Soil CO2 efflux at timberline on Mt. Fuji

Soil CO2 effluxes were investigated at timberline on Mt. Fuji. Three study plots along a sequence of vegetation zones (dwarf, tall Japanese larch, and Veitch\u27s silver fir proceeding downward) in the vicinity of timberline were selected for the measurement of soil CO2 efflux. The results showed differences in the temperature dependence of the soil CO2 efflux among the three study plots. The highest value (Q10 = 4.4) was derived at the upper plot where the vegetation and soil formation were underdeveloped. Environmental data also showed differences among the three plots in soil temperature and soil water content. The upper study plot was exposed to higher soil temperature and lower soil moisture than the other two plots because of poor vegetation cover and underdeveloped soil formation. The total soil CO2 efflux during the snow free period from June to October was estimated for the upper, middle, and lower plots as 3.3, 3.0, and 3.7 Mg C ha-1 5 months-1. The results suggest that the amount of soil CO2 efflux does not always correspond to vegetation and soil development

Response of germination and seedling growth to soil particle size of three herbaceous perennials on alpine zone of Mt. Fuji

Polygonum cuspidatum, P. weyrichii and Artemisia pedunculosa are herbaceous perennials in the alpine zone on Mt. Fuji. The effect of soil particle size on seed germination and seedling growth of these species was investigated. In the experiment three different particle size soils (large particle size LPS, medium particle size MPS, and small particle size SPS) were used. The other experiment was designed under three different watering intervals (every day, every two days, and every four days). Soil particle size had a great impact on seed germination and seedling growth. The highest percentage of seeds germinated in SPS and lowest in LPS soil, irrespective of the species. In the case of A. pedunculosa there was no significant difference of seed germination between SPS and MPS soils. However, the other two species had significantly reduced percentages of seed germination with increasing soil particle size. The maximum root length of seedlings was significantly longer in LPS and MPS compared to the SPS soil group, for all species. The number of root tips was increased with decreasing soil particle size, irrespective of the species. Further, larger aboveground biomass was found in seedlings of SPS than those of LPS and MPS. A. pedunculosa showed a slightly different pattern of seed germination and seedling growth compared to the two Polygonum species. Seed germination of A. pedunculosa was comparatively independent of soil particle size, and it may have conservative water use strategy. On the other hand, seed germination of Polygonum species was highly affected by the soil particle size, and those species may adapt to the water deficit condition by taking up water from deeper soil

Seasonal changes in the amount of carbohydrates and photosynthetic activity of Pinus pumila Regal on alpine in central Japan

Branches and needles of Pmus pumila REGEL were collected from a site in the Yatsugatake mountain range in central Japan They were divided into current, 1-year-old, 2-year-old and 3-year-old parts Then, soluble carbohydrate (total sugars and starch) included in each of them was analyzed by SOMOGYI-NELSON method Photosynthetic rate of needles was measured by an infrared CO_2 gas analyzer Total sugar contents of branches and needles showed high levels in the winter season, but starch content levels were low In the younger part, total sugar content showed a higher level than in the older part Net photosynthetic rate of needles was the highest in summer, and was slightly negative in winter

Carbon dynamics and budgets in three soil type agro-ecosystems in southern Finland

Sisältö: Kuuluu sessioon Interaction of soil, water and the atmosphere.vokKV