L19 Ecosystem Ecology

Question 1

define ecosystem ecology

Answer 1

Study of communities of different species (populations) and the physical/chemical environment they occupy with each influencing the other through time

Question 2

how do ecosystems function/how are the components linked together

Answer 2

• transferring energy through the ecosystem
• cycling nutrients within the ecosystem

Question 3

the chemistry of life is the chemistry of __________

Answer 3

carbon

Question 4

how does the biosphere cycle carbon

Answer 4

• lithosphere (rocks, soils, sediments)
• hydrosphere (oceans, lakes, rivers)
• atmosphere (air)

Question 5

the carbon cycle involves several processes that occur at various rates; describe them

Answer 5

• biological (fast)
• chemical (slow)
• geological (very slow)

Question 6

describe the study of CO2 in air in Hawaii

Answer 6

• seasonal periods of oscillation
• summer removal of CO2 doesn’t balance winter addition of gas
• general amt of CO2 has increased during monitoring period

Question 7

How do we know that humans are responsible for recent changes in CO2 concentrations in the atmosphere?

Answer 7

• proxy measurements from ice cores agree with Hawaii study
• using carbon isotopes, there have been decreases in carbon 13 & 14 eventhough carbon 12 has been increasing

Question 8

There has been an increase in atmospheric CO2 levels over the last 200 years. What are the causes of this increase?

Answer 8

• industrial revolution
• fossil fuel use

Question 9

what is the short-term carbon cycle and how is it regulated

Answer 9

fastest part of C cycle; biological processes such as oxygenic photosynthesis and aerobic respiration

Question 10

what is the long-term carbon cycle, and what processes drive it

Answer 10

carbon cycling over extremely long periods of time

• chemical and geological
• weathering, volcanism, oxidation of organic matter, biomineralization

Question 11

provide ways that carbon dioxide is added to the atmosphere

Answer 11

biological inputs, geological/chemical inputs, human impacts

• respiration/decomposition
• volcanoes, mid-ocean ranges, weathering, erosion
• urbanization, fossil fuels, deforestation

Question 12

describe ways that carbon dioxide is removed from the atmosphere

Answer 12

biological, geological/chemical removal

• photosynthesis, biomineralization
• chemical weathering, mineralization, sedimentation, fossilization

Question 13

Energy from sun _______ in ____ direction through ecosystems

Answer 13

flows; one

Question 14

matter is ______ within ecosystem

Answer 14

cycled

Question 15

what does biomass increase

Answer 15

growth and reproduction

Question 16

what is the energy transfer rule

Answer 16

Each level contains only 10% of the energy of the trophic level below it

Question 17

what are the most important biological interactions, why?

Answer 17

predatory and herbivory; major links in carbon and nutrient cycles

Question 18

what are biogeochemical cycles

Answer 18

processes cycling matter like carbon, oxygen, nitrogen, sulfur, phosphorus

Question 19

define reservoir

Answer 19

place where nutrients are stored for large amounts of time

Question 20

define flux

Answer 20

movement of nutrients among reservoirs

Question 21

define sources

Answer 21

pools that release more nutrients than they accept

Question 22

define sinks

Answer 22

pools that accept more nutrients than they release

Question 23

why is the carbon cycle important to understanding ecology and evolution

Answer 23

• Carbon cycling is linked to other nutrient cycles
• Changes in nutrient levels (e.g. oxygen) link to evolutionary changes and increases in biological diversity