Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
68 Cards in this Set
- Front
- Back
|
Symbiosis |
the intimate and protracted association between two or more different species
- coevolution is evident in these interactions |
|
|
Parasitism |
a close association between two species that is beneficial to one (parasite) and harmful to the other (host)
- exploitation for food and habitat - generally do not kill their hosts |
|
|
Cleptoparasitism |
when one animal (parasite) "steals" food gathered by another (host) |
|
|
Infection |
a heavy load of parasites
|
|
|
Disease
|
the outcome of an infection |
|
|
Microparasites |
characterized by small size and short generation time
- viruses, bacteria, protozoa |
|
|
Macroparasites |
relatively large with a comparatively long generation time and usually involve intermediate hosts and carriers
- invertebrates and fungi |
|
|
Hemiparasitic |
plants are photosynthetic plants that contain chlorophyll (e.g. mistletoe)
- depends on host for water (nutrients in water) |
|
|
Holoparasitic |
plants are nonphotosynthetic (e.g. dodder, broomrape)
- completely dependent on host for survival |
|
|
Ectoparasties |
those that live on the host's skin within the protective cover of feathers and hair |
|
|
Endoparasites |
live within the host (e.g., beneath the skin, bloodstream, gills of fish)
|
|
|
Parasitic Mode of Entry/Exit |
must gain access to and escape from the host - enter thru the host's skin, mouth, etc. - travel to the point of infection through pulmonary, circulatory and digestive systems
|
|
|
Direct Transmission |
type of transmission that can occur by direct contact with a carrier, or the parasite can be dispersed from one host to another
- microparasites transmitted this way more often |
|
|
Transmission of Macroparasites |
- female roundworms lay eggs in host's gut - feces are dispersed to environment - bird and mammal spread by direct contact |
|
|
Holoparasites |
e.g., squawroot and beech-drops |
|
|
Definitive Host |
the host species in which the parasite becomes an adult and reaches maturity |
|
|
Intermediate Host
|
harbor some developmental phase
- parasites may require one or more intermediate hosts, therefore dynamics of a parasite population is tied to interactions of various host species |
|
|
Host Response to Parasitic Invasions |
1. Grooming by mammals and birds 2. Inflammatory response - scabs or cysts - immune cells attack infection
|
|
|
Vertical Transmission |
parasites transmitted directly from the mother to the offspring --- because the host must survive to maturity for parasites to be transmitted |
|
|
Parasitism's Effect on Host Populations |
chestnut blight introduced to N.A., exterminated the native American chestnut
Dutch elm disease into America nearly exterminated American and English elms
Avian malaria eliminated most of Hawaii's native birds |
|
|
Parasites and Density-Dependence |
parasites may function as this on host populations
usually involves a native parasite maintained in the population by a small number of carrier individuals
- e.g., distemper in racoons, rabies on foxes |
|
|
Commensalism |
a relationship between two species in which one species benefits without significantly affecting the other |
|
|
Mutualism |
a relationship that is beneficial to both species
- rats infected with tapeworm - mollusks infected with flukes
often results from reciprocal exploitation instead of cooperative effor |
|
|
Benefits to Mutualism |
- access to resources (including habitat) - protection - reduced competition with third species - dispersal |
|
|
Level of Dependency Between Two Species
|
obligate mutualists cannot survive or reproduce without the mutualistic interaction
facultative mutualists can survive without the interaction |
|
|
Degree of Specificity |
specialists: species-specific interactions
generalist: association with a wide diversity of mutualistic partners |
|
|
Ecological Community |
the set of plant and animal species that occupy an area |
|
|
Community |
a group of species, that occupy a given area, interacting either directly or indirectly
- a spatial concept |
|
|
Community Attributes |
1. Number of species (species richness) 2. Relative abundance of species 3. Nature of species interactions 4. Physical Structure |
|
|
Species Richness |
(S) the count of the number of species occurring within the community
|
|
|
Relative Abundance |
represents the percentage each species contributes to the total number of individuals of all species |
|
|
Rank-Abundance Diagram |
plotting the relative abundance of each species against rank
- species evenness indicates the distribution of species richness |
|
|
Diversity Indexes |
provide a way to quantify the relationship between species number and relative abundance
- Simpson's - Shannon-Wiener - Beta |
|
|
Dominants |
when a single or few species predominate within a community |
|
|
Keystone Species |
species that has a disproportionate impact on the community relative to its abundance
- their removal initiates community change and often results in significant loss of diversity |
|
|
Food Chain |
a descriptive diagram that represents the flow of energy from prey to predator
- feeding relationships in nature are much more complex in nature |
|
|
Food Webs |
highly interwoven, with linkages representing a wide variety of species interactions |
|
|
Links |
the arrows from one species to another and indicate the consumed and consumer |
|
|
Basal Species |
feed on no other species but are fed upon by others |
|
|
Intermediate Species |
feed on other species, and they themselves are prey of other species
|
|
|
Top Predators |
prey on intermediate and basal species |
|
|
Guilds |
groups of species that exploit a common resource in a similar fashion
- potential for strong interactions between members
|
|
|
Functional Type |
defines a group of species based on their common response to the environment
- C3, C4, and CAM plants - Shade tolerant vs. shade intolerant |
|
|
Photic Zone |
where the availability of light supports photosynthesis |
|
|
Aphotic Zone |
the area in water without light
|
|
|
Benthic Zone |
in the water, where decomposition is most active |
|
|
Zonation |
the changing of the physical and biological structure of a community as you move across a landscape |
|
|
Community Dynamics |
the changing of community structure across the landscape reflects the shifting distribution of populations in response to:
Changing environmental conditions Interactions among species |
|
|
Sucession |
the gradual and seemingly directional change in community structure through time from field to forest
- common to all terrestrial and aquatic environments |
|
|
Sere |
the sequence of communities from grass to shrub to forest
each stage may only last one to two years, or several decades |
|
|
Early Successional (Pioneer) Species |
usually characterized by high growth rates, smaller size, high degree of dispersal, and high rates of per capita population growth |
|
|
Late Successional Species |
have lower rates of dispersal and colonization, slower per capita growth rate, and are larger and longer-lived |
|
|
Primary Succession |
succession on a site previously unoccupied by a community
- rock outcrops and cliffs - sand dunes - newly exposed glacial till |
|
|
Secondary Succession |
succession on a previously occupied site after disturbance
- disturbance doesn't always result in removal of all individuals |
|
|
Primary Succession and Sand Dunes |
sand is deposited by wind and water, sand particles may be piled up - dune position can shift, cover existing vegetation
|
|
|
Autogenic Environmental Change |
a direct result of the presence and activities of organisms within the community
- vertical profile of light in a forest is a direct result of vegetation structure |
|
|
Allogenic Environmental Change |
change governed by physical processes
|
|
|
Alteration of Light Environment |
in early stages of plant succession, shade-intolerant species can dominate
these species grow and shade the slower growing shade-tolerant species
eventually, shade-intolerant species are outgrown and cannot survive shaded conditions |
|
|
Sucession |
Results from changes in the relative tolerances and competitive abilities of species under autogenetically changing environmental conditions |
|
|
Chronosequences (chronoseres) |
groups of sites used to compare patterns of diversity throughout succession
some studies show that plant diversity increases with site age |
|
|
Peak Diversity |
this occurs during the middle stages of succession, corresponds to a transition period
rate of species displacement is influenced by growth rates of species involved in the succession |
|
|
Disturbance |
acts to "reset the clock" in succession |
|
|
Patterns of Diversity and Frequency of Disturbance |
high = diversity will remain low, later successional species have a chance to colonize
low = diversity will decline as later successional species displace earlier species
intermediate = colonization can occur but competitive displacement is held to a minimum |
|
|
Paleoecology |
the study of the distribution and abundance of ancient organisms and their relationship to the environment
- climatic oscillations between cold and temperate - reconstruction of plant dist. after last glacial maximum |
|
|
Concept of Community |
Gleason- an arbitrary concept, each species responds independently to the underlying features of the environment
Clements- a quasi-organism made up of interdependent species
- Continuum or Individualistic concept |
|
|
Organismal Community |
viewed as a spacial concept |
|
|
Continuum Community |
viewed as a population concept |
|
|
Community Structure |
the product of a complex interaction of pattern and process
- species respond to an array of environmental factors that vary over space and time |
