Lecture 1-Introduction to Ecosytems and Ecosystem Energetics

Question 1

what is a ecosystem

Answer 1

An ecosystem consists of all organisms (biotic factors) in an area functioning together with all the non-living physical (abiotic) factors of the environment. The biotic and abiotic components of an ecosystem are linked together through nutrient cycles and energy flows. Ecosystems usually encompass specific, limited spaces

Question 1

what is a habitat

Answer 1

A habitat is the natural environment in which a species, or group of species, lives and in which they can find food, shelter,
protection, mates etc. It includes all aspects of the physical environment, such
as soil, water, temperature, wind, wave action, currents etc. We can also
describe sub-habitats within a larger habitat

Question 2

what does mosaic landscape mean

Answer 2

a heterogeneous area, composed of different communities or a cluster of different ecosystems

Question 3

why do steppe grassland have colder soils

Answer 3

Because grass absorbs less solar radiation than trees, which keep the soil carbon pools and their greenhouse gases on ice for longer.

Question 4

how much percentage of annuall methane emissions come from livestock methane release.

Answer 4

Today around 20%

Question 5

what are primary producers

Answer 5

synthesise complex high-energy organic matter from simple low-energy molecules, powered by an energy source

Question 6

what are chemotrophs

Answer 6

produce complex organic matter from simple molecules, using chemical, rather than light energy

Question 7

what are “Black smokers”

Answer 7

are chimneys formed from deposits of iron sulfide, which is black

Question 8

what are “White smokers”

Answer 8

are chimneys formed from deposits of barium, calcium, and silicon, which are
white

Question 9

what is the different with energy flows and chemical matter cycles

Answer 9

Energy flows through ecosystems, while chemical matter cycles within them

Question 10

what is the Ecosystem energetics - terminology called Productivity

Answer 10

rate at which organic matter is created by
photosynthesis units = gCm-2yr-1

Question 11

what is the Ecosystem energetics - terminology called Standing crop biomass

Answer 11

amount of accumulated organic
matter found in an area at a given time (gCm-2)

Question 12

what are the four main factors that limit primary productivity in terrestrial ecosystems

Answer 12

1. Precipitation
2. Temperature
3. Light
4. Nutrients

Question 13

what does allochthonous mean

Answer 13

energy produced outside of ecosystem (e.g., leaf litter fall).

Question 14

what does autochthonous mean

Answer 14

energy produced within the ecosystem (e.g., phytoplankton, periphyton).