1Temperate GrasslandsTemperate GrasslandsTemperate Grasslands One of the most extensive of the biomes North America: prairies 350 million ha running from eastern deciduousforest border to western cordillerasKonza Prairie, KansasTemperate Grasslands One of the most extensive of the biomes Eurasia: steppes 250 million ha running from Hungary to ManchuriaMongolian steppeRussian SteppeTemperate Grasslands One of the most extensive of the biomes Argentina, Uruguay: pampas2Temperate Grasslands One of the most extensive of the biomes Argentina, Uruguay: pampasCortaderia -pampas grassTemperate Grasslands One of the most extensive of the biomes South Africa: grassveldtTemperate Grasslands Temperate grasslands are adapted to recurring drought (50 - 120 cm rain) Temperate grasslands appear homogenous but important structural andfloristic differences have developed in response to regional and localconditions (e.g. in prairie province) increasing latitude & east to west:warm to cold and moist to dryTemperate Grasslands American prairie gradients: west to eastShortgrass prairie, NebraskaKonza Prairie - mixed grass, KansasCurtis Prairie- tall grass,Wisconsin3Temperate Grasslands American prairie gradients: forest - grasslandCurtis Prairie- tall grass,WisconsinPrairie-oak savannaTemperate Grasslands soils are rich 'chernozens' or 'udolls’ thick organic layer of very dark humus; active earthworm and soil faunaactivity making this soil one of the most productive of terrestrial systems light rainfall and high evaporation makes mild leaching; therefore soil isneutral or only slightly acidicA horizon Changes: fire supression - once frequent and kept out woody species fire for agriculture stillprevalent in South African veldtand South American pampasTemperate Grasslands Changes: large areas converted to agriculture (wheat, maize, legumes)Temperate Grasslands4 Changes: loss of characteristic cursorial fauna of ungulates (bison,antelope, gazelle, wild horse) or equivalent flightless birds in SouthAmerica (rhea)Temperate GrasslandsPronghorns on short grass prairie, NebraskaBuffalo, South Dakota Changes: loss of characteristic cursorial fauna of ungulates (bison,antelope, gazelle, wild horse) or equivalent flightless birds in SouthAmerica (rhea)Temperate GrasslandsAntelope, Asian steppesRhea, Argentinan pampas grasses and sedges have high silica content in leaves ungulates acquired early on high-crowned teeth in which growthcontinually replaces the worn surfaces as adaptationTemperate Grasslands grasses and sedges have ability to resprout after grazing (good example isthe prairie ungulate replacer: the lawn mower) Changes: major extinction ofmegafauna in North America from thePleistocene - HoloceneTemperate GrasslandsMissouri in Pliocene 5-6mya“Overkill” hypothesis?5 Floristics of American prairies: Prairie peninsula of tall grasses may haveextended to East Coast - floristic (andfaunistic) linkagesTemperate Grasslands Floristics of American prairies: few endemic species suggesting thatprairies developed comparatively recentlyand attained present distribution only in post-glaciation or Holocene (Axelrod, 1985)Temperate GrasslandsAmorpha canadenseLeadplant (Fabaceae) Floristics of American prairies: widespread distribution across Beringiainto Eurasian steppes commonTemperate GrasslandsAnemone patensPasque flower (Ranunculaceae) Floristics of American prairies: 3 major families Poaceae - grassesTemperate GrasslandsAndropogon gerardii - big bluestemSorghastrum nutans - Indian grass6 Floristics of American prairies: 3 major families Poaceae - grassesTemperate GrasslandsPanicum virgatum -switch grassBouteloua - side oatsgamma grassSporobolus heterolepis -prairie dropseed Floristics of American prairies: 3 major families Fabaceae - legumesTemperate GrasslandsLupinus perennis - lupineBaptisia bracteata -creamy wild indigoAmorpha canescens - lead plant Floristics of American prairies: 3 major families Asteraceae - compositesTemperate GrasslandsSilphium terebinthinaceum / laciniatum -prairie dock, compass plantEchinacea - purple coneflower Floristics of American prairies: 3 major families Asteraceae - compositesTemperate GrasslandsSolidago rigida - stiff goldenrodLiatris aspera - blazing star7 Floristics of American prairies:Temperate GrasslandsAnemone patens - pasque flower(Ranunculaceae)Extra Credit!Take digital image of this“harbinger of spring” for prairiesClose the book on biomeswe will revisit some of these inNorth America after firstexamining the twin issues ofevolution of earth and
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