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77 Cards in this Set
- Front
- Back
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What are the sub-topics in ecology?
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Evolutionary ecology
Physiological ecology Population ecology Community ecology Ecosystem ecology Global ecology (Earth systems science) |
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Evolutionary ecology?
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Interplay between genetic composition of a species and environmental factors.
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Physiological ecology?
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Study of interactions between individual organisms and their environment--mechanisms and strategies they employ to survive. Ex--Aspens tendency to root sprout.
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Population ecology?
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Dynamics of populations of individuals within a species-- why is pin cherry typically an early successional species?
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Community ecology?
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Study of interactions among species in a community.
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Ecosystem ecology?
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How energy and materials are transferred and cycled through the environment
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Global Ecology / Earth Systems science?
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Study of the function of the entire earth and its interacting components.
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What are Earth's interdependent sub-systems?
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Lithosphere - geologic stuff
Hydrosphere - water! Biosphere - living things Atmosphere - Air, water vapor |
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Why does Earth's atmosphere have more oxygen than other planets?
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Photosynthesis
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What are the principal greenhouse gases?
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CO2, Methane, water vapor, ozone...
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What is albedo?
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The brightness of a surface, measured in terms of how much incoming light is reflected or absorbed and converted to heat.
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Positive feedback
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Series of events in a system that cause more of a particular change that initiated the series of events in the first place
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Negative feedback
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Series of events in a system that cause less of a particular change that caused the series of events to occur. (Kind of like a mitigating effect)
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Sources of carbon?
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Land use change --deforestation
Fossil fuel emissions Atmospheric increases Oceanic uptake Terrestrial vegetation |
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Evapotranspiration
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How water gets from soil to atmosphere-- evaporation and transpiration
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Community
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Interdependent groups of organisms
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Synergy
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Any system whose components are tied together through interaction and interdependence, with the result being the whole is GREATER than the sum of its parts.
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How many hectares of forest are lost annually?
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9.4 million (2005 estimate)
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What is a frontier forest?
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Large, ecologically intact natural forest that is relatively undisturbed by human activity-- likely able to survive indefinitely without human assistance.
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What is a metapopulation?
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2+ populations that exchange genes (Populations being members of the same species)
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What is a metacommunity?
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A set of local communities linked by interaction.
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What are the requirements for an ecosystem?
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Source of energy
Supply of raw materials Mechanisms for storing and recycling Mechanisms that allow it to persist |
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What is succession?
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A phenomenon of changes initiated by disturbance.
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What is disturbance?
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Any event that disrupts the composition, structure or function of an ecosystem
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Properties of disturbance?
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Scale
Intensity & Consequences Return interval Duration Species specificity |
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Disturbance regime?
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The types and characteristics of disturbances that typically affect a particular ecosystem
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Mutualism
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Relationship between species that results in mutual benefit
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density dependent controls
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Negative feedbacks on population growth--no one thing can grow infinitely large
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Allelochemicals
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Defense against feeding animals and pathogens-- chemicals that inhibit growth of competing plants
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Productivity
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Two types: Primary and secondary
How energy is cycled! |
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Primary producer
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Autotrophs-- convert solar energy to their own food.
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Secondary producer
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Heterotrophs-- eat green leafy plant goodness and consume energy captured by plants
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Feed-forward mechanism
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A mechanism that allows an organism to detect and respond to change.
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Global cycles of elements and nutrients
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Carbon cycle
Nitrogen cycle Sulfur cycle Hydrologic cycle |
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Factors that affect forest presence and distribution?
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topography, soils, climate, composition, human disturbances
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Transpiration?
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The flow of water vapor through the stomates of a leaf to the atmosphere. Plants can close stomates-- Transpiration is partly a biologically controlled process!
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Watershed
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Area of land from which water drains into a particular stream--drainage basin. Determined by topography.
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Hydraulic redistribution
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Deep roots draw water from deep soils into the tree during the day. Some water is re-released into shallow soils at night, keeping surface soils moist.
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Types of forests
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Boreal
Temperate Tropical |
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Characteristics of boreal forests?
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Above 50 degrees latitude and/or high elevations
Climate: Long, severe winters Mostly evergreen, with some deciduous species in young forests. Low species diversity. |
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Characteristics of temperate forests?
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Located in mid latitudes, usually 24 degrees to 50 degrees.
Two main groups: Temperate evergreen and temperate deciduous. (Mixed also exists) 6 month growing season Dormant season due to low temps |
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Characteristics of tropical forests?
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Three distinct types:
Tropical rainforests--high rainfall Seasonal rainforests--brief dry period Tropical deciduous forests -- extended dry period Warm all year, but differences in forest type are due to changes in precipitation High biodiversity, lots of trees, vines and epiphytes. |
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What factors affect distribution of forests?
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Climate-- regional and global
Latitude Prevailing winds Regional weather systems Ocean currents Topography and soils Elevation Slope Aspect |
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What is the difference between weather and climate?
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Weather: State of the atmosphere at any given time
Climate: The long-term average weather conditions over time |
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What affect does latitude have on climate?
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Differential heating of the earth's surface-- high latitudes get more indirect sunlight, low latitudes get more direct and concentrated sunlight over small areas of land.
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What affect do prevailing winds have on climate?
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Direction affects influence of water bodies and land masses on climate.
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What affect do slope and aspect have on forests?
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Slope affects the soil quantity and quality (nutrients get washed away in rains), aspect affects light
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Adiabatic cooling?
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Decrease in temperature as air rises.
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Orographic precipitation?
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Rainfall induced by cooling air as it rises
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Why are evergreens a late-successional species?
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Adapted to poor growing conditions--poor soil, slow growth rate, don't use as much water
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Aspect?
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In N hemisphere, south-facing slopes receive more direct sunlight. As you move up towards the poles, aspect matters more than it does near the equator.
Mountains and valleys have same aspect effect. South-facing slopes are usually drier. |
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Characteristics of a south-facing slope?
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Warmer
High evaporation Drier soil Less snowpack |
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Characteristics of a north-facing slope?
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Colder soils
Wetter soils Higher tree growth rate Accumulation of organic matter |
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Topoedaphic?
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Topo - topography
Edaphic - properties of soil and underlying substrate (texture, depth, moisture, chemical composition, etc.) |
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What do all trees need?
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Light
Water Reasonable temperatures Nutrients |
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What are some forms of disturbance?
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Fire
Floods Wind Disease Landslide Drought Ice Storm |
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What is the most common form of disturbance in Eastern U.S. forests?
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Wind from hurricanes
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How about fire?
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Many forests depend on periodic fires-- lodgepole and ponderosa pine forests, boreal forests..
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Serotinous cones
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Cones that require high temperatures to open and release seeds
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What does fire frequency depend on?
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Climate and soils
Vegetation type Lighting frequency |
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What does fire severity depend on?
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Fuel load
Weather conditions Forest structure |
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What are the effects of fire on the physical environment?
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Injury or death to some or all trees
Removal of soil organic matter Loss of nitrogen from soils, increase in other nutrients Increase in light and temperature at soil surface |
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Stand replacement fire
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All individuals killed--- NOT PRIMARY SUCCESSION!
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Fire ladders
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Small trees and other potential fuel that can serve as a "ladder" to the canopy of the forest.
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How many terrestrial biomes does Earth have?
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14, 7 are forested
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Hopkins biogeoclimatic law?
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Elevation change over 1000m is similar to that occurring over 5 degrees latitude.
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What models do "people" use to predict how global climate change will affect forests?
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Correlative models -- use stats to compare current distribution to climatic variables
Process models -- How environmental variables influence ecophysiology |
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Ecotypes?
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Genotypes within a given species
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Ecological amplitude
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Regarding a particular species, how frequent is it in a diverse array of habitats?
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Cloud forest
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2500m elevation -- Cool temps result in cloud formation
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What determines landscape patterns?
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Physical matrix of landforms and soils
Disturbance Relationships between various species that compose the community |
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What are some common adaptations to fire?
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thick, fire resistant bark
Serotinous cones Epicormic growth |
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What is epicormic growth?
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Branch "buds" underneath the surface of the bark that can sprout if the tree is totally defoliated by fire
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Effects of disturbance from wind
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Death or injury to individual trees
Addition of wood and organic matter to soils Increased light, temp and moisture at soil surface Increase in release of soil nutrients from decomposition |
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Biological legacies
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Indicator and tool for secondary succession-- organic matter for soils, seeds.. etc.
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Pioneer species
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Initiate recovery following disturbance.
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Why don't pioneer species persist indefinitely?
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Spend all their energy/resources to grow fast and tall, do not invest anything in defense mechanisms.
Also--pioneer species typically need lots of light, which a high density of mature pioneer species cannot provide to future generations. |
