UNIT 5: Soil properties, formation and more | GEOG 1111, Study notes of Geography

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SOILS
** fine material covering the earth's surface composed of both mineral & organic material; dirt
** weathering provides the raw materials (parent material) for soil formation & development
* Soil Characteristics:
* soil profile: the array of soil layers; their sequence from top (surface) to bottom (bedrock)
* soil horizon: a distinct layer of soil within the soil profile.
* Soil Properties:
* color * texture (clay, sand, silt)
* structure * consistence (cohesion)
* porosity * moisture
SOIL FORMATION
* an on-going process of a renewable resource, but not an inexhaustible resource
** Components of Soil
Minerals: elements or compounds with a crystalline structure; the building blocks of rocks; found in all soils.
Organic matter: the part that originally from living matter; decaying matter of plants, animals, and their waste products.
Water: fills spaces in the soil or forms a thin film around particles.
Air: also fill pour spaces
** Factors Involved in Formation
Parent Material: the type of rock and minerals the soil was formed from.
** residual soil: made from the underlying rock
** transported soil: made from material not found in underlying rock
Climate: if temperatures and precipitation (moisture) differ will yield different soils, even if from same parent material.
Biological Agents: decomposers, microorganisms, bacteria, fungi, type of humus or organic matter.
Topography: flat vs steep slopes; windward vs leeward slopes; sun exposure
Time: for a given place, more time means more complete development & increased thickness of soil Development Processes of Soil Horizons:
** Soils develop layers or horizons, often quite distinct, by 4 processes
Addition: grains of soil made by adding material to the soil already in place; adding organic matter
Transformation: weathering of rock, minerals, & soil particles already present; physically or chemically changing them
Depletion: particles are carried out of an area, and downward thru soil by percolating water, to an area below.
Translocation: deposition of particles in a lower area from an area above.
** SO, Soils develop Soil Profiles or a particular sequence of soil layers or horizons
* Main horizons:
'O' horizon : organic horizon, consisting entirely of organic material; by ADDITION
'A' horizon : upper most layer developed from parent material; by TRANSFORMATION
'E' horizon : lighter colored layer just below the 'A' horizon; by DEPLETION
' B' horizon : created by translocation of particles from the 'A' & 'E' horizons above; by TRANSLOCATION
'C' horizon : where the parent material is transformed by weathering into soil particles to become future soil; by TRANSFORMATION

Oxisols: tropical areas with high rainfall; rainforests ; rich in FE and AL oxides; subject to laterization.
Gelisols: cold & frozen soils subject to crytoturbation (frost churning); found in high latitudes & elevations GEOG1111: Unit Five Notes: Introduction to Biogeography 11/16/2011
INTRODUCTION TO BIOGEOGRAPHY
* the geography of flora (plants) and fauna (animals)
** Basic ideas:
Biodiversity or biological diversity : the variety of life forms, the ecological roles they perform and the genetic diversity they contain.
* # of species (life forms): 1.75 million identified & described. Estimates of between 3.7 & with a working estimate 13.62 million.
Types of diversity Genetic Diversity: variety in the genetic makeup among individuals within a species.
Species Diversity: variety among the species or distinct types of organisms found in different habitats of the planet.
Ecological Diversity: variety of forests, deserts, grasslands, streams, lakes, oceans, coral reefs wetlands & other biological communities Functional Diversity: biological & chemical processes or functions such as energy flow & matter cycling needed for the survival of species & biological communities

* Processes
* photosynthesis * energy flow within & between systems
* ecological efficiency: Trophic levels, food webs
* plant & animal succession
* geographic dispersal: Physical factors, Biotic factors
Basic Building Blocks: * Matter: from subatomic particles to ecosystems * atom –> molecules –> protoplasm –> cells –> tissues –> organs –> organ systems –> organisms –> populations –> communities –> ecosystems –> biosphere * based on atoms: protons, electrons, neutrons, ions elements: non-human made (‘natural’) & human-made compounds: organic (hydrocarbons, carbohydrates, etc) & inorganic
** 2 Sub-Areas:
Phytogeography Zoogeography
Plant distributions Animal distributions
BIOGEOGRAPHIC PRINCIPLES & PROCESSES

Photosynthesis: occurs in the cells of plants which contain chloroplasts, which contain the pigment chlorophyll.
6 CO2 + 6 H2O + energy ------------> C6H12O6 + 6 H2O + 6 O2 (sunlight) (glucose)
* the above process is broken down into several steps, the major two being the Light reactions & the Dark reactions (Calvin Cycle)
** Limitations of photosynthesis:
* rate of respiration by the plant (where the plant uses some of the energy- food created in photosynthesis; also involves glycolysis, & the Krebs Cycle)
* if increase respiration ----- then decrease efficiency of photosynthesis
* if increase heat (TEMPS) -- then increase respiration
* availability of water
ECOLOGICAL CONCEPTS ** Some basics of the biological component of the environment: Terms: Evolution or Biological Evolution: the change in a population’s genetic makeup, gene pool, through successive generations * all species descend from earlier, ancestral species Macroevolution: long-term, large scale changes that lead to new species (speciation), and the loss of other species. Microevolution: small genetic changes that occur in a population. * development of genetic variability through mutations, random changes of the DNA in a cell; brought about by: * exposure to external agents (radiation, chemicals, etc) * random mistakes during DNA replication * mutations are: random & unpredictable, only source of totally new genetic raw material ( without human help) , relatively rare events Natural Selection: process by which a particular beneficial gene or set of genes is reproduced in succeeding generations more than other genes. This leads to a population of organisms with a greater proportion of individuals better adapted to certain environmental conditions. Adaptation or adaptive trait: any genetically controlled structural, physiological, or behavioral characteristic that helps an organism survive & reproduce under a given set of environmental conditions. EX’s: structural adaptations: coloration, mimicry, protective cover, gripping mechanisms. physiological adaptations: hibernation, chemical protection behavioral adaptations: migration, various mating behaviors. Ecological Niche: total way of life or role of a species in an ecosystem; a;; physical, chemical, and biological conditions a species needs to live and reproduce in an ecosystem. Habitat: the physical location in which a species lives. Species: a group of organisms that resemble one another in appearance, behavior, chemical make-up & processes and genetic structure. Generalists: species with a broad ecological niche; can live in many different habitats, eat a variety of foods & tolerate a wide range of environmental conditions; less prone to extinction EX’s: humans, flies, cockroaches, mice & rats, raccoons, coyotes, channel catfish, various weed species, etc. Specialists: species with a narrow ecological niche; may live in only one type of habitat, tolerate only one type or a few types of food, tolerate only a narrow range of environmental conditions; more prone to extinction EX’s: red-cockaded woodpecker, giant pandas, snail kite, numerous tropical rain forest species Native species: species that normally live & thrive in a particular ecosystem in which they evolved or are 'naturally' found EX’s: American bison, American alligator, etc Nonnative species: species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem; also know as: exotic, alien, or introduced species. EX’s: kudzu, Argentine fire ants, nutria, etc Indicator species: species that serve as early warnings that a community or ecosystem is being degraded. EX’s: many birds, frogs, & toads Keystone species: species that play roles affecting many other organisms in an ecosystem EX’s: wolf, leopard, lion, sea otter, great white shark, various bees, bats, & ants * How quickly can a species adapt? Dependent on 3 limitations: 1) A change in environmental conditions can lead to adaptation only for traits already present in the gene pool of a population 2) The population’s ability to adapt can be limited by its reproductive capacity 3) Even if a favorable trait is present, most of the population would have to die or become sterile so individuals with the trait could dominate & pass the trait on Speciation: formation of two species from one species as a result of divergent natural selection in response to changes in environmental conditions. * mechanism: 2 phases 1) Geographic Isolation: separation of populations of a species into a different areas for fairly long times. 2) Reproductive Isolation: long-term geographic separation of members of a particular sexually reproducing species. Extinction: complete disappearance of a living species from the Earth; happens when a species cannot adapt & successfully reproduce under new environmental conditions or it evolves into one or more new species Background Extinction: normal extinction of various species as a result of changes in local environmental conditions; a few species here and there of varied taxa Mass Extinction: catastrophic, widespread extinction event in which major groups of species are wiped out over a short time; 25-70% of existing species wiped out by climate change or a comet strike, etc Mass Depletion: widespread, often global period during which extinction rates are higher than normal but not high enough to classify as a mass extinction * fossil/geologic evidence suggests that at least 2 mass extinctions & 3 mass depletions have occurred during the past 500 million years
GEOGRAPHIC DISPERSAL
Physical (Abiotic) Factors: factors which control the distribution of species GEOG1111: Unit Five Notes: Phytogeography 11/16/2011
PHYTOGEOGRAPHY * the study of the distribution of plants & their ecosystems, both spatially and temporally Biogeochemical Cycles ** all atoms, elements, molecules, substances, etc get cycled through environment. Some, however, are more important than others. ** those are important to organisms (to live, grow, and reproduce) are cycled between the nonliving and living components of the environment, in what are known as the biogeochemical cycles. * we will briefly discuss the following: Water, Carbon, Nitrogen, Phosphorus, & Sulfur Hydrologic (Water) Cycle ** The collection, purification, & distribution of the Earth’s water supply through both the abiotic & biotic components of the environment. * evapotranspiration * condensation * precipitation * run-off * consequences of this flow of water: * causes soil erosion & moves weathered fragments of rock, adding to erosion in one place & deposition in another * is a major medium for transporting nutrients within the Environment * purification of the water supply as it goes through evaporation & precipitation, as it flows through streams & lakes, and as it passes through the ground Carbon Cycle ** the flow of carbon, primarily as carbon dioxide (CO2), through theatmosphere, hydrosphere, lithosphere, & biosphere (the environment)
*Consequences: * key element in controlling the temperatures at the Earth’s surface; it is a “Greenhouse Gas” * a key element in the formation of organic molecules and compounds, upon which life on Earth is based. * removed from the air by producers (plants) to make complex Carbohydrates. * produced during aerobic respiration, primarily by animals, and released back into the air *stored as an ‘energy’ source in the form of fossil fuels; released back into the cycle when these are broken down (EX: burned by humans) ** Oxygen and Hydrogen cycle in a similar fashion to Carbon. All three are important elements in carbohydrates. Nitrogen Cycle ** the movement of nitrogen, in various chemical forms, through the environment * it is an important element for most organisms, BUT in its’ most abundant form, N2, it cannot be absorbed & used directly as a nutrient by plants & animals * it is broken down during lightening strikes & certain bacteria in the soil & aquatic systems can convert it into useful compounds * consists of several steps nitrogen fixation: process in which specialized bacteria convert gaseous nitrogen (N2), into ammonia (NH3) that can be used by plants. (EX: soybeans and alfalfa) nitrification: process in which most of the ammonia in soil is converted to nitrite ions ( NO2-) by aerobic bacteria, & nitrate ions ( NO3-) which are taken up by plants; animals get their N by eating plants or herbivores. ammonification: conversion of nitrogen-rich organic compounds into ammonia (NH3) & ammonium ions ( NH4+). denitrification: conversion of ammonia & ammonium ions back into nitrite & nitrate, and then into N2, which is released into the atmosphere. Phosphorus (P) Cycle ** cycles through the water, lithosphere, and living organisms and is commonly found as phosphate salts * is important for plant growth, but is a limiting factor in plant growth of its’ low abundance in soils. * since levels are low in soils, it must added in high-tech agricultural activities; this disrupts the normal cycle * if increased amounts of P are introduced into aquatic systems it can lead to increased plant, bacteria, & alga growth, which leads to oxygen depletion by the subsequent decomposition of the dead organic matter by aerobic decomposers Sulfur Cycle ** circulated through the environment in various compounds * can be added as hydrogen sulfide (H2S) from active volcanoes & the decay of organic matter by anaerobic bacteria; as sulfur dioxide (SO2) from volcanoes; sulfate salts (SO42-) from sea spray * human activities account for about 33% of all sulfur compounds & 99% of SO2 reaching the atmosphere * sulfur trioxide gas (SO3) reacts with water to from sulfuric acid (H2SO4), a component of acid deposition PLANT GEOGRAPHY * the study of the distribution of plants & their ecosystems, both spatially and temporally

** Biome: broadest justifiable division of plants and animals; an assemblage or association of plants and animals that forms a regional ecological unit.
* Basic Types:
Tropical Rainforest: dominated by tall, closely spaced broad-leaf evergreen trees; well developed 3-layer canopy.
* highest biodiversity of any terrestrial environment * within the 'Af' climate areas

Tropical Deciduous Forest: less dense canopy than Tropical Rainforest with less well developed canopy layers
2) cyclic autogenic: stages or assemblages can be repeated and often are. May also skip a stage.
3) allogenic: change in species composition brought about by outside forces or disturbance. i.e. disease, fire, flood, landslide, etc. * climax community: a kind of end point or final stage, where the plant assemblage is in balance or best suited for the existing climate & soil characteristics

GEOG1111: Unit Five Notes: Zoogeography 11/16/2011
ZOOGEOGRAPHY
** the geographical distribution of animal species & populations on the earth's surface
* What controls where an animal lives?
* the ecological niche or broader habitat that the species has evolved and adapted into.
Aquatic Life Zones ** two major divisions: Saltwater or Marine & Freshwater * can also be delineated into 3 layers: surface, middle, & bottom * important environmental factors to consider: salinity, temperature, access to sunlight, dissolved oxygen, availability of nutrients Marine systems: Coastal Zone: high net primary productivity; contains 3 ecosystems: Estuaries: areas where freshwater and saltwater mix. Coastal wetlands: land areas covered with saltwater all or part of the year; Salt marshes & Mangrove forest swamps Coral reefs: found in relatively shallow, tropical waters

Open Sea: low net primary productivity; divided into 3 vertical zones Euphotic: high levels of sunlight penetrate. Bathyal: medium levels of sunlight penetrate. Abyssal: very low levels of sunlight penetrate. Freshwater systems: Lakes: classified based in nutrient content and primary productivity. Oligotrophic lake: usually newly formed, nutrient- poor; often deep and have crystal clear blue or green water. Eutrophic lake: nutrient-rich; large supply of nutrients (N & P); usually shallower, murky brown or green color & poor visibility Mesotrophic lake: in between the first two; most lakes fall within this category.
Rivers & Streams: can be delineated into 3 zones: Source Zone: mountain (headwater) streams at high elevation Transition Zone: wider, lower-elevation streams Flood Plain Zone: area of rivers which empty into the ocean Inland wetlands Marshes: dominated by grasses Prairie potholes: depressions carved out by glaciers Swamps: dominated by trees and shrubs. Floodplains: receive excess water during heavy rains and floods.
Zoogeographic Realms: KNOW ZOOGEOGRAPHIC REALM MAP.
Neoarctic: encompasses North America, Greenland, and the Central Highlands of Mexico.
* one of the least diverse realms * EX: American bison, pronghorn antelope, Bald eagle, prairie dogs, Whooping crane, etc.

Paleoarctic: Europe, northern Asia(north of the Himalayas), & North Africa (north of the Sahara)
* also an area of low diversity * the Paleoarctic & Neoarctic sometimes combined as the Holarctic * EX: Siberian tiger, Giant panda

Neotropical: coastal Mexico, through Central and South America
* one of the richest & most varied faunal assemblages * EX: tapir, jaguar, llama, vicuna, macaws, numerous marsupials, boa constrictor, prehensile-tailed monkeys(Spider, Colobus, etc)

Paleotropical (Ethiopian): Sub- Saharan Africa * also one of the richest & most varied faunal assemblages * EX: zebra, giraffe, hyena, ostrich, gorilla, chimpanzee, numerous antelope sp., etc

Madagascan: the island of Madagascar and nearby Comoro Islands