Fagus Crenata Forest Research Articles

Floor conditions and the ecosystem of Fagus crenata forest in southwest Hokkaido

Floor conditions and the ecosystem of Fagus crenata forest in southwest Hokkaido

3種の力学的ダウンスケーリングシナリオを用いた我が国のブナ林分布適域の変化予測

3種の力学的ダウンスケーリングシナリオを用いた我が国のブナ林分布適域の変化予測

Pollen-vegetation relationship of surface pollen assemblages and objective vegetation reconstruction in the Hakkoda Mountains, northeastern Japan

To investigate the pollen–tree relationship of surface pollen sample from under canopy sites, surface pollen samples were analysed from 56 sites collected in the montane zone to the subalpine zone of the Hakkoda Mountains, northeastern Japan. The characteristic pollen assemblage was observed in each vegetation type. High percentages of Pinus Haploxylon type pollen were recognized in the Pinus pumila thicket. Abies pollen was characterized in the Abies mariesii forests and the Fagus-Abies mixed forests although it was strongly under-represented. Betula pollen increased in the upper part of Fagus-Abies mixed forest and reached the highest values in the Betula ermanii stands, which corresponded to the vegetation composition. Fagus pollen was abundant not only in the Fagus crenata forests and the Fagus-Abies mixed forests but also in the P. pumila thickets and the A. mariesii forests. Cryptomeria pollen, derived from Cryptomeria japonica plantations in the lower montane area, varied from 4 to 126% (average 52%) in all vegetation types. The scatter plot of pollen percentages and coverages indicated taxa-specific representation. Pinus Haploxylon type and Abies pollen were under-represented because of low plant height, low plant density and small dispersal ability of pollen, respectively. Fagus and Betula showed relatively good linearity. Quercus was over-represented although its coefficient of correlation was the worst, which may be caused by different distributions pattern of two Quercus species, Quercus crispula in the montane zone and dwarf oak Q. crispula var. horikawae in the subalpine zone. The pollen assemblage of the P. pumila thicket, the A. mariesii forest, the Fagus-Abies mixed forest and the F. crenata forest can be distinguished by Canonical Variate Analysis (CVA). CVA results allow clear assessment of former vegetation changes by objective interpretation of fossil pollen data from two forest hollow sites (KS-3 and KS-4 sites) in the Hakkoda Mountains. The vegetation at KS-3 prior to the To-a tephra layer (A.D.915) was a F. crenata forest, shifting to Fagus-Abies mixed forest after A.D.915. The low elevation site of KS-4 was continuously dominated by F. crenata forest, although a temporal change to Fagus-Abies mixed forest was observed.

Reduction of photosynthesis before midday depression occurred: leaf photosynthesis of Fagus crenata in a temperate forest in relation to canopy position and a number of days after rainfall

We investigated an effect of canopy position and a number of days after rainfall on reduction of photosynthetic rate in a Fagus crenata forest in summer 2008, during days when midday depression was not apparent. We compared in situ photosynthetic rate and photosynthetic rate that was calculated by photosynthetic light response curves measured in the morning. The ratio, in situ photosynthesis divided by the curve-estimated value, declined towards the end of each day for the upper leaves, but not for the lower leaves. Total photosynthesis was reduced only for the upper leaves by 12% during 5 days after the rainfall.

Risk assessment of ozone impact on Fagus crenata in Japan: consideration of atmospheric nitrogen deposition

Tropospheric ozone (O3) is considered to be the air pollutant relating to the decline of Fagus crenata forest in Japan. In the present study, we assessed a risk of O3 impact on the growth of F. crenata in Japan, giving consideration to the effects associated with atmospheric nitrogen (N) deposition based on the experimental study, national monitoring data for oxidant concentration and atmospheric N deposition, and a national vegetation survey. The average and maximum O3-induced relative growth reduction (RGred) of F. crenata across Japan were estimated to be 3.2 and 9.7%, respectively. Current levels of atmospheric N deposition were found to significantly affect the sensitivity of F. crenata to O3. When the N deposition was assumed as zero, the estimated average and maximum RGred were 2.3% and 5.7%, respectively. The inclusion of atmospheric N deposition data thus increased the estimated values for average and maximum RGred (by 38% and 71%, respectively). Our results demonstrate that a change in the sensitivity to O3 associated with atmospheric N deposition is an important consideration in the risk assessment of O3 impact on the growth of F. crenata in Japan.

Seasonal dynamics of soil microbial biomass C shows close correlation with environmental factors in natural Fagus crenata forests

Soil microbial biomass (Cmic) is an important factor regulating a number of ecosystem processes. In this study, we investigated seasonal variations in soil microbial biomass in natural climax beech (Fagus crenata) forests in a typical cold-temperate mountain region of Japan. Four permanent tower sites along an altitudinal gradient were selected and soil samples were collected once every month during the growing season of 2007. Soil microbial biomass (by fumigation-extraction method) and soil properties were later measured in the laboratory, while environmental factors (soil temperature, soil moisture) were continuously recorded in the field. Our results indicated large seasonal variations (130.4 ~ 5558.0 µg g−1) in soil microbial biomass in beech forests – a range that is much larger than previously reported. Statistically significant correlations are noted between soil properties with Cmic, but largely due to spatial linkages. On the other hand, the environmental factors of soil temperature and especially soil moisture largely control seasonal variations in Cmic. Furthermore, pH could be an important factor influencing seasonal change in Cmic at the 20–30 cm deep soil layer. The study suggests no direct correlation between plant eco-physiology and soil microbial biomass in seasonal courses of the forests.

Initial establishment and regeneration processes of an outlying isolated Fagus crenata Blume forest stand in the northernmost boundary of its range in Hokkaido, northern Japan

We investigated initial establishment and regeneration of an outlying isolated Fagus crenata forest stand at the northernmost boundary of its range in Hokkaido, northern Japan. The study site was located in the Sannosuke beech forest (42°46′48″N, 140°23′43″E), a representative outlying beech stand beyond its continuous range. A rectangular 0.75 ha plot was established on a southwest-facing slope and divided into 300 square sub-plots of 25 m2. Within each sub-plot, stems over 5 cm in diameter at breast height (DBH) were identified and measured. Furthermore, the location of stems over 10 cm in DBH (canopy stem) was recorded within each sub-plot, and their increment core samples were extracted. Wood from fallen logs was sampled to estimate the species composition of the coarse woody debris. Micro-relief of the plot was investigated by leveling with compasses for a 2.5 m × 2.5 m grid system. In the plot, the population of F. crenata was divided into three sub-populations by their frequency distribution of age. The oldest sub-population, over 121 years old, had been established in small-localized gap in the plot. The sub-population between 81 and 120 years old and the sub-population less than 80 years old were regenerated after a landslide and windthrow in a 1954 typhoon, respectively. Furthermore, dominant species in the plot shifted from Quercusmongolica var. grosseserrata to F. crenata. Consequently, regeneration of F. crenata, i.e., expansion of forest stands, at the northernmost boundary of its range was primarily dependent on episodic natural disturbance, which may be responsible for the reduction of their migration rate in Hokkaido, northern Japan.

Climatic determinants of the northern range limit of Fagus crenata forests in Japan

AbstractWe sought to identify the factors that determine the current northern range limit of Fagus crenata (Fagaceae) forests in Japan. Four climatic factors (warmth index, minimum temperature of the coldest month, summer precipitation and winter precipitation) can potentially explain the distribution. Five classification tree models were developed: one based on all four factors, the others based on the four permutations of three of the four climatic factors (i.e. each excluded one of the four factors). The performance and the distributions of F. crenata forests predicted by these models were then compared, with particular reference to the distributions in Hokkaido. The distribution predicted by the model developed without summer precipitation extended continuously northwards along the Sea of Japan coast beyond the current northern range limits, but the distributions predicted by the other three models showed gaps around the current limit. When the warmth index, minimum temperature of the coldest month or winter precipitation were excluded the contribution to the resulting models of the other three variables increased, thereby compensating for the exclusion. However, the exclusion of summer precipitation was not compensated by increases in the contributions of the other variables in the model developed without this factor. These results suggest that summer precipitation is the most influential factor explaining the absence of F. crenata forests in the areas immediately to the north‐east of the current northern range limit.

航空機レーザースキャナを用いたブナ林の林冠構造の解析

航空機レーザースキャナを用いたブナ林の林冠構造の解析

六甲山におけるブナ・イヌブナ個体群の現状とブナ林の復元可能性

The spatial distribution, population structure, habitat condition, and seed production of Fagus crenata and Fagus japonica, which are the dominant species of beech (Fagus crenata) forests, were investigated. The investigation was carried out on Mt Rokko in the southeastern part of Hyogo Prefecture, and it aimed to clarify the present states of the two species and collect information that can contribute to the restoration of Fagus crenata forests of Mt. Rokko. We identified 130 Fagus crenata and 1151 Fagus japonica individuals in the study area. Both species occurred disproportionately on the northern slope of Mt. Rokko, and their main habitats were steep slopes. Nut-bearing Fagus japonica individuals accounted for approximately 94% of the individuals more than 10 m in height. On the other hand, only a smaller proportion of Fagus crenata produced nuts. Fagus crenata mostly existed as canopy trees, and its saplings and seedlings were rare. Hence, it appeared that the restoration of the Fagus crenata forests of Mt. Rokko would be extremely difficult without human intervention. It was suggested that planting Fagus crenata seedlings is a requisite for restoring the beech forests of Mt. Rokko.

Probability distributions, vulnerability and sensitivity in Fagus crenata forests following predicted climate changes in Japan

Question: How much is the probability distribution of Fagus crenata forests predicted to change under a climate change scenario by the 2090s, and what are the potential impacts on these forests? What are the main factors inducing such changes?Location: The major islands of Japan.Methods: A predictive distribution model was developed with four climatic factors (summer precipitation, PRS; winter precipitation, PRW; minimum temperature of the coldest month, TMC; and warmth index, WI) and five non‐climatic factors (topography, surface geology, soil, slope aspect and inclination). A climate change scenario was applied to the model.Results: Areas with high probability (> 0.5) were predicted to decrease by 91%, retreating from the southwest, shrinking in central regions, and expanding northeastwards beyond their current northern limits. A vulnerability index (the reciprocal of the predicted probability) suggests that Kyushu, Shikoku, the Pacific Ocean side of Honshu and southwest Hokkaido will have high numbers of many vulnerable F. crenata forests. The forests with high negative sensitivity indices (the difference between simulated probabilities of occurrence under current and predicted climates) mainly occur in southwest Hokkaido and the Sea of Japan side of northern Honshu.Conclusion: F. crenata forest distributions may retreat from some islands due to a high WI. The predicted northeastward shift in northern Hokkaido is associated with increased TMC and PRS. High vulnerability and negative sensitivity of the forests in southern Hokkaido are due to increased WI.

Probability distributions, vulnerability and sensitivity in Fagus crenata forests following predicted climate changes in Japan

Abstract Question: How much is the probability distribution of Fagus crenata forests predicted to change under a climate change scenario by the 2090s, and what are the potential impacts on these forests? What are the main factors inducing such changes? Location: The major islands of Japan. Methods: A predictive distribution model was developed with four climatic factors (summer precipitation, PRS; winter precipitation, PRW; minimum temperature of the coldest month, TMC; and warmth index, WI) and five non-climatic factors (topography, surface geology, soil, slope aspect and inclination). A climate change scenario was applied to the model. Results: Areas with high probability (> 0.5) were predicted to decrease by 91 %, retreating from the southwest, shrinking in central regions, and expanding northeastwards beyond their current northern limits. A vulnerability index (the reciprocal of the predicted probability) suggests that Kyushu, Shikoku, the Pacific Ocean side of Honshu and southwest Hokkaido will have ...

Two types of matter economy for the wintering of evergreen shrubs in regions of heavy snowfall.

Plant adaptation to an environment subject to heavy snowfalls was investigated in four species of evergreen shrubs growing in a Fagus crenata forest in an area of Honshu on the Sea of Japan. These shrubs stored carbohydrates in some organs before the snowy season and were covered with snow for 4-5 months. Aucuba japonica var. borealis, Camellia rusticana, and Ilex crenata var. paludosa maintained a reserve of carbohydrates during the snowy season. In Daphniphyllum macropodum var. humile, the reserve of carbohydrates decreased during winter. The respiration rates in the first three species decreased from autumn to winter, whereas the decrease in D. macropodum was slight. It was found that the first three species could use reserve carbohydrates for the growth of new shoots after the thaw, whereas in the last species the growth of new shoots depends on high photosynthetic activity in late spring. Our findings suggest some types of matter economy in evergreen shrubs for wintering in an environment of heavy snow.

Photosynthetic Responses to Lightflecks of Fagus crenata Seedlings Grown in a Gap and Understory of a Deciduous Forest

Photosynthetic responses to a series of 1-min lightflecks (1,000 μmol m−2 s−1) superimposed on a background with different duration (1, 5, and 10 min) and intensity (25 and 50 μmol m−2 s−1) of low background photosynthetic photon flux density (PPFD) were measured in the leaves of Fagus crenata grown in a gap and understory of a Fagus crenata forest in the Naeba Mountains. The two background PPFD intensities most frequently occurred in understory and gap sites respectively. The maximum net photosynthetic rate (PNmax) and maximum stomatal conductance (gsmax) were higher in the gap seedlings than in the understory seedlings. However, when the background PPFD was 25 μmol m−2s−1, the net photosynthetic rate (P25) and stomatal conductance (gs25) were almost the same between the gap and understory. When the background PPFD duration was 1-min, the net photosynthetic rate (PN) at the end of each lightfleck increased progressively. When the background PPFD duration was 5- and 10-min, the increase in PN at the end of each lightfleck was less. This indicates that background PPFD duration is important to photosynthetic responses to lightflecks. The higher ratios of P25/ PNmax and gs25/ gsmax in the understory seedlings indicate that the understory seedlings can maintain relatively lower levels of biochemical and stomatal limitations than the gap seedlings under low light conditions. The ratios of PN/ PNmax at the end of each lightfleck (IS) and light utilization efficiency of single lightflecks (LUEs) that showed the influence of lightflecks on carbon gain were higher in the understory seedlings than in the gap seedlings when the background PPFD was 25 μmol m−2 s−1. This means that understory seedling are capable of utilizing fluctuating light more efficiently under low light conditions than the gap seedlings although the net carbon gain of single lightflecks (CGs) in the understory seedlings was not higher than that in the gap seedlings. There were no significant differences in IS and LUEs between understory seedlings at a background PPFD of 25 μmol m−2 s−1 and gap seedlings at a background PPFD of 50 μmol m−2 s−1. However, CGs in gap seedlings was higher than in understory seedlings. These results provide more evidence that F. crenata acclimate to a natural light environment in respect to relative induction state at low background PPFD and can capture the fluctuating light at the same efficiency in both the gap and understory seedlings under natural light environments.

The Influence of Previous Irradiance on Photosynthetic Induction in Three Species Grown in the Gap and Understory of a Fagus Crenata Forest

Photosynthetic induction responses to a sudden increase in photosynthetic photon flux density (PPFD) from lower background PPFD (0, 25, 50, and 100 μmol m-2 s-1) to 1 000 μmol m-2 s-1 were measured in leaves of Fagus crenata, Acer rufinerve Siebold & Zucc., and Viburnum furcatum growing in a gap and understory of a F. crenata forest in the Naeba mountains. In the gap, A. rufinerve exhibited more than 1.2-fold higher maximum net photosynthetic rate (PNmax) than F. crenata and V. furcatum. Meanwhile, in the understory F. crenata exhibited the highest PNmax among the three species. The photosynthetic induction period required to reach PNmax was 3-41 min. The photosynthetic responses to increase in PPFD depended on the background PPFD before increase in PPFD. The induction period required to reach PNmax was 2.5-6.5-fold longer when PPFD increased from darkness than when PPFD increased from 100 μmol m-2 s-1. The induction period was correlated with initial PN and stomatal conductance (gs) relative to maximum values before increase in PPFD. The relationship was similar between the gap and the understory. As the background PPFD increased, the initial PN and gs increased, indicating that the degrees of biochemical and stomata limitations to dynamic photosynthetic performance decreased. Therefore, photosynthetic induction responses to increase in PPFD became faster with the increasing background PPFD. The differences in time required to reach induction between species, as well as between gap and understory, were mainly due to the varying of relative initial induction states in PN and gs at the same background PPFD.

Population dynamics of four understorey shrub species during a 7‐yr period in a primary beech forest

Abstract. Shrubs persist in the understorey layer of forests throughout their lives, while tall trees remain there only during the juvenile stage and then grow into the canopy layer. Thus demographic parameters (recruitment‐, mortality‐, and growth‐rates) of shrub species are expected to differ from those of tall tree species. We investigated aspects of the demography of four dominant deciduous‐shrub species (Viburnum furcatum, Lindera umbellata var. membranacea, Magnolia salicifolia, and Hydrangea paniculata) in Fagus crenata forests at the beginning and at the end of a 7‐yr period in a 1‐ha permanent plot. For each species, the number of stems changed little (within ± 10%) during the study period, while total basal area increased markedly (11.7–33.8%), because (1) new stems continuously recruited by vegetative growth replaced the substantial number of dead stems, and (2) vegetative stems grew vigorously, probably due to nutrient support from parents. The results indicate that these four understorey shrub species have high ability to maintain their population size in the shaded forest understorey. While in each species more than half of the dead stems were standing dead, a substantial proportion of the dead stems (9.0–38.5%) showed signs of mechanical damage, such as stem breakage and suppression by fallen branches or trees. Snow pressure that resulted in decumbent stems was also an important mortality agent for V. furcatum (20.7%) and L. umbellata var. membranacea (5.6%). Probability of damage was constant across all DBH‐classes for all study species. In each species, newly recruited stems and dead stems were spatially aggregated, largely due to habits of vegetative growth and mechanical damage, respectively. This study revealed that several demographic traits, resulting from recruitment by vegetative growth and death by mechanical damage, were shrub‐species specific and markedly different from those of tall tree species.

Effects of forest management on plant species diversity in a landscape in the Fagus crenata forest region

Effects of forest management on plant species diversity in a landscape in the Fagus crenata forest region

Photosynthesis and Biomass Allocation of Beech (Fagus crenata) and Dwarf-bamboo (Sasa kurilensis) in Response to Contrasting Light Regimes in a Japan Sea-type Beech Forest

Regeneration of beech (Fagus crenata) forests depends on the formation of canopy gaps. However, in Japan Sea-type beech forests, a dwarf bamboo (Sasa kurilensis) conspicuously occupies sunny gaps. Therefore,F. crenata seedlings must escape the severe interference ofS. kurilensis in the gaps and persist beneath a closed canopy of the beech forest. We hypothesized that the growth ofF. crenata seedlings in the understory would be favored by their being more plastic thanS. kurilensis in photosynthetic and morphological traits, which would support the matter production ofF. crenata seedlings in a wide range of light availabilities. To examine this hypothesis, the photosynthetic-light response of individual leaves and the biomass allocation in aboveground parts (i.e., the culm/foliage ratio) were surveyed at sites with contrasting light availabilities in a Japan Sea-type beech forest in central Japan. InF. crenata, photosynthetic light utilization efficiency at relatively low light was greater, and the dark respiration rate was smaller in the leaves of seedlings (10 cm in height) beneath the closed canopy than in the leaves of saplings at the sunny forest edge. The culm/foliage (C/F) ratio of theF. crenata seedlings at the shady site was small, suggesting effective matter-production beneath the beech canopy. On the other hand,S. kurilensis both in the gap and beneath the beech canopy showed low plasticity in photosynthesis and the culm/foliage ratio. Because the shoot density ofS. kurilensis was smaller beneath the beech canopy than in the gap, the light availability at the bottom of theS. kurilensis layer was greater beneath the beech canopy. These results suggest that the photosynthetic productivity of theF. crenata seedlings would be enough for the seedlings to survive in the understory with a low density ofS. kurilensis shoots beneath the closed beech canopy.

Photosynthetic induction responses to variable light under field conditions in three species grown in the gap and understory of a Fagus crenata forest.

Photosynthetic induction responses to abrupt increases in photon flux density (PFD) to 800 and 1500 &mgr;mol m(-2) s(-1) from either darkness or 100 &mgr;mol m(-2) s(-1) were examined in situ in leaves of Fagus crenata Blume, Daphniphyllum humile Maxim., and Acer rufinerve Siebold & Zucc. growing in a gap and the understory of an F. crenata forest. Among the species studied, F. crenata exhibited the highest assimilation rate (A(100)), stomatal conductance (g(s100)) at the background PFD of 100 &mgr;mol m(-2) s(-1), and A(100)/A(max) (A(max) = maximum assimilation rate), in both the gap and the understory. Time required for full induction depended on both background PFD and maximum PFD. The induction period was 2-4-fold shorter at a background PFD of 100 &mgr;mol m(-2) s(-1) than in darkness. For the three understory species, time required to full induction was 2-3-fold longer when irradiance was increased from darkness to 800 &mgr;mol m(-2) s(-1) than when irradiance was increased from darkness to 1500 &mgr;mol m(-2) s(-1). Acer rufinerve showed higher initial stomatal conductance (g(s0)) and a shorter induction period in the understory than in the gap. Fagus crenata exhibited a similar g(s0) and induction period in both habitats. Daphniphyllum humile demonstrated lower g(s0) and a longer induction period in the understory than in the gap. These findings indicate that initial stomatal conductance is closely correlated with the photosynthetic induction response. We conclude that the photosynthetic induction response is affected by the light conditions experienced by plants before the sudden increase in irradiance and by the extent of the increase in irradiance.

Factors affecting changes in landscape diversity in rural areas of the Fagus crenata forest region of central Japan

We compared landscape diversity in a primary forest site and a coppice forest site in rural area of the Fagus crenata forest region of central Japan. We focused on the factors affecting landscape diversity, with special reference to land ownership, and the relationship between changes in landscape diversity and the spatial distribution of landscape elements. We were able to identify two patterns that led to increased landscape diversity in the study sites. In the first, which was most apparent in the primary forest site, increased diversity resulted primarily from an increase in the number of landscape elements. In the other, which was seen in the coppice forest site, increased diversity resulted from a decrease in the difference between the numbers of grid squares dominated by each landscape element while the number of landscape elements remained unchanged. Land ownership also had different implications for the increase of landscape diversity. The changes in the Contagion Index, which decreased in private land and increased in the national forest, showed that private land contains many small patches while the landscape of the national forest consists of a few large, contiguous patches. Thus, an evaluation of changes in landscape structure requires measuring a variety of indexes in addition to the diversity.