Variation in size and shape of Sphagnum hummocks in relation to climatic conditions in Hokkaido Island, northern Japan

Abstract

Regional variation in size and shape of Sphagnum hummocks of eight lowland mires throughout Hokkaido Island, northern Japan, was examined in relation to climatic factors. The size and shape of hummocks significantly differed among the regions: low and flat hummocks occurred in the northern region and next to the Sea of Japan; moderately raised and conical hummocks occurred in the western part of the Pacific coast; and extremely raised and cylindrical hummocks occurred in the eastern region. Multiple regression analysis revealed that the mean and maximum heights and height/basal area of hummocks were negatively correlated with evapotranspiration rate (E0) in summer, duration of sunshine, and air temperature. Of these, evapotranspiration rate in summer positively correlated with radiation and thermal factors. Mean height of hummocks within a mire was increased with precipitation during the growing season. Because the regional difference of the hummock form was not related to the difference in nutrient conditions, the effects of evapotranspiration and precipitation prevailed over edaphic conditions. Higher E0 in summer was considered to cause water stress for hummock species in the northern region and next to the Sea of Japan, whereas heavy rainfall relieved it in the western region of the Pacific coast. Consequently, lower and flat hummocks were a result of the higher E0 in summer, moderately raised and conical hummocks of the medium E0 and high precipitation, and extremely raised and cylindrical hummocks of a lower E0 due to prolonged foggy days.Key words: evapotranspiration, duration of sunshine, minerotrophy, ombrotrophy, precipitation.

Measurement and modelling of bryophyte evaporation in a boreal forest chronosequence

“…In poorly drained areas, moss growth and differential growth rates create and reinforce the hummock-hollow microtopography characteristic of these areas (Yabe and Uemura, 2001;Benscoter et al, 2005). Microtopography affects not only calculated fluxes-by 5-10% here, and sometimes much larger (30-40%) values (Vitt, 2007)-but also species distribution (Andrus et al, 1983) and small-scale water balance and carbon fluxes, due to turbulence effects on the local environment (Rice and Schneider, 2004) and small-scale variations in the water table (Roy et al, 1999).…”

Inhabitation Characteristics of Sphagnum palustre in Abandoned Paddy Terrace Wetland: a Case Report in Ansan

“…물이끼를 Andrus, 1988;Rydin, 1995;Rydin and Jeglum, 2009;Terasmae, 1955;Yabe and Uemura, 2001). (Lodwick and Snider, 1980 (Clymo, 1963(Clymo, , 1973.…”

Assessment of flora, plant communities, and hydrochemical conditions for adaptive management of a small artificial wetland made in a park of a cool-temperate city

“…The hummocks imitated Sphagnum-dominated hummocks on the bog surface located in Ishikari Plain and other alluvial plains at the Sea of Japan coast, of which heights were ca. 10 cm (Yabe and Uemura 2001). For the growing experiment, seven mire plants were bought from MID Toshikaihatsu, Osaka, Japan: Eriophorum vaginatum L., Sphagnum palustre L., Eriophorum gracile, Drosera rotundifolia, Menyanthes trifoliata, Rhynchospora alba, and Carex limosa.…”