53 terms

Ecology

STUDY
PLAY

Terms in this set (...)

Ecological Succession
Gradual change in species composition (number and type) making up a community over time
Primary Succession
starting with bare rock

o Bare rock → pioneer species (mosses and lichens and plants that don't need much to grow → small annual plants and soil development → perennial plants → shrubs → trees

o Occurs in areas of:
• Volcanic activity
• Receding glaciers
Secondary Succession
starts with soil in place (starts rapidly)

o Usually following disturbance of some type - abandoned fields/areas of deforestation/major storm events/dams forming reservoirs
General trends of succession
3 components of stability
Soil development increases in:
Depth/thickness/nutrients from decomposition

Plant community increases in
Average ht./biomass (amount of plant matter), vertical stratification/nutrients in plant matter

NPP increases

Increase in species diversity

Populations of species rise, than fall, and get replaced by others because of changes

Increase in relative community stability. Components of stability:
Inertia (persistence) - How well can this community resist being disturbed
Constancy - How well can a population maintain it's size or #'s
Resilience - If disturbed, how well/fast can community restore itself
Contrast in Trends
Temperate Grassland vs. Tropical Rainforest
Temperate Grassland
Lower inertia (burns easily)
High resilience (nutrients and roots remain in soil)

Tropical Rainforest
higher inertia (takes a while to burn)
low resilience (soil is poor in nutrients because nutrients are held in the plants)
Landscape Ecology Definitions
Landscape
Landscape ecology
Landscape structure
Landscape: heterogeneous (vs. homogeneous) area made up of several patches (ecosystems)
(Mountain landscapes, rural landscapes, urban landscapes)

Landscape ecology: landscape structure and processes

Landscape structure: size, shape, composition (what types are there), number, position of patches in a landscape
Origins of Landscape Structure
all the different sizes, shapes, etc. in the landscape structure we see today are due to variations in the 5 origins.

Geological processes - volcanoes, erosion, sedimentation
Climate differences - soil development differences
Organism impacts - nitrogen fixing plants enrich soil for other species, beavers bring more wetland areas
Fire (natural occurrence) mosaic of burned and enriched area
Human impacts - deforestation, land conversion (agriculture/development)
Corridors: 2 types
Narrowline: A row of trees or shrubs planted as a windbreak, Drainage ditches, Median strips in highways

Strip corridors (wider): Greenbelts of vegetation around neighborhoods, Buffer strips of natural vegetation along streams/rivers,Vegetation under power transmission lines
Functions of Corridors
Provide more habitat for species

Access to more patches, food, and shelter

Also allows for spread of disease between patches
Biomes
Large ecological regions with typical types of natural vegetation
3 Basic Types of Biomes
Deserts: evaporation > precipitation

Grasslands: moderate amount of rainfall

Forests: most precipitation
3 Types of Deserts and Organism adaptations
Hot - Warm/hot all year (ex: Sahara)

Temperate - cool winter/hot summer (ex: Majave Desert, Chihuahan Desert, S.W. US)

Cold - cold winter/warm summer (ex: Gobi Desert, N. China and Mongolia)

Plant adaptations -
Light colored: to reflect heat/light
Small size: less surface area for H20 loss
Deep tap roots: to reach groundwater record: 250 ft
Allelopathy: some cacti species exude chemicals out roots into soil to sterilize surrounding soil so other plants don't grow

Animal adaptations -
Light colored
Small size
Cryptic behavior during day/active at night only (cooler)
3 types of Grasslands
Tropical grasslands: Warm/hot year round (Savanna)

Temperate grasslands:
Hot dry summer, cool/cold winters
N&S America Europe and Asia
Initially very fertile soils, so heavily impacted by humans

Polar grasslands (arctic tundra) and high elevation grasslands (alpine tundra):
Short cool summers, long harsh winters
Low species diversity
Permafrost: (Year round ice underground
Allows seasonal ponds to form in summer = water source for wildlife)
5 types of Forests
Tropical Rainforests:
Moist and warm all year
Highest species diversity
Soil poor in nutrients BECAUSE:
Nutrients stored in vegetation AND
Surface runoff: nutrients are washed away from rain. Ex: tree falls and decomposes but nutrients wash into nearby river. America Amazon is one of the most nutrient rivers in the world

Tropical Dry (deciduous) forests in S.E. Asia and N. Australia:
Warm all year
Monsoon season: 4-5 months followed by drought for 7-8 months
Trees drop leaves seasonally when drought starts
Species diversity low because they can't survive 7-8 months w/o water

Temperate deciduous forest:
Warm summers/cold winters
Trees drop leaves in fall
N&S America, Europe & Asia
Heavily human impacted due to fertile soil from dropped and decomposed leaves

Temperate Rain Forest:
N. Canada, SE Alaska, New Zealand, and Chile
Smallest biome
High rainfall
High economic importance of trees

Northern Coniferous forests/Evergreen/Boreal/Taiga:
Circumpolar - Canada, Europe, and Siberia
Short summers, long winters
Low species diversity
Permafrost
Oceans Importance
• Part of all biogeochemical cycles
• Habitat for 260,600 species
• Absorbs solar radiation, releases it slowly and influences climate (Ex: warm gulf current from Caribbean all the way to Great Britain and warms Britain climate even though they are around the same latitude as Northern Canada)
• Resources: food, oil, sand, minerals, etc
• Mix and dilute wastes, up to a point
• Transportation route between land masses/islands
2 ocean zones
1. Open Sea with 90% area and 10% species
2. Coastal zone with 10% area and 90% species
•High tide mark to edge of continental shelf
•Avg. 43 miles offshore
Estuary
oPartly enclosed mouth of a river where river water enters ocean
oMixing of marine (tides) and fresh water
Other Marine Ecosystems
1. Coral Reefs: most are 5000 to 10000 years old
•High NPP → high species diversity
•They break waves and water is calm where they are located

2. Mangrove Forests
•Tropical
•Exposed roots trap sediments
•High NPP → therefore high species diversity

3. Deep Sea Thermal Vents
•Down thousands of feet
•Energy source is sulfur in hot water discharge → Chemosynthesis
•Organisms found there use Chemosynthesis as energy source

4. Rocky Shores
•Vertical Zonation of organisms

5. Kelp Forests
•Worldwide in temperate and polar zones (not tropical)
•Forage and habitat for many other species
•Kelp are not plants
•Giant Kelp have 20" growth a day
Lakes
Natural bodies of standing freshwater
3 types of Lakes
1. Eutrophic lakes
•shallow, turbid, high NPP and high fish pop.

2. Oligotrophic
•deep, clear, very low NPP and few fish
•Young geologically, mostly from volcanoes
•Slowly enriching near agriculture and human populated areas because they are becoming enriched with nitrogen form fertilizers ect. Vegetation slowly creeping into lakes and decomposing ads nutrients.

3. Mesotrophic
•intermediate in depth, nutrients, ect.
Wetlands: submerged all or part of the year.
3 componants
1. Hydric soils: rich in organic matter (dark in color)
2. Hydrology: water at least part of the year
3. Vegetation: adapted to submergence
Wetland Functions
•Flood control; wetlands hold more water than no wetlands
•Filter out nutrients and some pollutants
•High NPP and high species diversity; wildlife habitat for residents and migratory species
•Recreational importance: fishing/birding
Watersheds
(Drainage Basin) entire land area of streams and rivers draining into a river/ocean at one point
Geographic Ecology
study of patterns in plant and animal life that can be put on a map
Island trends
oAs the island area increases the # of species increases
oAs distance from the source of the species (mainland) increases the # of species decreases
Island Models with extinction and immigration
Extinction: the larger the island the lower the extinction rate.
The higher the # of species the higher the extinction rate. Steeper increase for small islands because they have more competition. Less steep of a line for large islands because they have more room.

Immigration:
The larger the distance from the source/mainland the lower the immigration.
The greater the amount of species, the smaller the immigration rate. Steeper decline for islands farther away. and less steep for closer islands because more species can get there.
Latitude trends and hypothesis for the case
From 0 degrees (tropics) → 90 degrees (north and south poles) the number of species decreases

1. Favorableness
•warm and moist conditions are more favorable and easier to adapt to

2.Productivity
•Higher NPP in the tropics and therefore more species

3. Niche breadth
•Narrower in the tropics, species have more specialized habitats, allows more species to co-exist

4. Environmental Heterogeneity
•Greater habitat complexity therefore more species can survive

5. Time since perturbation
•Tropics are geologically older and species have had more time to develop

6. Greater land area in tropics
•more species can be supported
Natural ecosystems vs. Simplified
Natural: not planned or maintained by humans
all biotic elements are free to interact with each other in any way they choose

Simplified: Ecosystem becomes simplified with loss have land. Humans have interfered. Natural ecosystems transformed into some other use
Examples of Natural -> Simplified
Forests and grasslands to wheat fields and factories
Fertile soil to nutrient depleted soil or covered over
Problems with Natural Ecosystems converted to simplified
Loss of species diversity
Loss of stability
Vulnerable to outside factors: weeds, disease, insects, fungus
First three laws of ecology - (Garrett Hardin founded field of human ecology)
1. We can never do merely one thing. There are always consequences/side effects of our actions (No wolves → more sheep for ranchers → overgrazing → erosion)

2. Everything is connected to and intermingles with everything else

3. Any substance we produce shouldn't interfere with any of the bio/chemical cycles
Rehabilitation vs. Restoration-(natural vs active)
Rehabilitation
•Taking a degraded area and improving it for re-use.
•Ex: Fertilizer added to soil → adds nutrients → crops continue growing
•Ex: Replanting trees after clear cutting for re-harvest in 40-60 years

Restoration
•Returning to a more natural state
•Natural restoration - via ecological succession
•Active restoration - where we take a role
Water sources: Surface vs. Groundwater
Surface: water that collects on the surface of the ground. Rivers, lakes, streams

Groundwater: water that occurs below Earth's surface in pore spaces within bedrock and soil, free to move under the influence of gravity
Aquifiers
shallow and accessible source of groundwater
Aquifier recharge vs withdrawl
Recharge: Groundwater is recharged naturally by rain and snow melt and to a smaller extent by surface water. Is a hydrologic process where water moves downward from surface water to groundwater.

Withdrawal: Removal or water surface and groundwater and transport to place of use.

If withdrawal is greater than natural recharge than there is a lowering of the water table.
Water table definition and concept
underground surface below which the ground is wholly saturated with water.

Water tables rise and fall with seasonal moisture, water absorption by vegetation, and the withdrawal of groundwater from wells, among other factors. The water table is not flat but has peaks and valleys that generally conform to the overlying land surface

If withdrawal is greater than natural recharge than there is a lowering of the water table
Water use
Agriculture - US: 41% China: 85%

Electric cooling (power plant turbine cooling) - US: 38% China: 0

Industry - US: 11% China 9%

Public Use (municipal water) - US: 10% China: 6%

Worldwide - 70% of all withdrawn water goes to agriculture
water resource problems 3 main ones and examples of why
1. Not enough water
-Drought
-Overuse
-Natural Causes
•Reduced precipitation
•Elevated temperatures
-Human causes
•Overuse
•Deforestation
•Mining
•Land cultivation

2. Too much water
-Flooding
-Natural causes
•Higher precipitation (storm events)
-Human causes
•Poor land use (water loss)

3. Contaminated drinking water
-"Dilution is the solution to pollution"
•Dumping in river
-Fertilizers, pesticides, chemicals, sediment, pathogens (disease causing), saltwater intrusion (coastal aquifers)
Water resource management - 2 basic approaches and examples of each
1. Increase water supply
-Dams → Reservoirs
•Done building dams in US because basically every major river has one.
•Environmental concerns
•Expensive to build
•Minimal potential today
-Tap more groundwater
•Overuse and lowering water table
•Little potential
-Watershed transfer
•Moving water from abundance to where it is needed
•Overall - expensive and controversial
-Desalinization
•Conversion of marine water to freshwater
•Complex and expensive to construct/operate
•Potential: Best in coastal locations where needed to avoid transportation and prices are slowly decreasing

2. Use water more efficiently - conservation
Agriculture, Industry, Cities, Homes: efficient sprinklers, recycle more water, conserve more water
types of water pollution
-Organic chemicals: oil, gasoline, detergents
-Inorganic chemicals: fertilizers, pesticides, industrial
-Pathogens: bacteria, viruses, parasites
-Sediments
-Heat: thermal pollution
-Radioactive substances
Point source vs. Non-point source
Point source: single, identifiable source

Non-point source: diffuse, hard to identify the source
Pollution in Streams vs. Lakes
Streams Can recover from some pollution, providing:
•No overload
•No flow interruption, reduction (dams, rivers dry up into series of pools in summer)

lake Pollution Usually very serious due to:
•Little water flow
•Little vertical mixing of water
Cultural eutrophication
•Nutrient overload from surrounding human activity (nitrates and phosphates) → fertilizers, manure, municipal sewage → algae bloom blocks surface from sunlight → algae decomposes and decomposers use too much oxygen → not enough for fish
Groundwater pollution why so serious? Contol/sources/prevention
Very serious due to
•Very little flushing (lateral movement: 1-100m/yr.)
•Very low oxygen content in water, so no organic matter breakdown (bacteria require oxygen)
•Out of sight - out of mind, often very serious before we can detect systems

•"pump n treat" somewhat helpful - dilutes concentration
•ID and prevention of sources at surface
Marine coastal pollution sources
most of worlds coastal areas are polluted due to 2 main things:
•Sediment from development and logging
•Raw sewage discharge

Recently, coastal dead zones
•Very low dissolved 02 levels due to nutrient overload
Marine Estuary Pollution from 3 directions
River pollution runoff
Runoff from nearby/adjacent towns/cities
Come in with tides (from pollution right offshore)
Oil Pollution sources
3 sources
•Taker spills
•Oil rig blowouts
•Waste oil form cities
(53% of the total oil pollution in the world doesn't get much press/attention)
Oil pollution effects
•Major long term impacts on marine and coastal wildlife/environment
Effects on fisherman that rely on shrimp or other fish
Oil Pollution control
•1990 international amendment - all new oil tankers required to have double hulls, all required by 2015
•More cities should recycle their oil
•Prohibit more deep water offshore drilling
Included Hazardous wastes EPA definition vs. Not included
Discarded chemicals potentially harmful because they are:
-Flammable
-Unstable (explosive)
-Corrosive (disinigrates metal)
-Toxic (to humans/wildlife)

Not included in definition and therefore not regulated
-Mining wastes
-Incinerator ash
-Radioactive wastes (separately regulated)
-Household hazardous wastes (HHW)
Love Canal
-Hooker Chemical company used Love canal as a toxic waste dump and dumped 22,000 tons of corrosive liquid dioxins
-Hooker company sold land to school board for a dollar and claimed they were not responsible anymore
-Major health problems with people in the area
-Eventually declared clean.
Disposal Methods of hazardous wastes
-"hide them" out of sight out of mind
•Deep well injection
•Surface storage in pits, ponds, and lagoons
•1994 EPA survey (70% had no liners or partial lienrs or liners weren't effective) NOT PROTECTIVE
•Landfills

-Shipping to developing countries for disposal
-Incinerate them not all chemicals are disposed → toxic ash?
-Detoxify them? (neutralize them)
•Denmark detoxifies 75% of what it produces
-Waste reduction, re-use and recycling
-Don't produce in first place
EPA super fund
-1980 EPA superfund for cleaning up hazardous waste site
•Funded w/ $16 billion dollars
•Step 1: Polluter pays
•Step 2: if no company is found → use fund

-National priority list to first clean up sites in/near cities
YOU MIGHT ALSO LIKE...