Temperate Deciduous Broad-leaved Forest Research Articles

Stemflow and dissolved organic carbon cycling: temporal variability in concentration, flux, and UV-Vis spectral metrics in a temperate broadleaved deciduous forest in the eastern United States

No known research has examined the concentration and flux of dissolved organic carbon (DOC) for stemflow across temporal scales from within single storm events to seasonal and annual scales or employed UV-Vis spectral metrics to examine the chemical character of dissolved organic matter (DOM) of stemflow drainage. Thus, our study examined stemflow DOC concentration and flux and DOM character from American beech ( Fagus grandifolia Ehrh.) and yellow poplar ( Liriodendron tulipifera L.) to address this data gap. Intrastorm stemflow DOC concentrations and fluxes diminished by an order of magnitude over time for American beech but remained relatively constant for yellow poplar. Stemflow DOM aromaticity, however, generally increased and E2:E3 ratios generally decreased as events progressed, suggesting transport of different compounds at different moments. Although less enriched in DOC than yellow poplar, American beech stemflow DOC fluxes were double per annum. Differential interspecific stemflow DOM characteristics are ascribed to (i) significant differences in SUVA254 values (aromaticity) for the leafless season and annually and (ii) significantly higher E2:E3 and SR ratios for yellow poplar stemflow than for American beech annually and across leafed and leafless seasons. Our results suggest that stemflow significantly affects the amount and chemical character of carbon flux to the forest floor that may engender hot spots around tree boles.

Plant Diversity and Its Elevational Gradient Patterns in Wulu Mountain, Shanxi, China

Samplings were gathered and examined in forests along altitudinal gradients of Wulu Mountain, China. The results indicated that the major communities in the forests can be classified as Quercus wutaishanica, Pinus tabulaeformis, Acer ginnala, Betula platyphylla, Pinus bungeana, Syringa reticulate- Acer ginnala and Betula platyphylla community. Our research suggests that the Quercus wutaishanica community appears to be a dominant community in a successional stage toward temperate deciduous broad-leaved forests. The species richness in different layers of these communities can be distinguished as, herb layer shrub layer tree layer. Both the Shannon-Wiener diversity index and Simpson diversity index showed similar patterns. The species diversity indices of different layers and overall importance value of the forest communities indicate that the forests appear to be successional and sub-climax communities in Wulu Mountain. Our research also suggests that there is a peak with higher species diversity index in the communities of middle elevation. We suggested that the pattern could be affected by temperature, moisture, and human disturbance. The pattern could also be influenced by the nature of successional stages and sub-climax communities.

Response of normalized difference vegetation index in main vegetation types to climate change and their variations in different time scales along a North-South Transect of Eastern China

Aims Climate change characterized by global warming has posed a great threat to terrestrial ecosystems and sustainable development of human society.Our objective was to examine the response of major vegetation types to climate change.Methods We used the biweekly dataset of the National Oceanographic and Atmospheric Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR) normalized difference vegetation index (NDVI) and climatic data from 752 standard stations in China for 1982-2006 to study the responses of 12 major vegetation types to changes in air temperature and precipitation.Important findings The NDVI trend was controlled by air temperature and precipitation at the transect scale,while the NDVI trend showed large spatial heterogeneity,possibly associated with changes in regional climate,land use and vegetation type.At the biome scale,annual NDVI of temperate deciduous shrubland (TDS) was significantly correlated with air temperature and that of temperate grass steppe (TGS) and subtropical and tropical coniferous forest (STCF) was significantly correlated with both air temperature and precipitation.No significant relationships were detected between NDVI and climatic factors in other types of vegetation.NDVI was most significantly correlated to the air temperature of the preceding four months.In addition,the time lag of NDVI responses to air temperature gradually decreased from January to April.Negative correlations were found between NDVI and air temperature from May to August in temperate coniferous forest (TCF),temperate deciduous broad-leaved forest (TDBF),TDS,STCF and subtropical and tropical grassland (STG).Results indicated a positive relationship between NDVI and precipitation of the same month in shrub and grassland types and a negative relationship between NDVI and precipitation of the same month in forest.

A Study on Surface Validation of the Satellite-derived Vegetation Growing Season in China—A Case of the Temperate Steppe Area and the Warm Temperate Deciduous Broad-leaved Forest Area

Satellite-derived beginning and end dates of growing season at 7 sites of the temperate steppe area and 5 sites of the warm temperate deciduous broad-leaved forest area in China were determined with the measures of seasonal midpoint NDVI(SMN),inflection point by Moulin(MOULIN) and by Zhang(LOGISTIC),and moving average(MA) using NOAA/AVHRR NDVI time series data from 1982 to 2000.The four measures were matched to surface observations and then their stabilities,accuracies,and validities were studied via compare of absolute error distributions,standard deviations,mean absolute errors,and correlation coefficients and so on.The results show that LOGISTIC is the most appropriate of the four measures in determining beginning date of growing season in both the steppe area and the forest area.As to satellite-derived end date of growing season in the steppe area,SMN performs best,followed by LOGISTIC with the senescence point defined as end date.In the forest area,of the four satellite-derived end date of growing season measures,LOGISTIC with the dormancy point defined as end date,is the most preponderant one.This paper provided a typical case and method to surface validation of the satellite-derived vegetation growing season and selection of various measures.

Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

Abstract. We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE) data were partitioned into gross primary productivity (GPP) and ecosystem respiration (Re) and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP) was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP) and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1). Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression), variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those managed for conservation rather than silvicultural objectives) as a strategy to mitigate atmospheric carbon dioxide increases.

Species composition and community structure of the Donglingshan forest dynamic plot in a warm temperate deciduous broad-leaved secondary forest, China

Community structure is one of the key features in the process of vegetation succession. Warm temperate mixed deciduous broad-leaved secondary forest is the main forest vegetation type in China's warm temperate zone. In order to better study the mechanisms of succession and species coexistence in this forest type, we established the Donglingshan 20-ha forest plot (DLS plot) in 2009 and 2010 using the same protocol as the well-established plot on Barro Colorado Island in Panama. In the plot, all free-standing woody plants with DBH (diameter at breast height) ≥1 cm were mapped, tagged, and identified to species. Here, we ad- dress preliminary results on floristic characteristics, community composition, and size-class, vertical, and spatial structure of the DLS plot. These datasets will serve as baseline information accessible to a wide range of future studies. We tagged a total of 52,136 genotype individuals (103,284 individuals including branches of genotype individuals), belonging to 58 species, 33 genera and 18 families. All of these tree species were deciduous. Floristic characteristics of the community suggested a temperate flora, including some subtropical and tropical elements. There were very obvious dominant species in the plot. Five species comprised 61% of

Annual Variation of Soil Respiration and Precipitation in a Temperate Forest (Quercus serrata and Carpinus laxiflora) Under East Asian Monsoon Climate

The consequence of changing pattern of precipitation on soil CO2 emission is poorly understood in montane forest ecosystems under monsoon climate in Asia. In this paper, the results of 3-year field measurements are reported on the annual soil respiration (R s) from a temperate deciduous broad-leaved forest (Quercus serrata and Carpinus laxiflora) in Korea, and its interannual variations are examined associated with changing precipitation. Based on biweekly chamber measurements from 2001 to 2004, the annual soil CO2 emission averaged to be 7.8 t C ha−1 with an annual variability of ∼20%. The soil temperature explained 22–97% of seasonal variations of R s each year whereas the water-filled porosity (WFP) and precipitation pattern had a major effect on the observed interannual variation. The optimum values of WFP during the main growing season depended not only on the amount but also on the intensity and frequency of precipitation. These results indicate that the changes in catchment hydrology can significantly alter the carbon sink/source strength of forest ecosystems in monsoon Asia.

Regionalization and distribution pattern of vegetation of Northeast China

Aims Our objectives were to consider a new scheme for vegetation regionalization of Northeast China, espe- cially for vegetation in the Songliao Plain, and to illustrate the distribution pattern of vegetation as determined by altitude. Methods We clustered the sites from Inner Mongolia steppe, east forest and central Songliao Plain with temper- ature, precipitation, soil types and underground water depth using principle component analysis (PCA). We also analyzed the physiognomy, topography of Northeastern China using GIS, vegetation types and soil types of Songnen Plain. Important findings The dominant vegetation of Songliao Plain is meadow, an unzonal vegetation type. The Sti- pa communities, an indicator of the zonal vegetation type, mainly distributed on the second mesa in Songnen Plain, are a sandland vegetation type that is distributed discontinuously among meadow vegetation. Therefore, the vegetation of Songliao Plain should be regionalized as an area of temperate broad-leaved deciduous forest, and the east boundary of temperate steppe region should be moved toward to the west of the Da Hinggan Mountains. The

Important foliar traits depend on species-grouping: analysis of a remnant temperate forest at the Keerqin Sandy Lands, China

Foliar traits are often interpreted to reflect strategies for coping with water and nutrient supply limitations. In this study, we measured several important leaf traits for 147 species sampled from a remnant, temperate deciduous broad-leaved forest in Keerqin Sandy Lands, Northeast China to test whether these traits are ‘invariant’ or dependent on water supply limitations. Our data show that average specific leaf area (SLA), nitrogen (N) and phosphorus (P) concentrations, leaf C/N, C/P and N/P were 273 cm2 g−1, 18.1 mg g−1, 1.60 mg g−1, 28.2, 343 and 12.4, respectively. However, most of these traits were significantly different (P < 0.05) for different species groupings based on growth forms, phylogenetic history, photosynthetic pathways, or habitats. SLA was positively correlated with leaf P concentration across the broad spectrum of 118 species and most species functional groupings. However, SLA was not correlated with N concentration across all species or within each species functional group. SLA and N and P concentrations in dry habitats were lower than those in wet habitats, whereas leaf C/N, C/P, and N/P had the opposite trend both across all species and within major species functional groupings (herb, monocots and C3 species). Our data indicate that SLA vs. leaf N and SLA vs. P relationships may be regulated differentially for different species functional groupings and that water limitation may have a greater influence than nutrient limitation for plant growth.

The effects of gap size on some microclimate variables during late summer and autumn in a temperate broadleaved deciduous forest

The creation of gaps can strongly influence forest regeneration and habitat diversity within forest ecosystems. However, the precise characteristics of such effects depend, to a large extent, upon the way in which gaps modify microclimate and soil water content. Hence, the aim of this study was to understand the effects of gap creation and variations in gap size on forest microclimate and soil water content. The study site, in North West England, was a mixed temperate broadleaved deciduous forest dominated by mature sessile oak (Quercus petraea), beech (Fagus sylvatica) and ash (Fraxinus excelsior) with some representatives of sycamore (Acer pseudoplatanus). Solar radiation (I), air temperature (T(A)), soil temperature (T(S)), relative humidity (h), wind speed (v) and soil water content (Psi) were measured at four natural treefall gaps created after a severe storm in 2006 and adjacent sub-canopy sites. I, T(A), T(S), and Psi increased significantly with gap size; h was consistently lower in gaps than the sub-canopy but did not vary with gap size, while the variability of v could not be explained by the presence or size of gaps. There were systematic diurnal patterns in all microclimate variables in response to gaps, but no such patterns existed for Psi. These results further our understanding of the abiotic and consequent biotic responses to gaps in broadleaved deciduous forests created by natural treefalls, and provide a useful basis for evaluating the implications of forest management practices.

Chemical properties and pedogenesis of yellowish/yellow brown forest soils in the submontane and mountain zones of Kyushu district, southwestern Japan

This study aimed to clarify pedogenetic processes and classification of yellowish Brown Forest Soils according to the Classification of Forest Soils in Japan and the Yellow Brown Forest soils according to the Unified Soil Classification System of Japan in the warm and cool temperate forest of Kyushu district, Japan. In addition, the study aimed to clarify a problem with the Unified Soil Classification System of Japan. Thirty-six soil profiles of Brown Forest Soils, including 13 yellowish Brown Forest Soils and 15 Yellow Brown Forest soils, were compared with regard to their chemical properties and the relationship with climatic conditions was assessed. The yellowish Brown Forest Soils had thin A horizons, low pH and low levels of free oxides in the B horizons, and a low amount of silica and a high aluminum and iron to silica ratio. These features were related to the paleo reddish weathering. The immaturely developed A horizon of the yellowish Brown Forest Soils was caused by these weathered, low-activity substances. The Yellow Brown Forest soils had low levels of active iron oxides and a low activity ratio of free iron oxides compared with the Haplic Brown Forest soils in the same thermal climatic conditions. The activity ratio of free iron oxides was correlated to mean annual air temperature with the carbon stocks and with many other chemical properties. Accordingly, classification of Brown Forest Soils was clearer according to thermal climatic conditions. The activity ratio of free iron oxides can become an effective index that distinguishes Yellow Brown Forest soils under warm temperate lucidophyllous forest and Haplic Brown Forest soils under cool temperate broad-leaved deciduous forest with considerable vertical soil zonality.

Biometric Based Carbon Flux Measurements and Net Ecosystem Production (NEP) in a Temperate Deciduous Broad-Leaved Forest Beneath a Flux Tower

Biometric based carbon flux measurements were conducted over 5 years (1999–2003) in a temperate deciduous broad-leaved forest of the AsiaFlux network to estimate net ecosystem production (NEP). Biometric based NEP, as measured by the balance between net primary production (including NPP of canopy trees and of forest floor dwarf bamboo) and heterotrophic respiration (RH), clarified the contribution of various biological processes to the ecosystem carbon budget, and also showed where and how the forest is storing C. The mean NPP of the trees was 5.4 ± 1.07 t C ha−1 y−1, including biomass increment (0.3 ± 0.82 t C ha−1 y−1), tree mortality (1.0 ± 0.61 t C ha−1 y−1), aboveground detritus production (2.3 ± 0.39 t C ha−1 y−1) and belowground fine root production (1.8 ± 0.31 t C ha−1 y−1). Annual biomass increment was rather small because of high tree mortality during the 5 years. Total NPP at the site was 6.5 ± 1.07 t C ha−1 y−1, including the NPP of the forest floor community (1.1 ± 0.06 t C ha−1 y−1). The soil surface CO2 efflux (RS) was averaged across the 5 years of record using open-flow chambers. The mean estimated annual RS amounted to 7.1 ± 0.44 t C ha−1, and the decomposition of soil organic matter (SOM) was estimated at 3.9 ± 0.24 t C ha−1. RH was estimated at 4.4 ± 0.32 t C ha−1 y−1, which included decomposition of coarse woody debris. Biometric NEP in the forest was estimated at 2.1 ± 1.15 t C ha−1 y−1, which agreed well with the eddy-covariance based net ecosystem exchange (NEE). The contribution of woody increment (Δbiomass + mortality) of the canopy trees to NEP was rather small, and thus the SOM pool played an important role in carbon storage in the temperate forest. These results suggested that the dense forest floor of dwarf bamboo might have a critical role in soil carbon sequestration in temperate East Asian deciduous forests.

지리산 왕등재늪의 식생변천사 연구

지리산 냉온대 낙엽활엽수립대의 식생변천사를 밝히기 위하여 왕등재늪(960 m a.s.l.) 퇴적물을 대상으로 화분 분석과 방사성 탄소 연대 측정을 실시하였다. 그 결과 주요한 화분 포자의 출현율의 변화로부터 다음과 같이 3개의 화분대(Pollen zone)와 2개의 아대(Subzone)로 구분하였다. I. Quercus zone(<TEX>$l50{\sim}114cm$</TEX>), II. Quercus-Pinus zone(<TEX>$114{\sim}43cm$</TEX>): IIa. Quercus-Pinus subzone(<TEX>$114{\sim}83cm$</TEX>), IIb. Quercus-Pinus-Herbs subzone(<TEX>$83{\sim}43cm$</TEX>), Ill. Pinus-Quercus zone(<TEX>$43{\sim}27cm$</TEX>) 퇴적물 깊이 <TEX>$111{\sim}116cm$</TEX>층의 방사성탄소연대는 <TEX>$1,160{\pm}40yr$</TEX> B.P.로 측정되었다. 이들로부터 지리산 왕등재 일대의 삼림은 크게 신갈나무를 우점으로 하는 시대, 신갈나무의 점진적인 감소와 소나무의 증가 시대, 소나무의 급격한 증가 시대로 변천하여 왔음을 알 수 있었다. 'Medieval Warm Period (MWP)'와 'Little Ice Age (LIA)'는 적어도 지리산주변 식생변화에 큰 영향을 미치지는 못하였고, LIA가 최성기에 이른 시기에 습지 주변의 초지의 확장과 소나무 속의 점진적인 증가가 확인 되었다. 그 이후 소나무의 갑작스런 증가는 산지 하부 지역에 대한 인간 간섭의 급증에 의한 식생변화의 반영으로 보인다. We carried out pollen analysis and radiocarbon dating from sediments of Wangdeungjae moor (960 m a.s.l.) to clarify vegetation history of temperate broad-leaved deciduous forest zone of Mt. Jiri. Three local pollen zones and two sub-zones were recognized on the basis of variation in the palynofloral assemblage: I. Quercus zone (150-114 cm), II. Quercus-Pinus zone (114-43 cm): IIa. Quercus-Pinus subzone (114-83 cm), IIb. Quercus-Pinus-Herbs subzone (83-43 cm), III. Pinus-Quercus zone (43-27 cm). Radiocarbon date from sediment depth 111-116 cm was estimated <TEX>$1,160{\pm}40yr$</TEX> B.P. From these results, overall vegetation around of Wangdeungjae moor and Mt. Jiri have changed from Q. mongolica dominant to steady decrease of Q. mongolica whereas steady increase of P. densiflora, finally abrupt increase of P. densiflora. 'Medieval Warm Period (MWP)' and 'Little Ice Age (LIA)' have not had an effect on change of vegetation around, at least, Mt. Jiri. But at maximum period of LIA, extension of grassland and steady increase of Pinus were recognized around the moor. After then, an abrupt increase of Pinus is supposed that vegetation change is reflected in human impact surging around foothills.

Leaf-fall phenology along a topography-mediated environmental gradient in a cool—temperate deciduous broad-leaved forest in Japan

Leaf-fall phenology was studied in a cool—temperate deciduous broad-leaved forest in central Japan in relation to the topographic environmental gradients that occur along a short mountain slope. Leaf-fall phenology was described quantitatively using data from leaf litter collected along the slope. In autumn, leaf fall at the study site tended to occur slightly earlier on the upper slope than on the lower slope. This pattern was found at both the stand and the species levels. Our results suggest that leaf-fall phenology may be affected by difference in microclimatic conditions, because environmental conditions are thought to be more severe on the upper slope than on the lower slope. The less intensive methods used in this study, the litter trap method, and Dixon's model succeeded in quantifying the phenological patterns of leaf fall within stands and within species along the short mountain slope.

Environmental variability and human adaptation during the Lateglacial/Holocene transition in Japan with reference to pollen analysis of the SG4 core from Lake Suigetsu

High-resolution pollen analysis of annually laminated sediments from Lake Suigetsu in Japan revealed that climate amelioration at 16,500 varve years before present (vy BP) triggered the expansion of cool temperate deciduous broad-leaved forest. The oldest pottery appearance in Japan coincided with this climate amelioration. Significant vegetation change occurred from 15,000 to 14,500 vy BP. The period during 15,000–14,500 vy BP was a time of ecological transition from a Glacial-type ecosystem, eventually destroyed by global warming, to a new Postglacial-type ecosystem represented by that in Lake Suigetsu. It is believed that the completion of this ecological transition actually took nearly 500–800 years. This drastic change in the ecosystem had forced people to create a new strategy of adaptation. The Japanese Neolithic Jomon culture, mainly sustained by gathering nuts and fishing, was widely established at this time. On the other hand, the cold period which correlates with the Younger Dryas in Europe had no significant ecological influence on the Japanese ecosystem and human culture.

The value of vegetation ecosystem services: A case of Qinling-Daba Mountains

According to differences in vegetation types and their coverage, combining the latest research, using theory and method on the value of vegetation ecosystem services, this paper not only calculated goods produced by different types of vegetation but also estimated the value of various vegetation ecosystem services and set up database, GIS and eco-account of vegetation ecosystem. The result was as follows: the value of vegetation’s primary productivity, soil and fertility conservation, water conservation, CO2 fixation and O2 release was 199.6 billion yuan/a, 22.64 billion yuan/a, 22.66 billion yuan/a, 352.24 billion yuan/a and 374.19 billion yuan/a, respectively. The total value of ecosystem services was 968.33 billion yuan/a. The temperate deciduous broad-leaved forest had the highest contribution rate, accounting for 16.42%. The result of value can reflect regional reality more exactly.

How the environment, canopy structure and canopy physiological functioning influence carbon, water and energy fluxes of a temperate broad-leaved deciduous forest--an assessment with the biophysical model CANOAK.

This paper focuses on how canopy structure, its physiological functioning and the environment interact to control and drive the exchange of carbon dioxide (CO2) and water vapor between a temperate forest stand and the atmosphere. First, we present an overview of how temporal and spatial variations in canopy structure (e.g., leaf area index, species, leaf inclination angles, leaf clumping) and physiological functioning (e.g., maximal stomatal conductance, photosynthetic capacity) modulate CO2 and water vapor fluxes. Then, with the biophysical model CANOAK, we quantify the effects of leaf dimension and thickness, vertical variations in leaf area and photosynthetic capacity, leaf clumping, leaf inclination angles, photosynthetic capacity, stomatal conductance and weather on the annual sums of CO2, water vapor and sensible heat exchange. Finally, we discuss how much detail is needed in a model to predict fluxes of CO2 and water vapor with acceptable fidelity.

A biome classification of China based on plant functional types and the BIOME3 model

A biome classification for China was established based on plant functional types (PFTs) using the BIOME3 model to include 16 biomes. In the eastern part of China, the PFTs of trees determine mostly the physiognomy of landscape. Biomes range from boreal deciduous coniferous forest/woodland, boreal mixed forest/woodland, temperate mixed forest, temperate broad-leaved deciduous forest, warm-temperate broad-leaved evergreen/mixed forest, warm-temperate/cool-temperate evergreen coniferous forest, xeric woodland/scrub, to tropical seasonal and rain forest, and tropical deciduous forest from north to south. In the northern and western part of China, grass is the dominant PFT. From northeast to west and southwest the biomes range from moist savannas, tall grassland, short grassland, dry savannas, arid shrubland/steppe, desert, to alpine tundra/ice/polar desert. Comparisons between the classification introduced here and the four classifications which were established over the past two decades, i.e. the vegetation classification, the vegetation division, the physical ecoregion, and the initial biome classification have showed that the different aims of biome classifications have resulted in different biome schemes each with its own unique characteristics and disadvantages for global change study. The new biome classification relies not only on climatic variables, but also on soil factor, vegetation functional variables, ecophysiological parameters and competition among the PFTs. It is a comprehensive classification that using multivariables better expresses the vegetation distribution and can be compared with world biome classifications. It can be easily used in the response study of Chinese biomes to global change, regionally and globally.

スギが混交する若齢天然生林の保育技術(I) : 除伐後16年間の林分構造の推移

スギが混交する若齢天然生林の保育技術(I) : 除伐後16年間の林分構造の推移

Gap-Disturbance Regimes in Different Forest Types of Japan

In this study, I defined a gap as a small opening formed in a forest canopy (area < 0.1 ha) and tried to synthesize gap-disturbance regimes of primary mature stands in different forest types of Japan, such as warm temperate evergreen broad-leaved (4 stands in 3 localities), cool temperate deciduous broad-leaved (10 in 5) and subalpine evergreen coniferous (3 in 1) forests. Mean percentage of the total gap area within the total forested area (percentage gap area) in each forest type was 17.0% in warm temperate (number of surveyed gaps was 161), 13.8% in cool temperate (278 gaps), and 8.0% in subalpine (100 gaps) forests. Mean gap density (ha-1) and mean gap size (m2) were 19.5 and 77.1 in warm temperate, 16.4 and 92.0 in cool temperate, and 19.1 and 41.9 in subalpine forests, respectively. These figures indicate that gap density is not substantially different among the forest types, but the mean gap size of subalpine forests is smaller than the other two, resulting in lower percentage gap area of this forest type. The gap size distributions were similar among the forest types; smaller gaps were much more frequent than larger ones, and gaps > 400 rrr were rare in warm temperate and cool temperate forests. In subalpine forests gaps > 200 m2 were rare. Gaps formed by multiple gapmakers comprised 19.9% of all gaps in warm temperate, 9.9% in cool temperate, and 44.9% in subalpine forests, which implies that gap formation by simultaneous tree fall or gap enlargement is more frequent in subalpine forests. Canopy trees died less often by uprooting in every forest type; dominant mode for the death of canopy trees was by leaving standing-dead or with broken trunks in every forest type. Since typhoons are obviously a chief agent of forest disturbance in Japan, frequency or magnitude of typhoon disturbance may influence these differences in the gap-disturbance regimes. In addition to the disturbance, tree architectures seem to affect some of these differences; narrower crown size of conifers compared with broad-leaved trees is considered one major cause for smaller gap size of the conifer forest.