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Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily
HOME > Lecture catalog / Research summary > Glossary > Biome
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Proposed by Clements (1916) and used by Clements & Shelford (after 1932) A major regional ecological community of organisms usually defined by the botanical habitat in which they occur and determined by interaction of the substrate, climate, and flora. The term is often limited to denote terrestrial habitats, for example, tundra, coniferous forest, and grassland. Oceans may be considered a single biome, the marine biome, although sometimes this is subdivided, for example, coral reef biome. There is no sharp distinction between adjacent biomes. (Hale & Margham 1991) A major regional ecosystem, characterized by its distinctive vegetation, a particular plant formation, and associated animals, microbes, and physical environment (life zone) (e.g., grassland, tundra, savanna). A biome is a subdivision of a continent on the basis of major differences in the life form of the vegetation, where life-forms reflect the regional climates and soils. (Dunster & Dunster 1996) |
Translation into Japanese'Biome' is transtrated 'Seibutsu-gunkei (生物群系)', or 'Shokubutsu-gunkei (植物群系)' into Japanese. The phonological translation is also used.
flora (フローラ)
physiognomy (相観) |
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Table. The characteristics of biome. (Mackenzie et al. 2001) Biome NPP biomass temperature precipitation Tundra low low low low (< 250 mm) as snow Desert depending low highly extremely low on rainfall variable (so-called arid regions) Grassland high low intermediate between that of deserts and forests Forest high high various high |
[ peat 泥炭 | wetland 湿原 ][ IGRF (偏角計算)]
Etymology: Lappish language tunturia that means land without trees
Primary regionsArctic tundraDistribution: circumpolar, with southern limits roughly following the mean summer position of the arctic cold frontsextends over ≈ 5% of the terrestrial ecosystems Climate: winter temperatures < -10°C
short growing season for plants with cool temperatures < 10°C microsite → significant role influencing plant distribution deep snow pack on leeward versus barren windward north-versus south-facing slopes drainage versus slope soil water drainage can result in ponding permafrost → polygon (methane emission)
ice wedge (氷楔) 
Fig. Arctic vegetation (From Bonanza LTER webpage) Turlough: areas seasonally flooded by karst groundwater with sufficient frequency and duration to produce wetland characteristics. They generally flood in winter and are dry in summer and fill and empty through underground passages (used in western Ireland) |
AlaskaWhere the tundra begins ...Although small pockets of trees exist beyond this point (= the northern edge of the Brooks Range), the continuous forest ends. It is not the deep cold that prevents trees growing in the far north. In fact, the coldest temperatures have been recorded in the forest, not the tundra. It is not the wind, the permafrost, or the lack of water, although they play a part. the main reason that trees do not grow north of here is that there are only a few days each year warm enough for photosynthesis to occur. To survive here, plants must work at conserving energy. Production and maintaining large woody stems or trunks is a luxury tundra plants cannot afford. ... and the Forest Ends
Species richness: high (depending on the scale) Alpine tundradistributionnot defined simply by precipitation and temperature fragmented distribution along mountain ranges (distribution is latitude dependent, being higher in equatorial regions) extensive, extending over ≈ 3% of the terrestrial ecosystems 80% of alpine tundra in the northern hemisphere Vegetation H/G (woody) and Perennials + long-day plant high species diversity and endemism Comparisons of arctic and alpine tundra environments Permafrost: yes vs no Diurnal temperature fluctuation: low vs high Solar radiation: low vs high |
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s.s. vegetation dominated by grasses (Poaceae) s.l. s.s. + sedge and rush with legumes and other herbs The major grassland types are: steppe and savanna Steppe (ステップ)Dry, grassy plain in semi-arid or continental climate• cold or temperate steppe: eastern Europe - central Asia • subtropical steppe - Mediterranean-like regions in Europe Savanna (savannah, サバンナ)mixed woodland-grassland, i.e. grassy woodland
wildfires - frequent |
Semi-natural grassland (半自然草原)disturbances, represented by wildfire, maintain the grasslandsGrasslands in Japanmostly maintained by human disturbances, such as prescribed fire, bush cutting and grazing |
Low precipitation with variable temperatures → low productivity and biomass
Desert in JapanEx. volcanic desert (火山荒原, 火山砂漠) + human impact (e.g., Erimo Cape 襟裳岬, Sarobetsu mire サロベツ原野)Xerophyte (乾生植物) = adapting to desert environments (dryness)
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Desertification (砂漠化)derived recently by human activities
Ex. over-cultivation, over-grazing, fuel wood ● Slash-and-burn agriculture (焼畑農業) ≈ shifting cultivation, bush-follow and swidden agriculture (local names) traditional agriculture system in tropical-temperate regions dominated by forests |