Lec 13 slides and reading (ch1) Flashcards
how is climatic warming changing the distribution of species?
Climatic warming is also changing the distributions of many species, causing many ranges to expand toward the poles.
downside of barriers
Barriers prevent dispersal movements, in particular the movement of an individual from its place of birth to a new place for breeding and reproduction.
-movement is crucial in many ecological situations, but nowhere are the effects of movements more clearly shown than in the study of distribution
-isolation, or lack of dispersal, thus became a cornerstone of the early naturalists’ view of how the animals and plants of the world came to be
-this isolation is thus the reason we go to Africa to see giraffes and not to South America, and why we go to Australia to see kangaroos and not to North America.
evolution has certainly produced different plants and animals in different geographical realms, but what assurance do we have that any one of these organisms could in fact live in a quite different area?
-This question can be answered very simply by a transplant experiment—move the organism to a new area
-If it survives there and reproduces, you have good evidence that the former distribution was restricted by a lack of dispersal
4 steps of the invasion process
transport, establishment, spread and impact
2 reasons why the transplant or movement of plants and animals into a new area can fail
either the biological environment may eliminate the newcomer or the physical-chemical environment may be lethal to the organism or prevent it from reproducing
how can mangrove trees be a good index for changes associated with ocean warming?
Mangroves are intertidal trees and shrubs that grow around the Earth along coastlines in tropical and warm temperate areas
-Mangroves grow in salt water and are sensitive to cold, so they are a good index of changes associated with ocean warming
-Mangrove species have expanded their geographical range toward the poles on five continents over the past half century, at the expense of salt marsh
-These changes are consistent with the poleward extension of temperature thresholds coincident with sea level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal
-The shift from salt marsh vegetation to mangrove dominance on subtropical and temperate shorelines will have effects on other species in the intertidal community
Changes in historic geographic ranges are now being caused by two main processes:
human introductions and climate change
ecology is the science of:
-how organisms interact with each other and with their environ (ecology=home/place to live)
-distribution and abundance of speciies
-the structure and function of ecosystems
-the science of biodiversity
how does ecology relate to evolution
ecology is the setting where evolution takes place
ecology and NS
interactions b/w organisms and their environ give rise to NS
-how organisms interact with biotic and abiotic part of environ
population
all the individuals of the same species in one place at one time (all the zebras in a savanna)
ecological community
all the species living together in one place at one time (all animals of savanna)
ecosystem
all the species plus the non-living environment (entire savanna)
why care about a species ranges
-understand where plants and animals can grow bc they give us food, clothing, wood, medicine, etc
-predict what will happen to biodiversity as the climate changes, a major goal of ecology
-predict how bd will respond to habitat destruction, pollution, invasive species, etc
-microbes also have ranges we want to understand to determine disease risk
infectious disease agents
also species with patterns of distribution we want to understand
