Marine Ecosystems Flashcards
What are the major environmental factors in marine systems that vary seasonally in mid-latitudes?
Light, nutrients and temperature are major factors in marine systems that vary seasonally in mid-latitudes
How might these changes influence primary productivity over the year?
Increased Light, nutrients and temperature equals increase phytoplankton blooms and overall primary productivity.
What is ENSO
ENSO or “El Nino southern Oscillation” refers to a climate phenomenon caused by fluctuations in ocean temperatures and atmospheric conditions.
Describe how the warm phase of ENSO impacts environmental conditions in the tropical Pacific.
The warm phase of ENSO is called “El nino”, this warming alters the typical atmospheric circulation patterns and weather conditions.
What impacts do these changes have on primary productivity in the tropical Pacific?
It can cause increased rainfall and floods in some regions but then drought in others. Higher rainfall leads to an increase in vegetation and an increase in herbivores and later increase in predators.
What is the NAO?
NAO or “North Atlantic Oscillation, is also a large-scale circulation pattern.
describe how the NAO affects ocean temperature, phytoplankton biomass, and zooplankton biomass in the Northeast Atlantic Ocean.
The positive NAO phase has a stronger pressure gradient and stronger winds with the wind position shifted further to north. Because of the stronger winds in positive NAO means there’s a decrease in spring phytoplankton bloom and warmer water temperature. The negative NAO phase has a weaker pressure gradient and weaker winds with the wind positions shifted further to the south. Because of the weaker winds in the negative NAO means increased phytoplankton bloom and cooler temperatures.
What is an ecological regime shift?
An ecological regime shift is when ecosystem resilience is exceeded. It is when there are abrupt changes in community structure and function
Example of an ecological regime shift
For example, kelp forests are abundant due to the presence of sea otters who are essential when it comes to controlling sea urchin population. Without sea otters sea urchins population would rapidly increase resulting in decrease of kelp forest.
How is disturbance in terrestrial ecosystems defined?
Disturbance in terrestrial ecosystems is defined as: “A relatively discrete event that removes organic material, such as plant biomass and/or soil.”
Under what circumstances would herbivory be considered a disturbance?
If said herbivory where causing changes in an ecosystem then it would be considered a disturbance.
When would herbivory not be considered a disturbance?
Herbivory is not considered a disturbance if it’s not causing directional changes in species composition/ecosystem function
How do NPP, respiration, and the carbon pools in plants and soils change through primary succession?
NPP: (early succession) starts off with low NPP, then it increases more diverse and complex plant species (mid succession), finally NPP stabilizes (late succession).
Respiration: (early succession) minimal/moderate decomposing community, (mid-succession) increase in plant biomass = more of the decomposer community, and finally (late succession) stabilize nutrient cycle.
Carbon pool in plants and soils:(early succession) low carbon pools in both plants and soils, nutrient poor soils, (mid succession) pools grow as plant biomass increases, (late succession) reaches equilibrium therefore the ecosystem is strong.
How do the factors identified in question 3 change through secondary succession?
If it were secondary succession it would be low stress tolerance/larger range of seed sizes with rapid growing rate,
Why do their trajectories differ from those in primary succession?
it’s different from primary because there is still soil disturbance and is less severe.
