Lecture 1 -- What is Ecology?

Question 1

Define an environmental system. What are the major parts?

Answer 1

An environmental system is the set of interactions between the elements of a biosphere

which includes energy, biotic bits (cells, organisms, species, populations), abiotic bits (water, climate, soil, nutrients)

Question 2

What is the science of ecology?

Answer 2

The study of all the relationships among the elements of environmental systems

Question 3

Provide an example of four different scales of environmental systems.

Answer 3

Cells (lichen cells)
Lichen community on a piling (a few centimeters
Tidal marsh habitat (hundreds of acres)
Entire estuary ecosystem (thousands of acres)

Question 4

Why can the community of lichens growing on a piling be considered a distinct environmental system?

Answer 4

Because there are physical factors which drive changes in the species

Question 5

Describe some of the biotic and abiotic components, and how the abiotic components affect the distribution of the biotic.

Answer 5

Biotic components of an environmental system can be anything from mammals to algae that live in an ecosystem.

Abiotic components could be water, soil, topography, manmade additions (roads, dikes, buildings)

Question 6

Resolving many of the most critical issues facing humanity today requires an understanding of the relationships among the components of ecosystems. Describe an example of an important challenge facing humans and why an understanding of environmental systems can help find a solution.

Answer 6

Right now humans are struggling with dead zones in the Ocean which are caused by eutrophication

Question 7

What are some biological and physical components of estuary ecosystems? What are some components that are anthropogenic?

Answer 7

Physical components include human parts and the physical system of the channel: water, soil, topography, dike systems

Biological: eelgrass, low marsh, high marsh, chinook salmon, benthic invertebrates

Anthropogenic components: disturbances caused by dike effects on sediment and freshwater distribution. Example: turns to farm land.

Question 8

What are 3 or 4 major abiotic factors that drive the development of habitats in estuaries?

Answer 8

stream flow
sedimentation
woody debris
anthropogenic effects

Question 9

Describe 4 ways in which climate change affects estuaries. How will these 4 things affect the estuary?

Answer 9

• increased commonality of record floods- damaged anthropogenic areas and damaged organisms that cannot withstand the heavy flooding
• increased sediment transport- burried ground cover (eelgrass and low marsh habitats) with transport
• lower low flows during summer months- limited flow for salmon reering
• estuarine mixing zone- larger salinity fluctuations throughout the yea

Question 10

How is climate change affecting the temporal pattern of river flow in Puget Sound rivers?

Answer 10

• higher highs in the winter

- lower lows in summer

Question 11

How does salinity affect the biotic components of estuaries?

Answer 11

• Salinity helps disperse the biotic components of estuaries because some plants/organisms can withstand higher salinity than others.

Question 12

How do rivers affect the salinity patterns in estuaries?

Answer 12

-lower river flows = higher salinity? slides say otherwise

Question 13

How does hydraulic energy (the energy of moving water, such as rivers and tides) affect habitats in estuaries?

Answer 13

Inflow from rivers transports sediement into estuary. Inflow from fresh and salt water sources converge and mix. Tides increase/decrease water depth and salinity for different zones at given time.

Question 14

How does disturbance affect environmental systems? Give an example of a specific disturbance and how it affects biotic/abiotic components and/or the processes or interactions among components.

Answer 14

Disturbances often harm but sometimes help ecosystems.

Hydrology, sediment deposition/erosion, large wood dynamics, floods, storms, salinity (seasonal, annual, decadal, long-term), nutrient regime (salmon), sea level, “engineer species”

Question 15

Give an example of a disturbance regime that has been affected by human activities, and how the change in the disturbance affects the ecosystem.

Answer 15

An example of human activities changing the disturbance could be building levees to protect home from flooding (such as along the WA coast) but there may the ecosystems which rely on these occasion floods to reboot their cycle. Now that levees are in place and the land doesn’t get floods, that ecosystem refresh doesn’t happen.

Question 16

Give an example of how levee systems affect the ecological processes in an estuary.

Answer 16

They can drown marsh and wetlands crucial to estuarine ecosystem, killing the plants and devastating populations of organisms that depend on them (such as the fish that use the plants as nurseries).

Question 17

Define ecosystem services. Give several examples.

Answer 17

Things produced by the environment for the benefit of humans.

Examples include clean water, timber, fisheries, pollination, flood control, nutrient cycle, detoxify and decompose waste, purify air, recreation, sense of well-being, etc.

Question 18

What is the difference between grey and green infrastructure? Give an example of both for estuary systems.

Answer 18

Grey infrastructure is man-made, green infrastructure occurs naturally.

A dike is grey infrastructure and tidal marsh is green infrastructure, both which serve as flood control for land.

Question 19

How do bulrush plants in a tidal marsh affect storm waves?

Answer 19

The roots hold soils in place, resisting erosion, and the vegetation breaks water as it passes, creating turbulence and slowing waves. Together, these lessen the impact and erosive damage of waves.

Question 20

How will sea level rise affect tidal marshes? How will it affect levee systems that protect human communities?

Answer 20

Tidal wetlands may drown, and levee systems may become inadequate/need to be altered to adapt to these changes, because the green infracture (tidal marshes) protects the grey infrastructure.

Question 21

What amount of sea level rise is currently (2012 model report) projected to occur in Puget Sound by 2100?

Answer 21

Puget Sound sea levels projected to rise about 24 inches by 2100

Question 22

How does sea level rise affect the future probability of what is currently a 100-yr coastal storm flood?

Answer 22

12” of sea level rise turns a 100-yr coastal storm flood into a 10-year event
24” of sea level rise turns a 100-yr coastal storm flood into an annual event

Question 23

Why is climate change affecting the size and frequency of large river floods?

Answer 23

Rather than precipitation being trapped as snow, then melting and releasing slowly into rivers, more falls as rain as the wet, winter climate warms. Thus a greater flow of runoff into rivers at once, raising flood levels.

Question 24

How does a change in flood size or frequency affect how much sediment is delivered to the estuary?

Answer 24

Larger or more frequent floods cause a greater disturbance and carry greater amounts of sediment/debris downstream into estuaries.

Question 25

Describe several ways in which estuary ecosystems are affected by the watershed that drains into them.

Answer 25

Sediment deposition from watershed shapes and helps nourish marshes.
Life in watershed deposits nutrients that carry downstream. Ex: after spawning, huge input of nutrients from salmon carcasses
Storms and floods carry in debris that provide platforms for estuarine life. Ex: root clumps washed downstream provide roosts for birds, firm surfaces for lichens, etc.
Amount/seasonality of inflow determine salinity of zones within estu

Question 26

Why is climate change reducing the level of river flow in the summer?

Answer 26

Little rainfall in summer, rivers depend on glacial/snow melt. With less precipitation as snow during winter, snowpack doesn’t build up and can’t provide much water in summer months.

Question 27

Why does it matter to an estuary if average summer flows from a river decline over time?

Answer 27

Decreased river inflow to estuaries will increase salinity during summer (affecting biodiversity and habitable zones), and reduce debris/nutrient inputs.

Question 28

How can a habitat restoration project reduce the risk of flooding for a community?

Answer 28

Wetlands reduce storm surges… [What else?]

Question 29

What is resilience? Describe what it means for an ecosystem and for a human community.

Answer 29

esilience = abiltity of an organism/system to resist to and recover from disturbances.
In an ecosystem: includes adapting for/surviving natural and human disturbances.
Human community: includes adapting to natural events (storms, floods, etc.) and maintaining sustainable resources.
*Human and ecosystem resilience are interdependent.

Question 30

A restoration project at the mouth of the Stillaguamish estuary altered the distribution pattern of salinity across the whole estuary ecosystem. How is this expected to affect tidal wetlands?

Answer 30

They are expected to expand due to a larger area of low salinity in shallow water, conditions condusive to brackish marsh.