self in the West in the Middle Ages. Since modern science was born out of this historical context in the seventeenth and eighteenth centuries, modern science assumes the same grammar of thought, i.e. begins with the notion of an independent self. We finally reveal that contemporary forest hydrology also has reproduced this grammar. We thus conclude that this difference in ontological grammar between contemporary forest hydrology and that of the ordinary public in Japan is a major cause for the incongruity between scientific knowledge and ordinary perceptions there. From this novel ontological perspective, we envision an alternative future of forest hydrology in Japan. [ABSTRACT FROM PUBLISHER]

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]

Previous studies have demonstrated a clear relationship between diameter at breast height (DBH) and tree transpiration ( Q) in multi-specific broadleaved forests. However, these studies were conducted with a limited range of tree sizes and species, and thus many multi-specific broadleaved forests fall outside these conditions. Therefore, this study examined the relationship between DBH and Q in a warm-temperate multi-specific broadleaved forest ( n = 12 species) with a wide range of tree sizes (5.0-70.0 cm DBH) using the Granier-type heat dissipation method. The results showed that, although sap flow density varied between individual trees and species, there was a significant relationship between log Q and log DBH ( r = 0.66, P < 0.001) because of the strong dependence of sapwood area on DBH. This study confirmed the applicability of the relationship for the stand transpiration ( E) estimates even in a multi-specific broadleaved forest with a wide variation in DBH. Our results also revealed that selecting the sample trees in descending order of DBH effectively reduced potential errors in E estimates for a specific sample size, as larger trees contribute more to E. This information should be useful for future studies investigating the transpiration of multi-specific broadleaved forests, reducing errors during the scaling-up procedure. [ABSTRACT FROM AUTHOR]

Stand transpiration ( E) estimated using the sap flux methods is affected by the azimuthal, radial, and tree-to-tree variations of sap flux. Although several studies have examined the relative importance of the three variations in estimating E, the seasonality of the three variations remains unknown. In the current study, we attempted to clarify whether the relative importance of these three variations could show seasonal changes. Using sap flux data measured in a subtropical cloud forest from August 2010 to July 2011, we calculated the differences resulting from omitting the three variations in estimating E. The effects of the three variations in estimating E showed seasonality. The azimuthal and tree-to-tree variations were more pronounced during winter, whereas the radial variation was more pronounced during summer. However, the effect of tree-to-tree variation was consistently much larger than the other two variations throughout the study period. The tree-to-tree variation is more important in estimating E monthly, seasonally and annually than both the azimuthal and radial variations, although all three variations have shown seasonality. In addition, the sensor allocation for summer would be acceptable for the practical estimation of E if aiming at the long time scale. [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]

Seeking to contribute to recent attempts to rethink the deepest foundations of the field, this paper offers news ways of contemplating time, specifically its relations to self, nihilism, and schooling. We briefly review how some leading Western thinkers have contemplated time before detailing Japanese scholars who have offered divergent, original, and arguably more sophisticated, theoretical accounts. We then illustrate these ideas by sketching how Japan ‘borrowed time’ following the abrupt political rupture of 1868, showing howLinear Timecame to be disseminated and diffused, largely through modern schooling. Last, we spotlight the nihilism that has arisen as consequence. Our primary aim is not empirical elaboration, however, but instead disclosure of a complex of relations that the field of comparative education has yet to discuss. We offer both the experience-cum-thought of Japan and this complex itself as reconstructive resources for the field which remains shallow in its parochial presumptions and unwillingness to engage ontologically. [ABSTRACT FROM PUBLISHER]

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]

Canopy transpiration ( E) varies among forest stands with different structures. To evaluate different E for Japanese cypress we observed E for 5 months, by use of the sap flow technique, in two adjacent stands of different ages with contrasting structures. Mean diameter at breast height was 13.5 and 44.6 cm and stem density was 2100 and 350 trees ha for the Sakuta and Hiwada plots, respectively. Mean E measured was 1.3 mm day for the Sakuta plot and 0.7 mm day for the Hiwada plot (or 53 % of that for the Sakuta plot). This difference between E was caused by differences between both mean stand sap flux density ( J) and stand sapwood area ( A): J for the Hiwada plot was 69 % of that for the Sakuta plot and A for the Hiwada plot was 75 % of that for the Sakuta plot. The difference between J was primarily caused by different reference J for given meteorological conditions, not by the different response of J to meteorological conditions. Previous studies of coniferous plantation forests in Japan reported that differences between E among stands with different structures were mainly caused by different A. This study revealed this is not always true, and that differences between J should also be considered when predicting differences between E among stands with different structures. [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]

Key message: Transpiration in conifer species was controlled by wind speed, similar to broadleaf species, indicating that caution is required when using the simplified Penman-Monteith equation. Abstract: The significance of aerodynamic controls on tree transpiration ( E) is critical when modeling E using the simplified Penman-Monteith equation. However, few studies have explicitly compared the significance of aerodynamic controls on E between conifer-type needles and broadleaf leaves. Although previous studies assumed that the response of E to wind speed ( w) could be insignificant in conifers, we hypothesized based on the evapotranspiration theory that the significance of E regulation by w is difficult to determine based on apparent such leaf-type differences. We performed sap flux measurements using a wind tunnel on two conifer species, Chamaecyparis obtusa var. formosana and Araucaria cunninghamii, and three broadleaf species, Swietenia mahagoni, Michelia compressa, and Plumeria rubra. Chamaecyparis obtusa and P. rubra showed no distinctive E response to w, while A. cunninghamii, S. mahagoni, and M. compressa had significant increases in E due to w, supporting our hypothesis. Our experimental and model calculation data suggested that the aerodynamic controls on E by w probably result from differences in stomatal conductance rather than leaf type. We emphasize the need to confirm the significance of aerodynamic controls on E using both direct and indirect measurements for coupling conditions between the leaf surface and atmosphere when modeling E, irrespective of leaf type. [ABSTRACT FROM AUTHOR]

Previous studies have revealed that the sapwood area at stand scale ( A) is an important factor determining changes in transpiration by canopy trees ( E). This study examined changes in A for four to six years after thinning of two Japanese cedar and two cypress plantation sites, each having three or four plots with different thinning intensities and one control plot. We focused on whether there was a difference in A (δ A) between a thinned plot and a control plot during the experimental period. We observed increased radial stem growth for plots with low stem density ( N) due to intensive thinning. However, δ A did not decrease to zero during the experimental period for any plot. The increased radial stem growth was not large enough to cancel the effect of low N due to thinning. These results imply that a lower E for thinned plantations as compared to non-thinned plantationsis remains for several years (more than 10 years, according to our results) after thinning and that thinning could be an effective method of reducing water consumption by canopy trees. [ABSTRACT FROM AUTHOR]

Difficult access to 40-m-tall emergent trees in tropical rainforests has resulted in a lack of data related to vertical variations in wood CO2 efflux, even though significant variations in wood CO2 efflux are an important source of errors when estimating whole-tree total wood CO2 efflux. This study aimed to clarify vertical variations in wood CO2 efflux for emergent trees and to document the impact of the variations on the whole-tree estimates of stem and branch CO2 efflux. First, we measured wood CO2 efflux and factors related to tree morphology and environment for seven live emergent trees of two dipterocarp species at four to seven heights of up to ∼40 m for each tree using ladders and a crane. No systematic tendencies in vertical variations were observed for all the trees. Wood CO2 efflux was not affected by stem and air temperature, stem diameter, stem height or stem growth. The ratios of wood CO2 efflux at the treetop to that at breast height were larger in emergent trees with relatively smaller diameters at breast height. Second, we compared whole-tree stem CO2 efflux estimates using vertical measurements with those based on solely breast height measurements. We found similar whole-tree stem CO2 efflux estimates regardless of the patterns of vertical variations in CO2 efflux because the surface area in the canopy, where wood CO2 efflux often differed from that at breast height, was very small compared with that at low stem heights, resulting in little effect of the vertical variations on the estimate. Additionally, whole-tree branch CO2 efflux estimates using measured wood CO2 efflux in the canopy were considerably different from those measured using only breast height measurements. Uncertainties in wood CO2 efflux in the canopy did not cause any bias in stem CO2 efflux scaling, but affected branch CO2 efflux. [ABSTRACT FROM PUBLISHER]

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]

To clarify characteristics of carbon (C) allocation in a Bornean tropical rainforest without dry seasons, gross primary production (GPP) and C allocation, i.e., above-ground net primary production (ANPP), aboveground plant respiration (APR), and total below-ground carbon flux (TBCF) for the forest were examined and compared with those from Amazonian tropical rainforests with dry seasons. GPP (30.61 MgC ha year, eddy covariance measurements; 34.40 MgC ha year, biometric measurements) was comparable to those for Amazonian rainforests. ANPP (6.76 MgC ha year) was comparable to, and APR (8.01 MgC ha year) was slightly lower than, their respective values for Amazonian rainforests, even though aboveground biomass was greater at our site. TBCF (19.63 MgC ha year) was higher than those for Amazonian forests. The comparable ANPP and higher TBCF were unexpected, since higher water availability would suggest less fine root competition for water, giving higher ANPP and lower TBCF to GPP. Low nutrient availability may explain the comparable ANPP and higher TBCF. These data show that there are variations in C allocation patterns among mature tropical rainforests, and the variations cannot be explained solely by differences in soil water availability. [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]

Understanding radial and azimuthal variation, and tree-to-tree variation, in sap flux density (Fd) as sources of uncertainty is important for estimating transpiration using sap flow techniques. In a Japanese cedar (Cryptomeria japonica D. Don.) forest, Fd was measured at several depths and aspects for 18 trees, using heat dissipation (Granier-type) sensors. We observed considerable azimuthal variation in Fd. The coefficient of variation (CV) calculated from Fd at a depth of 0–20 mm (Fd1) and Fd at a depth of 20–40 mm (Fd2) ranged from 6.7 to 37.6% (mean = 28.3%) and from 19.6 to 62.5% (mean = 34.6%) for the ­azimuthal directions. Fd at the north aspect averaged for nine trees, for which azimuthal measurements were made, was ­obviously smaller than Fd at the other three aspects (i.e., west, south and east) averaged for the nine trees. Fd1 averaged for the nine trees was significantly larger than Fd2 averaged for the nine trees. The error for stand-scale transpiration (E) estimates caused by ignoring the azimuthal variation was larger than that caused by ignoring the radial variation. The error caused by ignoring tree-to-tree variation was larger than that caused by ignoring both radial and azimuthal variations. Thus, tree-to-tree variation in Fd would be more important than both radial and azimuthal variations in Fd for E estimation. However, Fd for each tree should not be measured at a consistent aspect but should be measured at various aspects to make accurate E estimates and to avoid a risk of error caused by the relationship of Fd to aspect. [ABSTRACT FROM PUBLISHER]

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]

Changing trends in runoff and water balance under a warming atmosphere are a major subject of interest in recent climatic and hydrological research. Forest basins represent the most complex systems including critical hydrological processes. In this study, we investigate the relationship between annual total runoff ( Q), precipitation ( P), and mean temperature ( T) using observed data collected from 829 (forest) site years around the world. It is shown that the strong linear relationship between annual P and Q is a function of mean T. By empirically perturbing observed annual Q and P with T, a set of ΔQ-zero lines are derived for different mean T. To evaluate the extent to which the future changes in annual P and T alter Q, the future projections of ΔP and ΔT under a warming scenario (A1B) from five coupled AOGCMs (Atmosphere-Ocean General Circulation Models) are compared with the empirical ΔQ-zero lines derived in this study. It is found that five AOGCMs show different distributions with respect to the ΔQ-zero lines, which can be attributed to the contrasting dominant sensitivities of various influencing factors to water balance partitioning among models. The knowledge gained in this empirical study is helpful to predict water resources changes under changing climate as well as to interpret hydrologic simulations in AOGCM future projections. [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]

Sap flow techniques are practical tools for estimating tree transpiration. Though many previous studies using sap flow techniques did not consider azimuthal variations of sap flux density ( F) on xylem trunk to estimate tree transpiration, a few studies reported that ignoring the azimuthal variations in F could cause large errors in tree transpiration estimates for some tree species. Therefore, examining azimuthal variations in F for major plantation tree species is critical for estimating tree transpiration. Using the thermal dissipation method, we examined azimuthal variations in F in six trees of Japanese cypress Chamaecyparis obtusa (Sieb. et Zucc.) Endl., which is one of the most common plantation tree species in Japan. We recorded considerable variations among F at four different azimuthal directions. The F value for one aspect was more than 100% larger than those for the other aspects. We calculated differences between tree transpiration estimates based on F for one to three azimuthal directions and those based on F for four aspects. The differences relative to tree transpiration estimates based on F for four aspects were typically 30, 20, and 10% in accordance with the F for one, two, and three measurement aspects, respectively. This finding indicates that ignoring azimuthal variations could cause large errors in tree transpiration estimates for Japanese cypress. [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.

Temperature data in the mountain forest regions are often extrapolated from temperature data recorded at base stations at lower elevation. Such extrapolation is often based on elevation differences between target regions and base stations at low elevation assuming a constant temperature lapse rate throughout the year. However, this assumption might be problematic where slope circulation is active and decoupled from the regional circulation. To model the seasonal change in the lapse rate, the authors compared daily maximum ( Tmax) and minimum temperatures ( Tmin) observed at a mountain forest site (Kog–Ma; 1300-m altitude) with those observed at the bottom of the basin (Chiang–Mai; 314-m altitude) in northern Thailand, where slope circulation is active and decoupled from the regional circulation. The difference in Tmax between Kog–Ma and Chiang–Mai (Δ Tmax; Kog–Ma minus Chiang–Mai) was relatively unchanged throughout the year. However, the difference in Tmin between Kog–Ma and Chiang–Mai (Δ Tmin) changed seasonally. Thus, assuming a constant lapse rate throughout the year could cause large errors in extrapolating Tmin data in mountainous areas in northern Thailand. The difference Δ Tmin was related to nighttime net radiation (Rn), suggesting that nocturnal drainage flow affects the determination of Δ Tmin. This relationship would be useful in formulating seasonal changes in the lapse rate for Tmin. As Rn data are generally unavailable for meteorological stations, an index that relates to the lapse rate for Tmin and is calculated from Tmax and Tmin data is proposed. This index might be useful for accurately estimating Tmin values in mountainous regions in northern Thailand. [ABSTRACT FROM AUTHOR]

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.

In this study, we aimed to assess how sample sizes affect confidence of stand-scale transpiration (E) estimates calculated from sap flux (Fd) and sapwood area (AS_tree) measurements of individual trees. In a Japanese cypress plantation, we measured Fd and AS_tree in all trees (n = 58) within a 20 x 20 m study plot, which was divided into four 10 x 10 subplots. We calculated E from stand AS_tree (AS_stand) and mean stand Fd (JS) values. Using Monte Carlo analyses, we examined the potential errors associated with sample sizes in E, AS_stand and JS using the original AS_tree and Fd data sets. Consequently, we defined the optimal sample sizes of 10 and 15 for AS_stand and JS estimates, respectively, in the 20 x 20 m plot. Sample sizes larger than the optimal sample sizes did not decrease potential errors. The optimal sample sizes for JS changed according to plot size (e.g., 10 x 10 and 10 x 20 m), whereas the optimal sample sizes for AS_stand did not. As well, the optimal sample sizes for JS did not change in different vapor pressure deficit conditions. In terms of E estimates, these results suggest that the tree-to-tree variations in Fd vary among different plots, and that plot size to capture tree-to-tree variations in Fd is an important factor. The sample sizes determined in this study will be helpful for planning the balanced sampling designs to extrapolate stand-scale estimates to catchment-scale estimates. [ABSTRACT FROM AUTHOR]

In recent years, moso bamboo ( Phyllostachys pubescens) forest areas in Japan have rapidly expanded, and bamboo is now invading nearby natural or plantation forests. To date, only one study has examined the rainfall interception of a moso bamboo forest. In that study, it was reported that the interception ratio (interception/rainfall) of the bamboo forest did not exceed the interception ratios of other natural and plantation forests ( n = 4) in Japan. To expand the current state of knowledge about rainfall interception of bamboo forests, we measured throughfall and stemflow at another bamboo forest site. Annual rainfall ( Rf), throughfall ( Tf), and stemflow ( Sf) during the measurement period were 2,105, 1,556, and 322 mm, respectively. Annual rainfall interception at the plot ( I) was 228 mm. Tf/Rf, Sf/Rf, and I/Rf were 73.9, 15.3, 10.8%, respectively. I/Rf was less than 20% throughout the year except in October, the month with lowest rainfall. We also summarized rainfall interception data from 19 other natural and plantation forests. The I/Rf value of our site did not exceed the I/Rf values of these natural and plantation forests ( n = 19). Our data will be useful for assessing changes in water resources that result from replacement of natural or plantation forests by bamboo forests. [ABSTRACT FROM AUTHOR]

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]