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This study proves the existence of correlative inhibition, and demonstrates that role of light intensity in the growth and death varies among different levels of branching units. Within a tree crown, local light conditions vary within a branch and among different branches. Although the role of light intensity in the growth and survival of branches has been studied extensively, the effects of the spatial heterogeneity of light intensity on different levels of branching units are poorly understood. We investigated the effects of light intensity on the growth and death of primary branches (those branching off from the main stem) and secondary branches (those branching off from the primary branches) in the whole crown of Sakhalin spruce (Picea glehnii). The growth of shoot extension on a primary branch or secondary branch may be inhibited on sunlit trees compared to shaded trees when branches under relatively low local light intensity (rPPFD) levels, but it was increased with increasing rPPFD more rapidly on sunlit trees than on shaded trees. A relative importance analysis showed that, in the primary branches, branch growth was mainly influenced by rPPFD, and less influenced by its vertical position within the crown. However, the probability of death of a primary branch was equally influenced by its position within the crown and rPPFD. In contrast, rPPFD played a dominant role in both the growth and death of secondary branches. The results of our study suggest that local light intensity alone cannot fully explain the growth and survival of primary branches simultaneously, and the effects of light intensity vary among different levels of branching units.

Iron-sulfur (Fe-S) proteins play crucial roles in plastids, participating in photosynthesis and other metabolic pathways. Fe-S clusters are thought to be assembled on a scaffold complex composed of SUFB, SUFC and SUFD proteins. However, several additional proteins provide putative scaffold functions in plastids, and, therefore, the contribution of SUFB, C and D proteins to overall Fe-S assembly still remains unclear. In order to gain insights regarding Fe-S cluster biosynthesis in plastids, we analyzed the complex composed of SUFB, C and D in Arabidopsis by blue-native polyacrylamide gel electrophoresis. Using this approach, a major complex of 170 kDa containing all subunits was detected, indicating that these proteins constitute a SUFBC2D complex similar to their well-characterized bacterial counterparts. The functional effects of SUFB, SUFC or SUFD depletion were analyzed using an inducible RNAi silencing system to specifically target the aforementioned components; resulting in a decrease of various plastidic Fe-S proteins including the PsaA/B and PsaC subunits of photosystem I, ferredoxin and glutamine oxoglutarate aminotransferase. In contrast, the knockout of potential Fe-S scaffold proteins, NFU2 and HCF101, resulted in a specific decrease in the PsaA/B and PsaC levels. These results indicate that the functions of SUFB, SUFC and SUFD for Fe-S cluster biosynthesis cannot be replaced by other scaffold proteins and that SUFBC2D, NFU2 and HCF101 are involved in the same pathway for the biogenesis of PSI. Taken together, our results provide in vivo evidence supporting the hypothesis that SUFBC2D is the major, and possibly sole scaffold in plastids. This article is protected by copyright. All rights reserved.

Summary Proteins that contain iron–sulfur (Fe–S) clusters play pivotal roles in various metabolic processes such as photosynthesis and redox metabolism. Among the proteins involved in the biosynthesis of Fe–S clusters in plants, the SUFB subunit of the SUFBCD complex appears to be unique because SUFB has been reported to be involved in chlorophyll metabolism and phytochrome‐mediated signaling. To gain insights into the function of the SUFB protein, we analyzed the phenotypes of two SUFB mutants, laf6 and hmc1, and RNA interference (RNAi) lines with reduced SUFB expression. When grown in the light, the laf6 and hmc1 mutants and the SUFB RNAi lines accumulated higher levels of the chlorophyll biosynthesis intermediate Mg‐protoporphyrin IX monomethylester (Mg‐proto MME), consistent with the impairment of Mg‐proto MME cyclase activity. Both SUFC‐ and SUFD‐deficient RNAi lines accumulated the same intermediate, suggesting that inhibition of Fe‐S cluster synthesis is the primary cause of this impairment. Dark‐grown laf6 seedlings also showed an increase in protoporphyrin IX (Proto IX), Mg‐proto, Mg‐proto MME and 3,8‐divinyl protochlorophyllide a (DV‐Pchlide) levels, but this was not observed in hmc1 or the SUFB RNAi lines, nor was it complemented by SUFB overexpression. In addition, the long hypocotyl in far‐red light phenotype of the laf6 mutant could not be rescued by SUFB overexpression and segregated from the pale‐green SUFB‐deficient phenotype, indicating it is not caused by mutation at the SUFB locus. These results demonstrate that biosynthesis of Fe–S clusters is important for chlorophyll biosynthesis, but that the laf6 phenotype is not due to a SUFB mutation., Significance Statement We demonstrate that Fe‐S biosynthesis is required for Mg‐protoporphyrin monomethylester cyclase activity, an essential step in the synthesis of the chlorophyll precursor protochlorophyllide. However, we show that the long hypocotyl phenotype reported for the laf6 mutant is not due to a deficiency in the Fe‐S biosynthesis protein SUFB, but instead is the result of a second site mutation.

In order to understand the relationships between understory bamboo and soil properties, we compared microbial community structures in the soil of a Betula ermanii boreal forest with Sasa kurilensis present and removed using high-throughput DNA sequencing. The presence of understory S. kurilensis strongly affected soil properties, including total carbon, total nitrogen, nitrate, and the C:N ratio as well as relative soil moisture. Marked differences were also noted in fungal and bacterial communities between plots. The relative abundance of the fungal phylum Ascomycota was 13.9% in the Sasa-intact plot and only 0.54% in the Sasa-removed plot. Among the Ascomycota fungi identified, the most prevalent were members of the family Pezizaceae. We found that the abundance of Pezizaceae, known to act as mycorrhizal fungi, was related to the amount of total carbon in the Sasa-intact plot. The relative abundance of Proteobacteria was significantly higher, whereas those of Planctomycetes and Actinobacteria were lower in the Sasa-intact plot than in the Sasa-removed plot. Furthermore, the results obtained suggest that some species of the phylum Planctomycetes are more likely to occur in the presence of S. kurilensis. Collectively, these results indicate that the presence of S. kurilensis affects microbial communities and soil properties in a B. ermanii boreal forest.

Despite the relevance of leaf area index (LAI) to forest productivity, few studies have focused on the interannual variability of LAI of an evergreen stand and its relationship with stand growth and meteorological factors. We estimated the change in LAI of an evergreen conifer (Chamaecyparis obtusa) stand over 19 years from a dataset using allometric methods. The LAI varied between 7.1 and 8.8 m2 m−2, with a 95% confidence interval of 2 m−2 over the 19 years. This LAI range was maintained such that the gradual increase in leaf area (LA) of the largest trees counterbalanced the gradual loss in LA of the smallest trees. Meanwhile, more trees showed a temporary decrease in LA in years with low summer precipitation. The LAI and current-year mean temperature for July and August (TJA) were weakly correlated, whereas the correlation coefficient increased (r = 0.93) when LAI was correlated with the moving average TJA over the previous 6 years, which agreed with the estimated turnover time of canopy foliage. The annual stem biomass growth rate was significantly positively correlated with summer precipitation, but not with LAI. These results will be useful for refining models in studies on forest growth and global climate change.

The increase in light availability resulting from canopy changes or opening is not always beneficial and can inhibit photosynthesis of tree seedlings already under other environmental stress. Tree seedlings' responses to compounded abiotic stress depend on their life-history traits, and understanding the variations of such responses is important for understanding population dynamics under a changing climate. In this study we investigate how the photosynthesis of juveniles of two canopy tree species with different life-history traits, Abies sachalinensis and Betula ermanii, differs in two contrasting sites at a sub-boreal forest in northern Japan—one under a deciduous canopy (Closed site) and the other at a wide canopy opening (Open site). Seedlings at the Open site had low Fv/Fm (quantum yield of photosystem II) for a longer period than those at the Closed site. Abies sachalinensis at the Closed site showed lower Fv/Fm in spring than those at the Open site, but recovered after the canopy's new leaves flushed, indicating its acclimation to the shaded condition. Mean Pmax (light-saturated photosynthetic rate at ambient CO2 levels) of A. sachalinensis seedlings was affected by site and air temperature, while B. ermanii seedlings were also affected by precipitation. Only B. ermanii's seedlings presented growth in the period studied, in spite of observed mid-day drops to Fv/Fm attributed to water-deficit-related photoprotection. Results suggest that the climate change predicted for the Hokkaido area may increase the competitive advantage of broad-leaved deciduous species, such as B. ermanii, in relation to evergreen conifers like A. sachalinensis.

Stem diameter at breast height (DBH) and tree height (H) are commonly used measures of tree growth. We examined patterns of height growth and diameter growth along a stem using a 20-year record of an even-aged hinoki cypress (Chamaecyparis obtusa (Siebold & Zucc.) Endl.) stand. In the region of the stem below the crown (except for the butt swell), diameter growth rates (ΔD) at different heights tended to increase slightly from breast height upwards. This increasing trend was pronounced in suppressed trees, but not as much as the variation in ΔD among individual trees. Hence, ΔD below the crown can be regarded as generally being represented by the DBH growth rate (ΔDBH) of a tree. Accordingly, the growth rate of the stem cross-sectional area increased along the stem upwards in suppressed trees, but decreased in dominant trees. The stem diameter just below the crown base (D_[CB]), the square of which is an index of the amount of leaves on a tree, was an important factor affecting ΔDBH. D_[CB] also had a strong positive relationship with crown length. Hence, long-term changes in the D_[CB] of a tree were associated with long-term changes in crown length, determined by the balance between the height growth rate (ΔH) and the rising rate of the crown base (ΔH_[CB]). Within the crown, ΔD's were generally greater than the rates below the crown. Even dying trees (ΔD ≈ 0 below the crown) maintained ΔD > 0 within the crown and ΔH > 0 until about 5 years before death. This growth within the crown may be related to the need to produce new leaves to compensate for leaves lost owing to the longevity of the lower crown. These results explain the different time trajectories in DBH-H relationships among individual trees, and also the long-term changes in the DBH-H relationships. The view that a rise in the crown base is strongly related to leaf turnover helps to interpret DBH-H relationships.

Iron-sulfur (Fe-S) proteins play crucial roles in plastids, participating in photosynthesis and other metabolic pathways. Fe-S clusters are thought to be assembled on a scaffold complex composed of SUFB, SUFC and SUFD proteins. However, several additional proteins provide putative scaffold functions in plastids, and, therefore, the contribution of SUFB, C and D proteins to overall Fe-S assembly still remains unclear. In order to gain insights regarding Fe-S cluster biosynthesis in plastids, we analyzed the complex composed of SUFB, C and D in Arabidopsis by blue native-polyacrylamide gel electrophoresis. Using this approach, a major complex of 170 kDa containing all subunits was detected, indicating that these proteins constitute a SUFBC

Abies sachalinensis and Picea glehnii are co-dominant tree species and major components of the forests of Hokkaido, Japan. Recent work suggests that a reversal in potential competitive superiority at different developmental stages could be important to explain their coexistence. Such shifts in competitive advantage can be mechanistically understood by studying the corresponding physiological differences between distinct life stages. Accordingly, our objective was to investigate in the field the photosynthesis of shade-growing juveniles of these species from two different size-classes, seedlings and saplings. Our results show that seedlings of both species had higher concentrations of photoprotective xanthophylls than saplings, especially in spring, and suggest that seedlings have a lower threshold of stress tolerance than saplings. Photosynthetic capacity per needle area and lateral shoot extension rate decreased from the seedling to the sapling stage in A. sachalinensis, while in P. glehnii, both increased from the seedling to the sapling stage. Abies sachalinensis had higher photosynthetic rates at the seedling stage but lower rates at the sapling stage than P. glehnii. Nevertheless, A. sachalinensis had a higher lateral shoot extension rate than P. glehnii at both stages. Our physiological results support previous ecological observations that A. sachalinensis is a superior competitor to P. glehnii in the understory, and show that its competitive advantage is higher at the seedling stage than at the sapling stage.

The present paper shows simulated results of seasonal and inter-annual variations in energy and carbon exchanges and forest dynamics in a sub-boreal deciduous forest using a fully coupled atmosphere–vegetation interaction model [multilayered integrated numerical model of surface physics-growing plants interaction (MINoSGI)]. With careful adjustment of site-specific eco-physiological parameters, MINoSGI reproduced successfully stand biomass–tree density relationship based on the forest inventory data for 7 years (1999–2005) and seasonal and inter-annual variations in energy and CO2 fluxes measured by means of eddy covariance technique for 3 years (2003–2005) in the sub-boreal forest, northern Japan. In addition, MINoSGI estimated annual evapotranspiration (E vt) at 328.6 ± 25.8 mm year−1, net primary production (NPP) at 372.1 ± 31.5 gC m−2 year−1 and net ecosystem exchange (NEE) at −224.2 ± 32.2 gC m−2 year−1. We found the estimate of annual NEE in our site lies among the estimates at other forest stands with the almost same climatic conditions in northern Japan, although the tree species and stand age of these forests are different from those of our site. Overall, MINoSGI was found useful to present simultaneous simulations of forest dynamics, surface energy, and carbon exchanges of a forest stand in the future from micro-meteorological and ecophysiological points of view.

A consistent measure of forest canopy height is required for among-site comparisons of meteorological properties and for comparison of model results such as distributions of wind and other scalars calculated by large eddy simulations with observations. The aerodynamic canopy height has been proposed as a useful measure of canopy height, which is determined by micrometeorological methods without depending on stand inventory data. However, the aerodynamic canopy height is obtainable only if the necessary meteorological instruments are installed. In this study, we explored an alternative measure of forest canopy height based on tree inventory data. When cumulative trunk basal area from the shortest tree is plotted against corresponding individual tree height, it shows a sigmoidal curve with its inflection point occurring at a height class. The above-ground height of this inflection point (hereafter cumulative basal area inflection (CuBI) height) is defined as forest canopy height, as many tall trees with relatively large basal area belong to this height class. The difference between the aerodynamic canopy height and the CuBI height was always smaller than 12%, whereas the differences exceeded 20% for at least one of the forests when canopy height was determined using alternate methods. This suggests that, unlike other canopy height definitions, CuBI height is a consistent index of the aerodynamic canopy height, little affected by criterion of the trees composing the upper canopy or by the presence/absence of many shorter understory trees. Because chronological changes in size-structure of tree height and trunk diameter have long been studied for many forests, CuBI height may be used as an index of chronological change in the aerodynamic canopy height.

Four 2-year watering treatments were applied to Betula ermanii seedlings to investigate their responses to soil water conditions: ID [irrigated well (I) in the previous year and water deficit (D) in the current year], DD, DI, and II. RGR of the seedlings in current-year water deficit without experiencing previous-year water deficit (ID) was smaller than that of seedlings irrigated well in both years (II). Surprisingly, RGR did not differ between 2-year-water-deficited (DD) and -well-irrigated (II) treatments. There was no difference in the area-based photosynthetic rate of the late leaves, which are formed in the current-year environment, between the four water treatments, but their leaf longevity was shortened by water deficit. Area-based photosynthetic rate of the early leaves, whose buds are formed in the previous year environment, was smaller in ID than in II, but it did not differ between DD and II. The de-epoxidation state of the xanthophyll cycle was greater in ID than in DD. Leaf mass per area (leaf dry weight/leaf area) did not differ among the four water treatments. Specific root length (root total length/root dry weight) did not differ between ID and II. It was greater in DD than in II, probably resulting in increased water uptake efficiency. Photoprotective systems such as xanthophyll contents and antioxidant enzyme activities did not differ among the four treatments. Morphological responses of B. ermanii roots seem to be important as whole-plant-level responses to water deficit for maintaining RGR, in addition to leaf-level photosynthetic and phenological responses of two types of leaves. Our results partly explain how B. ermanii seedlings survive and maintain growth even under varying soil water conditions in the boreal forest.

The response of Picea glehnii, a cold-tolerant species in the boreal zone, to air temperature (T) was investigated for its cold-acclimated needles (i.e. the ones subjected to gradual decrease in T) and nonacclimated needles (i.e. the ones subjected to a sudden decrease in T) were compared under low temperature. Cold-acclimated needles showed a greater increase of zeaxanthin and lutein contents than nonacclimated ones, whereas the nonacclimated needles showed a greater increase of thylakoid-bound ascorbate peroxidase (tAPX) activity than cold-acclimated ones under chilling conditions (after cold acclimation). These results suggest that: (1) low T induces the increase of zeaxanthin and lutein content, and tAPX activity; (2) accumulated zeaxanthin and lutein protect needles from photooxidative stress by dissipating excess energy before the reactive oxygen species (ROS) are formed in response to a gradual decrease in T (with cold acclimation and subsequent chilling condition), and by tAPX scavenging ROS formed in the case of a sudden decrease in T (without cold acclimation and chilling condition).

Radial growth responses to climate were studied in two species of birch broadly distributed across Kamchatka Peninsula. Wood cores were obtained in different locations and environments, from upper to lower treelines, and from wet maritime sites at the Pacific to the subcontinental interior of the peninsula. Response functions were calculated using the four longest meteorological records (1920s–2000) in Kamchatka. In Betula ermanii Cham., the dominant species in mountains and maritime woodlands, ring width in high-elevation (500–600 m) trees increased with warm and less rainy June and July and decreased with rainy/snowy cool weather during the prior September and October. Radial growth in B. ermanii low-elevation trees increased with higher winter precipitation, suggesting that water from melting snow prevents water stress and possibly desiccation in low-elevation trees. In Betula platyphylla Sukaczev, a common taiga species in interior Kamchatka, low summer temperatures limited growth at its upper distributional limit (300–350 m) and in cool, wet sites dominated by Picea ajanensis Lindl. et Gord. On drier sites dominated by Larix cajanderii Mayr., growth was limited by warm April and dry June weather. Variable responses along elevation–continentality gradients reinforce the necessity of a site-dependent differentiation for the assessment of impacts of climate change on species performance and geographic range shifts.

A simulation study was carried out to investigate simultaneously the effects of eco-physiological parameters on competitive asymmetry, self-thinning, stand biomass and NPP in a temperate forest using an atmosphere–vegetation dynamics interactive model (MINoSGI). In this study, we selected three eco-physiological relevant parameters as foliage profiles (i.e. vertical distribution of leaf area density) of individual trees (distribution pattern is described by the parameter η), biomass allocation pattern in individual tree growth (χ) and the maximum carboxylation velocity (Vmax). The position of the maximal leaf area density shifts upward in the canopy with increasing η. For scenarios with η 12 (foliage concentrated in the uppermost canopy layer), a low degree of competitive asymmetry was produced. These scenarios resulted in the survival of subordinate trees due to a brighter lower canopy environment when η 12. In contrast, competition between trees was most asymmetric when 4 ≤ η ≤ 12 (vertically widespread foliage profile in the canopy), especially when η = 8. In such cases, vertically widespread foliage of dominant trees lowered the opportunity of light acquisition for subordinate trees and reduced their carbon gain. The resulting reduction in carbon gain of subordinate trees yielded a higher degree of competitive asymmetry and ultimately higher mortality of subordinate trees. It was also shown that 4 ≤ η ≤ 12 generated higher self-thinning speed, smaller accumulated NPP, litter-fall and potential stand biomass as compared with the scenarios with η 12. In contrast, our simulation revealed small effects of χ or Vmax on the above-mentioned variables as compared with those of η. In particular, it is notable that greater Vmax would not produce greater potential stand biomass and accumulated NPP although it has been thought that physiological parameters relevant to photosynthesis such as Vmax influence dynamic changes in forest stand biomass and NPP (e.g. the greater the Vmax, the greater the NPP). Overall, it is suggested that foliage profiles rather than biomass allocation or maximum carboxylation velocity greatly govern forest dynamics, stand biomass, NPP and litter-fall.

We examined the effects of different life history strategies and tree competition on species coexistence in a northern coniferous forest. We investigated the growth and demography of trees with stems ≥1 cm dbh in a 2-ha study plot in the Taisetsu Mountains of northern Japan. Three species, Abies sachalinensis, Piceajezoensis, and Piceaglehnii, were found to be dominant in the forest. A. sachalinensis was the most dominant species in the understory, while the two Picea spp. were more abundant in the larger dbh size classes. The turnover rate of A. sachalinensis was about twice that of the Picea spp. The relative growth rate of understory trees in each species did not differ between different canopy conditions (closed canopy or canopy gap). The competitive advantage between A. sachalinensis and P. glehnii switched as they grew from understory (A. sachalinensis superior competitor) to canopy trees (P. glehnii superior competitor). Meanwhile, A. sachalinensis and P. jezoensis exhibited different environmental preferences. We propose that reversal in competitive superiority between different growth stages and trade-off between longevity and turnover are more important factors to promote their coexistence than regeneration niche differentiation related to canopy gaps in this sub-boreal coniferous forest.

In a Japanese forest, CH4 uptake rate and methanotrophic community structure in the soil were investigated at four sites of different vegetation. At two of these sites, undergrowth was dominated by Sasa senanensis, and that of another was dominated by Sasa kurilensis. At the rest site, undergrowth had been removed artificially. The tree-layer composition differed between the two sites with S. senanensis, but tree layer of the other two sites were dominated by the same species. At the site lacking undergrowth, observed CH4 uptake rate was twice as high as that at the other sites. Under laboratory conditions, soil sample from the site lacking undergrowth exhibited CH4 consumption rate higher than that of the adjacent site with the same dominating tree species. The community structures of methanotrophs were investigated with denaturing gradient gel electrophoresis (DGGE) of the gene encoding particulate methane monooxygenase (pmoA). The banding patterns observed were different depending on the type of undergrowth vegetation. The sequences of the DGGE bands were closely related to each other and belonged to the “upland soil cluster alpha” (USCα). These results imply possible close relationship between the undergrowth vegetation and methanotrophic communities in forest soils.

Roughness length and zero-plane displacement over boreal, cool- and warm-temperate forests were observed and parameterised using forest structure data. Previous models for roughness length and zero-plane displacement using leaf area index and frontal area index did not describe intersite differences, and the model for zero-plane displacement did not express seasonal variations with the change of leaf area that was smaller in dense forest than in sparse forest. The observed results show that intersite differences of normalised zero-plane displacement were related to stand density, and seasonal variations were related to leaf area index at each forest, with the degree depending on stand density. From these observations, a new concept is proposed for normalised zero-plane displacement: the basal part is primarily determined by the density of stems and branches (stand density), while the seasonal variation depends on the density of leaves (leaf area index), which is limited to the residual of the basal part. Based on this concept, a new model was developed and verified to express both intersite differences and seasonal variations in observed roughness length and zero-plane displacement.

We used an aerodynamic method to objectively determine a representative canopy height, using standard meteorological measurements. The canopy height may change if the tree height is used to represent the actual canopy, but little work to date has focused on creating a standard for determining the representative canopy height. Here we propose the ‘aerodynamic canopy height’ h a as the most effective means of resolving the representative canopy height for all forests. We determined h a by simple linear regression between zero-plane displacement d and roughness length z 0, without the need for stand inventory data. The applicability of h a was confirmed in five different forests, including a forest with a complex canopy structure. Comparison with stand inventory data showed that h a was almost equivalent to the representative height of trees composing the crown surface if the forest had a simple structure, or to the representative height of taller trees composing the upper canopy in forests with a complex canopy structure. The linear relationship between d and z 0 was explained by assuming that the logarithmic wind profile above the canopy and the exponential wind profile within the canopy were continuous and smooth at canopy height. This was supported by observations, which showed that h a was essentially the same as the height defined by the inflection point of the vertical profile of wind speed. The applicability of h a was also verified using data from several previous studies.

In order to more accurately evaluate the functional activity of forest stands by canopy production and evapotranspiration, we improved the methods for field measurements and statistical modeling to estimate foliage configuration (spatial distribution of leaves) while simultaneously reconstructing the three-dimensional photosynthetically active photon flux density (PPFD) distribution (PPFD pattern) in a forest canopy. By using a sensor (photodiode) array, a PPFD pattern was observed in summer 2002 under the canopy in an even-aged, pure stand of Japanese mountain birch Betula ermanii Cham. (17-year-old) in Hokkaido, northern Japan. A Markov Chain Monte Carlo (MCMC) sampling technique is developed such that a set of foliage configurations generated by the model referred to as the Gibbs foliage canopy (GFC) approximates the field-measured PPFD pattern. The posterior distribution of the foliage configurations is generated by the parallel tempering MCMC of eight independent series of foliage configurations. The GFC model generated the posterior distribution of the LAI estimates (mean 4.56) that appeared to be appropriate in comparison to other LAI estimates of the B. ermanii stand based on the indirect and nondestructive methods by LAI-2000 (LAI = 3.43) and litterfall traps (LAI = 5.56) because they could be under- and overestimated, respectively. Our evaluations of the canopy production and evapotranspiration rates suggest that the relationship between LAI and canopy functions was not very simple because it depended on the nonlinear functional forms of the leaf responses of photosynthesis and transpiration to PPFD. The current study demonstrates an application of MCMC techniques that can generate a set of possible structures of unobserved/unobservable objects based on the high resolution data set obtained by some indirect (or remote-sensing) methods.

We investigated how removal of understory dwarf bamboo (Sasa kurilensis Makino et Shibata) affected growth and water use of young Betula ermanii Cham. trees in a secondary forest in northern Japan. We compared current-year shoot morphology, leaf water-relations characteristics, and whole-tree water use of B. ermanii trees growing with dwarf bamboo in the understory (intact plot) to those of trees growing where dwarf bamboo was experimentally removed (removal plot). Current-year shoot length and internode frequency increased, while internode length and individual leaf area decreased in response to dwarf bamboo removal. Carbon isotope composition (δ13C) of leaves did not change indicating that leaf water-use efficiency was unaffected by the presence/absence of dwarf bamboo. Pressure–volume analysis indicated that leaves in the removal plot had lower water uptake ability. During mid-summer, trees in the removal plot sustained high sap flow velocity after peaking at midday, while that of trees in the intact plot declined. In addition, whole-tree sap flux and soil-to-leaf hydraulic conductance were both higher for trees in the removal plot. We inferred that the observed changes reflect hydraulic homeostasis of B. ermanii trees to maintain constant water-use efficiency in response to belowground competition with dwarf bamboo. Removal of dwarf bamboo is, therefore, an effective silvicultural prescription to enhance growth of overstory trees by relieving belowground competition for soil water.

We investigated the spatial distribution and growth of the Siberian dwarf pine (Pinus pumila) in a valley–foothill larch–birch (Larix cajanderi–Betula platyphylla as canopy trees) mixed forest of fire origin located in central Kamchatka with the aim of elucidating the ecological features of P. pumila when it is an undergrowth species in a forest. The spatial distribution of all individuals of all tree species was clumped, and the spatial distribution of the two canopy tree species did not repulsively affect that of P. pumila (i.e., its establishment site). These results suggest that the regeneration of P. pumila does not depend on canopy gaps. However, the analysis using a growth model indicated that the canopy trees negatively affected the growth of P. pumila and that the negative effect of L. cajanderi on P. pumila growth was stronger than that of B. platyphylla. The direction of the crown extension of P. pumila was weakly related to the open-space direction. Our results suggest that, although the spatial pattern of establishment of P. pumila is not repulsed by the distribution of canopy trees, the crown can spread horizontally toward the more sparsely populated areas of the canopy trees where they may have higher growth rates.

In many Japanese forests, the forest understory is largely dominated by dwarf bamboo (Sasa) species, which compete with overstory vegetation for soil nutrients. We studied the rate of leaf litterfall, and decomposition and mineralization of carbon (C) and nitrogen (N) from various components (leaf, root, wood, and rhizome) of overstory and understory vegetation in a young Betula ermanii forest from 2002 to 2004. Total litterfall was 377 g m−2 year−1, of which the overstory vegetation contributed about two thirds. A litter decomposition experiment conducted for 770 days indicated that mass loss of different litter components varied significantly, except for Sasa kurilensis wood and rhizome. Relative decomposition rates were significantly greater in the first growth period (June to October) than the dormant period (November to May) in most cases. Rainfall was the most important abiotic variable, explaining 75–80% of the variability in mass loss rates. Concentrations of ethanol soluble substances and N were significantly positively correlated (r=0.77 to 0.97, P

Open-canopy moss-rich woodlands dominated by Picea abies and Betula pubescens in northern Finland may undergo cyclic development with reciprocal replacement of the tree species due to the positive feedbacks on soil conditions. Although relations to the abiotic environment are well understood, intra- and interspecific interactions during development of sparse boreal forests have received less attention. We studied tree regeneration, growth and survival with respect to size and density of neighboring trees in four stands representing roughly four stages of the Picea–Betula forest cycle. We conducted spatial analysis (Ripley’s K-function) of mapped locations of live and dead stems to reconstruct the distribution of stems prior to mortality, and to infer possible causes of tree population decline. The prevalence of standing dead stems enabled us to test if mortality was associated with density and size of neighboring trees. Logistic regression was used to test for relationships between tree survival and local crowding indices. We also examined spatial autocorrelations of individual size characteristics to determine the mode and spatial extent of tree interactions. Picea abies had reduced recruitment in open areas occupied by mosses and dwarf-shrubs, and preferentially regenerated near B. pubescens, whereas B. pubescens formed small clumps (and occasionally these consisted entirely of stems from a single tree) that showed local repulsion from large P. abies trees. Size of neighboring trees was the primary determinant of individual growth and survival, whereas neighborhood density per se had only a weak effect. Picea abies had negatively correlated sizes among close neighbors (0–4 m radius) indicating that dominant trees suppress their smaller neighbors. Negative autocorrelations prevailed at the transition stages where the patches of smaller trees were concentrated around evenly spaced large trees. Tree sizes became spatially independent at the mature phase. We hypothesize that both low light and soil nutrient availability causes the P. abies population decline. Dominant trees in this high latitude forest have large light depletion zones and shallow root system to promote strong above- and below-ground competition with younger trees. Higher mortality rates within canopy patches were not compensated for by recruitment in gaps, causing P. abies population to decline steadily.

We investigated the changes in soil microbial biomass C (MBC), microbial biomass N (MBN) and N mineralization in Sasa kurilensis-present (SP) and S. kurilensis-removed (SR) stands in a Betula ermanii forest. The mean levels of MBC and MBN were significantly higher in the SR stand than in the SP, which may have positively influenced the N-mineralization rate as depicted by a significant positive correlation between these variables and the N-mineralization rate. N immobilization and subsequent N release along with decreased use of available soil N due to S. kurilensis removal may have ensured greater N availability in the SR stand.

Dwarf bamboos (mainly Sasa species) form dense undergrowth in many forests in Japan and compete with overstory vegetation for soil resources. For a better understanding of the interaction between tree and undergrowth root for soil nutrients, we compared soil N availability, root biomass and its substrate quality in two Betula ermanii stands. In one stand, the aboveground part of undergrowth (Sasa kurilensis) had been removed for 5 years (SR) and in the other, the undergrowth was present (SP). The SR stand had significantly higher NO3-N levels in soil (1.7–5.5 mg kg−1 at different soil depths) than the SP stand (1.2–1.7 mg kg−1), which may affect the amount and substrate quality of fine root. Although the total (live + dead) of the root and rhizome (root–rh) mass did not differ between the two stands, the total production by these categories was about half in the SR stand than the SP stand. Further, the proportion of dead root–rh mass was about two times in the SR stand than the SP stand. In the investigated depth (to 30 cm), the contribution of the C and N inputs to the total in the uppermost layer (0–10 cm deep) was greater in the SR stand (56–59%) than the SP stand (38–42%). Total root–rh of S. kurilensis in the SP stand contributed to about 38–40% of the total C and N input, and in the SR stand the contribution was still about half that of the SP stand. Further, the acid-insoluble C:N ratio in very fine root and live fine root of B. ermanii was significantly less in the SR stand. The contribution of N content in very fine root to the total root–rh was much greater in the SR (45%) stand than the SP stand (36%). These results suggest that the remaining S. kurilensis detritus and the decreased N use by this species after its removal resulted in increased N availability for B. ermanii. Natural regeneration of tree species after simultaneous death of Sasa species, which is very common in Sasa-dominant forests in Japan, may in part, be facilitated by the presence of residues of the root–rh of Sasa species.

� Background and Aims Fire is the dominant disturbance in central Kamchatka boreal forests, yet patterns and mechanisms of stand recovery have not been investigated. � Methods Measurements were made of 1433 stems >1� 3 m height and annual radial increments of 225 randomly selected trees in a 0� 4-ha plot of a 53-year-old fire-origin mixed-species stand to examine the spatio-temporal variation in establishment, growth, size inequality and the mode of competition among individual trees. Growth variations were related to tree size, age and local interference with neighbours. � Key Results Betula platyphylla formed the main canopy following a fire in 1947, with Larix cajanderi and Pinus pumila progressively reinvading the lower tree and shrub stratum. Most B. platyphylla originated from sprouts in small patches (polycormons) during the first 15 post-fire years. Betula platyphylla had normal distributions of diameter and age classes, but negatively skewed height distribution, as expected from shade-intolerant, pioneer species. Larix cajanderi had fewer tall and many short individuals. The smaller and younger B. platyphylla grew disproportionately more in diameter than larger trees from 1950 to 1975, and hence stem size inequalities decreased. The reverse trend was observed from 1995 to 2000: larger trees grew more, indicating an increasing asymmetry of competition for light. Betula platyphylla had steady diameter growth in the first 25 post-fire years, after which the growth declined in smaller trees. Neighbourhood analysis showed that the decline resulted from increased competition from taller neighbours. � Conclusions The observed growth patterns suggest that mode of interactions altered during stand development fromearly stages of weak competition for soil resources released byfire tolater stages of asymmetric competition for light. Asymmetric crown competition started later than reported in other studies, which can be attributed to the lower stem density leaving much space for individual growth, greater relative importance of below-ground competition in this site of nutrient-poor volcanic soil, and the vegetative origin of B. platyphylla. Larix cajanderi growing under B. platyphylla had steady diameter growth during the first 20 years, after which growth declined. It is suggested that early succession fits the tolerance model of succession, while inhibition dominates in later stages. a 2004 Annals of Botany Company

Oxygen and carbon isotopic ratios (δ18O and δ13C) were analyzed for cellulose extracted from tree rings of 5 oak trees (Quercus crispula) and 4 fir trees (Abies sachalinensis) standing in a 1 ha plot of a sub-boreal conifer-hardwood mixed forest, northern Japan. The δ18O variations were well correlated between individual trees of Q. crispula (canopy trees) and A. sachalinensis (recently grown-up sub-canopy trees), although A. sachalinensis had about 1 ‰ higher δ18O values than Q. crispula on average and there was an apparent one-year phase lag between δ18O variations of the two species. The similar inter-annual variation in δ18O among different individuals and species suggests a common environmental control. Contrary to δ18O, the inter-annual variations in δ13C did not possess any common trends among individual trees for either Q. crispula or A. sachalinesis, suggesting that the ecological effects, such as spatial heterogeneities in δ13C and/or concentration of CO2 in canopy air and/or competition for light with neighboring trees, regulate the δ13C of photosynthetic products in each tree. Seasonal variations of the δ18O and δ13C within annual tree rings of Q. crispula showed random and cyclic characteristics, respectively. The difference between the annual patterns of δ18O and δ13C supports the idea that δ18O is controlled by some environmental factors, which change from year to year, but δ13C is primarily governed by physiological conditions of the tree itself, which repeat regularly in every growing season. The historical variation in δ18O of tree-ring cellulose in Q. crispula has negative correlations with those in both of winter and summer precipitation amounts, whereas it does not show any relationship with temperature, probably due to multiple source areas of water vapor for the precipitation at the studied area. Because the δ18O of precipitation in northern Japan is positively correlated with air temperature, the correlation between δ18O and winter precipitation suggests that, in a year of heavy snowfall, the soil in this forest retains larger amount of lower δ18O water derived from snowmelt, which is taken by roots of Q. crispula in summer. On the other hand, the negative correlation with summer precipitation cannot be elucidated by the δ18O of rainfall, but must be explained by a higher relative humidity in the growing season in a year of larger summer rainfall. Our results confirm the potential of δ18O of tree-ring cellulose to reconstruct past climate in a forest with a heavy snowfall, and suggest the importance of the hydrological knowledge in an atmosphere-soil-plant system for the utilization of tree-ring δ18O in paleoenvironmental purposes.

The development of crown architecture strongly affects tree growth and survival. Growth and death of primary branches (those branching off from the main stem) and secondary branches (those from a primary branch) in the lowest part of the crown were investigated for Picea glehnii in an even-aged plantation. Probability of death of a primary branch decreased as the length between its basal location and the crown base (L-CB) increased (p = 0.04), but this probability was not significantly related to the relative photosynthetic photon flux density (rPPFD) above the primary branch (p = 0.18). The probability of producing one or more current-year shoots on a primary branch increased with increasing rPPFD above the primary branch (p = 0.01); however, this probability was unrelated to L-CB (p = 0.29). Secondary branches at the distal part of a primary branch produced more current-year shoots and exhibited a lower probability of death than proximal branches (p < 0.01), probably because rPPFD above the distal secondary branches was greater than the proximal branches (p < 0.01). Our results suggest that, while local light conditions are relevant to shoot production and shoot death on a primary branch, the death of an entire primary branch may be related to some morphological attributes concerning the length to the crown base.

Four ecotypes of A. thaliana (L.) (Ct-1, Pf-0, Old-1 and Per-i) from low to high latitudes were grown under different light (300 micro mol photon m-2s-1 and 150 micromol photon m-2s') and temperature (22 and 14 degreesC) conditions to investigate their effects on phenotypic plasticity and ecotypic variations in plant growth and first flowering time. The results suggest that in A. thaliana low temperature decreases both phenotypic plasticity and ecotypic variations in first flowering time and total dry matter at final harvest under different light intensities. Relative growth rate is the most stable parameter of A. thaliana that is hardly affected by ecotype (no effect), light (no effect) or temperature (small effect) and this may one of the reason why A. thaliana is widely distributed on earth as a result of adaptations to different environments.

Viviparous seedlings of the mangrove species Rhizophora apiculata and R. mucronata were divided into even lengths of the top, middle, and bottom parts, and these cut pieces were planted in the field. The mortality and growth were monitored for 38 months after transplantation, and compared with intact seedlings planted in the same place. Both mean diameter and stem height of R. mucronata cut pieces were largest for the bottom parts, intermediate for the middle parts, and the smallest for the top parts. Among cut pieces of R. apiculata, the pattern for diameter was the same, but the mean stem height showed no differences among treatments. For both species, the mortality was associated with the initial volume of individual cut pieces. The bottom cut pieces with large volumes showed lowest mortality. Almost all cut pieces of R. apiculata formed prop roots above ground, but only 30% of R. mucronata cut pieces formed them. In the 38-month-old plantation, the mean diameters of the various cut-piece treatments of R. apiculata and R. mucronata were, respectively, 0.78–1.37 and 0.56–0.89 times as large as those for the intact seedlings; corresponding values for mean stem heights were 0.81–0.85 and 0.50–1.00. These results suggest a possibility that cut pieces can be a useful plantation material.

Patterns of crown spread and branch retention of two shade-intolerant species (Betula platyphyllaandB. maximowicziana) were compared with three more tolerant species (Quercus mongolica,Acer sieboldianumandMagnolia obovata). Branching height (height of the lowest living branch) rose more rapidly with age for the twoBetulaspecies than for the shade tolerant species. Branching heights ofA. sieboldianumandM. obovatawere similar, irrespective of tree height and age, and larger trees tended to produce wider crowns than theBetulaspecies when trees of similar height were compared. In all species, the branch basal area (cross-sectional area of a branch at its base) and the leaf area per branch generally increased as the branch position on a stem became lower. Therefore, retaining larger branches contributed significantly to the support of a larger leaf area per tree. The number of larger branches (branch basal area >80 cm2) for bothBetulaspecies was significantly smaller than that of the shade tolerant species. The branch retention pattern ofBetulaspecies was probably a consequence of intolerance of the leaves to shade. The decline ofBetulaspecies with forest succession is likely to occur through their inability to retain branches with a large base area in closed forests.

Masting is an intermittent synchronous production of large seed crops by plant populations. The cause and mechanism of masting were analysed using a resource budget model for an individual plant. The model produced characteristic masting behavior that is made up of intermittent large crops, crop failures and semi-regular masting cycles. The ratio of seedling cost to flowering cost (RC) played the most important role in the model. The species with a largeRCvalue (RC≥1) showed intermittent fruiting whereas species with a small value (RC

1. Patterns of stem growth of a mid-successional evergreen Oak species (Quercus glauca) in a mixed hardwood forest were examined to explore the trade-off relationship between stem-diameter growth and height growth. 2. The mean cross-sectional area (and the corresponding mean diameter) of a stem at a point in time was defined as the stem volume divided by tree height. Based on this definition, a simple equation representing the trade-off relationship between the height growth and mean diameter growth was formulated. 3. In the long term, allocation to height growth was encouraged at the seedling stage and it gradually declined with time, with the decline in the suppressed seedlings being more pronounced than in the dominant trees. 4. However, both the suppressed and the dominant trees showed acceleration of height growth at various ages. Such a fluctuation in the allocation of biomass to height growth is likely to have been caused by chronological changes in light conditions, and meandered the trajectory of allometry between the height and mean diameter. 5. The observed stem growth patterns of the individual trees could explain the chronological changes in the diameter–height relationship of the population.

The spatial pattern of the crown spread ofQuercus glauca in a hardwood community was investigated in order to consider the effect of the patterns on its survival in a secondary hardwood community. The shape of a crown was defined by the spatial spread of the leaves (PCM crown), and by the spread of their branches (elliptic cylinder crown). The stem volume growth rate of a tree was strongly correlated with the corresponding total leaf area, which was then significantly correlated with the defined crown volume. This indicated that the stem volume growth depended on the crown volume as well as the total leaf area. An increase in leaf area was largely attained by the spatial volume of the crown, not by an increase in the leaf area density. The leaves inside the crown began to spread horizontally relative to the crown size as the total leaf area and tree size increased. On the other hand, for the crowns representing the branch spread, the crown shape (crown width/depth ratio) did not differ by internal leaf area and tree size. Such a spatial pattern was likely to be adaptive for a species that dominates at a mid-stage of secondary sere.

An investigation was made in a mixed broad-leaved forest in Japan to determine the three-dimensional structure of the crowns of the component species. Vertical extensions and positions of foliage above a circle with a 20-cm diamter on the forest floor were measured using a grid of 177 points in the forest. The first leaf layer above a point was defined to be the highest aggregation of the foliage above the point, and the second leaf layer to be the one below. There were generally two leaf layers above each point, the first and the second. Each of the nineteen species in the plot belonged to either the first leaf layer or the second. Because the leaf layers varied in height from place to place in the forest, the two leaf layers were not separated clearly. Mean vertical depth of each leaf layer was about 2 m irrespective of the leaf layers and component species. Since the depths were similar among the species, species mean crown volumes (volumes of the spaces occupied by foliage) per unit land area mainly depended on horizontal extensions of their crowns, or the coverage. That is, species varied in their horizontal rather than vertical crown extensions. There was an upper limit (6 m) to the sum of vertical depths of the leaf layers above a point on the forest floor. On an average, about three species occurred above a point.

[1] The effects of wind disturbance on forest dynamics and ecosystem CO2 exchange were examined in cool temperate forests of northern Japan during 2004–2008 using eddy covariance (EC) measurements. One site was a young, even-aged, monoculture, deciduous forest; the other was an uneven-aged mixed forest of evergreen and deciduous overstory tree species, including some over 200 years old. On 8 September 2004, a strong typhoon struck the forests, after which leaf and branch amounts decreased in young growth forest, but foliage showed little change in old growth forest. By 2006, foliage at the young-growth forest had recovered to the 2004 pretyphoon state. Average daily accumulated gross primary production (GPPd), terrestrial ecosystem respiration (TERd), and net ecosystem exchange (NEEd) were assessed for six growth stages annually. After the typhoon, large increases in GPPd were found during the growing stage of overstory tree species with high photosynthetic rates compared to that before the typhoon. Pronounced increases in GPPd and corresponding large reductions in NEEd were detected at the young-growth forest, indicating that NEEd was largely regulated by GPPd throughout the growing stages. Although EC measurements contain uncertainty, our continuous EC measurements revealed that interannual variability in meteorological variables and structural changes in foliage have only small impacts on GPP and NEE, while photosynthetic recovery of foliage from typhoon damage has high potential to increase GPP and enhance NEE as compared with those under nondamage conditions.

Background/Question/Methods _Abies sachalinensis_ (Sakhalin Fir) and Picea glehnii (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change.Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of these species, on different developmental stages.The study is taking place on a sub-boreal forest plot in north Japan (N 44º 19’, E 142º 15’). Twenty shade-growing individuals of both species were divided into two height classes: seedlings, if height < 50cm; and saplings, if height > 100cm. The canopy coverage over each individual was assessed by analyzing hemispherical photography and average light incidence. Leaf pigments are being analyzed by chromatography. Light response curves and chlorophyll fluorescence are being measured seasonally, except in winter. Results are analyzed through General Linear Models. The study period was from spring 2009 to summer 2010. Results/Conclusions Results show an inversion of the photosynthetic adaptation between seedlings and saplings, and also between species. Picea seedlings and Abies saplings have greater total chlorophyll content and higher photosynthetic rates than Picea saplings and Abies seedlings. As a consequence, the superior competitor between similar sized individuals of both species appears to change between size-classes, with Abies presenting higher photosynthetic rates at the sapling class and Picea at the seedling class. Nevertheless, no significant growth has been observed in any of the groups until now. Results also disagree with some of the previously reported photosynthetic characteristics of these species, with Picea seedlings displaying more traits usually associated with shade adaptation than Abies seedlings.

Total basal area (BA), mean relative growth rate of individual basal area (RGRbam), annual leaf-fall rate (L), and number of trees (N) on a species basis were measured in a secondary forest mixed with evergreen and deciduous trees in the warm-temperate zone of Japan. Every species had a characteristic tree size and composed the tree and the shrub layers. The layer for each species, and the tree size of the species were represented by the species mean basal area per tree (BA/N orbam). A power form equation was obtained for the relation between the species mean leaf-fall rate per tree (L/N orlm) andbam.RGRbam was correlated with leaf-fall rate per unit basal area (L/BA) rather than withbam. This suggested thatRGRbam is associated less with mean tree size (bam) and dominance as total basal area (BA), and more with annual leaf production per unit basal area, provided thatL is equal to the annual leaf production per species.Rhus succedanea, the most dominant species in the forest plot, was typical in that it showed lower values ofRGRbam andL/BA than other tree species. This would suggest a decline ofR. succedanea in a secondary forest.

Background Changes in the timing of phenological events may cause the annual carbon budget of deciduous forests to change. Therefore, one should take such events into account when evaluating the effects of global warming on deciduous forests. In this article, we report on the results of numerical experiments done with a model that includes a phenological module simulating the timing of bud burst and other phenological events and estimating maximum leaf area index. Results This study suggests that the negative effects of warming on tree productivity (net primary production) outweigh the positive effects of a prolonged growing season. An increase in air temperature by 3°C (5°C) reduces cumulative net primary production by 21.3% (34.2%). Similarly, cumulative net ecosystem production (the difference between cumulative net primary production and heterotrophic respiration) decreases by 43.5% (64.5%) when temperatures are increased by 3°C (5°C). However, the positive effects of CO2 enrichment (2 × CO2) outweigh the negative effects of warming ( Conclusion Although the model was calibrated and validated for a specific forest ecosystem, the implications of the study may be extrapolated to deciduous forests in cool-temperate zones. These forests share common features, and it can be conjectured that carbon stocks would increase in such forests in the face of doubled CO2 and increased temperatures as long as the increase in temperature does not exceed 5°C.

We fitted a truncated bivariate normal distribution to the relationship between diameter and length of current-year shoots in Betula platyphylla saplings, and examined the effects of light intensity at the branch tip and branch height on the relationship. We measured shoot length, diameter at the shoot base, light intensity at the branch tip, and branch height for all shoots on 49 sampled saplings. The relationship between shoot diameter and shoot length was almost linear with a positive intercept. The truncated bivariate normal distribution could describe the relationship of shoot diameter and shoot length none of which was an independent variable. The result of model fitting revealed that, given a shoot length, shoot diameter was larger for shoots that were located in higher positions in crowns and captured more light.

The "foliage cluster (FC) model" shows that the size (the amount of leaves, number of yearly shoots and total twig length), turnover time, and branching (i.e., forking) structure of a twig becomes stable in the top of the crown in an oak species by forming a "stable FC" [1]. A stable FC can be treated as a basic component of the crown structure and as an alternative to individual leaf or current-year shoot. The FC model is composed of several equations approximating the branching structure of twigs. Differences in size and branching morphology among twigs are represented by differences in values of the parameters of the equations. We described details of our analyses of data taken from real twigs and applied to the equations implemented in the FC model.

Forking branches are a structural pattern characterizing a tree species. For a tree species, as a sessile organism, the forking structure is essential for gaining solar energy by spreading leaves in lighter spaces as quickly as possible. The structure is an outcome of a process in which a mother shoot of a branch produces multiple daughter shoots, and thus allows a tree to exponentially increase the amount of leaves available for photosynthetic production. On the other hand, in closed hardwood forests, tree crowns are so close to each other that there is very little space for “exponential” expansion of tree crowns [8]. How can the nature of branch forking, which appears to result in an exponential increase of leaf amount, be consistent with crown development in closed hardwood stands where crown expansion is limited due to a lack of available space? To answer such a question, analyses of demographic (birth and death) and morphological patterns of annual shoots (the portion of shoots elongated during a year) in tree crowns are useful, since they can clarify how the shoot population in a crown develops and is maintained [1, 2, 3, 5, 6, 7, 9, 10, 11, 12, 13]. Here, we begin by showing an example of the structural pattern of a branch as observed in the top canopy of a closed hardwood forest. We then show how the observed pattern can be formed by introducing a model simulating demographic and structural patterns of the annual shoots.