To consider the way for the recovery of a beech forest in an abandoned cropland surrounding Komado moor in Fukushima Prefecture, Japan, we clarified soil profile on each plant community type. Moreover we examined the relationship between the plant community types and the characteristics of the soil (soil hardness, and soil permeability). The area surrounding the moor, excluding the abandoned cropland, was a secondary beech forest. In the abandoned cropland, five community types were identified. The shrub type, in which Sasa senanensis or Rubus crataegifolius was dominant, was distributed at the forest edge and along the stream. The Phragmites communis type was distributed over the area of water logging. The pasture type and the Miscanthus sinensis type were distributed on flat land and on the slope, respectively, and the Miscanthus sinensis type was divided into the poor-growth subtype (glass height<2.0m) and the good-growth subtype (glass height≧2.Om). The former was distributed on the upper slope near the farm road, and the latter, on the lower slope. The soil type of the beech forest was moderately moist brown forest soil drier type. On the other hand, the ground level of the abandoned cropland was 30-40cm lower than that of the beech forest. The soil profile of the abandoned cropland was composed of a till layer and B layer. The till layer was yellowish-brown in color, had a nutty structure, and was composed of clayey soil. The B layer was yellowish-brown in color, had a massive structure, and was composed of clayey soil. However, the till layers of the good-growth subtype and the pasture type were thicker than those of the poor-growth subtype. Furthermore, the quantity with root and humus of the good-growth subtype and the pasture type were greater than that of the poor-growth subtype. The soil hardness of the good-growth subtype and the pasture type was softer than that of poor-growth subtype. Also, the water permeability of the good-growth subtype and the pasture type at a depth of 40cm were higher than that of poor-growth subtype. These results suggest that the cause of the difference in the community types seemed to be the difference with the disappearance quantity of surface soil. The difference of the soil hardness, water permeability, and humus thickness was estimated to appear the difference with the disappearance quantity of surface soil. Moreover, we clarified the plat community type which it is possible for a beech forest to be recovered in abandoned cropland and showed a way for a beech forest recovery.

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Zoning of understory vegetation by temperature was made, and application of it to vegetation control was discussed from the view of protection of surface soil loss by using the data collected from 68 Hinoki cypress plantations distributed over the whole area of Kochi Prefecture, Southwestern Japan. Based on percent coverage, "species coverage index" was determined for every undergrowth species with visual observation. All species were classified into the following six life forms : conifer seedling, evergreen tree, deciduous tree, herb-Chamaephyte, Gleichenia japonica-Dicranopteris linearis (the commonest two species of fern under Hinoki plantations in southwestern Japan, being referred to as "commonest fern" in the following) and dwarf bamboo. "Life form coverage index" was calculated as the total of "species coverage index" of every species belonging to each life form. Three zones were distinguished along the gradient of Kira's Warmth Index. They were separated by breaks of distribution pattern of life form coverage indices of evergreen tree (Coldness Index, -10) and commonest fern (Warmth Index, 105-110) ; Gleichenia japonica-Dicranopteris linearis zone, the warmest zone, being with both evergreen tree and commonest fern, Evergreen oak zone without commonest fern, and Deciduous tree zone without both evergreen tree and commonest fern. Relative frequency of five vegetation types that are known to have different efficiency of erosion control, poor vegetation type, Gleichenia japonica-Dicranopteris linearis type, herb-Chamaephyte type, deciduous tree type and evergreen tree type differed between the zones. The relationship between relative frequency of different vegetation types and stand density (Yield Index) also differed from zone to zone. Based on these results, we concluded the applicability and usability of the zoning to understory vegetation control from the view of protection of surface soil loss.

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P/PET_t ratios of many meteorological stations in the Inner Mongolia Autonomous Region were assessed with climatic normals for 1951 to 1980, 1961 to 1990 and 1971 to 2000. Distribution maps for each of the six grades of lands aridity in the three periods were drawn with these ratios. The advance of aridity in each steppe was determined by comparing the three maps. The temperature rise in the twenty years during the first to third period was about 0.8℃. This is nearly equal to the value assessed from the increase rate between 1971 and 1988 (0. 349℃/year) and very close to the value determined by Yatagai and Yasunari (1994). Simulated P/PET_t ratios of eleven stations selected for the third period were nearly equal to the actual values of the period. Here, the simulation was a recalculation of P/PET_t with the mean monthly temperature and adding 0. 698℃ to the original value of each month and each station. Therefore, the decrease of P/PET_t is caused by an increase of temperature. As a result, we concluded that the movement of distribution area of each steppe in the Inner Mongolian Autonomous Region is caused by the gradual increase of temperature with global warming.

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We investigated the possibility of formulating broadly applicable equations and parameters for estimating the biomass of planted Pinus merkusii Jungh. et de Vr. forests. We selected four plantations of different stand ages (5, 11, 19, and 24 years) in West Java, Indonesia, and destructively sampled 55 trees after tree census, (1) Coefficients of allometric equations for estimating biomass from tree census data : When the allometric equations contained height data [Yn = a・(DBH-2・height)^b], we did not detect significant differences between forests in the predictor variables in the equations. (2) Parameters for estimating biomass from stem volume data, i.e., basic density, biomass expansion factor, and root-to-shoot ratio : Some parameters obtained by this study differed from the trends in the default values in the Good Practice Guidance for Land Use, Land Use Change and Forestry, provided by the Intergovernmental Panel on Climate Change. Those default values should thus be refined to reduce errors. (3) Other parameters : Using tree census data collected at 20 sites in Indonesia by the Forest and Nature Conservation Research and Development Center, chrono-sequential changes in biomass were estimated using an allometric equation obtained in the present study. The estimated stand-level biomass of a 21-year-old stand ranged from 161. 75 to 456. 34 t ha^<-1> and, according to multiple-regression analysis, varied significantly with tree density and site index.

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In order to clarify population structure and dynamics in a 1.0-ha lucidophyllous forest in southwestern Japan, we conducted two successive censuses of trees with DBH&ge;5 cm in 1998 and 2001. The overall annual mortality of 1.54% was higher than recruitment rate of 1.32%. Distylium racemosum, the most dominant species in the plot, showed in verse-J shaped DBH class frequency distribution, and was expected to be maintain their population and dominance in the future. Quercus salicina, the second most dominant species, had small trees (DBH<15 cm), and showed similar structure as Distylium racemosum. However, distribution pattern of small trees implied that Quercus salicina could not regenerate without gap formation. As compared with neighboring old-growth forest (about 18 km northwest of the plot), some species decrease (e.g. Persea japonica and Actinodaphne longifolia) or lack of their dominance (e.g. Pasania edulis) in the plot, and these differences may reflect the past disturbances. The structural differences and lack of very large trees (i.e. DBH >70 cm) suggested that this forest was an old secondary forest.

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The effects of an artificial shading shelter system in open planting condition were evaluated based on the physiological responses of the planted seedlings, Dyera costulata (Miq.) Hook. f. (Apocynaceae). The shelters were set on bare and grass lands at an abandoned pasture in Malaysia. Seedlings of D. costulata were planted both inside and outside the shelters. The maximum net photosynthetic rate at light saturation (Pn_<max>) and predawn Fv/Fm, which indicates chronic photoinhibition, were measured with the seedlings. In the all treatments, D. costulata two weeks after planting showed a lower Pn_<max> than the seedlings of before planting. The Pn_<max> of the seedlings planted in the open decreased significantly in the afternoon, because of a high leaf-to-air vapor pressure deficit (VPD_<leaf>). The Pn_<max> of the seedlings planted in the shelter, in contrast, had little decline in the afternoon. The measurement of predawn Fv/Fm in seedlings planted in the shelter showed lower degrees of photoinhibition than seedlings planted outside the shelter. Thus, this shading system can relieve the photosynthetic depression and chronic photoinhibition in planted seedlings in the open condition.

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Artificial shading systems were experimentally developed in order to establish a plantation technique for degraded tropical forest ecosystems in Malaysia. For evaluating whether or not the planted seedlings grow properly with this shading system, photosynthetic active radiation (PAR), air temperature (T) and vapor pressure deficit (VPD) were measured inside and outside of the shelters. During shaded time, all climatic element values were lower than that of outside. The value of T and VPD did not increase dramatically when sun light directly entered the shelter. Although the micro-climatic factors showed slightly higher than adequate values needed for photosynthetic metabolism, the shelter created better conditions than those of open areas. Therefore, the present shading system would improve the conditions for planted seedlings in degraded areas.

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[in Japanese]

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