ch 57: biosphere

what is the biosphere

includes all living communities on earth

sunlight, temperature, wind, water, ocean circulation, elevation, and topography

factors that impact the conditions observed within the biosphere

how does sunlight-angle of incidence impact energy received from the sun

determines how directly sunlight hits earth. more direct sunlight = more energy and warmer climates

how does earth’s orbit impact energy received from the sun

create seasons

what are circulation patterns

basic flow of air currents around the globe, relationship between temperature and air density

how does circulation patterns help support the various ecosystem types

warm air rises and cool air sinks → creates circulation patterns that influence rainfall, deserts, and ecosystem distrubution

water-basics of ocean circulation

moves heat and nutrients around earth and affects climate and marine ecosystems

regional and local effects, esp topography, that impact environmental conditions and ecosystem types

mountains and landforms influence rainfall, temperature, wind, and local climates

elevation - relationship to temperature, precipitation, ecosystem types, and rain shadows

decreases with elevation. mountains create rain shadows where one side receives rain and other is dry

continentally - impact of large continents (monsoons)

heat and cool differently than oceans, creating monsoons and seasonal wind shifts

a major terrestrial ecosystem defined by climate and vegetation

biome

what abiotic factors dictate which biome will be present

temperature and precipitation

warm/wet climates

support forests

cold/dry climates

support tundra or deserts

water and temperature control what

photosynthesis, productivity, and organism survival

what does temp and precipitation not account for in terms of variation within regions and within similar biomes in diff parts of the world

for local differences like spil, elevation, microclimates, or species interactions

what defines/differentiates biomes

differ mainly in climate, vegetation, and productivity

what organisms are likely to inhabit biomes and how do human actions impact their community composition

deforestation, agriculture, pollution, and climate change after biodiversity and species composition

tropical rainforest

warm and wet year-round with extremely high biodiversity and productivity

savannah

tropical grassland with seasonal rainfall and scattered trees

temperature grassland

moderate rainfall, rich soils, dominated by grasses, adapted to fire

deserts

very low precipitation with organisms adapted to conserve water

tundra

cold biome with low precipitation and permafrost

temperature forests

seasonal climates with rainfall

taiga

cold conifer forests

freshwater habitat

aquatic habitats with low salt concentration such as lakes, ponds, rivers, and wetlands

marine habitat

saltwater ecosystems covering most of earth’s surface

photic zone

light penetration/photosynthesis

littoral zone

shallow edges

aphotic/benthic zone

deep dark bottom

thermal stratification

layering of warm and cold water caused by density differences

oligotrophic

low nutrients, high oxygen, clear water

eutrophic

high nutrients, algae-rich, low oxygen

oceanic zones and productivity

open oceans have low nutrients and low productivity

continental shelf ecosystems and their biodiversity

shallow nutrient-rich waters with high biodiversity and productivity

banks and their ecological importance

are productive fishing areas

coral reefs and their ecological importance

support extremely high biodiversity

esturaries

mix freshwater and saltwater and are highly productive ecosystems

deep sea habitat

cold and dark

hydrothermal vents

support life using sulfur-oxidizing bacteria instead of sunlight

human impacts on the biosphere and their consequences for biodiversity: pesticides

DDT biomagnified in food chains, thinning bird eggshells, and reducing bird populations

water pollution and runoff pollution

cause eutrophication and oxygen depletion in water systems

deforestation and habitat loss-rainforests, prairie, and others

habitat destruction reduces species richness, disrupts food webs, and increases extinction risk

changes in fire frequency and intensity due to human activities and fire suppression

alters natural fire cycles, changing ecosystem structure and species composition

zoonotic disease proliferation and spreading

human contact with wildfire and habitat disruption → spread of disease from animals to humans

ocean pollution - acidification

increased by CO2

ocean pollution - impact on corals

harms corals and shell-forming organisms

ocean pollution - microplastics

contaminate marine ecosystems

how does human impacts change ecosystem stability and resilience to natural disasters such as hurricanes and erosion

destruction of wetlands, forests, and coral reefs reduces protection against storms and erosion

ozone depletion

reduction of stratospheric ozone caused mainly by CFCs, increasing harmful UV-B radiation

CO2’s role in temperature regulation

traps heat in the atmosphere through the greenhouse effect

how have global temps changed over earth’s history since the industrial revolution and why

they have risen rapidly due to fossil fuel emissions

what changed with temperature and how does this impact biodiversity and ecosystem properties

increased greenhouse gases causes warming, habitat shifts, coral bleaching, altered migration, and biodiversity loss

what are the impact of climate changes and how do they impact facets of biodiversity and human society

affect species ranges, agriculture, flooding, disease spread, extreme weather, and ecosystem stability

how do global warming impact aspects of ecosystem dynamics, population ecology, and community ecology, to bring out the decline in biodiversity we observe

alters habitats, shifts species ranges, changes perdator-prey interactions, disrupts food webs, increases extinction risk, and changes population dynamics faster than many species can adapt