Ecology- Ch 1 and 2

Temperature and Precipitation

Biomes are strongly influenced by?

Tundra

Climate diagram shows low precipitation Moderate temperatures (due to proximity to sea) More below freezing (not shaded) months Short growing season

Urban Ecology

New discipline in ecology that studies urban areas as complex, dynamic ecological systems influenced by biological, physical, and social components

Aeroecology

New discipline of ecology that studies the earth-atmosphere boundary ex: technology in ecology such as drones

Warm

Temperature begins at 0C in climate diagrams for ____ climates

Biomes

Tropical rain forest, tropical dry forest, tropical savanna, desert, Mediterranean woodland, temperate grassland, temperate forest, boreal forest, tundra, mountains

Mediterranean Woodland & Shrubland

*Climate:* fall, winter, and spring are cool and moist; summer is hot and dry; fires are common due to hot/dry summers *Soils* low to moderate fertility, fragile *Biology:* highly diverse, organisms exhibit adaptations to drought (evergreen trees with small, tough leaves); plants fire-resistant (i.e. thick fire resistant bark); many plants die-back during summer (to avoid hot)

Tropical Rain Forest

*Geography:* most occur within 10 degrees latitude N or S of equator; wettest place on earth located in this biome *Climate:* warm/wet all year; little variation in temperature; precipitation often exceeds 100mm/mo *Soils:* heavy rains cause leaching, rapid decomposition of organic matter, soils often nutrient poor/low in organic matter *Biology:* very diverse, highly productive, dominated by large trees (can reach 80m), 1 acre may contain 300 tree species, organisms evolved to use all levels

Desert

*Key determinant:* evaporation > precipitation for most of year Extreme events: drought, flash floods, high temperatures Occupy 20% of earth 2 main bands: at 30N and 30S (subtropical air descends drying the landscape) Highest recorded temperature: Death Valley (134C in 1913)

Boreal Forest (taiga)

*Soils:* low fertility, thin acidic; low temperatures maintain slow decomposition; nutrients tied up in plant litter in forest floor *Biology:* dominated by coniferous trees (fir, spruce), many large mammals (caribou, reindeer, wolves, black and grizzly bears), small mammals (lynx, wolverine, red squirrels)

Temperate Forest

*Soils:* usually fertile; generally more fertile in deciduous dominated forests *Biology:* diversity of trees < tropical forests; but biomass can be greater; vertically stratified (due to high canopy); understory has shade-tolerant shrubs

Mediterranean Woodland & Shrubland

-Climate of ancient greece; mild climate (high biological richness), occur on all continents except Antarctica; common around Mediterranean Sea and SW part of US (between 30-40 latitude) Alternative names: Chaparral (western N. America), Matoral (Spain), Garrigue (eastern Mediterranean), Fynbos (S. Africa), Mallee (Australia)

Temperate Grassland

-North American prairie; largest biome in North America Wetter than deserts (but do have droughts); do not have distinct wet/dry periods like Mediterranean scrubland; winters cold and summers hot *Soils:* often deep, fertile, with lots of organic matter *Biology:* dominated by herbaceous vegetation, high summer temp, encourage fire, supported huge herds of bison and pronghorns in N. America

Sample ecological questions

-Why do zebras have stripes? (not predatory but thermoregulatory)

General Rules of Climate Diagrams

1) When precipitation exceeds temperature: adequate conditions for plant growth (blue line is above the red line) 2) When temperature exceeds precipitation: potential evaporation exceed precipitation causing dry periods (red line is above the blue line) Can use these to help identify seasonality/ biomes

Solifluction

Annual freezing thawing slowly moves soil down slopes Ex: found in tundra

Deserts

Beige shading indicates temperature (red) line is above the precipitation (blue) line indicating dry conditions can show which biome

Distinct wet and dry periods

Beige shading shows dry conditions during warm months (months shaded red) but has blue shading showing temperature lines (red) fall below the precipitation (blue) lines during cold months to show wet conditions can indicate which biome?

Wettest Place on Earth

Cherrapunji, India; receives 500 in of rain per year 15x amount of precipitation received in Arlington It's located in a tropical rain forest

Tropical Savanna

Climate Diagram shows all months shaded red (above freezing all year round) Alternates between wet (blue shading) and dry (beige shading) seasons; but the wet season is shorter and drier Similar to tropical dry forests Constant temperature but shorter magnitude of the wet season

Tropical Rain Forest

Climate Diagram shows all months shaded red (above freezing all year round) Annual variation in temperature is slight Precipitation exceeds temperature (blue above red line)= moist conditions Dark blue and light blue shading= wet seasons Located in northern hemisphere: jan-dec

Mediterranean Woodland and Shrubland

Climate Diagram shows all months shaded red (above freezing all year round) Moderate temperature all year round Shows summer drought (beige shading) Shows moist, cool wet seasons

Tropical Dry Forest

Climate Diagram shows all months shaded red (above freezing all year round); but temperature more variable Alternates between wet (blue shading) and dry (beige shading) seasons Located in southern hemisphere: june to july

Temperate Forest

Climate Diagram shows: Seasonal drought (beige shading) associated with coniferous forests Moderate variation in temperature (not all months shaded red) Deciduous forests associated with low seasonal variation in precipitation/ Deciduous- decent precipitation all year

Boreal Forest (Taiga)

Climate diagram shows: Great Temperature variation; modified temp and precipitation scales reflect cold, dry climate Proximity to sea moderates temperatures Growing season limited

Temperate Grassland

Climate shows temperatures below (not shaded) and above freezing (shaded red)- not all months are hot Maximum temperatures and precipitation coincide Winters usually cold and dry Blue above red line= more precipitation, wet seasons

Boreal Forest (Taiga)

Covers 11% of planet, confined to N. hemisphere, located in between temperate grasslands/forest and tundra Winters longer than any of the previous biomes, short summers Moderate amounts of precipitation: 200-600mm; low temps and long winters maintain low evaporation

Tundra

Covers most land north of arctic circle Cold and dry Shorter summers than boreal forest, Precipitation: 200-600 mm *Soils:* slow decomposition, consistent freezing/ thawing cycle, unique soil process (solifluction) *Biology:* dominated by herbaceous plants (grass, moss, lichens); imported food for grazing mammals, still supports large populations of native animals

Rain Forest

Darker blue shading indicates shift in scale meaning wet seasons; shaded (light) blue because precipitation line (blue) lies above the temperature line (red) to indicate moist conditions can show which biome

Tropical Dry Forest

Distinct wet and dry seasons; often found N and S of rain forests (between 10-25 degrees latitude) *Soil:* generally have more nutrients than rain forests; high vulnerability to erosion *Biology:* canopy height correlated with precipitation; many organisms migrate seasonally during dry season (to wetter area), not as diverse as rainforests

Increases

Ecology _____ in ecological capacity Biosphere- Region- Landscape- Ecosystem- Community- Interactions- Population- Individuals

Present

Ecology can transcend the study of observations in the ______ ex: paleoecology

Question Driven

Ecology is _____ ______ Studies are designed based upon: -scientific question -temporal/ spatial scales -research tools available -data collection and analysis

Temperate Forest

Giant Sequoia: largest trees by volume, grow to avg height of 280 ft, 26 ft in diameter Found between 30-55 latitude, North America: found from Atlantic coast to great plains, NW, even up to Alaska Moderate temperature ranges Precipitation: 650-3000mm When winters mild: deciduous trees dominate When winters severe: coniferous trees dominate

Shape of the Earth

Influences spatial variation in temperature due to being a globe

Tilt of the Earth

Influences spatial variation in temperature due to increased solar radiation causes summer and hot seasons in the northern hemisphere but the opposite in the southern hemisphere But as the northern hemisphere faces away from the sun it has winter and cold temperatures but the opposite in the southern hemisphere

Shape of the Earth and Tilt

Key factors that produce common patterns of climate variation?

Natural History

Knowledge of ____ _____ is often used to guide the field of ecology Forms the basis of ecology

Deserts

Mean annual precipitation lower than any other biome Hot all year round with constant dry seasons (beige shading and red line above blue line) Shows low precipitation Above freezing/ hot all year round (all months shaded red)

Deserts

Not all _____ are the same -Some receive very little rainfall (Sahara) while others experience significant rainfall -Some deserts can be very cold: average winter temperatures in Gobi Desert can approach -20C Extremes in precipitation: parts of Sahara desert avg 0.3, Sonoran receives 300mm *Soils:* low in organic matter, contain high salt concentrations, salt in soil increases aridity *Biology:* low in plant cover; plants exhibit many specialized adaptations to minimize water loss (spines, only producing leaves during rainfall), no leaves, seed dormancy); animals use behavior to avoid extreme heat (nocturnal during summer but active during day in winter)

Robert Macarthur

Pioneer in ecology; theory of island biogeography (quantitative count number of birds and competition) Observation: 5 species of warblers inhabit the same trees Question: How do species coexist? Multiple species in same habitats via niche divergence

Solar Radiation

Precipitation levels also depend, in part, on the amount of ____ ____ Near equator: increased direct sunlight, air rises, cools, and then condenses causing loss of moisture to produce heavy rainfall (but also dry seasons) in the tropics Air devoid of moisture moves north or south to much dryer areas such as deserts

Theory

Predicts that species with the same ecological requirements will lead to competition and eventual exclusion

All year round

Red shading of all the months indicates that average minimum temperature is above freezing?

Climate Diagrams

Represent a way to visualize temperature and precipitation; also a way to identify biomes Temperature is on the left and precipitation on the right If location is in N. Hemisphere: goes from Jan.-Dec./ If in the S. Hemisphere: goes from June-July Red line= temperature Blue line= precipitation If blue line is above red line: net (+) productivity in the environment such as plant growth i.e. wet conditions If red line is above the blue line: increased evaporation i.e. dryer conditions Red shading in the months= above freezing (0C) No shading in the months= below freezing

Natural History

Study of how organisms in a particular area are influenced by factors such as climate, soils, predators, competitors, and evolutionary history To make hypotheses & collect data, need to know how organisms interact in the environment

Cold

Temperature scale originating below 0C in climate diagrams depicts ____ climates (months not shaded to show below freezing)

Ecology

The study of the relationships between organisms and the environment (and the solutions to the problems within their environment) Simple definition; broad scientific discipline

Paleoecology

Tracks changes over long periods of time; uses past patterns to make inferences over time Ex: lake sediment accumulates over time (can study contents to quantify changes)

Tropical Savanna

Tropical gradients with scattered trees, Most occur N or S of tropical dry forests (in Africa S of Sahara desert/ In South-Central Brazil, much of Venezuela); fewer trees Less Trees due to: fires (summer storms have intense lightning that causes fires and kill young trees but grasses quickly rebound) and soils *Soils:* low permeability (keep water near soil surface), trees cannot thrive in waterlogged soils, also reason why they persist in dry areas *Biology:* most activity on/near ground level; the few tree species are usually fire resistant; populated by wandering animals that move in response to seasonal variation in food and rainfall (most mass migratory events ex. > 1.5 million wildebeests each year)

Physiological Ecology

how organisms are physiologically adapted to their environment Sub discipline of ecology at the individual level Ex: how do organisms deal with flying at the same altitude as fighter jets

Behavioral Ecology

the study of the ecological and evolutionary basis for animal behavior Sub discipline of ecology at the individual level Ex: males are pretty and display reproductive behaviors versus fighting