The Scope of Ecology

         Ecology is the scientific study of the interactions between organisms and
         their environments
         Ecological research ranges from the adaptations of organisms to the
         dynamics of ecosystems
         Ecology provides a scientific context for evaluating environmental issues

    Abiotic Factors of the Biosphere

         Climate and other abiotic factors are important determinants of the
         biosphere's distribution of organisms

    Aquatic and Terrestrial Biomes

         Aquatic biomes occupy the largest part of the biosphere
         The geographical distribution of terrestrial biomes is based mainly on
         regional variations in climate

    Concepts of Organismal Ecology

         The costs and benefits of homeostasis affect an organism's responses to
         environmental variation
         An organism's short-term responses to environmental variations operate
         within a long-term evolutionary framework

Chapter  50
ecology - the study of how organisms interact with their environments.
abiotic components - nonliving chemical and physical factors.  Major abiotic factors are: temperature, water, sunlight, wind, rocks and soil, periodic disturbances, and climate.
biotic components (by-OT-ik) - pertaining to the living organisms in the environment.
organismal ecology - concerned with the behavioral, physiological, and morphological ways in which individual organisms meet the challenges posed by their abiotic environment.
population - a group of individuals of one species that live in a particular geographic area.
community - all the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction.
ecosystem - a level of ecological study that includes all the organisms in a given area as well as the abiotic factors with which they interact; a community and its physical environment.
biosphere (BY-oh-sfeer) - the entire portion of Earth that is inhabited by life; the sum of all the planet's communities and ecosystems.
biome (BY-ome) - one of the world's major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment.
tropics turnover -
photic zone (FOH-tik) - the narrow top slice of the ocean, where light permeates sufficiently for photosynthesis to occur.
aphotic zone (ay-FOE-tik) - the part of the ocean beneath the photic zone, where light does not penetrate sufficiently for photosynthesis to occur.
thermocline - a narrow stratum of rapid temperature change; occurs in the ocean and in many temperate-zone lakes.
benthic zone - the bottom surfaces of aquatic environments.
benthos - communities of organisms occupying the benthic zone.
detritus (deh-TRY-tis) - dead organic matter.
littoral zone - shallow, well-lit waters close to shore.
limnetic zone - well-lit, open surface waters farther from shore in a lake.
profundal zone - the deep aphotic region of a lake.
oligotrophic lake - a nutrient-poor, clear, deep lake with minimum phytoplankton.
eutrophic lake - a highly productive lake, having a high rate of biological productivity supported by a high rate of nutrient cycling.
mesotrophic lake - between the oligotrophic and eutrophic extremes, with a moderate amount of nutrients and phytoplankton productivity.
wetland - an area covered with water that supports aquatic plants; range from periodically flooded regions to soil that is permanently saturated.
estuary - area where a freshwater stream or river merges with the ocean; often bordered by extensive coastal wetlands.
intertidal zone - the shallow zone of the ocean where land meets water.
neritic zone (neh-RIT-ik) - the shallow regions of the ocean overlying the continental shelves.
ocean zone - the region of water lying over deep areas beyond the continental shelf.
pelagic zone (pel-AY-jik) - the area of the ocean past the continental shelf, with areas of open water often reaching to very great depths.
coral reefs - formed by a diverse group of cnidarians that secrete hard external shape, forming a substrate upon which other corals, sponges, and algae grow; constitute a conspicuous and distinctive biome.
oceanic pelagic biome - in the open ocean, far from shore; is constantly mixed by ocean currents.
abyssal zone (uh-BIS-ul) - the portion of the ocean floor where light does not penetrate and where temperatures are cold and pressures intense.
canopy - the top layer in a forest.
permafrost - permanently frozen stratum in the arctic tundra.
regulators - animals and plants that use behavioral and physiological mechanisms to achieve homeostatis in the face of environmental fluctuations in temperature, moisture, ligh intensity, and concentrations of a variety of chemical factors.
conformers - organisms that allow some conditions within their bodies to vary with external changes.
principle of allocation  - the concept that each organism has an energy budget, or a limited amount of total energy available for all of its maintenance and reproductive needs.
acclimation (uh-KLY-mih-ty-ZAY-shun) - physiological adjustment to a change in an environmental factor.
 
 
 
 
 

    Introduction to Behavior and Behavioral Ecology

         Behavior results from both genes and environmental factors
         Innate behavior is developmentally fixed
         Classical ethology presaged an evolutionary approach to behavioral biology
         Behavioral ecology emphasized evolutionary hypotheses: science as a
         process

    Learning

         Learning is experience-based modification of behavior
         Imprinting is learning limited to a critical time period
         Many animals can learn to associate one stimulus with another
         Practice and exercise may explain the ultimate bases of play

    Animal Cognition

         The study of cognition connects nervous system function with behavior
         Movement from place to place often depends on internal coding of spatial
         relationships
         The study of consciousness poses a unique challenge for scientists

    Social Behavior and Sociobiology

         Sociobiology places social behavior in an evolutionary context
         Competitive social behaviors often represent contests for resources
         Mating behavior relates directly to an animal's fitness
         Social interactions depend on diverse modes of communication
         The concept of inclusive fitness can account for most altruistic behavior
         Sociobiology connects evolutionary theory to human culture
 
 

Chapter  51
behavior - what an animal does and how it does it.
ethology - trying to understand how a variety of animals behave in their natural habitats.
fixed action pattern (FAP) - a highly stereotypical behavior that is innate and must be carried to completion once initiated. fluid-feeder An animal that lives by sucking nutrient-rich fluids from another living organism.
sign stimulus - an external sensory stimulus; is what triggers a FAP.
behavioral ecology - a heuristic approach based on the expectation that Darwinian fitness (reproductive success) is improved by optimal
behavior.
search image - a set of key characteristics that will lead an animal to a desired object.
optimal foraging - the concept that natural selection will favor animals that choose foraging stategies that maximize the differential between benefits and costs.
learning - the modification of behavior resulting from specific experiences.
maturation - developmental changes in neuromuscular systems.
habituation - a simple kind of learning involving a loss of sensitivity to unimportant stimuli, allowing an animal to conserve time and energy.
imprinting - a type of learned behavior with a significant innate component, acquired during a limited critical period.
critical period - a limited phase in an individual animal's development when learning of particular behaviors can take place.
associative learning - the acquired ability to associate one stimulus with another; also called classical conditioning. assortative mating A type of nonrandom mating in which mating partners resemble each other in certain phenotypic characters.
classical conditioning - a type of associative learning; the association of a normally irrelevant stimulus with a fixed behavioral response.
operant conditioning (OP-ur-ent) - a type of associative learning that directly affects behavior in a natural context; also called trial-and-error learning.
play - behavior that has no apparent external goal but involves movements closely associated with goal-directed behaviors.
cognitive ethology - the study of animal cognition; attempts to illustrate the connection between data processing by nervous systems and animal behavior.
cognitive maps - based on the theory that many animals formulate internal representations or codes of the spatial relationships amond objects in their surroundings.
kinesis (kih-NEE-sis) - a change in activity rate in response to a stimulus.
taxis (TAKS-iss) - a movement toward or away from a stimulus.
migration - regular movement over relatively long distances.
social behavior - any kind of interaction between two or more animals, usually of the same species.
sociobiology - the study of social behavior based on evolutionary theory.
agonistic behavior (ag-on-IS-tik) - a type of behavior involving a contest of some kind that determines which competitor gains access to some resource, such as food or mates.
ritual - use of symbolic activity.
dominance hierarchy - a linear "pecking order" of animals, where position dictates characteristic social behaviors.*territory
territory - an area that an individual defends, usually excluding other members of its own species.
parental investments - the time and resources an individual must expend to produce offspring.
lek - a small area in which male birds and insects display communally.
promiscuous - mating with no strong pair-bonds or lasting relationships.
monogamous - mates remain together for a longer period (one male mating with one female).
polygamous - an individual of one sex mating with several of the other.
polygyny (pol-IJ-en-ee) - a polygamous mating system involving one male and many females.
polyandry (POL-ee-AN-dree) - a polygamous mating system involving one female and many males.
pheromones (FAIR-uh-mone) - a small, volatile chemical signal that functions in communication between animals and acts much like a hormone in  influencing physiology and behavior.
altruism (AL-troo-IS-tik) - the aiding of another individual at one's own risk or expense.
inclusive fitness - concept which describes the total effect an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives to increase the production of their offspring.
coefficient of relatedness - proportion of genes that are identical in two individuals because of common ancestors; an important quantitative measure of inclusive fitness.
kin selection - a phenomenon of inclusive fitness, used to explain altruistic behavior between related individuals.
reciprocal altruism (AL-troo-IZ-um) - altruistic behavior between unrelated individuals; believed to produce some benefit to the altruistic
individual in the future when the current beneficiary reciprocates.
 
 

    Characteristics of Populations

         Two important characteristics of any population are density and the spacing
         of individuals
         Demography is the study of factors that affect the growth and decline of
         populations

    Life History Traits

         Life histories are highly diverse but exhibit patterns in their variability
         Limited resources mandate trade-offs between investments in reproduction
         and in survival

    Population Growth Models

         An exponential model of population growth describes an idealized population
         in an unlimited environment
         A logistic model of population growth incorporates the concept of carrying
         capacity

    Population Limiting Factors

         Density-dependent factors regulate population growth by varying with the
         density
         The occurrence and severity of density-independent factors are unrelated to
         population density
         A mix of density-dependent and density-independent factors probably limits
         the growth of most populations
         Some populations have regular boom and bust cycles

    Human Population Growth

         The human population has been growing almost exponentially for centuries
         but cannot do so indefinitely
 

Chapter  52
population - a group of individuals of one species that live in a particular geographic area.
density - the number of individuals per unit area or volume.
dispersion - the distribution of individuals within geographical population boundaries.
mark-recapture method - technique commonly used to estimate wildlife populations.
clumped - most common pattern of dispersion, with the individuals aggregated in patches.
grain - ecological concept that relates to the spatial variation, or environmental patchiness, of individual organisms.
uniform - evenly spaced pattern of dispersion; results from direct interactions between individuals in the population.
random - unpredictable, patternless dispersion; occurs in the absence of strong attractions or repulsions among individuals of a population.
demography - the study of statistics relating to births and deaths in populations.
age structure - the relative number of individuals of each age in a population.
birthrate (fecundancy) - the number of offspring produced during a certain amount of time.
deathrate - the number of individuals in a species that die during a certain amount of time.
generation time - the average span between the birth of individuals and the birth of their offspring.
sex ratio - proportion of individuals of each sex in a species.
life tables - a table of data summarizing mortality in a population.
cohort - a group of individuals of the same age.
survivorship curve - a plot of the number of members of a cohort that are still alive at each age; one way to represent age-specific mortality.
life history - the traits that affect an organism's schedule of reproduction and death.
semelparity - type of life history in which most of an organism invests most of it's energy in growth and development, expends this energy in a single large reproductive effort, and then dies.
iteroparity - type of life history in which an organism produces fewer offspring at a time over a span of many seasons.
zero population growth (ZPG) - occurs when the per capita birthrates and death rates are equal.
intrinsic rate of increase - the difference between the number of births and the number of deaths, symbolized as rmax; the maximum population growth rate.
exponential population growth - the geometric increase of a population as it grows in an ideal, unlimited environment.
carrying capacity - the maximum population size that can be supported by the available resources, symbolized as K.
logistic population growth - a model describing population growth that levels off as population size approaches carrying capacity.
K-selected populations (equilibrial populations ) - the concept that in certain (K-selected) populations, life history is centered around producing relatively few offspring that have a good chance of survival.
r-selected populations (opportunistic populations) - the concept that in certain (r-selected) populations, a high reproductive rate is the chief determinant of life history.
intraspecific competition - the reliance of individuals of the same species on the same limited resouces.
density-dependent factor - any factor influencing population regulation that has a greater impact as population density increases.
density-independent factor - any factor influencing population regulation that acts to reduce population by the same percentage, regardless of size.
 
 

    Early Hypotheses of Community Structure

         The interactive and individualistic hypotheses pose alternative explanations
         of community structure: science as a process

    Interactions Between Populations of Different Species

         Interspecific interactions can be strong selection factors in evolution
         Interspecific interactions may have positive, negative, or neutral effects on a
         population's density: an overview
         Predation and parasitism are +/- interactions: a closer look
         Interspecific competitions are -/- interactions: a closer look
         Commensalism and mutualism are +/0 and +/+ interactions, respectively: a
         closer look

    Interspecific Interactions and Community Structure

         Predators can alter community structure by moderating competition among
         prey species
         Mutualism and parasitism can have community-wide effects
         Interspecific competition influences populations of many species and can
         affect community structure
         A complex interplay of interspecific interactions and environmental variability
         characterizes community structure

    Disturbance and Nonequilibrium

         Nonequilibrium resulting from disturbance is a prominent feature of most
         communities
         Humans are the most widespread agents of disturbance
         Succession is a process of change that results from disturbance in
         communities
         The nonequilibrial model views communities as mosaics of patches at
         different stages of succession

    Community Ecology and Biogeography

         Dispersal and survivability in ecological and evolutionary time account for the
         geographical ranges of species
         Species diversity on some islands tends to reach a dynamic equilibrium in
         ecological time
 

Chapter  53
community - all the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for
potential interaction.
species richness - the number of species in a biological community.
relative abundance -
species diversity - the number and relative abundance of species in a biological community.
individualistic hypothesis - introduced by H.A. Gleason, theory that depicted the community as a chance assemblage of species found i the same area simply because they happen to have similar abiotic requirements.
interactive hypothesis - by F.E. Clemens, depicted the community as an assemblage of closely linked species, locked into association by mandatory biotic interactions that cause the community to function as an integrated unit.
interspecific interactions - those that occur between populations of different species living together within a community.
coevolution - the mutual influence on the evolution of two different species interacting with each other and reciprocally influencing each other's adaptations.
predation - an interaction between species in which one species, the predator, eats the other, the prey.
predator - eats the prey.
prey - is eaten by the predator.
parasitism - a symbiotic relationship in which the symbiont (parasite) benefits at the expense of the host by living either within the host (endoparasite) or outside the host (ectoparasite).
parasitoidism - insects, usually small wasps, lay eggs on living hosts.
herbivory - a heterotrophic animal that eats plants.
cryptic coloration (KRIP-tik) - a type of camouflage that makes potential prey difficult to spot against its background.
aposematic coloration (AP-oh-so-MAT-ik) - the bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators.
mimicry - a phenomenon in which one species benefits by a superficial resemblance to an unrelated species. A predator or species of prey may gain a significant advantage through mimicry.
Batesian mimicry (BAYTZ-ee-un MIM-ih-kree) - a type of mimicry in which a harmless species looks like a different species that is poisonous or otherwise harmful to predators.
Müllerian mimicry (myoo-LER-ee-un) - a mutual mimicry by two unpalatable species.
parasite (PAR-uh-site) - an organism that absorbs nutrients from the body fluids of living hosts.
host - is harmed or at least loses some energy or materials in the process of parasitism.
endoparasites - organisms that live within their host, such as tapeworms and malarial parasites.
ectoparacites - parasites that feed on the external surface of a host, like mosquitoes and aphids.
interspecific competition - when populations of two or more species in a community rely on similar limiting resources.
interference competition - actual fighting over resources.
exploitative competition - the consumption or use of similar resources.
competitive exclusion principle - hypothesis that two species with similar needs for the same limiting resources cannot coexist in the same place.
ecologial niche (nich) - the sum total of an organism's utilization of the biotic and abiotic resources of its environment.
fundamental niche - the set of resources a population is theoretically capable of using under ideal circumstances.
realized niche - the resources a population actually uses.
resource partitioning -the division of environmental resources by coexisting species populations such that the niche of each species differs by one or more significant factors from the niches of all coexisting species populations.
character displacement - the tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric population of the same two species.
symbiosis - an ecological relationship between organisms of two different species that live together in direct contact.
symbiont (SIM-by-ont) - the smaller participant in a symbiotic relationship, living in or on the host.
parasitism - a symbiotic relationship in which the symbiont (parasite) benefits at the expense of the host by living either within the host (endoparasite) or outside the host (ectoparasite).
commensalism (kuh-MEN-sul-iz-um) - a symbiotic relationship in which the symbiont benefits but the host is neither helped nor harmed.
mutualism (MYOO-choo-ul-iz-um) - a symbiotic relationship in which both the host and the symbiont benefit.
keystone species - a predatory species that helps maintain species richness in a community by reducing the density of populations of the best  competitors so that populations of less competitive species are maintained.
exotic species - species that has been accidentally of intentionally introduced into new communites by humans.
stability - the tendency of a community to reach and maintain an equilibrium, or relatively constant condition, in the face of disturbance.
disturbances - events, such as storms, fire, floods, droughts, overgrazing, or human activities, that damage communities, remove organisms from them, and alter resource availability.
ecological succession - transition in the species composition of a biological community, often following ecological disturbance of the  community; the establishment of a biological community in an area virtually barren of life.
primary succession - a type of ecological succession that occurs in an area where there were originally no organisms.
secondary succession - occurs where an existing community has been cleared by some disturbance that leaves the soil intact.
recruitment - process in which species from distant areas that are not directly associated with the disturbed patch or its immediate vicinity are the major colonizers.
dynamic equilibrium hypothesis - maintains that species diversity depends mainly on the effect of disturbance on the competitive interactions of populations.
intermediate disturbance hypothesis - posits that species diversity is greatest where disturbances are moderate in both frequency and severity, because organisms typical of different successional stages will be present.
biogeography - the study of the past and present distribution of species.
 
 

    Trophic Relationships in Ecosystems

         Trophic relationships determine an ecosystem's routes of energy flow and
         chemical cycling
         Primary producers include plants, algae, and many species of bacteria
         Many primary and higher-order consumers are opportunistic feeders
         Decomposition interconnects all trophic levels

    Energy Flow in Ecosystems

         An ecosystem's energy budget depends on primary productivity
         As energy flows through an ecosystem, much is lost at each trophic level

    Cycling of Chemical Elements in Ecosystems

         Biological and geological processes move nutrients among organic and
         inorganic compartments
         Decomposition rates largely determine the rates of nutrient cycling
         Field experiments reveal how vegetation regulates chemical cycling: science
         as a process

    Human Impacts on Ecosystems

         The human population is disrupting chemical cycles throughout the
         biosphere
         Toxins can become concentrated in successive trophic levels of food webs
         Human activities are causing fundamental changes in the composition of the
         atmosphere
         The exploding human population is altering habitats and reducing
         biodiversity worldwide

Chapter  54
ecosystem - a level of ecological study that includes all the organisms in a given area as well as the abiotic factors with which they interact; a community and its physical environment.
trophic structure - the different feeding relationships in an ecosystem that determine the route of energy flow and the pattern of chemical cycling.
trophic levels - the division of species in an ecosystem on the basis of their main nutritional source. The trophic level that ultimately supports all others consists of autotrophs, or primary producers.
primary producers - an autotroph, which collectively make up the trophic level of an ecosystem that ultimately supports all other levels; usually a photosynthetic organism.
primary consumers  - an herbivore; an organism in the trophic level of an ecosystem that eats plants or algae.
secondary consumers - a member of the trophic level of an ecosystem consisting of carnivores that eat herbivores.
detritivores - nonliving organic material, such as feces, fallen leaves, and the remains of dead organisms.
detritus (deh-TRY-tis) - dead organic matter.
food chain - the pathway along which food is transferred from trophic level to trophic level, beginning with producers.
food webs - the elaborate, interconnected feeding relationships in an ecosystem.
production - the rate of incorporation of energy and materials into the bodies of organisms.
consumption - the metabolic use of organis materials for growth and reproduction.
decomposition - the breakdown of organic materials to inorganic ones.
primary productivity - the rate at which light energy or inorganic chemical energy is converted to the chemical energy of organic compounds by  autotrophs in an ecosystem.
gross primary productivity (GPP) - the total primary productivity.
net primary productivity (NPP) - equal to the gross primary productivity minus the energy used by the producers for respiration (R_s)
            *NPP = GPP - R_s
biomass - the dry weight of organic matter comprising a group of organisms in a particular habitat.
standing crop biomass - the total biomass of photosynthetic autotrophs present at a given time; the total dry weight of all organisms.
limiting nutrient - single nutrient that is no longer present in adequate supply; limits the further productivity.
secondary productivity - the rate at which all the heterotrophs in an ecosystem incorporate organic material into new biomass, which can be equated to chemical energy.
ecological efficiency - the ratio of net productivity at one trophic level to net productivity at the next lower level.
pyramid of productivity - diagrammatically represents the multiplicative loss of energy from a food chain.
biomass pyramid - representsthe ecological consequence of decreasing energy transfers through a food web; each tier represents the standing crop biomass in a trophic level.
turnover time - standing crop biomass compared to an organism's productivity.
pyramid of numbers -
biogeochemical cycles - nutrient circuits that involve both biotic and abiotic components of the ecosystems.
nitrogen fixation - the assimilation of atmospheric nitrogen by certain prokaryotes into nitrogenous compounds that can be directly used by plants.
nitrification - ammonium in soil is used by certain aerobic bacteria as an energy source; their activity oxidizes ammonium to nitrite (NO₂-) and then to nitrate (NO₃-), which can then be used by plants.
denitrification -
ammonification - decomposition of organic nitrogen back to ammonium by bacterial and fungal decomposers.
long-term ecological research (LTER) -
biological magnification - a trophic process in which retained substances become more concentrated with each link in the food chain.
greenhouse effect - the warming of planet Earth due to the atmospheric accumulation of carbon dioxide, which absorbs infrared radiation and slows its escape from the irradiated Earth.

    The Biodiversity Crisis: an overview

         Numerous examples indicate that estimates of extinction rates are on track
         The major threats to biodiversity are habitat destruction, overexploitation,
         and competition by exotic species
         Biodiversity is vital to human welfare
         Change in ecological and evolutionary time is the focus of conservation
         biology

    The Geographic Distribution of Biodiversity

         Gradual variation in biodiversity correlates with geographical gradients
         Biodiversity hot spots have high concentrations of endemic species
         Migratory species present special problems in conservation

    Conservation at the Population and Species Levels

         Sustaining genetic diversity and the environmental arena for evolution is an
         ultimate goal
         The dynamics of subdivided populations apply to problems caused by
         habitat fragmentation
         Population viability analyses examine the chances of a species persisting or
         becoming extinct in the habitats available to it
         Analyzing the viability of selected species may help sustain other species:
         science as a process
         Conserving species involves weighing conflicting demands

    Conservation at the Community, Ecosystem, and Landscape Levels

         Edges and corridors can strongly influence landscape biodiversity
         Nature reserves must be functional parts of landscapes
         Restoring degraded areas is an increasingly important conservation effort
         Sustainable development goals are reorienting ecological research and will
         require changing some human values

Chapter  55
endangered species - species that is in danger of extinction throughout all or a significant portion of its range.
threatened species - those that are likely to become endangered in the foreseeable future throughout all or a significant portion of their range.
metapopulation - a subdivided population (a network of subpopulations) of a single species.
source habitat - area of habitat where a population's reproductive success exceeds mortality, and from which excess individuals disperse.
sink habitat - habitat where mortality exceeds reproductive success.
population viability analysis (PVA) - new approach to conservation problems, a method of predicting whether or not a species will persist in a particular environment.
minimum viable population size (MVP) - the smallest number of individuals needed to perpetuate a population, subpopulation, or species.
minimum dynamic area - amount of suitable habitat needed to sustain a viable population.
effective population size (N_e) - based on the number of adults that successfully breed (contribute gametes to the next generation).
landscape ecology - the application of ecological principles to the study of land-use patterns.
movement corridor - a narrow strip or series of small clumps of quality habitat connecting otherwise isolated patches.
zoned reserve systems - method of landscape management where protected areas are surrounded by lands that are used and altered more extensively by human activity.
restoration ecology - applies ecological principles in developing weays to return degraded ecosystems to conditions as similar as possible to their natural, predegraded state.
bioremediation - the use of living organisms, usually prokaryotes, fungi, or plants, to detoxify polluted ecosystems.
sustainable development - the long-term prosperity of human societies and the ecosystems that support them.
Sustainable Biosphere Initiative - research agenda designed to define and acquire the basic ecological information necessary for the intelligent and responsible development, management, and conservation of Earth's resources.