Life on Land: Natural History and Evolution (Chapter 2)

Vocabulary flashcards covering key terms and concepts from the notes on terrestrial biomes, climate, soils, and ecosystem processes.

Biome

Major divisions of the terrestrial environment, defined largely by the predominant plants and climate.

Tropical Rain Forest

Warm, wet year-round tropical biome with high species diversity, dense canopy, epiphytes, and nutrient-poor soils.

Tropical Dry Forest

Tropical biome with a pronounced dry season; trees may shed leaves; soils often old and vulnerable to erosion.

Tropical Savanna

Tropical grassland with scattered trees; alternating wet and dry seasons; fire-adapted grasses; impermeable subsoil influences vegetation.

Desert

Biome with very low precipitation and often extreme temperatures; plants and animals show water-conserving adaptations; soils can be low in organic matter and may have caliche.

Mediterranean Woodland and Shrubland

Biome with cool, moist winters and hot, dry summers; evergreen plants; fire-adapted and drought-tolerant traits.

Temperate Grassland

Extensive grass-dominated biome with deep fertile soils; fire maintains grasses; historically roving herbivores; largely converted to cropland.

Temperate Forest

Biome with deciduous or coniferous trees; moderate to high rainfall; multi-layered vegetation; fertile soils.

Boreal Forest (Taiga)

Northern conifer-dominated forest; long cold winters; moderate precipitation; thin soils; permafrost in some areas.

Arctic Tundra

Cold, dry biome with short summers; permafrost; low vegetation; abundant migratory birds in summer and large mammals in some regions.

Mountain

Not a single biome; elevational climate gradients create diverse biomes along a mountain’s height; rain shadow and isolation drive unique communities.

Climate Diagram

A standardized graph showing monthly temperature and precipitation to summarize climate and water availability.

Palmer Drought Severity Index (PDSI)

Quantitative drought index using temperature and precipitation relative to long-term averages; negative values indicate drought, positive indicate moist conditions.

Coriolis Effect

Apparent deflection of moving air due to Earth's rotation; rightward in the Northern Hemisphere, leftward in the Southern Hemisphere.

Trade Winds

Winds flowing toward the equator in the tropics; northeast trades in the Northern Hemisphere and southeast trades in the Southern Hemisphere.

Westerlies

Prevailing mid-latitude winds blowing from the west (30°–60° latitude) in both hemispheres.

Polar Easterlies

Prevailing winds from the east at high latitudes.

Rain Shadow

Dry area on the leeward side of a mountain caused by moisture loss on the windward side.

Microclimate

Localized climate variation within a biome caused by small-scale factors like slope, aspect, and vegetation.

O Horizon

Organic soil layer at the top of the soil profile containing fresh or decomposing organic matter.

A Horizon

Top mineral soil horizon with incorporated organic material; generally nutrient-rich.

B Horizon

Subsoil layer where clays and humus accumulate and are transported from above; often distinctive color and banding.

C Horizon

Deep, weathered parent material; deepest horizon, may contain rock fragments; underlying unweathered parent material.

Caliche

Calcium carbonate–rich hardpan horizon formed in aging desert soils.

Lithosol

Desert soils with little organic matter; dominated by rock and mineral material.

Permafrost

Permanently frozen soil layer found in tundra and some boreal regions.

Solifluction

Slow downslope movement of water-saturated soil in frozen landscapes, common in tundra.

Epiphyte

A plant that grows on another plant (often in the canopy) without extracting nutrients from it.

Mycorrhizae

Fungal associations with plant roots that enhance nutrient uptake.

Functional Traits

Plant characteristics that enable survival in a given environment (e.g., waxy leaves in deserts) shaped by selective pressure.

Selective Pressure

Environmental factors that favor certain traits, driving evolution.

Primary Producer

Photosynthesizing organisms (plants, algae) that form the base of the food web by converting solar energy into biomass.

Primary Production

Rate at which primary producers convert energy into biomass per unit time.

Secondary Producer

Organisms that obtain energy by consuming other organisms; part of the food web and energy transfer.

Epiphyte Mat

Layer of epiphytic plants in the canopy that stores nutrients and supports high diversity.

Natural History

Study of how organisms in a given area are shaped by climate, soils, predators, competitors, and evolutionary history.

Weather

Day-to-day atmospheric conditions; contrasted with climate, which is long-term patterns.

Ecological Fire Ecology

Fire as a disturbance shaping vegetation structure and ecosystem processes, notably in savannas and Mediterranean woodlands.