Unit 5: Biomes and Biodiversity

Comprehensive vocabulary flashcards covering terrestrial and aquatic biomes, vertical zonation, stratification, biodiversity levels, threats summarized by the HIPPO acronym, and species conservation categories.

Biome

A large biological community whose distribution is largely determined and predicted by regional temperature and precipitation ranges.

Biodiversity

The number and variety of different biological species that live in an area or biological community.

Vertical zonation

The distinct vegetation zones that are defined and differentiated by changes in altitude and elevation.

Tropical rainforest

A warm, wet biome occurring where rainfall is abundant—exceeding $200\,\text{cm}$ ($80\,\text{inches}$) per year—and temperatures remain warm to hot year-round.

Tropical seasonal forest

Drought-tolerant forests characterized by distinct wet and dry seasons that look brown and dormant during dry months but burst into vivid green during rainy months.

Savanna

An open grassland with sparse tree cover found where rainfall is insufficient to support dense forest growth.

Desert

A hot or cold, dry biome occurring where precipitation is uncommon and slight, typically receiving less than $30\,\text{cm}$ of rain per year.

Temperate grassland

A midlatitude biome with rich, deep soils occurring where there is enough rainfall to support abundant grass cover but not enough to sustain forests.

Chaparral (Mediterranean scrub)

A biome characterized by summer droughts and dominated by evergreen shrubs with small, leathery leaves forming dense thickets

Deciduous

Trees or vegetation that shed their leaves seasonally, such as broad-leaved trees losing their foliage during the winter in temperate zones.

Coniferous

Cone-bearing evergreen trees equipped with thin, waxy needles that help reduce moisture loss in environments where moisture is limited.

Temperate rainforest

A cool, rainy coastal coniferous forest often enshrouded in fog, found in the Pacific Northwest and other extremely wet regions.

Boreal forest (Taiga)

A northern conifer-dominated biome lying north of the temperate zone, with cold-tolerant trees including pines, hemlocks, spruce, cedar, and fir.

Tundra

A treeless landscape occurring at high latitudes or on mountaintops where temperatures are below freezing most of the year and the growing season lasts only $2$ to $3\,\text{months}$.

Phytoplankton

Tiny, free-floating photosynthetic algae that serve as the primary producers supporting the marine food web.

Pelagic zone

The open water column of an ocean or body of water, distinct from the bottom substrate.

Benthic

Pertaining to the bottom layer or substrate of an aquatic system, such as the ocean or lake floor, and the community of organisms inhabiting it.

Epipelagic zone

The sunlit top layer of the pelagic ocean zone where photosynthetic organisms are active.

Abyssal zone

The deep ocean pelagic layer extending down to approximately $4{,}000\,\text{m}$.

Hadal zone

The deepest oceanic trenches and layers found deeper than $6{,}000\,\text{m}$.

Littoral zone

The coastal shoreline zone of an ocean or lake, spanning the nearshore aquatic margins.

Intertidal zone

The shoreline area that is submerged during high tide and exposed to air during low tide.

Chemosynthesis

The biological conversion of carbon compounds by specialized microbes using inorganic sulfur compounds discharged from deep-sea hydrothermal vents rather than sunlight.

Mangroves

A diverse group of salt-tolerant trees that grow in shallow, calm, warm marine coastal zones across the globe.

Estuary

A partially enclosed coastal bay where a freshwater river empties into the sea, mixing fresh water with saline ocean water.

Salt marsh

A shallow coastal wetland regularly or periodically inundated by seawater, often found around estuaries.

Tide pool

A rocky depression on a shoreline that receives ocean water at high tide and retains water in small pockets during low tide.

Epilimnion

The warm, upper layer of water in a stratified lake characterized by high light and oxygen availability.

Thermocline

The sharp temperature boundary in a lake

Hypolimnion

The cold, dense, lower layer of water lying below the thermocline in a thermally stratified lake.

Wetland

A shallow ecosystem in which the ground surface is saturated or flooded with water for at least part of the year, supporting hydric-adapted vegetation.

Swamp

A wetland ecosystem that is dominated by trees (a wooded wetland).

Marsh

A wetland ecosystem that lacks trees

Bog

An area of water-saturated ground predominantly composed of deep accumulation layers of undecayed vegetation known as peat.

Genetic diversity

A measure of the variety of different versions of the same genes present within an individual species.

Species diversity

The total number of different kinds of organisms occurring within a biological community or ecosystem.

Ecological diversity

The overall structural richness, trophic variety, and functional complexity of a biological community.

equator

Most of the world’s biodiversity concentrations are

near the _____, especially tropical rainforests and

coral reefs.

Existence value

The intangible, moral, or philosophical benefit people receive simply from knowing that wildlife and natural systems exist.

Extinction

The irreversible, complete elimination and loss of a species from the Earth.

HIPPO

An acronym formulated by E. O. Wilson summarizing the primary human-driven threats to biodiversity: Habitat destruction, Invasive species, Pollution, Population of humans, and Overharvesting.

Habitat fragmentation

The process of dividing continuous natural habitat into smaller, isolated patches, reducing interior area and isolating wildlife populations.

Invasive species

Non-native organisms that establish, rapidly spread, and thrive in new territories free of their natural predators, diseases, or resource constraints.

Overharvesting

The exploitation or removal of individual organisms from a population at a rate faster than natural reproduction can replace them.

Endangered species

A classification under the Endangered Species Act defining species that are in imminent danger of extinction throughout all or a significant portion of their range.

Threatened species

A legal classification under the Endangered Species Act for species that are likely to become endangered, at least locally, within the foreseeable future.

Vulnerable species

Species that are naturally rare or have been locally depleted by human activities to a level that places them at conservation risk.

Keystone species

A species whose removal or elimination causes disproportionate and cascading disruptions across the entire biological community (e.g., beavers and wolves).

Indicator species

A species closely linked to specific biotic communities, successional stages, or environmental conditions, whose presence or absence reflects ecosystem health (e.g., trout and mayflies).

Umbrella species

A species that requires large expanses of relatively undisturbed habitat to maintain a viable population, indirectly protecting many other species within that range (e.g., grizzly bears and tigers).

Flagship species

An especially charismatic or attractive organism that evokes strong public emotional reactions and serves as a symbol to stimulate conservation support (e.g., pandas and polar bears).

temperature precipitation

Biome type can be

predicted based on the _____ and

_____ found in an

are

latitudinal

Many temperature-controlled biomes occur in

____ bands

boreal

A band of ____ (northern) forest crosses Canada

and Siberia.

Tropical equator

_____ forests occur near the _____.

temperature precipitation elevation latitude

_____ and _____ change with _____

as well as with _____

cooler greater

In mountainous regions, temperatures are ___ and

precipitation is usually ____ at high elevations

dry tropical forests

tropical seasonal forests are also called

evergreen deciduous

Temperate Forests can be

_____ or _____

north temperate

Boreal Forests (Taiga) Lie ___

of the ____ Zone

taiga

boreal forest is also known as

coastlines nitrogen phosphorus

In oceans, photosynthetic activity tends to be

greatest near ____, where ____,

____, and other nutrients wash offshore and

fertilize primary producers.

2.3 miles

average ocean depth

Deep-sea Thermal Vent Communities

These communities are

based on microbes that

capture sulfur

compounds released

from thermal vents on

the ocean floor.

coral reefs

are among the

best-known marine

systems, because of their

extraordinary biological

productivity and their

diverse and beautiful

organisms.

clearing for coastal shrimp and fish farms

leading cause of mangrove destruction

2.5 1.2

Only __% of the water on Earth is freshwater.

Of that amount, only about __% is accessible

surface water.

surface

Near the ____ is a subcommunity of plankton,

mainly microscopic plants, animals, and protists.

water column

Fish move through the _______, sometimes

near the surface and sometimes at depth

bottom

_____ or benthos, is occupied by a

variety of snails, burrowing worms, fish, and other

organisms

Coastal wetlands

help buffer the forces of storms

open systems

streams and rivers are

biodiversity

the variety of living things

10-15

Of all the world’s species, only ____ percent live

in North America and Europe.

30 billion

Pharmaceutical products derived from developing

world plants, animals, and microbes bring in more

than $____ per year.

99

Studies

of the fossil record suggest that more than __

percent of all species that ever existed are now

extinct

Habitat destruction, Invasive species, Pollution,

Population of humans, and Overharvesting

HIPPO

habitat loss

The most important extinction threat for most

species—especially terrestrial ones—

Fish and Wildlife Service

Once a species is listed, the ____ is given the task of preparing a recovery plan

2/3

__ of listed species occur on privately owned

lands

20 m

The photic zone extends approximately how deep into the water?

75%

Oceans cover roughly how much of the Earth's surface?

invasive species

The exotic pet trade of Burmese Pythons and the release of overgrown "pets" into the Florida Everglades

34

What percentage of amphibians are currently endangered? __ %.

habitat destruction

Conversion of forests and grasslands into farmland

pollution

Chlorinated hydrocarbon pesticides such as DDT bioaccumulate in the food chain and decimate populations of predators such as the American Bald Eagle

6,120

The estimated value of one hectare of tropical rainforest in $USD is __ 

1,940

According to Figure 5.22, the Succulent Karroo is home to how many native species? __

overharvesting

Wild fisheries are in steep decline due to destructive and unsustainable harvesting practices such as bottom trawling