Possible Ecology Exam Taylor University Reber
Ecosystem
-Structure -Function
Microscopic decomposers
Bacteria, fungi, actinomycetes
Therophytes
annual plants
Direct Measurements
Correlation with absolute age.
Macroparasites
Large (fleas, ticks, and roundworms)
Sedimentary Cycles
More Localized
Microparsites
Small (viruses, bacteria, and protozoans), transmission
Pennslvanian
Swamp Forests
Mesozoic
Swamps to deserts - climate was cooler and drier.
Communities Adapted to Fire
Tallgrass prairie, Black spruce forest (Taiga), Southern Pine
Periodicity
Temporal Patters
Rivet
each individual species plays a small but significant role
Redundancy
function is more important
Epiphytes
plants growing on other plants
Relative measures
relative density, relative coverage, relative frequency
Nutrient Use Efficiency
• Amount of biomass per unit of nutrient taken up (same concept as WUE)
Sources of CO2
• Burning of fossil fuels • Land clearing
Classic Metapopulation Model
• Colonization and extinction among roughly equal-sized patches
Sulfur Cycle
• Gaseous (oxide) sources: volcanic eruptions, fossil fuels • H2S is the dominant sulfur form emitted from freshwater wetlands and anoxic soils • Weathering of pyritic rocks (mining) - produces acidic conditions in aquatic communities
Nitrogen Cycle
• Gaseous biogeochemical cycle • Nitrogen is required for protein synthesis • 79% of the atmosphere • Most limiting nutrient (terrestrial)
Carbon Cycle
• Gaseous cycle • Autotrophs fix the carbon • Consumers and decomposers release CO2 • Cycling rates (temperature dependent; boreal forest vs. tropical rainforest) • Cycling varies daily and annually
Biological Concentration through Trophic Levels
• Heavy metals and fat soluble organics are concentrated up the food chain • DDT is the premier example • Each trophic level accumulates the pesticide at a higher concentration
Edges
• Induced edge - periodic disturbance • Inherent edge - stable and naturally occurring (example: change in the abiotic soil conditions)
Nitrogen Input : Decomposition Cycle
• Most nitrogen is returned via the decomposition cycle • Ammonification • Nitrification (Nitrosomonas, Nitrobacteria) • Denitrification (reducing conditions)
Ecosystem ecologist
• Studies the flow of matter and energy • Nutrient flow
Landscape Ecologist
• The landscape is composed of patches • Examines the interaction between the patches and the ecological processes
The Quality of Energy
• Visible light (400 - 700nm) • PAR - Photosynthetically Active Radiation • UV-A and UV-B • Near infrared and far infrared
Transmission Utilizing an Intermediate Vector
•Some parasites are transmitted between hosts by an intermediate organism, or vector
Coverage (Dominance per Smith)
"space" occupied (cover, basal area, volume)
Species Diversity
- Describes the variety and distribution of organisms in the community • Function of species richness and species evenness • Species richness - # of species • Species evenness - abundance of individuals among the species
Characteristics of Deserts
- Found at 30o North and 30o South latitude • High pressure cells dominate • Low precipitation (< 12 inches annually) • High temperatures - most of the plants grow during the cooler winter months • Plants - thick epidermal tissues, lack of leaves
Site Quality and Litter Quality
- Low nutrient environments: o Long-lived leaves (extreme example: Black Spruce) o Low concentration of nutrients in the foliage o Elevated production of fine roots
Direct Transmission
- Macroparasite • Bird and mammal ectoparasites (lice, ticks, mites) are spread by direct contact • Holoparasites — squawroot and beech-drops • Spread of fungal infection (Dutch Elm disease) when infected roots grow onto the roots of a neighbor (root grafting)
Intermediate Disturbance Hypothesis
- Patterns of diversity depend on the frequency and scale of disturbance • Intremediate disturbance hypothesis (M. Huston and J. Connell)
Parasites - Specialists
80% of the 550 aphid species in Great Britain feed on one host genus Nematode pinworm (Enterobius) each of 13 primate species has a specific nematode that is a parasite Exception - peach - potato aphid that can attack over 500 plant species
Hydrologic Cycle
Carries Mobile Ions
Gross/Pickett/Rothrock/Squiers
Composition of the seed bank as a primary factor in successional charge.
Detritus
Dead Organic Matter
Clements View on Community
Each organism either had a positive or neutral association with the organisms around them
Inhibition Model
Early occupants hold the site against all invaders.
Macroscopic decomposers
Earthworms, nematodes, insect larvae
Internal Cycling of Nutrients
Ecosystem and Autotrophic Level
Secondary Consumers
First Level Carnivores
Primary Succesion
From bare rock to a complex community.
Gaseous Cycles
Global in nature
Primary Consumers
Herbivores
Henry Cowles
Lake Michigan dune systems - succession as great cycles tied to geomorphic process - plant communities are dynamic, ever-changing.
Facilitation Model
Later stage species depend upon early stage species to prepare a favorable environment.
Food Web
Linking of the Food Chains
Mid-Cenozoic - Tertiary (30 million ybp.)
Madro-tertiary Geoflora arrives on the scene; southern Rockies and Northern Mexico - similar to the chaparral communities of southern California
Vine and Matthews
Magnetic reversals at ridge crests.
Early Paleozoic
Mostly reef communities
Arctic-Tertiary Geoflora
Norther part of the content similar to forests in th southern Appalachians and parts of China and Japan.
Direct Transmission
Occurs by direct contact with a carrier, or the parasite can be dispersed from one host to another through the air, water, or other substrates
Frist Trophic Level
Producers, autotrophs, plants.
Importance value
RD + RF + RC (the highest value would be 3)
Lotic
Rapid moving water systems.
Black Smokers
Rich in Copper Sulfides
White Smokers
Rich in Zinc Sulfides
Transmission Can Involve Multiple Hosts and Stages
Same parasites species cannot complete their entire life systole in a single host species. The definitive host is the host species in which the parasite becomes an adult and reaches maturity. Intermediate hosts harbor some developmental phase. Many plants and animals parasites are strsmitted indirectly.
Harry Hees
Sea floor moves away from mid-ocean ridge
Resource Ratio Model
Sites shift from low nutrient/ high light to high nutrient/low light.
Lentic
Slow moving water system.
Neotropical Tertiary Geoflora
Southern part of the continent broadleaved evergreen angiosperms similar to modern topical rainforests and savannas.
Fredric Clements
Succession is a linear process to a predictable climax community "mono climax hypothesis".
Locations of Tropical Rainforests
The Amazon basin of South America is the largest and most continuous rain forest in the world The second largest is in Southeast Asia The third largest is in West Africa
Tolerance Model
The species that are the most efficient in exporting the resource will succeed.
Food Chain
Who eats who
Secondary Succession
After a disturbance, the soil is intact.
Autotrophs and decomposers
Are the most important.
Frederick Clements View on Community
each species is an integrated component of the whole
Zonation
horizontal layering
Gleason
individualistic nature of species "continuum concept"
A biotic community
o A structural unit o A functional unit characterized by "coupled" metabolic transfers
Distribution and adaptations of life is affected by the variation in oxygen, temperature, and light
o Light is increasingly attenuated with water depth o Temperatures vary seasonally with depth o Oxygen can be limiting
Nutrients - Inputs and Recycling
o Nutrient-poor sites encourage below ground productivity o Nutrient-poor sites produce plants with low quality tissue for herbivory (quantitative inhibitors) o Nutrient-poor sites produce low quality litter
Eight major terrestrial biomes
o Tropical forest* o Temperate forest* o Coniferous forest* o Temperate grasslands o Savannas* o Chaparral (scrublands) o Tundra o Desert
Cryptophytes
perennial buds are buried in the ground
Phanerophytes
perennial buds are up in the air
Mineralization
release of inorganic compounds from decomposing matter (Nitrogen and phosphorus)
Immobilization
removal of inorganic nutrients from the soil solution by the decomposers
Gleason
species are dependent on requirements and are tolerant over a set range of conditions
Clements
the community acted like a large "organism"
The Concept of Community
• "A biotic community is a group of interacting populations of plants and animals" o Can be terrestrial or aquatic
Theory of Island Biogeography and Landscape Patches
• "Any patch of habitat isolated from similar habitat by different, relatively inhospitable terrain traversed only with difficulty by organisms of the habitat patch may be considered an island." (D. Simberloff) o Mountaintops o Bogs o Ponds o Dunes o Areas fragmented by human land use o Individual hosts of parasites
What is Ecology?
• "Ecology is the study of the interactions between organisms and their environment."
Metapopulations
• "Populations that are spatially structured into assemblages of local breeding populations with migration between them that affects local population dynamics, including the possibility of reestablishment following extinction" (Hanski and Simberloff, 1997)
American Bison Timeline
• 1500 - ~30 million bison in N.A. • 1802 - Bison pushed out of Ohio • 1820 - Native Americans pushed west • 1830's - mass destruction begins • 1860's - railroad, Buffalo Bill, two herds
American Bison Timeline
• 1872 - 2 million bison killed that year • 1875-76 - last great hunting season on the Southern Great Plains • 1877 - a few remaining bison were killed in T.X. • 1884 - Most of the northern herd was gone • 1890 - 750 wild bison left in the U.S. • 1905 - 100 animals in both Yellowstone and the National Zoological Park in Washington D.C.
Energy Flow and Laws of Thermodynamics
• 2nd law - entropy increases • Measure of disorder is entropy • What is the difference between an open and closed system? • If everything is going downhill, how can life exist on earth?
The Lithosphere
• 46% oxygen • 27% silicon • 8% aluminum • 5% iron • Oxygen and silicon comprise the silicate minerals (quartz, feldspars, micas, and clays) • Aluminum and silicon (clay lattice structure in soils) - source of most of the inorganic molecules necessary for plant growth
Indiana Wetlands
• 5,600,000 acres in 1780 (24.1% of total land area) • Currently 813,000 acres (3.5% of total) • Remaining wetlands have lost structure and function
The Hydrosphere
• 70 % of the surface of the earth is covered by oceans • Open oceans lack high productivity (Why?) • Salts (dissolved minerals from the rock cycle)
Composition of the Atmosphere
• 75% nitrogen • 23% oxygen • 360 ppm of carbon dioxide (and rising) • < 1% water • Carbon dioxide and water are the main "greenhouse gases" - methane also is important • Heat in the atmosphere comes from reradiated energy
Decreasing Energy and the Trophic Levels
• 90% of the energy is lost going from one trophic level to another • Lost energy - low grade heat • Implications for the top carnivores • The argument for vegetarianism
Human Energy Needs
• A human needs about 2,300 kcals/day • 1 American uses 230,000 kcals/day • To run a color T.V. for 6 hours 2,300 kcal of energy is required
Ecological Issues & Applications: Land-use Changes Are Resulting in an Expansion of Infectious Diseases Impacting Human Health
• About 300,000 people contract the disease annually • Parasite - bacterium (Borrelia burgdorferi) • Vector - backlogged tick (Ixodes scapulars) • Tick life cycle has four stages: egg, larva, nymph, adult
Community Information (Dominance)
• Abundance - an estimated "general impression" (rare, occasional, common, frequent, abundant) • Density - # per unit area, a precise measure but not a measure of distribution • Frequency - % of plots in which a species occurs, a measure of distribution but not # of organisms
Deep Time
• Age of universe is 15 to 20 billion years • Earth is 4 - 5 billion years old
Human Impacts
• Agricultural clearing • Most of Indiana was cleared by burning
Edges and Ecotones
• An edge is where two or more different vegetative communities meet • Ectone - where communities intergrade
Environmental Heterogeneity Influences Community Diversity
• An increase in the variety of food resources has the potential to increase the number of consumer species that can be supported in a community • A field study of nectar-feeding insects and flowering plants in eight prairie grassland communities in south central Minnesota found a positive correlation between bee species richness and for species richness
Estuarine Organisms
• Anadromous fish - live in saltwater and return to freshwater to spawn o Striped bass o Shad o Croaker • Oyster bed and oyster reef • Sea grasses - widgeon grass and eel-grass
The Fundamental Niche Constrains Community Structure
• As environmental conditions change from location to location, the possible distribution and abundance of species will change-in turn changing the community's structure • Geographic distributions of species reflect the occurrence of suitable environmental conditions
Succession Also Involves Heterotrophic Species
• As the species composition and structure of vegetation change, animals can lose their habitat • Different species are seen in early stages of succession than in the later stages o Grassland species disappear o Scrubland species colonize o Eventually the scrubland species disappear and are replaced by forest animals • Complexity of the vertical structure increases through succession
The Greenhouse Effect
• Atmosphere is transparent to visible light • Infrared wavelengths radiate off the surface of the earth the atmosphere • CO2 and other greenhouse gases trap this keeps the Earth relatively warm
Location
• Australia • Central and Southern Africa • Kankakee sandy outwash - Illinois and western Indiana
The Individual vs. the System
• Autecology: the interaction between an individual and its environment • Synecology: the larger scope - results from the whole system
Basic Ecosystem Components
• Autotrophs • Consumers • Abiotic matter
Benthic Zone
• Benthic refers to the floor of the sea and benthos refers to plants and animals that live there • The bottom community is strictly heterotrophic (except in vent areas) and depends on the organic matter drifting to the bottom
Biomes
• Biomes are biotic units - classified by predominant plant types o Developed by F.E. Clements and V.E. Shelford • Biome types form in response to a distinctive climatic pattern o First noted by R. Whittaker (Cornell University) • Topography, soil type, disturbance, and exposure also can influence the occurrence of a biome in a location
Interactions:
• Biotic (levels of: individuals, populations, communities, ecosystems) • Abiotic • Determine the distribution of the organisms
Human Interactions with the Ozone Layer
• CFCs, methane, nitrous oxide • Thinning of the ozone layer - protection from ultraviolet light
Acidic Deposition
• CO2 reacts with H2O (normal rainfall pH=5.6) • Both wet and dry deposition • Sulfur and nitrous oxides (from fossil fuels) • Nitrogen is high in acidic deposition
Energy Flow in Ecosystems
• Calorie = kilocalorie (large calorie) = 1000 calories • 1 calorie = heat required to raise 1 ml (1 cm3) of water 1o C @STP • 1 kilocalorie = 3.97 BTU • 1 barrel of oil (42 gallons) = 1,500,000 kilocalories
North American Chaparral
• Chaparral - shrubby evergreen oaks • Chaparral is derived from the Madro-Tertiary Flora • Uniform distribution of the vegetation • Dry community - fire adapted
Global Climate Change
• Climatic change is an inherent characteristic of Earth (paleoclimatology) • The amount of tilt in Earth's rotation affects the amount the amount of incoming energy o Tilt of Earth's axis varies from 22.5° to 24° over a cycle of 41,000 years • Variations in climate have been a continual force on biological systems • The human species has the ability to alter Earth's climate
Sir Ernst Haeckel (1869)
• Coined the term ecology from the Greek oikos (meaning house or place to live) • Ecology is the study of the relationship of organisms to their environment
Characteristics of the Boreal Forests
• Commonly called the "Taiga" • Occurs at 60o N latitude or high elevations • Arctic tundra (to the north) or alpine tundra (at higher elevations) • Circumpolar
Mycorrhizae
• Conifers, oaks, and birch trees need this fungal symbiont • Fungal species increases the surface area of the root • Plant roots exude low molecular weight compounds • Morel mushrooms and truffles (endomycorrhizae)
The Theory
• Continued emissions of CO2 will lead to global warming
Rainfall
• Convectional at equator • Cyclonic (30o N to 60o N) - Indiana's weather • In Cyclonic weather patterns: • High pressure - flow is clockwise and outward from the center (no rain - cool and dry) • Low pressure - flow is counter-clockwise and the air moves inward and upward (rain - hot and muggy)
Mutualism and Agriculture
• Crop health and density is dependent upon humans • 35% of all the world's land area is cropland or pasture
Oligotrophic lakes
• Deep, nutrient-poor lakes • Low surface to volume ratio • Canadian lakes, northern MI lakes
Detritus and Grazing Food Chain
• Detrital food chain is the major pathway of energy flow in terrestrial and littoral ecosystems • Less than 10% of the net primary productivity is lost to herbivory in forests • In grasslands - 40 % of the net primary productivity is consumed by the herbivores • Open water systems are dominated by grazing herbivores
Hydrothermal Vents
• Diverging plate boundary • Vents form when cold seawater flows down through cracks in the basaltic lava floor and the waters react with the hot basalt; water becomes enriched with minerals (e.g., copper, iron, sulfur, zinc)
Ecology of Savannas
• Dominated by high temperatures and low precipitation (mean temperature usually >18°C) • Distinct seasonality in precipitation • Vegetation is fire-adapted • Presence of large herbivores • Importance of termites - especially in Africa and Australia
Species Richness and Island Size
• Early explorers noted that large islands hold more species than do small islands o J.R. Forster on Captain Cook's voyage (1772-75) o P. Darlington: on islands, a tenfold increase in land area leads to a doubling of the number of species
Continental Drift Theory
• Earth's Lithosphere is composed of plates • James Hutton (1726 - 1797) - principle of uniformitarianism • Charles Lylell (1779) - structural changes are controlled by uniformitarianism • Wegner (1924) proposed the concept of continental drift
Shortgrass Prairie
• East of the Rockies • Low precipitation • Blue drama and buffalo grass dominate • Forbs are not as prevalent • "Bread basket" of America
The Reintroduction of a Top Predator to Yellowstone National Park Led to a Complex Trophic Cascade
• Ecologists have monitored changes in vegetation in the park since the wolves were reintroduced • As the wolf population has increased, the elk population has declined
Rules of Ecology
• Ecology is a science • Genes and environment are both important • There are multiple constraints on organisms • Understanding complexity requires models (mathematical or conceptual) • Chance is important
Ecological Efficiencies (IL cornfield)
• Edgar Transeau (used .405-hectacre, 1 acre plot, produced about 100 bushels of corn) • Total energy (incoming) 2043 million kcal • Total energy consumed 943 million kcal
The Reintroduction of a Top Predator to Yellowstone National Park Led to a Complex Trophic Cascade
• Elk are browsing herbivores • As their population increased, the deciduous vegetation in the park declined • Some species, such as aspen, did not regenerate in areas heavily used by elk
Functional Processes
• Energy flow (forest system vs. grassland system) • Food webs • Nutrient cycles • Development and evolution
Transition Zones
• Environmental conditions in transition zones enable certain plant and animal species to colonize border environments o Animals usually require two or more habitat types within their home range • Edge species are those restricted exclusively to the edge environment • Indiana is the home of "edge" wildlife
Vertical Structure
• Epilimnion (max Ps, warm water) • Metalimnion (thermocline) • Hypolimnion (cold, low oxygenated water) • Fall and spring turnover
Nutrient Cycling in Coastal Ecosystems
• Estuaries are very productive • Shallow water with ample sunlight - a lot of primary producers • Nutrients are available • Ocean tides bring in oxygenated water • Comparison (East vs. West Coast)
Community ecologist
• Examines the patterns and interactions seen in groups • Predation and competition
Steep Gradient Streams
• Fast moving • Bottom is usually bedrock • Driven by the detritus cycle • Larval stages of insects: caddisflies (shredders), mayflies (collectors) • Few macrophytes • Appalachian streams
Energy in Biological Material
• Fat : 9 kilocalories per gram • Protein : 5.2 kilocalories per gram • Carbohydrates : 4 kilocalories per gram
Large Scale Zonation in Communities
• Forest communities within the Eastern Deciduous Forest • Community types correlate with physiography • Slope position and aspect Great Smoky Mountains and the Taiga
Effects of Acidic Deposition
• Fraser fir in the high elevations of the Smoky Mountains (woolly adelgid?) • Effects on forest systems - lack of frost hardiness, other nutrients become limiting, decrease in root biomass
Rich Diversity of Life
• Freshwater wetlands support a diverse community o Benthic, limnetic, and littoral invertebrates, especially crustaceans and insects o Small fish o Waterfowl o Amphibians and reptiles (emergent growth) o Herbivores: muskrat o Predators: raccoon, fox, skunk, etc.
Early ecologists
• Friedrich von Humbolt (Prussian naturalist, 1769-1859) - correlated vegetation types with environmental characteristics • Henry Cowles (1897) - work on the Indiana dunes (succession) • F.E. Clements (1916) - introduced the concept of a climax community • Victor Shelford (1911) - animal physiology "law of tolerance"
Formation
• Glacial erosion, deposition (kettle lakes) • Formed when sediment and debris dam up water behind them — oxbow lakes • Shifts in the Earth's crust • Animal induced - beavers • Human-created dams, quarries and surface mines
Production Terminology
• Gross Ps • Net Ps = gross Ps - leaf respiration • Net primary production = Net Ps - non leaf respiration
Methods of Studying Productivity
• Harvest method
Methods of Studying Productivity
• Harvest method • CO2 gas analyzer (net primary productivity) • Aquatic systems: "light and dark bottles" o The concentration of dissolved oxygen is compared between the "light" and "dark" bottles o No photosynthesis will occur in the dark bottle and the oxygen content of water will decline
Mojave Desert
• High elevation desert (east of the Sierras, 3000 - 6000 ft) • Joshua tree, creosote bush • Colorado Desert (Part of the larger Sonoran Desert) lower elevations
Abiotic Nitrogen Fixation
• High energy fixation (lightning) o (N2) is converted to ammonia and nitrate by energy from cosmic radiation, meteorite trails, or lightning — this accounts for only 0.4 kg N/ha annually (5 - 8% of total nitrogen fixed) o Can be as high as 20 kg N/ha (Florida)
Characteristics of Tropical Forests
• High plant diversity - especially trees • Forest floor dark - lacking in litter layer • Epiphytes and vines are common • Insect biomass high - especially ant populations • Cradle of primate evolution
Temperate Rainforest
• Highly productive • Coastal areas of Alaska; western areas of Washington and Oregon, northern California • Low evapotranspiration, high rainfall • Example: Olympic National Forest • Douglas-fir, and Western red cedar
Corridors Are Playing a Growing Role in Conservation Efforts
• Highways across migratory routes lead to the deaths of many animals that try to cross these barriers • Construction of wildlife overpasses and underpasses allows animals to safely cross these highways
Behavioral ecologist
• How an animals behavior is adapted to its environment • Periodicity in feeding, activity, and reproductive times
Federal Jurisdictional Definition
• Hydric soil (either organic or mineral) • Hydric plants o Obligate wetland plants require saturated soils o Facultative wetland plants can grow in either saturated or upland soil • Wetland water hydrology (surface water present or water in the rooting zone during some part of the growing season)
The Quality of Energy (Reaching Earth)
• Incoming energy: drives photosynthesis • Incoming energy: produces the infrared wavelengths that heats the surface • Conversion from the solar constant to ultimately plant biomass is very inefficient • Plants utilize red and blue wavelengths
Models of Global Climate Change
• Increase in temperature (between 1o C and 3.5o C) and precipitation by 2100 - Changes unevenly distributed o Warming the greatest in the northern hemisphere in the winter months • More extreme weather patterns
The Box and Arrow Model
• Inputs and outputs • Homeostatic mechanisms stabilize the system • Feedback loops • Most ecosystems are fairly "open" o Mature beech maple forest vs. an agricultural field
Human Influences
• Introduced species (lakes are fairly closed communities) • Cultural eutrophication (golf courses to feedlots)
Metapopulation Theory - A Central Concept in the Study of Landscape Dynamics
• Island biogeography examines the species richness of a single habitat patch as a function of colonization and extinction • Metapopulation theory examines the colonization and local extinction of local populations of a species on an array of patches in a broader landscape • How are metapopulation dynamics different at the scale of an individual patch versus the landscape scale?
Mooar Brothers
• John quit his job in New York and joined Josiah in Kansas City, Kansas, and the brothers entered into a partnership in 1872 • Josiah did most of the hunting, and John transacted the business affairs (In eight years Josiah Wright estimated they killed and marketed over 22,000 buffalo for meat and hides)
Mooar Brothers
• Josiah Wright Mooar was hunting buffalo for meat in Kansas by the age of twenty years old • Josiah Wright sent some flint hides to his older brother, John Wesley Mooar in New York • John found a market for them at $3.50 each
Species Interactions
• Keystone predation usually results in higher species diversity - reduces the abundance of superior competitors (starfish example) • Tales of grizzlies, wolves, moose, and birds
Ecology - Perspective
• Landscape • Ecosystem • Physiological • Population • Behavioral • Community
Mainland-island Metapopulation
• Large "mainland" subpopulation that is immune to extinction • This "mainland" is able to export colonists to small "island" subpopulations • "Subpopulations" are prone to extinction • The habitat found in the "mainland" is similar to the habitat which is found in the "islands"
Possible Results of Global Climate Change
• Large shifts in biomes • Tropical rain forest distribution reduced by 25 percent if [CO2] 2x • Increased decomposition (positive feedback) • Rising sea levels (reef development?) • Extinctions (habitat tracking becomes important; Wabash River corridor) • Agricultural impacts? Human health?
Heavy Metals and Chlorinated Hydrocarbons
• Lead - sources: leaded fuel, paints, sewage sludge • Lead is bioaccumulated • Chlorinated hydrocarbons - DDT • DDT is soluble in lipids • DDT is still used for pest control outside of the US
Horizontal Structure
• Littoral province - salt water marshes, estuaries (very productive, high species diversity) • Neritic province - located over continental shelves • Oceanic province - the open ocean
Horizontal Structure
• Littoral zone (macrophytes and high net primary production) • Limnetic zone (open water zone - phytoplankton and zooplankton)
Sonoran Desert
• Low elevation • Saguaro, prickly pear, and organ pipe cacti (bat and bird pollinators) • Chollas, creosote bush, ocotillo, and palo verde • Long-lived annuals
Mineral Transfers via the Decomposers
• Low molecular weight carbon compounds (sugars, starches) - easy to degrade • Cellulose, hemicellulose, lignin (main structural elements of plants)
Mineral Transfers via the Decomposers
• Low molecular weight carbon compounds - easy to degrade • Cellulose, hemicellulose, lignin (main structural elements of plants)
Origins of the Grasslands
• Madro-Tertiary Geoflora • Less than 7 million years ago
Temperate Broadleaf Forests (Eastern Deciduous Forest)
• Maple-basswood forests (Great Lakes states) • Oak-chestnut or central hardwood forests (Appalachian Mountains) • Magnolia-oak forests (Gulf Coast states) • Oak-hickory forests (Ozarks)
Cowardin Wetland Classification
• Marine • Estuarine • Riverine (confined within a channel) • Lacustrine (depression > 20 acres, lacking trees) • Palustrine (depressional < 20 acres)
Regulation by Parasites
• Microparasites - ideal situation - hosts live in herds • Long-lived infective stage without long-term immunity • Immunity reduces parasite populations • Populations with no evolved resistance (American chestnut - chestnut blight)
Temperate Coniferous Forests
• Montane - mid-elevations in the mountainous regions o North America Rocky Mountains • Low elevations — Ponderosa pine
Temperate Coniferous Forests
• Montane - mid-elevations in the mountainous regions o North America Rocky Mountains • Low elevations — ponderosa pine • Southern Pine o Fire-adapted ecosystem (in the pine-palmetto communities fires are even more frequent) o Longleaf and slash pine
Global Carbon and Soil
• More carbon is stored in soils than in living matter • The average carbon/volume of soil increases from the tropics to the boreal forest and tundra o The greatest accumulation - where decomposition is inhibited (e.g., frozen or waterlogged soils)
Landscape Ecology
• Mosaic: the patchwork of different types of land cover • The landscape mosaic is defined by changes in the physical and biological structure of the distinct communities, called patches • Landscape ecology: the study of the causes behind the formation of patches and boundaries and the ecological consequences of these spatial patterns on the landscape
Obligatory Nonsymbiotic Mutualism
• Mutualists live apart • Tropical Ficus trees and wasps • Acacia and ants • Coral and pistol shrimp
Mutualism and Nutrient Uptake
• N-fixing bacteria (Rhizobium-legumes Frankia-Alnus spp.) • Mycorrhizal fungi o Increase phosphorus uptake o Ecto and endo mycorrhizae o Important in low nutrient environments
Nutrients Control and Primary Production (Terrestrial Systems)
• NPP increases with increasing nutrient availability • P. Reich (University of Minn.) examined the relationship between soil nitrogen availability and aboveground NPP in oak savanna stands o Increasing primary productivity with available nitrogen
Biological Nitrogen Fixation
• Nearly all of the nitrogen fixation is done by the prokaryotes • Biological fixation by Rhizobium, Frankia, cyanobacteria, and specialized lichens
Biological Nitrogen Fixation
• Nitrogen is necessary by all living organisms for growth • Atmospheric nitrogen is stable and not usable by living things • Nitrogen must be fixed or combined with other elements (high energy cost - 10g of glucose per 1g of nitrogen)
Evolutionary Responses
• No advantage to the parasite if the host dies • Australia - European rabbit and myxomatosis (virus spread by mosquitoes) • Human and sickle cell anemia
Thermal Inversions
• Normal conditions: temperature decreases going up in altitude in the troposphere • Inversion - air temperature rises as elevation increases • Topographically-induced inversions, climatic-induced (cool nights, high pressure: subsiding and warming) • Implications for air pollution
Locations of the Grasslands
• North America - between the Rocky Mountains and the Eastern Deciduous Forest • Eurasian Steppes • South American Pampas (Argentina) • Velds (Southern Africa)
Zonal Distribution of Productivity
• Not all areas of the globe have equal productivity • Tropical rainforests and estuaries - very productive • Intensive agriculture is 2x as productive as a temperate deciduous forest
Ecological Dominance
• Not all organisms in a community are equally important in defining the nature and function of the community • Relatively few species often exert the controlling influence giving the "ecological identity"
Theory of Island Biogeography
• Number of species established on an island: a dynamic equilibrium between the immigration of new colonizing species and the extinction of previously established ones o R. MacArthur (Princeton University) and E.O. Wilson (Harvard University) developed this theory in 1963 • Theory has been applied to the study of terrestrial landscapes
Nutrient Cycling in Stream Communities
• Nutrient spiraling (cycling) in streams • Nutrients are carried downstream via the organic matter • Physical characteristics of the stream channel are important • Inputs are not constant (Eastern Deciduous Forest)
Southern California - Spotted Owl Metapopulation
• Occurs in southern California as a group of discrete populations within the San Bernardino Mountains of southern California • Habitat is discontinuous in part because of human development activities • Individual populations have shown recent declines, reason: increased isolation of habitat patches and natural environmental stochasticity
Species Diversity and Succession
• Old-field studies - plant species diversity increases with time • Colonization increases species richness • Species replacement decreases species richness • Peak in plant diversity is in the middle stages of succession (usually)
Physiological ecologist
• Organisms react with their environment to accomplish homeostasis • Homeostasis involves the maintenance of time, matter, and energy budgets that allow for the growth and reproduction by the individual
Ehrlich - Checkerspot Butterflies
• P. Ehrlich (Stanford University) studied the population dynamics of the checkerspot butterfly (Euphydryas editha) in the San Francisco Bay area of California o Over the past 30 years, various local populations have gone extinct and been recolonized by other butterflies of the metapopulation o In this study, local populations are connected via dispersal
Pelagic Zone
• Pelagic ecosystems lack the supporting structures and framework of large, dominant plant life • The dominant autotrophs are phytoplankton, and their major herbivores are tiny zooplankton
Vertical Structure of Oceans
• Pelagic zone (body of water) • Benthic zone (ocean bottom)
The Reintroduction of a Top Predator to Yellowstone National Park Led to a Complex Trophic Cascade
• Perching birds have been positively affected by the regrowth of willow trees (released from browsing) • Provides a more structurally complex habitat that allows for greater songbird richness and diversity
Grassland Ecology
• Perennial plants • Fibrous root systems • Fire-dominated ecosystems • Soil development - Mollisols
Obligatory Symbiotic Mutualism
• Permanent and dependent • Lichens - fungus and an alga (or cyanobacterium) combined within a spongy body (thallus) o The alga supplies food to both organisms o The fungus protects the alga from harmful light intensities, accelerates photosynthesis of alga, and absorbs water and nutrients for both organisms • Mycorrhizal Fungi (found in 90% of all plants) • Endomycorrhizae fungi (> 70% of all plant species) • Ectomycorrhizae fungi (woody plants)
Ecology can be defined by...
• Perspective • Habitat • Organism • Application
Pelagic Zone
• Photic zone (top 200 meters) • Mesopelagic (200 - 1000 meters in depth, maximum concentration of NO3- and PO4-3) • Bathypelagic (darkness prevails, low temperature, high pressure)
Ecology - Organism:
• Plant • Animal • Microbe • Zooplankton • Human • Deer • Tree
Lakes - Physical Characteristics
• Ponds and lakes may be stratified horizontally and vertically • Profundal zone - beyond the depth of effective light penetration (compensation depth of light) • Benthic zone - bottom region that is the primary place of decomposition
Food Webs - Community Structure
• Primary producers • Secondary producers • Trophic levels • How is the world green? (top-down or bottom up control)
Controls of Nutrient Cycling Rates
• Primary production and decomposition rates • Soil type (% O.M.,%N) • Quality of the litter • Climate
Ecology is...
• Quantifiable (nutrient budgets to population dynamics) • Basic science (chemistry, biology) • A relatively young discipline (<150 years old) • The basis for the environmental science discipline and the environmental movement that began in the late 1960s o Silent Spring by Rachel Carson o The first Earth Day (April 22, 1970)
Regulation by Parasites
• Regulation of bighorn sheep populations (lungworm) • Avian malaria (carried by introduced mosquitoes) eliminated most of Hawaii's native birds
Geologic Time
• Relative dating • Geologic eras (correlation of fossil types) • Earliest fossils from the Precambrian (stromatolites) • 600 may the appearance of "hard parts" • Precambrian, Paleozoic, Mesozoic, Cenozoic
Species Interactions
• Removal of single species tends to have little effect, oldfield plant communities (Fowler) • Interactions are diffuse • Snowshoe hare is preyed upon by 11 of the 12 species that inhabit the boreal forest (not the American Kestrel)
Interior Species
• Require conditions characteristic of interior habitats avoid abrupt changes associated with border environments o The probability of finding certain species may increase or decrease with patch size depending on whether they are edge or interior species
Horizontal Structure (map view)
• Riffle - fast moving water, shallow, high O2; species: darters, sculpins, daces • Run - deeper, fast moving • Pool - stagnant, decomposition • Riparian zone - transition between the aquatic and the terrestrial environments
Environmental Heterogeneity Influences Community Diversity
• Robert MacArthur measured structural heterogeneity of vegetation and bird species diversity in 13 communities in the northeastern United States • Index of species diversity • Index of foliage height diversity • Strong relationship between bird species diversity and vertical structure (foliage height diversity) • An increase in the variety of food resources has the potential to increase the number of consumer species that can be supported in a community • A field study of nectar-feeding insects and flowering plants in eight prairie grassland communities in south central Minnesota found a positive correlation between bee species richness and for species richness
Human Influences
• Row crop agriculture • Grazing - drier areas
Spartina Experiment cont...
• S. alterniflora allocates more growth to above-ground structures - advantage in high water - tolerates water depth better than S. patens • S. patens is outcompeted in drier areas by Juncus gerardi (allocates more growth to below-ground structures) • Upper limits set by competition
Ecosystem ecologists
• S.A. Forbes (entomologist at U of I) - food chains in lakes • R.L. Lineman - 1942 paper on the trophic interactions and energy flow through Cedar Bog Lake in Minnesota (published after his death) • Eugene Odum - (PhD from the University of Illinois, taught at University of Georgia) - energy flow, wrote "Fundamentals of Ecology" - first ecology textbook in 1953
Phosphorus Cycle
• Sedimentary cycle • Natural phosphate deposits are reservoirs • Mining of phosphates (agricultural) • Phosphorus forms many insoluble salts
Facultative Mutualism
• Seed dispersal in the Eastern Deciduous Forest (jays, squirrels) • Ants and seeds with nutritious seed coat • Frugivores (raccoons and birds, bats in the tropics) • Scarification
Effects of Acidic Deposition
• Severe in the soils with low buffering capacity (weathered from granite) • Aquatic systems are especially sensitive (Northeastern lakes, vernal pools)
Eutrophic lakes
• Shallow, nutrient rich, numerous sediments on lake bottom • High surface to volume ratio • The common Indiana lake
Past Communities of Indiana
• Silurian bedrock (Paleozoic) in Grant Co. • Surface geology (Pleistocene) - 2.5 million years in length • Three major advances o Interglacial periods (warmer) o Wisconsin (40,000 - 10,000 yep) o Vegetative zones - southward shift
Wegner's Theory
• Similar "fit" of continents • Wegner - continents "plowed" through the oceanic lithosphere (centrifugal and tidal forces were responsible) • Similar strata (rock types) and fossils - S. America, Africa (South African geologist Alexander Du Toit) • Glacial deposits in southern hemisphere
Simpson's Index of Diversity
• Simpson's index (D) = ∑(ni/N)2 o ni the number of individuals of species i o N the total number of individuals • Probability that two individuals randomly selected will belong to the same species • As diversity increases - D decreases (counterintuitive) • Sometimes written Simpson's Index = 1- D
Shallow Gradient Streams
• Slow moving • Macrophytes present • Dragonfly larvae - smallmouth bass food • Vermillion River, Csangamon River (IL), Mississinewa River (Grant Co. IN)
Decomposition Rates Influenced by
• Soil temperature • Soil moisture • Soil pH • Litter quality
Temperate Broadleaf Forests (Eastern Deciduous Forest)
• Soil type and precipitation dictate vegetation type • Types of forests • Mixed mesophytic forest (Appalachian plateau) • Beech-maple and northern hardwood forests (northern regions) • Maple-basswood forests (Great Lakes states) • Oak-chestnut or central hardwood forests (Appalachian Mountains) • Magnolia-oak forests (Gulf Coast states) • Oak-hickory forests (Ozarks)
The Quantity of Energy (Reaching Earth)
• Solar constant 2 cal cm-2 min-1 • 30% of the energy is reflected back into space • 25% of the energy is reflected by the atmosphere • 5% of the energy is reflected from the surface of the earth • ~20% of the energy is absorbed by the atmosphere • About one half of the energy hits the earth (45% is absorbed by the surface)
Studying Productivity - Harvest Method
• Standing crop - biomass at a specific time • Periodic sampling of the standing crop - rate determination • Regression analysis - using a characteristic to predict standing crop biomass or change in biomass
Defining Conditions
• Suitable habitat occurs in discrete patches that may be occupied by local breeding populations • Even the largest local population has a risk of extinction • Habitat patches must not be too isolated to prevent recolonization after local extinction • The dynamics of the local populations are not synchronized
Where are we?
• Sun is 93 million miles away (8 minutes for sunlight to hit us; 5 days - Pluto) • Sun is a yellow star (within 20 light years there are 20 other yellow stars) • Milky Way is 100,000 light years across (it contains 100 billion stars) • Milky Way is in a cluster of galaxies (local group)
The Global Heat Engine
• Sun-powered • Energy to drive the biogeochemical cycles • photosystems of photosynthesis (Ps) • Energy to drive global climate and define weather patterns • Energy to shape the face of the land (erosion) • Explains the large scale distributions of ecosystems
Benefits Derived from Wetlands
• Surface water protection • Flood control • Groundwater protection • Recreation - waterfowl habitat, fishing, boating, etc.
Plants may be
• Tall or short • Evergreen • Deciduous • Woody • Herbaceous
North American Grasslands
• Tallgrass prairie is forms a narrow band just west of the Eastern Deciduous Forest • Mixed-grass prairie - central Kansas, Nebraska, Dakotas • Shortgrass prairie - rain shadow of the Rockies (dominated by sod-forming blue drama and buffalo grass)
The Temporal Aspect of Productivity
• Temperate vs. tropical systems • Wet and dry seasons - grasslands
Concept of an Ecosystem
• Tensely (1935) coined the term "ecosystem" - biological and physical components of the environment are a single interactive o The biotic and abiotic • Spatial concept
Ecology - Habitat:
• Terrestrial • Lakes and Streams • Marine • Arctic • Rainforest • Thermal Vents • Urban
Controls of Primary Productivity
• Terrestrial NPP increases with increasing mean annual temperature and rainfall • Mean annual temperature is a function of o Mean daily temperature o Length of the growing season • The higher the rainfall, the more water available for transpiration stomata can remain open to take in CO2 for longer amounts of time
Consumers Vary in Efficiency of Production
• The assimilation efficiency is the ratio of assimilation to ingestion (A/l) o Ingested food (l) - Expelled (W) = Assimilated (A) • The production efficiency is the ratio of production to assimilation (P/A) o Production (P) = Assimilated energy (A) - Respiration (R)
Where on Earth is Life Supported?
• The biosphere (atmosphere, hydrosphere, and lithosphere)
Community Dynamics
• The changing nature of community structure across the landscape reflects the shifting distribution of populations in response to: o Changing environmental conditions o Interactions among species • Community structure is dynamic o Shifting pattern of species' dominance and diversity through time
The Reality - What is Seen
• The global average surface temperature has increased by 0.74°C since the early 20th century o Minimum temperatures (0.2°C/decade) are increasing about twice the rate of maximum temperatures (0.1°C/decade) • Global ocean heat content has increased significantly since the late 1950s (0.4°C/decade) o Most has occurred in the upper 300 m of the ocean
Ecological Issues & Applications: Land-use Changes Are Resulting in an Expansion of Infectious Diseases Impacting Human Health
• The impact of forest clearing on the spread of Lyme disease has been well-documented • The number of reported cases in North America has dramatically increased
The Watershed
• The land area drained by a stream or river • Size depends on the order of the stream (1st, 2nd, 3rd, etc.) • Watershed in northeastern Indiana delineated by glacial features
Nitrogen and Carbon Cycles - Linked
• The limitation of one nutrient can affect the cycling of all the others (e.g., macro and micro plant nutrients) o Nitrogen availability will influence a plant's Rubisco concentration o Rubisco concentration affects photosynthetic rate and carbon assimilation o The carbon cycle is directly affected by nitrogen availability
Environmental Gradients
• The lower limits to plant growth are gradients upper limits are competition • Zonation in salt marsh communities (Juncus gerardi and Spartina patens do not tolerate salinity) (Spartina alternatiflora tolerates inundation and salinity)
Patch Size and Shape and Species Diversity
• The minimum habitat size needed to maintain interior species differs between plants and animals • Plants: environmental conditions are more important to persistence than is patch size • Several studies (e.g., R.F. Whitcomb) have revealed a pattern of increasing bird species diversity with patch size
The Reintroduction of a Top Predator to Yellowstone National Park Led to a Complex Trophic Cascade
• The populations of the major deciduous trees have increased • aspen, cottonwood, willow • Fewer trees are being browsed, and the trees are growing taller
Source-sink Metapopulation
• The source area is very high quality habitat • Individuals from the source area disperse to the poorer quality sink habitats • Individuals in the sink populations are under stress and reproductive rates will not sustain the populations
Where are we?
• The sun is 93 million miles away (8 min. for sunlight to reach the earth) • The moon is 250,000 miles away • The earth travels in an elliptical orbit around the sun (closer in the winter than it is in the summer) • The tilt of the earth is 23.5 degrees
Where are we?
• The sun is 93 million miles away (8 min. for sunlight to reach the earth) • The moon is 250,000 miles away • The earth travels in an elliptical orbit around the sun (closer in the winter than it is in the summer) • The tilt of the earth is 23.5o • This tilt causes the seasonal weather patterns
Ecology - Application:
• Theoretical • Conservation • Agricultural • Public Policy • Academic • Management • Restoration
Course Topics
• Theory and practice of science as a way of knowing • Basic principles of modern ecology and their applications • Basic laboratory and field techniques used by ecologists • Statistical applications • Provide ecological concepts that will be applicable to several disciplines (ecology is an interdisciplinary science)
Classic Metapopulation
• There is a balance between subpopulation extinction and recolonization • The local populations are approximately the same size • These subpopulations are isolated enough to be separate entities, but interconnected enough to permit recolonization which will balance extinction
Population Ecologists
• Thomas Malthus (1766-1834) - an economist who noted the populations grow geometrically and then outstrip food supply, Charles Darwin was influenced by Malthus • Lotka and Volterra - population growth, predation, and competition
Fates of the Increased Levels of CO2
• Transformation into carbonates in the ocean (sink for carbon) • Increased plant uptake (fertilizer effect) • Decomposition rates?
Characteristics of the Boreal Forests (cont...)
• Unique animal community o Herbivores include caribou, moose, snowshoe hare, red squirrel, and porcupine o Predators include wolf, lynx, pine martin, and owl • Nesting location of migratory neotropical birds • Periodic outbreaks - herbivorous insects (e.g., spruce budworm)
Ecological Efficiencies (IL cornfield)
• Used in Ps 33 million kcal • Used in transpiration 910 million kcal • Energy not used by plants 1100 million kcal • Energy released by respiration 8 million kcal • Efficiency of Ps is 1.6 %
The Climate Rules cont...
• Warm air rises and cold air sinks • Heat rises (low pressure) - warmer and wetter • Air sinking (high pressure) - cooler and drier • The spin of the earth affects air and water moving on the surface (deflected to the right in the northern hemisphere and to the left in the southern hemisphere)
Vertical Structure
• Water column (top, very oxygenated) • Benthic zone - bottom and substrate
Social Parasitism
• Waterfowl (wood ducks, black-bellied ducks, and golden eyes) - driven by competition for nest sites • Ants (Formicine genus) • Brown-headed cowbird
The Climate Rules
• Weather is an event - climate is a long-term integration • The more nearly the sunlight hits the surface of the earth at a right angle - more energy is transferred per unit area (irradiance is greatest at the equator) • Land heats up and cools down more quickly than does water
Great Basin Shrublands
• West of the Rockies • Sagebrush • Temperate (cool) desert
Tallgrass Prairie
• Western Indiana, Illinois, Iowa, northern Missouri • Moderate temperature and precipitation • Species - grasses: big bluestem, little bluestem, Indian grass; forms: compass plant, coneflowers, black-eyed Susans
Nutrients - Inputs and Recycling
• Wetfall - input via precipitation • Drywall - input from aerosols • In forests - through fall through canopy and stemflow • Internal cycling of nutrients is important (especially in nutrient-poor sites)
Questions that ecologists can ask
• What is the relationship between precipitation and plant growth? • What factors cause changes in the populations of rare species? • How do different plant communities develop and recover after a disturbance such as fire? • What impact does grazing have on a plant community? Forest vs. grassland? On species diversity?
Estuaries
• Where freshwater meets saltwater • Geology is important (PNW vs. coastal Carolina) • Influenced by tidal oscillations (daily temperature and salinity fluctuations) • Benthic organisms common • High levels of nutrients • High levels of productivity
Species Diversity Increases...
• With sample size • In tropical locations • In high competition habitats • In communities with many habitat types • In low disturbance areas
The Reintroduction of a Top Predator to Yellowstone National Park Led to a Complex Trophic Cascade
• Wolves were exterminated from Yellowstone in the 1920s • In the seven decades that followed, the elk population dramatically increased, despite attempts to actively manage it
Effects of Continental Drift
• World-wide distribution of plants and animals • Climatic changes • Extinction events - land bridges
Mediterranean Shrublands
• Xeric broadleaf evergreen shrubs and dwarf trees • Mattoral - equivalent to the North American chaparral
Richard Levins Definition (1970)
•"A population of organisms consisting of many local populations"
Direct Transmission
•Microparasites are more often transmitted directly (influenza, smallpox) • Macroparasites • Female roundworms (Ascaris) lay eggs in the host's gut which are expelled with the feces • Feces are dispersed to the surrounding environment, and if they are swallowed by the host of the correct species, the eggs hatch!
Tropical Rainforests and Diversity
•Tropical rain forests account for more than 50 percent of biological diversity o A 10 km2 area of tropical rain forest may contain 1500 species of flowering plants and up to 750 species of trees o The lowland tropical forest of peninsular Malaysia contains nearly 7900 species! • Nearly 90 percent of all nonhuman primate species exist in the tropical rain forests
Stratification
canopy, understory, herb layer; lakes as well
