Chapt 2 Vocab and outline: ecosystem biosphere environment abiotic factors biotic factors habitat microhabitat homeostasis optimal range stress zone zone of tolerance phytoplankton desiccant ectotherms endotherms metabolism salinity solutes osmosis nutrients limiting nutrients anaerobic organisms aerobic organisms eutrophication

algal bloom population geographic range sampling methods mark-recapture method population density dispersion clumped pattern uniform pattern random pattern generation time survivorship survivorship curve
Type I survivorship curve
Type II survivorship curve
Type III survivorship curve life history clutch size biological fitness recruitment larval settlement exponential growth logistic growth carrying capacity density-dependent factor

density-independent factor r-strategist
K-strategist community niche fundamental niche realized niche interspecific competition intraspecific competition competitive exclusion resource partitioning herbivores carnivores keystone species symbiosis mutualism commensalism parasitism parasite host photosynthesis autotroph primary productivity light-dark-bottle method heterotroph

first-order (primary) consumers second-order (secondary) consumers third-order (tertiary) consumers omnivores detritivores detritus decomposers food chain food web dissolved organic matter (dom) trophic level ecological efficiency ten percent rule energy pyramid pyramid of biomass pyramid of numbers biogeochemical cycle precipitation nuclei pelagic division water column benthic division neritic province oceanic province photic zone disphotic (twilight) zone

aphotic zone plankton nekton neuston intertidal zone shelf zone bathyal zone abyssal zone hadal zone epifauna infauna
Chapter Summary
1. An organism’s environment consists of all the external factors acting on that organism.
Organisms expend energy to maintain homeostasis, a relatively constant environment for their cells.
Characteristics of the physical environment determine the amount of energy necessary to maintain homeostasis.
2. In ecological terms, a population is a group of the same species that occupies a specific area.
Factors that affect reproduction and mortality rate, such as survivorship and life histories, have a significant effect on the size of populations. Populations grow when more organisms are added through reproduction and immigration than are lost through death and emigration. Characteristics of the environment, such as space and available food, limit the number of organisms an area can support. The carrying capacity is set by density-dependent or density-independent factors.
3. A community is composed of populations of organisms that occupy the same habitat at the same time. The role an organism plays in its environment, in a sense its “profession,” is its niche.
Interactions with other organisms and the physical environment, however, limit it to a smaller part of the niche called its realized niche.

2.
II.
A.
1. a. b. e. f. c. d. g.
I.
A.
1.
4. Although energy constantly flows through ecosystems, nutrients necessary for life are constantly recycled. Producers capture the energy of sunlight in the chemical bonds of organic molecules. Consumer organisms rely on these molecules as a source of food because they cannot synthesize their own. The complex feeding networks that result are known as food webs. The energy that an organism receives from photosynthesis or from feeding on other organisms is temporarily stored until the organism is consumed by another or decomposed. Energy transfer from one trophic level to the next is not efficient.
5. The biosphere contains all of the Earth’s communities and ecosystems. Estuaries, rocky coasts, sandy shores, salt marshes, mangrove swamps, kelp forests, and coral reefs are some examples of marine communities and ecosystems. Ecologists divide the marine environment into two major divisions: the pelagic division, composed of the ocean’s water (the water column), and the benthic division, the ocean bottom. These divisions can be subdivided into zones on the basis of distance from land, light availability, and depth.
Chapter Outline
Study of Ecology
Ecology, ecosystems, and biospheres.
Energy flows through the ecosystems in the biosphere.
Nutrients cycle through biosphere ecosystems.
Ecology and the Physical Environment
The environment.
Abiotic factors.
Temperature.
Salinity. pH.
Sunlight.
Ocean currents.
Wave action.
Sediments.

2.
B.
Biotic factors.
Habitat: where an organism lives.
1. a. b. c.
Marine habitats include (but are not limited to):
Rocky shores.
Sandy shores.
Mangrove swamps. d. e.
Coral reefs.
Deep-sea vents.
2. Marine habitats are unique and characterized by specific abiotic factors that define their worldwide distribution.
2.
3. a. b.
3.
C.
Microhabitats: small subdivisions within a larger habitat.
Maintaining homeostasis.
1. Homeostasis: internal balancing of factors in response to changing external conditions. a. Changes in external environment such as temperature, salinity, and dissolved oxygen require marine organisms to adapt in order to survive.
Physiological mechanisms and behavioral adaptations for maintaining homeostasis.
Homeostasis and the distribution of marine organisms.
Optimal range.
Zones of stress. c.
D.
Zones of intolerance.
Characteristics of the abiotic environment.
1. Physical environment: Physical parameters of marine ecosystems determine the biological communities found in the ecosystem.
2. Sunlight: The amount of sunlight in an ecosystem determines how much photosynthetic activity
(food production) occurs in that ecosystem. a. Phytoplankton. b. Vision.

1. a.
2.
B. b. c. d. e.
7.
III.
A.
1.
C.
6. a. b. c. c. Desiccation.
3. Temperature: Surface water temperature varies less than ambient air temperature; temperature variation impacts marine organisms living in intertidal areas.
4. a. b. c.
Salinity.
Solutes.
Osmosis.
Salt and water balance.
5. Water pressure: Water pressure increases one atmosphere (760 mm Hg) for every 10 meters of water depth.
Metabolic requirements: All organisms require nutrients to survive and grow.
Nutrients.
Limiting nutrients.
Anaerobic organisms (anaerobes).
Aerobic organisms (aerobes).
Eutrophication.
Metabolic wastes: All organisms produce waste as a result of metabolism.
Populations
Population range and size.
Geographical range.
Sampling method.
Population density.
Dispersion.
Uniform distribution.
Random distribution.
Clumped distribution.
Changes in population size.

1. Population size increases as a result of births (natality) and immigration (new organisms joining the population from other populations).
2. Population size decreases due to deaths (mortality) and emigration (organisms leaving the population to join different populations).
3. Survivorship: the relationship between age and mortality; this relationship is frequently illustrated using a graph in which age is the independent variable (x-axis) and population size is the dependent variable (y-axis). a. Type I survivorship curve: Mortality is greatest at the end of the life span of the species. b. c.
Type II survivorship curve: Mortality is constant throughout the life span of the species.
Type III survivorship curve: Mortality is greatest early in the life span of the species.
4. Life history is divided into three phases: birth, reproduction, and death; population size is a function of: a. Age of first reproduction.
5. a.
3.
4. b. b. c. d.
D.
Clutch size.
Number of reproductive events.
Biological fitness.
Population growth.
1. Continuous population growth without environmental limitations produces an exponential growth curve.
2. Initial population growth rate is exponential until population size reaches a level at which the environment cannot support additional growth and the population size becomes relatively constant.
Recruitment.
Carrying capacity.
Population regulation.
Density-independent limiting factors.
Density-dependent limiting factors. c. d. r-strategists. k-strategists.

1.
2.
3.
D.
3.
V.
2.
3.
A.
1.
4.
1.
2. b. c. d.
C.
IV.
A.
1. a.
1.
2.
3.
B.
Communities
Niche.
Fundamental niche.
Realized niche.
Connell’s barnacles.
Biological interactions.
Competition.
Interspecific competition.
Intraspecific competition.
Competitive exclusion.
Resource partitioning.
Predator-prey relationships.
Herbivore.
Carnivore.
Keystone species.
Symbiosis.
Mutualism.
Commensalism.
Parasitism.
Ecosystems: Basic Units of the Biosphere
Energy flows through an ecosystem.
Producers/autotrophs.
Photosynthesis.
Primary productivity.
Consumers.

5.
6.
Heterotroph.
First-order (primary) consumers.
7.
8.
Second-order (secondary) consumers.
Third-order (tertiary) consumers.
9. Omnivores.
10. Detritivores.
11. Food chain and web.
12. Dissolved organic matter (DOM).
2.
3.
B.
1.
VI.
A.
2.
3.
B.
1.
4.
13. Trophic level. a. 10% rule.
14. Trophic pyramids. a. Pyramid of energy. b. c.
Pyramid of biomass.
Pyramid of numbers.
Biogeochemical cycles: cycling of nutrients through trophic structures.
Hydrological cycle (water cycle).
Carbon cycle.
Nitrogen cycle.
The Biosphere
Distribution of marine communities in the biosphere (refer to Figure 2-24).
Pelagic division.
Neritic zone.
Oceanic zone.
Photic zone.
Disphotic zone.

5.
6.
2.
3.
7.
8.
C.
1.
4.
5.
6.
Aphotic zone.
Plankton.
Nekton.
Neuston.
Benthic division.
Intertidal zone.
Bathyal zone.
Abyssal zone.
Hadal zone.
Epifauna.
Infauna.