Life on Land Chapter 2 PDF

Life on Land Chapter 2 1  Terrestrial Biomes Biome is a large, relatively distinct terrestrial region with a similar climate, soil, plants, and animals, regardless of where it occurs in the world Biome is distinguished primarily by their pred...

Life on Land Chapter 2 1  Terrestrial Biomes Biome is a large, relatively distinct terrestrial region with a similar climate, soil, plants, and animals, regardless of where it occurs in the world Biome is distinguished primarily by their predominant plants and are associated with particular climates. ❖ Terrestrial biomes examples ▪ Grassland, ▪ desert, ▪ tropical rainforest, ▪ deciduous forests ▪ Coniferous forests ▪ Tundra There are two basic aquatic biomes, Freshwater and marine. 2 Geographic and seasonal variations in temperature and precipitation are fundamentalBiomes components determine biome types 3 4  Weather vs. Climate Weather – conditions of atmosphere at particular time and place Climate – long-term average of weather Ocean influences Earth’s weather and climate patterns. Earth’s climate includes interactions of: ❖ Atmosphere (air part of biosphere) ❖ Hydrosphere (water part of biosphere) ❖ Geosphere/lithosphere (land part of biosphere) ❖ Cryosphere (frozen water part of biosphere) Biosphere (all the four parts) ©❖2011 Pearson Education, Inc. 5 6  Temperature, Atmospheric Circulation, and Precipitation Spherical shape and tilt of earth’s axis cause uneven heating of earth’s surface. ❖ Such uneven heating of earth’s surface drives air circulation patterns and consequently precipitation patterns. At the equator, warm, moist air rises. ▪ Then cools, condenses, and falls as rain. ▪ Warmer, dry air falls back to surface create deserts. Rainforests found near equator. Dry hot air coming from above equator will create major deserts found near 20-25o N / S. 7 Solar-Driven Air Circulation 8 Temperature, Atmospheric Circulation, and Precipitation Coriolis effect causes apparent deflection of winds clockwise in the N hemisphere and counterclockwise in the S hemisphere. 9 10  Soil : Foundation of Terrestrial Biomes Soil is a complex mixture of living and non- living material. ❖ Classification based on vertical layering (soil horizons). ▪ Profile provides a snapshot of soil structure in a constant state of flux. 11  Soil Profile The soil profile is defined as a vertical section of the soil from the ground surface downwards to where the soil meets the underlying rock 12 13  Soil Horizons O horizon: Organic Layer freshly fallen organic material - most superficial layer. A horizon: Mixture of minerals, clay, silt and sand. B horizon: Clay, humus, and other materials leached from A horizon - often contains plant roots. C horizon: Weathered parent material. 14 ▪There are twelve orders of soil ❖ Entisol ❖ Histosol ❖ Mollisol ❖ Oxisol ❖ Alfisol ❖ Vertisol ❖ Andisol ❖ Spodosol ❖ Ultisol ❖ Aridisol ❖ Gelisol ❖ Inceptisol 15 16 17  Ultisol (Laterization) Ultisol ❖ Warm climate soil ❖ Redish or yellowish ❖ Low nutrient content Laterization: when PPT greatly exceeds ET in warm climates, water rapidly percolated through soil and into groundwater. Soluble soil nutrients are constantly leached out of soils, leaving behind the less soluble ions (Al+++ and Fe++) which give soil color (whitish for Al and red for Fe) and H+ make soil acidic and nutrient poor. 18 Highly oxidized and deeply weathered soils in West Tennessee. 19 Aridisols (or desert soils) are a soil order in USA soil taxonomy. Aridisols (from the Latin aridus, for “dry”, and solum) form in an arid or semi-arid climate. Aridisols dominate the deserts and xeric shrublands, which 20 occupy about one third of the Earth's land surface  Aridisol (Salinization) ❖ Salinization: in very dry climates and when loss of soil moisture due to evapotranspiration exceeds precipitation, water leaves the soil through the surface. The minerals (NaCl) dissolved move upward from the Evapotranspiration in the UAE is groundwater and result in a 3300 mm, but rainfall is less than salt crust on the surface of 100 mm the soil. Irrigation of dryland can result in soil salinization. This becomes a problem in Arabia, Australia, Northern Africa, China, and major areas of dryland irrigation. 21  Spodosols (Podsolization) Spodosols ❖ Cool moist regions ❖ Acid, shallow leaching horizon ❖ Deep layer of deposition, lower soil fertility 22  Tropical Rainforests Little temperature variation between months. Daily temperature variation could be more than seasonal temperature variation Found near the equator in Africa, South America, Australia, and the Pacific Islands Soil is nutrient poor and acidic Most plants have shallow roots Annual rainfall of 2,000 - 4,000 mm relatively evenly distributed. ❖ Quickly leaches soil nutrients. 23  Most species-rich biome Nutrients tied up in vegetation, not soil Vegetation: 3 distinct canopy layers 24  Tropical Savanna Most occur north and south of tropical dry forests within 10o - 20o of the equator. Climate alternates between wet / dry seasons. ❖ Drought associated with dry season leads to lightning-caused wildfires. Soil low in nutrients due to leaching Vegetation ❖ Wide expanses of grass ❖ Occasional Acacia trees ▪ Have fire adaptive characteristics 25  Tropical Savanna Temperature: Varies little throughout the year Seasons regulated by precipitation, not temperature 760-1500 mm/yr Animal: Contain the greatest number of grazing animals on Earth. Vegetation: Tropical grassland + scattered Acacia trees 26  Desert Major bands at 20-25o N and S latitude. Found on every continent Water loss (evapotranspiration) usually exceeds precipitation (rainfall). The driest biome on Earth Soil usually extremely low in organic matter, especially humus. The soil ranges from gravel to sand. Evapotranspiration in the UAE is 3300 mm, but rainfall is less than 100 mm 27  Desert Plant cover ranges from sparse to absent. Animal abundance low, but biodiversity may be high. ▪Get water from foods ▪Thick outer coat ▪Burrow during day ▪Large ears ▪Smaller animals = less surface area 28  Barrel Cactus Desert Plant Adaptations: ▪ Spines ▪ Succulents ▪ Thick, waxy cuticle ▪ Roots are very deep, but in succulents have shallow, broad roots Joshua Tree http://www.blueplanetbiomes.org/desert_plant_page.htm Ocotollio 29  Mediterranean Woodland and Shrubland Occur in all continents except Antarctica. Climate cool and moist in fall, winter, and spring, but can be hot and dry in summer. Fragile soils with moderate fertility. Trees and shrubs are typically evergreen (i.e., green all over the year). Fire-resistant plants due to fire regime. Long history of human intrusion. ❖ Cleared for agriculture. 30 Mediterranean Woodland and Shrubland 31  Temperate (with cold/very cold temperatures during winter and warm summer) Grassland Extremely widespread distribution. Annual rainfall 300 - 1,000 mm. Experience periodic droughts. Soils tend extremely nutrient rich and deep. Thoroughly dominated by herbaceous vegetation. 32  Temperate Grassland Large roaming ungulates. Bison vs. cattle 33  Temperate Forests (Old Growth Forests) Characterized by 4 seasons Rainfall averages 650 - 3,000 mm. ▪ Characterized by an abundance of deciduous (leaf dropping) trees Soils: Deep fertile soil, rich in nutrients 34  Temperate Forest (Old Growth) ▪Characterized by an abundance of deciduous (leaf bearing) trees ▪Characterized by 4 seasons Soils: Deep soil layers, rich in nutrients 35  Boreal Forests (Taiga) Confined to Northern Hemisphere. ❖ Covers 11% of earth’s land area. Thin, acidic soils low in fertility. Generally dominated by evergreen conifers. Relatively high animal density (like deserts). Historically, low levels of human intrusion. 36  Tundra Covers most of lands north of Arctic Circle. ❖ Climate typically cool and dry with short summers. ▪ 200 - 600 mm precipitation. Low decomposition and primary production rates (like deserts). Supports substantial numbers of native mammals (i.e., high diversity). Human intrusion historically low, but increasing as resources become scarce. 37  Tundra ▪Temp rarely higher than 100C ▪ Short growing season (50-160 days) Nutrient poor acidic soils with little organic material Low primary productivity and decomposition 38  Mountains: Islands in the Sky Built by geological processes and thus concentrated in belts of geological activity. Climate changes with elevation (altitude) and latitude. Soils are generally well-drained and thin. Flora and fauna change with elevation. Historically used as a source of raw materials for human settlements. 39 Mountains: Islands in the Sky 40