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ENVL 101 Unit 2: Ecology - Coggle Diagram
ENVL 101 Unit 2: Ecology
Ch. 6: Wild Species & Biodiversity
Biological Wealth
: Makes up our ecosystem capital. Important because it provides instrumental value.
Instrumental value
: Value based on usefulness (usually for humans/ anthropocentric).
Food, raw material, medicine, recreational.
Intrinsic value
: Value for own sake.
Biocentrism
: Biosphere is of central importance (biotic factors).
Ecocentrism
: Ecosphere is of central importance, including biotic & abiotic factors.
Land ethics with Aldo Leopold- Wilderness protection
Biodiversity
: Species diversity, genetic diversity, and range of community and ecosystems.
Declining: Up to 1 million species are threatened with extinction, many within decades.
Main reasons for biodiversity loss:
HIPPO
Pollution
Biological
Physical
Chemical
Population (human)
Puts pressure on species
Direct use of organisms
Habitat conversion
Pollution
Competition for land
Invasive species
Non-native organisms, invaded through accidental, deliberate, and/or gradual means.
Overexploitation
Overharvesting faster than can be replenished because we are some greedy apes.
Habitat destruction
Fragmentation
Simplification
Conversion
Intrusion of other species (invasives mostly)
Consequences
Loss of ecosystem services
Loss of keystone species
Loss of aesthetics/ ecotourism
K vs R strategists: R can better handle unstable environments
Many unknown consequences
Tropics are highly diverse, with extinction of species particularly high. This is partially due to deforestation issues.
Ch. 7: The Value, Use and Restoration of Ecosystems
Ecosystem Capital
: Natural resources' monetary value.
We exploit these resources and then lose sight of their ecological value
Consumptive
: Harvest food, shelter, tools, fuel & clothing (more common in developing countries & even rural US)
Productive
: Exploitation for economic gain. Enormous source of revenue.
Protecting ecossytems
Conservation
: Management and regulation of ecosystem use.
Preservation
: Ensures continuity of ecosystem (or species), regardless of potential utility. Keeping an ecosystem as it is.
Maximum Sustainable Yield (MSY)
: Highest possible rate of use of use system can match with own rate or replacement/ maintenance. Can apply to maintenance of parks, air and water quality, and soils.
Precautionary principle
Potential problem of Common-pool resources
Optimal population
Ecosystems Under Pressure
: Particularly marine & forest
Sustainable Forest Management
Even cutting= clear cutting. destroys ecosystems.
Uneven cutting= selective cutting. Leaves some patches for ground cover and to help reestablish a natural forest.
Consequences of deforestation
o Productivity reduced
o Reduction in nutrients and biomass
o Biodiversity reduced
o Soil erosion increased
o Alters hydrology: more runoff= more erosion
o CO2 sequestration lost
Tropical forests
: Primarily cleared for agriculture.
Slash & burn introduces carbon to the soil but rainfall washes away the nutrients, so the process must be repeated.
Marine fisheries
52% MSY, 16% overexploited, 8% depleted
Plastic pollution
Bottom trawling
: – Trawl nets float at bottom of ocean to capture fish. Similar to clear cutting forests in terms of ecosystem destruction.
Ocean Ecosystems
Open-ocean aquaculture
: farming coastal species in ocean several miles from shoreline.
Aquaculture
: Farming of aquatic organisms. Growing in developing countries. Problems with fish poop getting into the groundwater, resulting in an overabundance of nutrients leading to too much algea
Coral reefs
Bleaching due to warming waters
Chemical sunscreens are harmful- oxybenzome
Boating propellors also damaging
Protection and Restoration
Wilderness
is given the greatest protection by law with 109 million acres of protected land.
National Parks & Wildlife Refuges
are the second most protected land by law, with 84-96 million acres,
National Forests
are the third most protected areas of land, with 740 million acres, but 2/3 of it is managed for commercial timber.
Non-Federal Lands
are at the fourth greatest level of protection, typically through land trusts.
Ch. 8 & 9: The Human Population & Essential Resources
The Human Population
We are far different from any other species on Earth.
Can think and make decisions about lives
Different life circumstances = different concerns
Technology has improved well-being
Demography
: field of collecting, compiling, and presenting information about human populations.
People have seemed to follow a J-curve in population growth, but really we are becoming an S-curve. We have far surpassed our carrying capacity of 7.6 billion with our current population being nearly 8.1 billion.
Ways to increase our carrying capacity
More vaccines- can prevent/ combat diseases.
Green technology.
Less processed, more whole foods. Leads to less corn for livestock and biofuel.
Population Ecology
Humans may be broadly considered K-strategists, but we do have the ability to choose to be more like R-strategists.
Revolutions promoting human population growth
Medical
: Disease treatment and germ theory developed
Green
: Post WWII agriculture- pesticides, fertilizers, GMOs
Industrial
: Starting to use fossil fuels in machinery
Environmental
: Present day stewardship for the planet to help reduce population & overconsumption
Neolithic
: First farming tools & crop animal husbandry
Incomes & environmental degradation are connected
High income nations
: highly developed- high CO2 emissions
Moderate income nations
: moderately developed
Low income nations
: Still developing- problems like untreated sewage
Rural problems
: Dirty, trash piled up, poverty, deforestation, overexploitation of resources for sake of survival.
Urban problems
: Overcrowding, crime, poor infostructure, smog, lack of sanitization.
Population and Consumption
Population growth rates are higher in low income nations because there are both more births and more deaths. The total fertility rate tends to be greater than 2 because childhood mortality is not uncommon in these areas, so they choose to procreate more in hopes of more children surviving into adulthood.
Consequences of rapid population growth in low income nations
Intensifying cultivation- small farms can't support families
Open up new land (slash & burn) destroys ecosystems
Land owned exclusively by wealthy
Resource overexploitation
Illicit activities
Migration
Affluent Countries
Environmental Footprint
: estimate of amount land and ocean required to provide resources and absorb wastes.
Formula for human impact on environment:
I = P x A x T
Population (P), affluence and consumption patterns (A), and technology in society (T)
Due to wealth
Small population= large impact
Stewardship (S) in developed countries can moderate environmental impacts: Divide PAT by S
How affluence and poverty impact the environment differently
Affluence
:
Overconsumption/ resource depletion
Don't care- needs are more than met already
Want precious/ rare things
Have the luxury to be concerned about the environment
Financial meals to invest in green tech research
Insane CO2 emissions & lots of waster (plastic)
Policies for environmental conservation
Poverty
:
Don't have the privilege to be concerned about environment
Must deplete/ degrade forests, rivers, soils to survive
Sanitization issues- contaminated water
Overexploitation to survive
Air pollution
United States
We lead in consumption of 11 of 20 major commodities
Eat twice global meat average
Are less likely to use public transportation, buy local, eat fruits and vegetables, or use reusable grocery bags
Lead world in paper consumption
Lead world in pollutant production
Comprise 4.5% of population but produce 22% CO2
Ch. 5: Ecosystems: Energy, patterns, & disturbances
Trophic Levels
: What is eating what.
Aquatic
:
*Inverted because less energy is needed to transfer up.
Terrestrial
:
Biomass
: Percent of energy consumed at each trophic level.
Primary Producers
: Plants. 100% of biomass.
Primary Consumers
: Herbivores. 10% of biomass.
Secondary Consumers
: 1% of biomass.
Tertiary and Quaternary consumers
: 0.1% and 0.01% of biomass respectively.
Categories of Producers-
Autotrophs
: Produce organic compounds to survive (primary producers).
Chemotrophs
: Producers use inorganic molecules (like H2S) to gain energy for survival.
Categories of Consumers-
Heterotrophs
: Consume organic materials to surive (consumers).
Disturbance
: Significant change that alters ecosystems and displaces or kills organisms within.
System Equilibrium
: Species interact constantly in well-balanced relationship. Often response to disturbance.
Succession
: Transition of one biotic community to another.
Secondary Succession
: Area cleared by disturbance and then reinvaded by plants and animals from other ecosystems.
Aquatic Succession
: Soil particles erode from land or plant detritus build up in ponds or lakes, eventually filling them.
Primary Succession
: Area lacking plants and soil is initially invaded by plants when soil forms (moss on rocks).
Tipping Point
: Situation in human impacted ecosystem where small action catalyzes major change in system state (like the overmined places in Virginia and Pennsylvania).
Resilience
: Ability of ecosystems to return to normal after disturbance.
Restoration
: Returning ecosystems back to original state. Requires: 1) Abiotic factors unaltered/ can be returned to original state. 2) Viable populations formerly inhabiting ecosystem must still exist.
Management
: Manage an ecosystem in its current state.
Problems to focus on:
World population will increase drastically over next half century.
N and P cycles raise nutrients in land and water 2 to 3 times.
15% more agriculture land.
Global deforestation.
More water diverted.
We may lose up to 50% of world’s biodiversity.
Biome
: large geographical area with similar biotic
community
Disturbances are similar to those noted at ecosystem level but at larger scale.
2 factors most control biomes:
Climate & Vegetation
.
