PP 1: Frameworks of Terrestrial Ecology: Site and Physiography

what is bio-ecology

ecosystems are centered on organisms, added to a non-specific abiotic environment

what is the geo-ecological approach to terrestrial ecology?

focuses on geographic spaces/physical units where organisms live, while considering the whole ecosystem and its parts

What are the four characteristics of an ecosystem?

climate, physiography, soil, and biota

what are the two broad categories of ecosystem factors?

abiotic and biotic factors

what are abiotic factors?

physical factors that make up the envrionment

what is a “site”?

the sum total of all physical factors of a specific place; it is non-organic

what are biotic factors

the organisms themselves

How are site and biota related?

they are convenient to separate, but inseparable in reality because they interact and affect each other

along what gradient is a site defined?

• by moisture because that’s where the nutrients are

dry → dry-mesic → mesic → wet-mesic → wet

Why is moisture important in defining a site?

• plant nutrient uptake depends on water, making moisture a limiting factor

What is physiography?

• the physical geography of an area, including its surface features, form, and substance

What are the two components of physiography?

• form = shape of the land

• substance = parent material

What are some characteristics used to describe physiography

• physiographic setting

• specific landform

• parent material

• landscape position

• position relative to other landforms

What does physiography indirectly affect or control?

• climate

• moisture flux

• water table position

• nutrient status

What ecological processes can physiography directly or indirectly influence?

• disturbance

• species occurrence and composition

• growth and biomass accumulation

• how ecosystems change (succession)

• variation within and among species

What are the four major physiographic systems in glaciated terrain?

• Outwash plains

• Ice contact terrain

• moraines

• lake plains

outwash plains info

• water laid

• both dry and wet

• stratified drift

Ice contact terrain

• water laid

• includes kames, kettles, and eskers

• semi-stratified drift

Moraines information

• ice laid

• includes end, ground, and interlobate moraines; unstratified drift

lake plains information

• lacustrine

• sand or clay

• stratified drift

What factors affect moisture availability in dry/upland areas?

• water table position

• capillary fringe

• perched water table

• soil texture and structure

• soil organic matter

• aspect

• slope position

• slope percent

• spatial relationship to other features

What are important ecological factors in wetlands?

aeration, nutrients, and microclimate

Why can oxygen become limiting in wetlands?

heavy moisture and poor drainage limit oxygen during the growing season

how does water movement affect wetlands

it affects aeration and nutrient availability

how does landscape position affect wetland microclimate

wetlands tend to occur low in the landscape, making them colder