ENV100H1 Lecture Notes - Lecture 11: Photic Zone, Arthur Tansley, Millennium Ecosystem Assessment

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Published on 8 Oct 2016
School
UTSG
Department
School of Environment
Course
ENV100H1
Professor
Page:
of 5
Ecosystem ecology
- Study of interactions among organisms and their physical environment as an integrated
system
- Extremely interdisciplinary
- Systems thinking employed
- Perfect example of systems thinking
- What separates it is not about the individuals rather the bigger concepts
oFlows and reservoirs
- Looking at it from a big picture
oex. Flows of energy, nutrient transport, carbon budget, etc.
- systems thinking in the environment
Ecosystem concept
- Sir Arthur George Tansley
oOne of the original ecologists
- Systems are the basic units of nature
oOne of the seminal concepts
oEx. How is that antelope interacting with is physical environment
What is an ecosystem?
- Way of looking at organisms and their interactions with the environment as an integrated
system
- Focuses on functions, processes, fluxes, biogeo cycles, etc.
Why should we care about ecosystem ecology?
- A mechanistic basic for understanding the earth system
- Layer of earth systems that involves the living world
- Ecosystems provide goods and services to society
oSupport life
- Human activities are changing ecosystems and therefore the Earth System
- Our activities are disrupting those systems
Ecosystem services
- Good way of understanding the relevance of environmental science
- Functioning ecosystems provide ecosystems services
- Support life
- Millennium Ecosystem Assessment
oPut dollars and cents value on ecosystems to show benefits
- Ecosystems and the services they provide are financially significant and that to degrade
and damage them is tantamount to economic suicide
Ecosystem services
- Improve water quality (wetlands)
- Ecosystems capture carbon on their own
- Nutrient retention and cycling
find more resources at oneclass.com
find more resources at oneclass.com
oDamaged ecosystems tend to be leaky
oLose nutrients
- Erosion control
oGood stable forest provides soil stability
oDeforestation washes soil off
- Pest control
- Renewable resources
- Medicine
- Recreation
- Etc.
Canada’s boreal forest
- David Schindler
oWhat’s the boreal forest really worth?
- Do not value forest just by the products you get from it
oTimber, etc.
- Value it as a living forest without being harvested
oStores 67 billion tonnes of carbon = 303 years of carbon emissions
oCarbon bank account = 3.1 trillion; 93 billion annually into our economy
oHidden natural economy that allows the more visible economy to run
Simple ecosystem model
- 4 main components
oabiotic environment
difficult to say if soil is part of the biotic or abiotic environment because it
depends what part of the soil you are talking about
water
soil minerals
atmospheric gases
oprimary producers
plants, algae
capture energy from the sun with co2 and water and produce glucose
molecules from that
oconsumers
odecomposers
breaks down dead thing
ocircle of life = ecosystem science
- most ecosystems based on photosynthesis; only a few who do not do this
- species are not usually treated as separate units; functional role is what is important
odo not think too much about the species
oall we think about is that there are producers and consumers
- abiotic components are of equal importance as biotic components (movement of nutrients
and energy are focus of investigation)
oall biotic and abiotic components are important
find more resources at oneclass.com
find more resources at oneclass.com
- human activities are often important
How big is an ecosystem? What is the timescale of an ecosystem?
- Seems really big but it does not have to be
- It is a way of thinking of how organisms interact with what is around them
- The size does not really matter
oCan be huge or small
- Ecosystems are nested and hierarchical
oRussian doll (ecosystems inside ecosystems)
- We can study them on a number of differential spatial and temporal scales
oTemporal – time that you take
Short term
Ex. How do things change from summer to fall
Long term
Ex. How has carbon sequestration changed since the last glaciation
- Time scales vary a lot and it’s all ecosystem science
- Flows within them
Spatial scale
- Study things on many different scales
- Spatial scale depends on the question being asked
Spatial boundaries of ecosystems
- Often indistinct boundaries
oEx. Pond boundaries changing
oChanges quite a lot
Always inputs and always outputs
- Most systems are open
- Organisms may move between aquatic and terrestrial environment
oEx. trees drop leaves into pond
- Lots of cycles going on on Earth that connect with other cycle
Temporal scale
- Can be
oInstantaneous
oSeasonal
oSuccessional
- Evolutionary history
- Geologic history
Energy flow in ecosystems
- Ecosystem is an economy and energy is the currency
oHow to run a household
- Ecosystems are based on autotrophs
find more resources at oneclass.com
find more resources at oneclass.com

Document Summary

Study of interactions among organisms and their physical environment as an integrated system. What separates it is not about the individuals rather the bigger concepts: flows and reservoirs. Looking at it from a big picture: ex. Flows of energy, nutrient transport, carbon budget, etc. systems thinking in the environment. Sir arthur george tansley: one of the original ecologists. Systems are the basic units of nature: one of the seminal concepts, ex. How is that antelope interacting with is physical environment. Way of looking at organisms and their interactions with the environment as an integrated system. Focuses on functions, processes, fluxes, biogeo cycles, etc. A mechanistic basic for understanding the earth system. Layer of earth systems that involves the living world. Ecosystems provide goods and services to society: support life. Human activities are changing ecosystems and therefore the earth system. Good way of understanding the relevance of environmental science. Support life: put dollars and cents value on ecosystems to show benefits.