Week 6

EEMB 120

landscape

heterogenous area composed of distinctive patches arranged in mosaic

lanscape ecology

study of relationships between landscape structures, patterns, and processes

landforms

natural feature of the earth's surface

ecosystem engineers

organisms that influence structure of landscapes, ecosystems, or communities(beavers and humans)

zoogeochemistry

result of animal activity on chemistry(nutrient makeup) of their environment

patch

relatively homogenous area that differs from surroundings

matrix

background habitat in a landscape within which patches are embedded

habitat fragmentation

formation of patches from separation of landscapes due to human activity or natural disasters

boundary

zone composed of edges of adjacent ecosystems, some abrupt or some gradual

edge effect

increased biodiversity associated with boundaries

corridor

connectivity channels between patches, often created by humans; mitigates effects of fragmentation by maintaining patch connectivity

filter effect

different corridor sizes allow some organisms to cross but restrict others

How is landscape structure quantified?

patch number, size, shape, position, and composition

S

patch shape; increasing value >1 indicates less circular shape

P

patch perimeter

A

patch area

heat wave

weather-related phenomenon responsible for greatest loss of human life

urban heat islands

result from replacing trees and other vegetation that moderates surface and air temperatures with buildings, paved roads, concrete walks

How can we combat urban heat islands?

increased vegetation, green roofs, energy-efficient transportation, reflective roofs and paving

ecotone

transition zone between two ecosystems

interdisciplinary research

studies that integrate multiple scientific fields

landscape element

component of a landscape; patch or corridor

landscape process

ecological processes that occur across a landscape; dispersal or disturbance

landscape structure

arrangement of landscape elements

geographic ecology

study of ecological structure and process at large geographic scales

theory of island biogeography

number of species increases with increasing island area, but decreases with increasing island isolation

non-equilibrium hypothesis

large areas can support more individuals; large populations are less likely to go extinct due to chance events; larger islands have fewer extinctions; degree of isolation determines immigration rate

immigration rate on islands…

is highest on “empty” islands and decreases as it “fills up”

extinction rate on islands…

increases as number of species increases; more species means smaller population of each and more competition

immigration and extinction curves cross…

at equilibrium where a certain number of species that are immigrating and going extin

What would happen to the immigration curve if the island moved further from land?

immigration rate would decrease, which al

tests of theory

theory predicts equilibrium number of species which is roughly constant through time, not identity of species

species turnover

change in species composition on island through ecological time due to ongoing processes of successful colonization and loss from island

latitudinal gradient hypotheses

relationship between continental area(latitude) and species richness; pattern of increased number of species in tropics is pervasive and dramatic

What are the six categories of the latitudinal gradient hypotheses?

time since perturbation, productivity, environmental heterogeneity, favorableness, niche breadths and interspecific interactions, and differences in speciation and extinction rates

SLOSS debate

single large island or several small islands

remote sensing

gathering information about an object without direct contact with it through EM radiation

geographic information systems

computer-based systems for storing, sorting, analyzing, and displaying geographic data

global positioning system(GPS)

determines locations on Earth’s surface using satellites as reference points

troposphere

lowest atmospheric layer where weather occurs; highest concentration of atmospheric gases

stratosphere

atmospheric layer above the troposphere; contains highest ozone concentration to shield Earth from UV light

greenhouse effect

warming of Earth’s atmosphere due to trapping of heat by greenhouse gases

El Niño

climate pattern characterized by warming of the central and eastern Pacific Ocean and higher barometric pressure; warm current appears off the coast of Peru, during winter

La Niña

climate pattern characterized by cooler-than-average Pacific Ocean temperatures and higher barometric pressure

southern oscillation

atmospheric component of El Niño/La Niña events; seesaw of air pressure

ENSO(El Niño-Southern Oscillation)

dynamic, large-scale system; promotes storm formation over eastern pacific and increased precipitation in north and south America

How does El Niño harm fish populations?

warm water shuts off upwelling, reduces nutrient supply and phytoplankton production, reduced food for coastal consumers and declines fish pop.

edge effects and forest fragmentation from deforestation

fragments exposed to great solar radiation and wind, hotter and drier with higher solar intensity, decreases diversity of many animal groups

atmospheric composition

periods of low CO2 correspond to low temperatures(ice ages), higher CO2 during interglacial periods

What are three major periods of interruptions in pattern of atmospheric CO2?

WWI, Great Depression, WWII

human impacts on climate change

increased intense precipitation events, increased frequency of severe drought, potential spread of insect-transmitted diseases, increased coastal flooding with sea level rise

mesosphere

atmospheric layer above the stratosphere, where temperatures decrease with altitude

thermosphere

uppermost atmospheric layer; temperature increases with altitude

Suess effect

decline in ¹⁴C/¹²C ratio due to fossil fuel emissions

walker circulation

east–west circulation pattern of air across the tropical Pacific

How can vastly different habitats arise in fragments?

variation in shape and density

In the American Southwest, forest habitats extended unbroken in what period?

Pleistocene

Where does remote sensing of chlorophyll a reveal that marine plankton biomass is highest?

in cooler, upwelling areas near shore