Human Ecology Flashcards
How many humans are born every second in comparison to the number that die every second?
4 humans born and 2 die (Gain 2.3 humans every second)
Describe the variables in the equation G=ΔN/Δt and describe what the equation measures
G=Rate of change in the population size
ΔN= the change in the number of individuals
Δt= interval of time
Describe variables in G=rN
G= Rate of change in population size
N=Number of individuals in population
r=per capita rate of increase = birth rate – death rate
Specifically discuss r and what happens to population size when r> or r
r= per capita rate of increase
r>0 means that population is increasing
r=0 population size is constant
r
What is K and what happens to G when K is ,= N?
K=carrying capacity (number of individuals earth can sustain)
When K=N: Growth rate is zero
When K>N: Growth rate is positive
When K
What two types of factors influence population growth in nature?
1) Density Independent Factors
2) Density Dependent Factors
Describe birth rate:
Number of deaths per year per person
Total Fertility Rate
number of children born on average during a woman’s reproductive life
Doubling time:
Time it takes population to double in size
What percent of the worlds population and what percent of the world population growth do developing countries represent?
80%, 90%
What four factors determine total fertility rate?
Culture
Economic
Demographic
Political
What is the demographic transition model?
model of economic and cultural change to explain declining death rates, declining birth rates, and rising life expectancies in as become industrialized
What are the four transition stages in the demographic transition model?
1) Pre-Industrial Stage
2) Transitional Stage
3) Industrial Stage
4) Post Industrial Stage
What is happening to birth and death rates in Pre-Industrial stage?
Both rates are very high
What is happening to birth and death rates in transitional stage?
Birth rate is constant put death rate is decreasing due to food production and increased medical access
What is happening to birth and death rates in Industrial stage?
Death rates hit a constant level while birth rates begin to decline due to increased opportunity for woman and increased access to birth control
What is happening to birth and death rates in post Industrial stage?
Birth rates and death rates are low
What is the optimist economist view of human population growth?
world population growth will stabilize this century due to demographic transitions in developing countries.
Pessimist view of human population growth?
eloping countries of the world are too environmentally and/or politically unstable, and will not experience a demographic transition. Aid to developing countries will decrease death rates but not birth rates.
Technologist View
Improving in technology and investing in technology TODAY will outpace demands of increasing populatioins
Social Justice View
Population is a SYMPTOM not a problem. We must redistribute resources.
Ecologist View
Population growth is the problem. The earth has a carrying capacity. If developing countries proceed through the demographic transition the same way developed countries have, per capita resource consumption will put us over the carrying capacity.
What are two consequences of a growing population like that of the baby boom era?
Not enough people paying into social security to support the population when they get old AND medicare/medicaid increases 7x
China’s One Child Policy
They said a legal married age for males and females, contraceptives are free, and people are limited to having one child (except some circumstances Ex: twins)
What is the 4-2-1 problem in china?
Each child has 2 parents and four grandparents
What is the sex ratio problem in china?
There are 1.2 males for every female do to selective abortion and infanticide of females
How do we ensure the high trajectory scenario is not the path taken?
1) educate women
2) Family Planning
3) increased access to healthcare
4) Providing contraception
How did Bangladesh reduce TFR?
using education and investing in family planning!!
What is the Easter Island Metaphor?
Deforestation, degradation of topsoil, and over-harvesting of animal explains the collapse of this civilization. THEY EXCEEDED CARRYING CAPACITY
Carrying Capacity
The number of people a geographical area can support before people need more resources than are available
Ecological Footprint
Basically measures how much we consume (demand of human activity on biosphere)
Biocapacity
The amount of area (land) available to generate resources and absorb waste
Global Hectares (gha)
A unit weighted based on ability of land to produce resources (need more pastures than crops to make the same amount of resources so they have different hectares) Cropland has larger gha
What are the 6 assumptions for ecological footprint:
1) Amount of resources used and the waste generated can be quantified and tracked
2) Resource/waste flow measured by productivity area necessary to MAKE them
3) Global hectares are accurate
4) Each hectare represents a single use of a particular resource
5) Human demand (ecological footprint) can be compared to biocapacity in hectares
6) Area demanded can exceed area supplied if demand on an ecosystem exceeds that ecosystems regenerative capacity.
Ecological Footprint Equation:
EF=demand for product(P)/ National Yield of product (Y) * the conversion to hectares
Biocapacity Equation:
BC= A(area available) X YF (yield factor a ratio of national to world average yields) X EQF (global hectares per hectare)
What is the equation for Ecological Footprint of Consumption?
EFc=EFp+EFi-EFe C: consumption P: Production I: Imported Commodity E: Exported Commodity
What are the six limitations of the ecological footprint of production? ?
1) availability of non renewable resources excluded
2) Some inherently unstable activites can not be accounted for (radioactivity)
3) Doesn’t take environment management into account
4) Doesn’t look at ecosystem degradation over time
5) Doesn’t measure resilience of eco
6) Doesn’t account for use/contamination of water
How does all this add up in the global context?
Basically we are consuming more than earth can generate (EF has exceeded capacity since the 60’s)
What countries account for the majority of EF?
Developed countries
How many countries house half of the biocapacity?
8!! Brazil highest because of forest
How does this all play out in terms of america?
If everyone on earth consumed at the rate of americans, we would need 4.5 earths to sustain us.
What Continent has the smallest EP per person but largest EP overall?
Asia
What Continents are ecological debtors
Asia, North America, Europe
Discuss North America specifically interms of EP
Has the highest biocapacity in the world, use 17% of worlds EP per person but only have 5% of worlds population
EF vs. Income Level
Low income has stable EP, middle have growing EP, high income has high carbon footprint but similar to middle
Human Developtment Vs. EP
We want to raise HDI while maintaining a low EF
HDI
composite measurement of life expectancy, education, income
How do we achieve high HDI and low EF?
sustainable energy, eating local, recycling waste, guided development, reduce dependency on wood, public trans
Food Chain efficieny
proportion of energy transferred from one trophic level to the next
What is the best things for humans to eat to keep EP low?
Grains!
How are crop yields and the chronically undernourished related?
In order to sustain the improvement in calorie intake of people in developing countries, we must increase the crop yield or this will not be sustained
What is a system?
an set of connected components that interact to for a unified whole
What is an ecosystem?
he assemblage of organisms (organic) together with their physical and chemical environment (inorganic)
What are the two rules of an ecosystem?
Energy flows THROUGH ecosystems and and elements cycle WITHIN ecosystems
Where does primary production fit into the food chain?
It is the base
Why is transforming energy into biomass not 100% efficient?
Because of secondary Biomass production which creates waste in the form of urine and feces
How much energy is assimilated in each level of the food chain and how much of primary production energy reaches the top?
10% each level so only 1% of primary reaches the top
For the reasons associated with energy assimilation in the food chain what foods SHOULD humans be eating?
GRAINS because they give you “more bang for your buck”
What is entomophagy and why should we do it?
The practice of eating insects. We should do it because you get way more protein, only takes 1 gallon of water to make 1lb of protein, and is 68% protein by weight
What is another source of protein besides insects?
PLANTS
NPP
Energy accumulated into biomass each year
Norman Borlaug contribution to food production?
Figured out how to double food production!! The founder of the Green Revolution
What are the 5 components of the green revolution?
1. Development of higher yielding varieties of crops 2. Irrigation infrastructure 3. Modernization of management techniques 4. Synthetic nitrogen fertilizers 5. Pesticides/herbicides
What has happened to production of grain vs. per capita production since green revolution?
Per capita has leveled off while grain continues to increase in production
Where imporvments after green revolution more impressive in terms of per capita or overall?
OVERALL
What is happening to availability of crop land in developing countries?
It is decreasing
What is a genetically modified organism?
an organism whose genome has been directly modified with genetic engineering. e.g. Removing or adding genes, often from a different species
What was the Flavr Savr tomato and how did it work?
A genetically engineered tomato that could stay on the vine until completely ripe. Inserted antisense gene. Increased shelf life by preventing the production of the enzyme polygalacturonase, which degrades the cell wall, increasing susceptibility to fungal infections
How does genetically engineered salmon work
Growth hormone from chinkcon salmon injected into other salmon reducing time it takes salmon to reach adulthood (the gene is engineered to work all year long instead of only one season)
Elements are recycled in ecosystem
Just remember this
What is the assimilation process?
conversion from inorganic
to organic form (like photosynthesis)
Dissimalitory Proccess
conversion from organic to inorganic form (respiration)
Describe four steps of water cycle:
1) Evaporation
2) Vapor into clouds
3) precipitation
4) Runoff
Why is water scarce?
Because a lot of it is locked up in glaciers and ice caps making it inaccessible :(
What is most water used for?
To produce crops!!
How can you increase water use efficiency?
1) irrigation technology
2) crop rotation based on water use
3) increase biomass produce: water uptake ratio
What is groundwater?
Water underground in the cracks/spaces/ in soil, sand rocks
What is good about groundwater? (3)
1) High quality and low seasonal fluctuation
2) Less susceptible to pollution
3) Investment scaled to demand
Aquifer
layer in ground of permeable or porous material like sand where water is stored and flows
What is the high plains water district?
The area where the High Plains aquifer is. Has a great amount of water and has a depeletion rate 10X higher than other regions. Will be 50% smaller in 2050.
Artesian aquifer
water is confined under
pressure between layers of impervious rock
• Porous nature of limestone filters water as it passes through – does not require treatment
– Like a saturated sponge with pipes than an
underground pool
• A lot of water, but only a small percentage is economically feasible to get
when is a spring dry?
when aquifer is less than 95% full
managing water quality
Once water becomes contaminated, it will be difficult or impossible to clean.
– Protection of endangered species,
ecosystems, recreation
– Limit development in recharge and contributing zones –much of which is not within city limits
Weather
haracteristics of the atmosphere over a short period of time,
usually no more than a few days
Climate
The statistics of weather over long period of time
IPPC
Fifth Assesement report: a collaboration of countries working to understand climate change
Historical Temperature
Data network showing temperature throughout years
How does ice core help understand climate?
Stores information about past: nowfall that collects on glaciers each year captures atmospheric concentrations of dust, sea-salts, ash, gas bubbles and human pollutants
What is Dating Horizons
analyzing isotopes of oxygen to determine when massive events occurred (like volcanic erruption)
Tree rings
trees are the oldest thing on planet. Look at rings vs temperature data (correlates)
Varves
Layer in earth under water. Can look at calcium carbonate and see how it relates to CO2 in atmosphere
Northern Temp Reconstruction
last three decades have been the warmest since 1850. Rate of increase has gone up GLOBALLY
Why do we use anomolies?
SO THAT THE DATA CAN BE COMPARED AND COMBINED. They measure the deviation from the average temperature normalizing the data from different regions do see the extreme differences in average temp
How confident are we in global warming?
SUPER because there is hard science to back it up
Light=
energy=temperature change
Greenhouse gases
1) Sunbeam goes through greenhouse gas region but some reflect back up (refraction).
2) Radiation that gets through warms up surface of earch and then reflects back up
3) Some gets reflected back down as greenhouse gase
Radiative Foce
Contribution of gas to the energy balance in atmosphere
Who are the players in greenhouse gases?
Water, carbon dioxide, methane, nitrous oxide
Aspects of carbon cycle:
1) Energy assimilated and dismillated quickly (photosyntheis and respiration)
2) Atmosphere ocean exchange (Ocean is CO2 sink)
3) carbon sediments disolution a slow process LARGEST STORAGE OF EARTHS CARBON)
Flux in carbon cycle is relatively slow so what is the problem?
The carbon is experiencing the cumulative effect (not getting absorbed fast enough by carbon sinks)
How do we fix the cumulative effect problem?
Reduce fossil fuel use, plant more trees, microbes to suck up carbon, algae as biofuel, reduce livestock
What is the evidence of antrhopogentic contribution?
Hard science shows increase in carbon since ice age (nitrous oxide and methane have also increased)
Where do greenhouse gases come from?
Forestry, ag, industry, energy supply, transportation, builidings
Wha is the multilayered approach?
Dealing with all parts of the problem together
Effect Size
shows contribution of radiative forces
What molecules effect earths atomosphere balance?
CO2, N2O, H2O
Aerosols Effect On enviroment
Definintly contribute to green house gases and have POSITIVE (aditional) effect on atmosphere
CO2
most important effector of atmosphere and the one we know the most about
Temp Vs. CO2
Strong correlation between increased temp and increased CO2 in atmosphere
How do we predict climate change effect?
using models looking at representative concentration pathways
Variable climates
we will have an increase in cold and hot climates resulting in decreased crop yield
Sea Ice Decline
This is the most porminent indicator of climate change. There will be NO sea ice by 2070.
What are the consequences of sea ice decline?
Loss of habitat
Sea Level rising (galveston under water in 50 years)
Acidification of ocean
Coral Bleaching
Species Range Shift
Species are shifting in there variation due to climate change (such as butterflys)
What are the effects of climate change on reproduction in animals?
Reproduction time increasing
Migrate earlier and mess up food chain
Ex: Tree swallows nests-birds breed earlier than normal
The Ozone Hole
Aerosols caused hole in ozone but source of problem has identified steps to reverse effects
Biodiversity
The number, variety and variability of living organisms and how these change from one location to another and over time
Biomes
are areas with similar abiotic factors such as climate, relief, geology, soils and biotic factors such as vegetation.
Biodiversity hotspots
places where there is a ton of diversity in species
Total species richness (TSR)
number of species in a given region
Challenge of species richness
hard to detect different species but but does not capture the complexity of the ecological systems we are try to protect.
Ecologicl Indicators
use quantitative data to measure aspects of biodiversity, ecosystem condition, services, or drivers of change.
cosystem extent and status
the coverage of ecosystems
Ecological Capital
further divided into biotic raw material (such as total species richness) and abiotic raw materials (such as soil nutrients), indicates the amount of resources available for ecosystems to
function.
Ecological Functioning
such as lake trophic status) measures the performance of ecosystems
Are more species rich systems more ecologically complex?
NO! alot of the species are doing the same thing
How do you measure more than species richness?
Abundance, Variation, Distribution
Abundance
how much there is of any one type.
• Abundance matters more than the presence of a range of genetic varieties or species for maintaining ecosystem function.
Variation
e number of different types over space and time.
• For understanding population persistence, variation in genetic composition among individuals in a population can provide more insight than species richness.
Distribution
where quantity or variation in biodiversity occurs.
To improve our predictions of how diversity loss influences the goods and services of ecosystems what three things must we do?
(1) link the ecosystem functions to the provisioning and regulating
services of ecosystems
•(2) expand the focus of research to better mimic realistic extinction scenarios and trophic structures of natural ecosystems
• (3) develop mathematical models that can scale experimental results to whole landscapes.
Ecosystem services
the benefits ecosystems provide to humans.
Provisioning services
such as food, clean water, timber, fiber, and genetic resources
Regulating Services
such as the regulation of climate, floods, disease, water quality, and pollination
Cultural Services
such as recreational, aesthetic, and spiritual benefits
supporting services
such as soil formation, and nutrient cycling
Invasion resistence
More diverse ecosystems are more resistant to invasive species
Climate regulation
diversity of plants influences climate at local, regional, and global scales
Pest, Disease, Pollution
The ecosystem’s ability to control pests is strongly dependent on biodiversity and benefits food security, rural households, and national incomes of many countries.
Pollination
worldwide declines in the diversity of pollinating insects that are essential for the reproduction of many plants
Corals
- Habitat construction
- Nurseries for many animals • Spawning grounds for fish
- Nutrient cycling • Wave buffering and sediment stabilization • Aesthetic beauty = tourism
What is going on now with biodiversity?
Current rates of change and loss exceed those of the historical past by several orders of magnitude and show no indication of slowing.
What is going on with species extinction?
Humans have increased extinction rate by 3X
Driver
any natural or human-induced factor that directly or indirectly causes a change in an ecosystem
What is the major drive in terrestrial systems?
Land use change
What is the biggest driver in marine biodiversity loss?
Overfishing!!
3 drivers in freshwater systems?
Physical change (like dams)
invasion of species
Pollution
Eutrophication
nrichment of an ecosystem with chemical nutrients, typically compounds containing nitrogen, phosphorus, or both
