Authorship：Corresponding author   Language：English  

DOI： 10.3759/tropics.19.93

CiNii Books

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Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Tropical Ecology  

DOI： 10.3759/tropics.20.11

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER JAPAN KK  

We studied vegetation changes in a small floating mat bog in Mizorogaike Pond (Kyoto, Japan), which had experienced a severe decrease in the number and area of hummocks caused by nutrient loading in the 1960s and 1970s, to examine whether reducing the extent of nutrient loading can restore degraded wetland vegetation. However, nutrient loading in the region has been minimized since the 1980s. We examined the distributions of hummocks and Sphagnum cuspidatum mats in 1980, 1988, and 2006, as well as nine major vascular plants that dominated the hollows on the floating mat in 1980 and 2006. The total area of normal hummocks formed by Sphagnum palustre increased from 5865.3 m(2) in 1980 to 5913.6 m(2) in 1988 and 8485.2 m(2) in 2006. The total area of the S. cuspidatum mats also changed, from 416.4 m(2) in 1980 to 322.3 m(2) in 1988 and 1012.5 m(2) in 2006. Examination of the spatial distribution patterns of major plants revealed that emergent plants decreased in the northern part of the mat, but increased in the southern part. Thus, the improved pond water quality was effective at restoring hummocks, although nutrient loading may have caused some irreversible changes in the wetland vegetation.

DOI： 10.1007/s10201-010-0312-6

Web of Science

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Language：English   Publisher：Society of Agricultural Meteorology of Japan  

DOI： 10.2480/agrmet.66.3.1

J-GLOBAL

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We investigated soil net nitrogen mineralization rate, above- and belowground biomass allocation, and nitrogen use in a Cryptomeria japonica plantation chronosequence. Total biomass accumulation showed an asymptotic accretion pattern, and the peak total biomass accumulation rate occurred approximately 30 years after afforestation. Soil net nitrogen mineralization rate was lowest 30 years after afforestation. Between years 30 and 88, net nitrogen mineralization increased again. These results indicate that an imbalance in soil nitrogen supply and plant nitrogen demand occurred approximately 30 years after afforestation. Furthermore, leaf nitrogen concentration, which was used as an index of plant nitrogen status, was lower in mature forest than in young forest, suggesting that mature stands did not take up nitrogen as successfully. If soil resources such as nitrogen limit plant growth, plants may increase biomass allocation to fine root structure; however, fine root biomass was not higher in 30- and 88-year-old stands than in younger stands, suggesting that changes in biomass allocation may not be effective against nitrogen deficiency in a C. japonica plantation chronosequence. © The Japanese Forest Society and Springer 2009.

DOI： 10.1007/s10310-009-0135-7

Scopus

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Publishing type：Research paper (scientific journal)  

Lake Mizoro-ga-ike in Kyoto is a natural monument in Japan that contains a temperate floating mat bog and a diverse plant community. The lake has undergone eutrophication since the 1940s. Management to conserve the lake was begun in the 1960s. To evaluate the present condition of the lake, we investigated the quality of water collected in and around the lake in November 2005, 2006, and 2007 and the soil in the catchment forest in June 2006. The soil analyses indicated that the forest is nitrogen limited, and the water passing through the catchment is nutrient poor and suitable for conserving the lake. The water quality analyses indicated that the lake has three sources of pollution: water from a water purification plant to the southeast, contaminated water from a road that runs along the northern boundary, and sewage from a hospital to the northeast. Since January 2003, a pump has been used to deal with the effect of water leaking from the water purification plant. However, the condition of the lake did not change between 2003 and 2007 because the pumping is insufficient. Therefore, we cannot expect an improvement in the water quality unless a better pump is used.

DOI： 10.18960/hozen.14.2_153

Scopus

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Other Link： http://orcid.org/0000-0002-7070-616X

Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese  

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Language：English   Publishing type：Part of collection (book)   Publisher：World Scientific Publishing Co.  

Artificial nutrient loading has been linked to the decrease in plant diversity in peatlands, riparian areas, and swamps. Mizoro-ga-ike pond is one of the natural monuments of Japan and contains temperate floating mat and diverse plant community. The pond had experienced eutrophication by sewage and tap water. As the inflows of nutrient-rich water had been lessened, the amount of source area of the pond has decreased to 30%. We investigated factors that control water chemistry in and around the pond to assess the present situation of the pond. The pond has two mouths of inflows. One of the inflows includes leaked water from a tap water reserver. The other is the surface flow collected by a ditch. The result of water quality census indicates the pond has two sources of nutrient-rich water. One is the drainage from the surface water polluted by the road for automobile that flows into the northern coast of the pond, and the other is the tap water-contaminated water entering from the southern coast. Also the result of the census indicates that emergent plants such as reeds and wild rice modify the effect of nutrient-rich water by exploiting nutrients. Especially, it was suggested that the nursery effects of emergent grasslands that spread southern part of the pond protect the less robust plants, Nuphar subintegerrimum.

DOI： 10.1142/9789812708915_0013

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Language：English   Publishing type：Research paper (scientific journal)  

CiNii Books

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Other Link： http://hdl.handle.net/2433/80085

Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER TOKYO  

Spatial and temporal ground-surface dynamics are major factors that affect regeneration and species coexistence in tropical peat swamp forests. We studied the seedling survivorship and morphological features of two tree species that play important roles in maintaining the ground-surface dynamics of a peat swamp forest in Sumatra. Large Swintonia glauca trees form mounds, whereas large Stemonurus scorpioides trees occupy non-mounds. We monitored the demography of naturally dispersed Swintonia and Stemonurus seedlings that germinated in 2000. Survivorship of Swintonia seedlings was high under conditions of late germination, high-light environment, and elevated ground surface, and was negatively affected by distance to the nearest conspecific adult. Survivorship of Stemonurus was high under conditions of early germination and high conspecific seedling density, and was also negatively affected by distance to the nearest conspecific adult. The allometric features of Stemonurus seedlings indicated characteristics of stress tolerance, that is, low growth rate and thick, porous roots. Stemonurus, which has large wingless seeds, regenerated in non-mounds around the parental trees, while winged Swintonia seeds dispersed farther from the parent and established in patchily distributed gaps and mounds. Thus, Swintonia seedlings can survive on non-mound sites within gaps and possibly create mounds, while Stemonurus seedlings tend to maintain non-mounds around the parental trees.

DOI： 10.1007/s11284-006-0185-7

Web of Science

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Language：English  

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Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOCIETY  

We studied the relationship between the coexistence of tree species and the dynamics of organic matter in forests. A tropical peat swamp forest was selected as a model ecosystem, where abiotic factors, such as geological topography or parent rock types, are homogeneous and only biological processes create habitat heterogeneity. The temporal or spatial variation of the ground elevation of peat soils is mainly caused by changes in the balance between organic matter inputs to soils and decomposition, which is affected by the growth and death of influential trees. To clarify the processes of elevation dynamics, we measured the microtopography around some tree groups, estimated organic matter (in the form of litter and roots) in soils under three kinds of microtopographic conditions, measured decomposition rates and detected dominant species' shifting distribution patterns in different stages of growth in relation to the locations of tree groups creating specific microtopographic conditions. We found that growth or death of buttressed trees has the greatest effects on the rising or sinking of ground surfaces through changes in litter supply and root production. We discuss here the possibility of extending our model to other forest types.

DOI： 10.1098/rspb.2005.3095

Web of Science

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Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Center for Southeast Asian Studies, Kyoto University  

We reconsidered the typology of Sumatran peat swamp forests according to the three zones of lowland plains proposed by Furukawa. Flood zones, occurring edges of lowland plains, are covered mainly by freshwater swamp forests. Central zones feature the sequential zonation of mixed peat swamp forests, <i>m&eacute;ranti paya</i> forests, and <i>padang suntai</i> forests. Tidal zones are covered by mangrove forests and mixed peat swamp forests. Sequential zonation was also reported in peat swamp forests of Sarawak and Brunei, but the flora of these two areas is unique within the western Malay Archipelago. By virtue of the distribution and composition of flora, the patterns of vegetation zoning are thought to be similar among the lowland plains of the Malay Peninsula, Kalimantan and Sumatra, although zonation was sometimes simpler than this because of climatological and geomorphological conditions.

DOI： 10.20495/tak.40.1_74

CiNii Books

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Other Link： http://hdl.handle.net/2433/53719

Language：Japanese  

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Language：Japanese  

DOI： 10.11519/jfsc.118.0.685.0

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Language：Japanese   Publisher：日本陸水学会  

DOI： 10.14903/jslim.71.0.174.0

J-GLOBAL

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Language：English  

J-GLOBAL

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Language：Japanese  

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Language：Japanese  

DOI： 10.14848/esj.ESJ52.0.281.0

J-GLOBAL

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Language：Japanese   Publisher：ECOLOGICAL SOCIETY OF JAPAN  

DOI： 10.14848/esj.ESJ52.0.297.0

J-GLOBAL

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