AP Environmental Science – Ecology

The study of the interactions among and between organisms in their abiotic environment.

A group of organisms of the same species that live together in the same area in the same time.
A natural association that consists of all the populations of different species that live and interact within an area at the same time.
A community in addition to its physical environment.
A group of similar organisms whose members interbreed in the wild to produce fertile offspring.
Several interacting ecosystems in a heterogeneous region.

The layer of earth containing all living organisms – combination of all landscapes.
The Order of Life
Atom – Molecule – Cell – Tissue – Organ – Organ Systems – Body – Organism – Population – Community – Ecosystem – Landscape – Biosphere
Any relationship/association between members of different species. Includes Ammensalism, commensalism, mutualism…
The independent evolution of two interacting species, i.e flowering plants and animal pollinators
A symbiotic relationship in which both partners benefit i.

e rhizobium and legumes; zooxanthellae and corals.

Symbiotic relationship in which one organism benefits and the other is neither harmed nor helped i.e silverfish and army ants
A symbiotic relationship in which the parasite obtains nourishment from the host, but does not kill the host.
The consumption of one species by another. Predator consumes prey, of course
A parasite that causes disease and sometimes death in the host.
The organism that the parasite latches onto.

Mutualistic associations between the plant roots and fungi – fungi absorbs phosphorous while plant provides carbohydrates.
Temperate Grassland
A grassland with hot summers, cold winters, and rainfall = 25-75cm. Nutrient minerals below topsoil; considerable organic material.
Mediterranean Climates
Temperate environments with mild winters, abundant rainfall and dry summers.
A biome with mild and moist winters and hot, dry summers.

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Vegetation is small-leaved evergreen shrubs and small trees.

A category of aquatic organisms that are larger, more strongly swimming organisms such as fishes, turtles, and whales.
A category of aquatic ecosystems that are bottom-dwelling that fix themselves to one spot, burrow into the sand, or walk about the bottom. i.

e oysters, sponges, barnacles, worms, clams, crawfish, insect larvae.

Flowing-water ecosystem
A freshwater ecosystem in which water flows in a current. i.e rivers and streams.
Headwater Streams
Cool, shallow, swiftly-flowing and highly oxygenated streams that are usually sources of a river.

Algal Blooms
Population explosions of algal and cyanobacterial populations in the fall and the spring, caused by the sudden presence of large amounts of essential nutrient minerals in surface waters.
Freshwater Wetlands
Lands that shallow freshwater covers for at least part of the year. Characteristically organic material-rich soils and water-tolerant vegetation.
A coastal body of water partly surrounded by land with access to the open ocean and a large supply of fresh river-water.

Ocean Zonation
Three main zones: intertidial zone, benthic zone, pelagic zone. Pelagic = neritic and oceanic provinces
Intertidial Zone
High levels of light and nutrients with lots of oxygen (highly productive); action-packed zone.
Abyssal Benthic Zone
Benthic environment from 4000 to 6000 meters
Hadal Benthic Zone
Benthic environment from 6000m to the bottom.
Sea Grasses
Flowering plants adapted to complete submersion in salty ocean water.

Occur in shallow water where photosynthetic productivity = high

Environmental Stressors
‘Hardships’ or basically environmental conditions such as drought and high soil temperatures. Better tolerated in presence of mycorrhizae.
Smaller plants such as mosses, orchids and ferns that remain attached to the bark of the tree’s branches.

Example of commensalism.

Habitat Fragmentation
Diversion of habitats that formerly occupied large, unbroken areas into smaller areas by land-transforming activities such as roads, fields or urbanization.
Warning Coloration
Bright colors on an organism’s body that conspicuously marks it as poisonous or dangerous. i.e Poison arrow frog
The method of blending into the surroundings that some organisms have to prevent untimely predation. i.e pygmy seahorse
Interaction b/w organisms that vie for the same resources in an ecosystem.
Intraspecific Competition
Competition among individuals in a population
Interspecific Competition
Competition between different species.

Ecological Niche
Totality of organism’s adaptations, use of resources, and lifestyle.
Organism’s living space.
Fundamental Niche
Potential, idealized ecological niche of an organism.
Realized Niche
Lifestyle and resources that an organism actually pursues.
Limiting Resource
Any environmental resource that (due to scarcity) restricts the ecological niche of an organism
Competitive Exclusion
Principle by GF Gause that states that no two species may occupy the same niche because one species will outcompete the other.
Resource Partitioning
Coexisting species’ niches differ from one another in one or more ways to accommodate the same lifestyle e.g North American warblers in different parts of the tree
Keystone Species
A species (often predatorial) that exerts a profound influence on a community in excess of that expected by its relative abundance.

Simple words = you take this one out and a bunch of other species become scarce. e.g wolves

A biome in which lack of precipitation limits plant growth; found in temperate and sub-tropical regions. Rain: ;ess than 25 cm; arid with extreme fluctuations of hot/cold
Tropical grassland with scattered trees or clumps of trees. Low/seasonal rain; soil low in essential nutrients.

Tropical Rainforest
Lush, species-rich forest biome where the climate is moist + warm
Vertical zonation
Elevation-latitude phenomena that occurs with change in biomes when you climb up a mountain. Polar – Arctic tundra – Boreal Forest- Temp Forest and Snow – Alpine Tundra – Subalpine Coniferous – Deciduous
Standing-Water Ecosystem
Body of freshwater surrounded by land and does not flow; lake/pond
Littoral Zone
Shallow water area on shore of lake/pond where light reaches the bottom. Emergent vegetation and deeper-dwelling aquatic plants/algae.
Limnetic zone
Open water that is away from the shore. Less vegetation but photosynthesis as far as the sun allows
Profundal Zone
Deepest zone with rare life. Mineral-rich and anaerobic.
Salt Marsh
Shallow wetlands dominated by salt-tolerant grasses.

Contained in temperate estuaries.

Mangrove Forest
Tropical equivalent of salt marshes that cover 70% of tropical coastlines
Chesapeake Bay
Largest and most productive estuary in the US.
Largest brown algae that reach depths of 60m.

Common in cooler marine temperatures. Primary photosynthetic producers, abundant in shallow waters.

Coral Reefs
Built from accumulated CACO3 and found in warm, shallow sea water. Partly composed of red coralline algae.
Symbiotic algae that live and photosynthesize in the tissues of animals that live in coral reefs.
Fringing Reef
Most common type of coral reef in which shore is attached to shore of volcanic island/continent and has no lagoon.
Circular coral reef that surrounds a central lagoon of quiet water. Forms on top of the cone of submerged volcanic island.

Species Richness
The number of different species in a community determined by isolation, dominance, abundance of niches, closeness to adjacent communities, habitat stress, geological history.
Transitional zone where two or more communities meet.
Edge Effect
Effect obtained when all or most ecological niches of adjacent communities as well as niches unique to ecotones occur in ecotones.
Ecosystem Service
Important environmental benefits such as clean air, water, and fertile soils, provided by ecosystems.
Community Stability
Ability of community to withstand environmental disturbances.
Large and relatively distinct terrestrial region with similar climate, soil, plants, and animals.
The average of all the weather conditions over a period of time.

Treeless biome in far north that consists of boggy plains covered by lichens and and mosses. Harsh, very cold winters with short summers.
Layer of permanently frozen ground that can very in depth and thickness. Found in Tundra biomes.

Primary Productivity
The existence of phtosynthetic organisms; usually the base of the food chain.
Also called boreal forest; cold and severe winters with acidic and nutrient-poor soil.
Boreal Forest
Region of coniferous forest in NE hemisphere, south of Tundra
Temperate Rainforest
Coniferous biome with cool weather, dense fog, and high precipitation.

Single-species agriculture.
Temperate Deciduous Forest
Forest biome in temperate areas with modest rainfall. Topsoil rich in organic matter, clay lower layer, broad-leaved hardwood trees, lose foliage annually.
Filter below or permeate quickly
Concentration of dissolved salts such as NaCl in a body of water.
Free-floating photosynthetic algae and cyanobacteria that form the base of food webs.

Non-photosynthetic protozoa and larvae.
Microscopic organisms capable of vertical migration.
Thermal Stratification
The temperature changes sharply with depth in temperate lakes – this is called T.S.
In the summer, cooler and denser water remains at the bottom of the lake separated from warm, less dense water above by THIS abrupt temperature transition.

Fall Turnover
Cooling and sinking of water to attain uniform temperature that occurs due to falling temperature in autumn.
Spring Turnover
Surface water sinks and bottom water rises to mix when the ice melts during a ‘turnover’ or water during spring.
Barrier Reef
A literal barrier in the form of a reef that separates lagoon from the sea. Largest: Great Barrier Reef in Australia
Neritic Province
Part of pelagic environment that overlies the ocean floor from the shoreline to a depth of 200m.
Euphotic zone
Comprises of the upper reaches of the pelagic environment.

Phytoplankton – Zooplankton – Nekton – Carnivorous Nekton

Oceanic Province
Overlies the ocean floor at depths greater than 200m. Largest marine environment. Cold, no sun, high hydrostatic pressure.
Marine show
Organic debris that drifts down from upper and lighted regions of oceanic province. Benefits organisms of oceanic province.
Comprehensive Everglades Restoration Plan
Plan to supply clean water to Everglades and south Florida by (a)reduced phosphorous from runoff bc sugar farmers will clean it up (b)Marshes to clean runoff (c)Re-engineered canals, levees, pumps to restore natural flow of water.