Chapter 52

Flashcards about ecology, the biosphere, climate, biomes, and species distribution.

What environmental factors limit where a species is found?

Climate, including temperature and precipitation, has the strongest effect on where terrestrial organisms live. Light and nutrient availability are two factors that have a strong effect on where aquatic organisms live.

What is Ecology?

Ecology is the scientific study of the interactions between organisms and the living and nonliving components of their environment.

What is Organismal ecology?

Organismal ecology is concerned with how an organism’s structure, physiology, and behavior meet the challenges of the environment.

What is Population ecology?

Population ecology analyzes factors affecting population size and why it changes over time.

What is Community ecology?

Community ecology examines the affect of interspecific interactions on community structure and organization.

What is Ecosystem ecology?

Ecosystem ecology emphasizes energy flow and chemical cycling between organisms and the environment.

What is Landscape ecology?

Landscape ecology focuses on the exchanges of energy, materials, and organisms across multiple ecosystems.

What is Global ecology?

Global ecology examines how the exchange of energy and materials influences the function and distribution of organisms across the biosphere.

What are the four major physical components of climate?

Temperature, precipitation, sunlight, and wind

What is the effect of Sunlight at higher latitudes?

Sunlight hits at an oblique angle, making the light energy more diffuse and less intense

What is the cause of Seasonality in middle to high latitudes?

The tilt of Earth’s axis of rotation and its annual passage around the sun

How do ocean currents influence the climate of nearby terrestrial environments?

By heating or cooling overlying air masses that pass over land

How do mountains affect climate?

Mountains influence air flow over land, affect the amount of sunlight reaching an area, Warm, moist air cools as it rises up a mountain and releases moisture on the windward side and Cool, dry air absorbs moisture as it descends on the leeward side, creating a “rain shadow”

How do terrestrial organisms, particularly forests, can alter climate at local and regional scales?

The darker color of forests cause them to absorb more solar energy than deserts or grasslands and by transpiration, which causes evaporative cooling, which reduces surface temperatures and increases precipitation rates

What is Microclimate?

Microclimate refers to very fine, localized patterns in climate

What has caused climate change?

The burning of fossil fuels and deforestation have increased the concentration of greenhouse gases in the atmosphere

What are Biomes?

Major life zones characterized by vegetation type (terrestrial biomes) or physical environment (aquatic biomes)

What is a climograph?

A climograph plots the annual mean temperature and precipitation in a region

What is an ecotone?

The area of intergradation of Terrestrial biomes, may be wide or narrow

What is the major human impact on tropical forests?

Deforestation

What is the major impact humans have had on the Temperate Grassland?

Most grassland in North America and Eurasia has been converted to agricultural land

What is permafrost?

A permanently frozen layer of soil, restricts the growth of plant roots

What Physical and chemical environment characterized Aquatic biomes?

the average salt concentration in marine biomes is 3%, whereas in freshwater biomes it is less than 0.1%

What impact do Oceans have on the biosphere?

Water evaporated from the oceans provides most of the planet’s rainfall, Photosynthetic marine organisms provide most of the planet’s O2 and consume large amounts of CO2 and Ocean temperatures effect global climate and wind patterns, and moderate the climate of nearby land

photic zone

The upper zone that has sufficient light for photosynthesis

aphotic zone

The lower zone that receives little light

thermocline

A temperature boundary that separates the warm upper layer from the cold deeper water

oligotrophic lake

Nutrient-poor and O2-rich lake with low organic content in sediments

eutrophic lake

Nutrient-rich and high in organic content in sediments lake; O2 is periodically depleted in deeper layers due to high rates of decomposition

estuary

A nutrient rich and productive transition zone between a river and the sea

What is Dispersal?

The movement of individuals or gametes away from their area of origin or centers of high population density

What are Species transplants?

Species transplants are used to determine if dispersal is key factor limiting distribution and involve the intentional or accidental relocation of organisms from their original distribution

Tropical Forest Location

Equatorial and subequatorial regions

Tropical Rain Forest Rainfall

200–400 cm annually

Tropical Dry Forest Rainfall

150–200 cm annually with a long dry season

Desert Location

Near 30º N and S of the equator and in continental interiors

Desert Precipitation

Low and variable (less than 30 cm per year)

Adaptations of Desert Plants

Heat and desiccation tolerance, water storage, and reduced leaf surface area (C4 or CAM photosynthesis)

Savanna Location

Equatorial and subequatorial regions

Savanna Precipitation

Seasonal (average 30–50 cm per year) with dry seasons lasting eight to nine months

Dominant Savanna Plants

Grasses and forbs adapted to fire and drought

Chaparral Location

Midlatitude coastal regions

Chaparral Precipitation

Highly seasonal with rainy winters and dry summers (annual average about 30–50 cm)

Dominant Chaparral Plants

Shrubs, small trees, grasses, and herbs adapted to fire and drought

Temperate Grassland Location

Many continents

Temperate Grassland Precipitation

Highly seasonal with dry winters and wet summers (annual average 30–100 cm)

Dominant Temperate Grassland Plants

Grasses and forbs adapted to droughts and fire

Taiga Location

Northern North America and Eurasia

Taiga Precipitation

30–70 cm annually; coastal coniferous forests may receive over 300 cm

Dominant Taiga Vegetation

Evergreen conifers (pine, spruce, fir, and hemlock)

Temperate Broadleaf Forest Location

Primarily at midlatitudes in the Northern Hemisphere

Temperate Broadleaf Forest Precipitation

Significant precipitation during all seasons (annual precipitation varies from 70 to over 200 cm)

Dominant Temperate Broadleaf Forest Plants

Deciduous trees in the Northern Hemisphere and evergreen eucalyptus in Australia

Tundra Location

Expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes

Tundra Precipitation

Lower in arctic tundra (20–60 cm) than in alpine tundra (>100 cm)

Dominant Tundra Vegetation

Mostly

Tropical Forest

Equatorial, high temperatures and rainfall, high animal diversity, major deforestation.

Desert

Near 30º N/S, low and variable precipitation, extreme temperatures, plants adapted for water storage. Urbanization reduces biodiversity.

Savanna

Equatorial, seasonal precipitation, warm temperatures, fire-adapted plants, threatened mammals due to cattle ranching.

Chaparral

Midlatitude coastal, seasonal precipitation, shrubs adapted to fire and drought, reduced areas due to agriculture and urbanization.

Temperate Grassland

Seasonal precipitation and temperatures, plants adapted to drought and fire, agricultural land conversion.

Northern Coniferous Forest (Taiga)

Northern, cold winters, variable precipitation, evergreen conifers, rapid logging of old-growth stands.

Temperate Broadleaf Forest

Midlatitudes, significant precipitation, deciduous trees, mammal hibernation and bird migration, heavily settled by humans.

Tundra

Arctic, low temperatures and precipitation, herbaceous vegetation, permafrost restricts root growth, oil and mineral extraction.

Aquatic Biomes

Characterized by physical and chemical environment; marine biomes average 3% salt; freshwater less than 0.1%.

Zonation in Aquatic Biomes

Stratified into photic (light) and aphotic (no light) zones; thermocline separates warm and cold layers; turnovers mix oxygen and nutrients.

Lakes

Vary in size, salinity, O2, and nutrients; types: oligotrophic (nutrient-poor) and eutrophic (nutrient-rich); algal blooms caused by nutrient enrichment.

Wetlands

Water-saturated soil, high productivity, purify water, reduce flooding. Many have been destroyed by draining and filling.

Streams and Rivers

Prominent current; headwaters (cold, clear) to downstream (warm, turbid); pollution degrades water; damming impairs functioning.

Estuaries

Transition between river and sea, varying salinity, saltmarsh grasses and algae are major producers, disruption from filling, dredging, and pollution.

Intertidal Zones

Submerged/exposed by tides, high oxygen and nutrients, rocky or sandy substrates, oil pollution and construction disrupt.

Oceanic Pelagic Zone

Open water, mixed by currents, high oxygen, lower nutrients, phytoplankton and zooplankton dominate, harm from overfishing and pollution.

Coral Reefs

Calcium carbonate skeletons of corals, warm and clear water, mutualistic algae, threats from collection, overfishing, and pollution.

Marine Benthic Zone

Seafloor, cold and high pressure, hydrothermal vents, chemoaut