Chapter 12 - Interdependence and Communication Flashcards
Remember definitions (16 cards)
What is an ecosystem?
An ecosystem is an interacting set of biotic and abiotic components that are linked by processes of energy transfer and material cycling.
What is a biome?
A biome is an area dominated by a particular type of vegetation such as tundra, grassland or tropical forest.
What is a catchment?
A catchment is a valuable unit in which to study ecosystem processes i.e. hydrological catchments.
e.g., the Amazon basin or small streams.
What is a closed system?
A closed system has no inputs or outputs.
What is an open system?
An open system is linked to the rest of the environment through exchanges of energy, materials or information.
e.g, rivers and saltmarshes.
What is a trophic cascade?
This is a phenomena in which even the slightest effects on predators can be magnified in a downward flow of effects on grazers and plants in the lower trophic levels.
What is a metapopulation?
A metapopulation is a set of ecosystems connected by spatial flows of energy, materials and organisms across ecosystem boundaries.
i.e. local ecosystems are governed by more than local interactions.
Describe edge effects and give examples.
Edge effects is when the boundary between the interior and exterior of a patch of land have different physical environments, for example more wind or sunshine.
Skole and Tucker (1993) loss of tropical forest in Amazon from 1978 to 1988. Estimated that the area affected by edge effects caused by deforestation, exceeded the area that had been deforested. Impact on wildlife goes beyond direct loss of habitat.
Laurance et al (1997) tree mortality increased due to microclimate changes and increased wind turbulence in plots within 100 metres of a forest edge. These plots lost up to 36 % of their above ground biomass within the first 10 to 17 years after fragmentation.
What is a coupled ecosystem? Give an example.
A coupled ecosystem is when two different ecosystems are used by the same species. For example, white-tailed deer use a forest ecosystem for shelter and deposit droppings (nutrient subsidy) and a cropland ecosystem provides soybeans for the deer to eat.
What does POP stand for?
Persistent Organic Pollutants
used in pest control and industrial purposes
What makes POPs so bad?
They resist biological, photolytic and chemical degradation.
Highly soluble in fat.
They bioaccumulate.
They biomagnify, increase in concentration the higher they get up in the food chain.
How do POPS spread?
Wania and Mackay (1996) stated that one mechanism in which they travel is the grasshopper effect which is a repeated process of evaporation, transport in the atmosphere and deposition.
What does semi volatile mean in terms of POPS?
POPS can travel over long distances because they can occur either in the vapour phase or adsorbed on atmospheric particles.
e.g. the pesticide DDT has even been found in polar bears.
What happens when precipitation exceeds evapotranspiration?
Excess water can be held in the pores in soil.
It can drain through larger pores and into underlying rocks and escape as run off.
What is a catena?
A catena is a soil profile down a slope where each of the soils, although a part of the same parent rock, are distinct from each other but linked.
Different because of horizontal and vertical water movement down the slope and proximity of water table to surface.
A catena is an example of an open, connected system involving inputs and outputs.
What does it mean if a soil horizon is gleyed?
Water logged and anoxic
