Indianpipe –Monotropa uniflora

Tetraphis pellucida

Range size and abundance Ecologists have long suspected that a species that is widespread in its distribution may tend to be more common or abundant in its population size What causes such patterns? 1. sampling error 2. ecological specialization 3. local population model

Biomes A Biome is a large, relatively distinct terrestrial ecosystem characterized by particular climate, soil, plants and animals, regardless of where it occurs on earth A biome's boundaries are determined by climate more than by any other factor

Tundra

Tundra occurs in extreme northern latitudes where the snow melts seasonally (southern hemisphere has no equivalent) Tundra has long, harsh winters and very short summers - growing season is 50 to 160 days depending on location – summer days are long Tundra soils are young - formed after last ice age, nutrient poor, little organic matter - have permafrost - permanently frozen layer of soil

Taiga

Taiga - evergreen forests of the north Taiga is found in northern America, Asia and Europe - covers 11% of land Winters cold and severe - growing season longer than tundra - so greater than 160 days - little precipitation, about 50 cm (20 inches) per year Soil is acidic, mineral-poor, deep layer of poorly decomposed pine and spruce needles at surface Numerous lakes and ponds

Temperate rain forests

Occurs on northwest coast of North America, western Australia, southern South America, Japan very high precipitation to 380 cm (80 to 152 inches), much condensation from coastal fogs - little seasonal temperature variation - winters mild and summers cool Nutrient poor soil, but may have high organic content

Temperate deciduous forests

Occur where temperate zone precipitation ranges from 75 to 125 cm (30 to 50 inches) Typically have hot summers and cold winters soil has rich topsoil with much organic matter, deep clay-rich lower layer

Temperate grasslands

Occur where annual precipitation is 25 to 75 cm (10 to 30 inches) Summers hot, winters cold, rainfall is often sporadic soil is rich in organic matter, minerals build up in top layer of soil, dead organic matter from annual die-back of grasses builds up soil organics, grass roots may form turf or sod shortgrass prairies may be called steppes more rainfall than deserts but not much - 10 to 15 inches

Mediterranean ecosystems

Mediterranean - thickets of evergreen shrubs and small trees some temperate areas have climates with mild winters with abundant rainfall and very dry summers - called Mediterranean climates - occur around Mediterranean, California, western Australia, Chile, South Africa In California we call this ecosystem chaparral - soil is very thin and nutrient poor Fires are common, frequent in late summer, early autumn plants usually dense growth of evergreen shrubs, but may have short scrubby pines and oaks - often have sclerophyllous leaves - hard, small, leathery leaves that resist water loss

Deserts

Deserts are very dry habitats of both temperate and tropical zones - low water content of the desert atmosphere leads to wide daily temperature range deserts vary greatly depending upon amount of precipitation - usually less than 25 cm (10 inches) per year desert soil poor in organics, rich in minerals some deserts so dry have virtually no plant life - Namib and Atacama desert

Tropical savanna

Savannas are a tropical grassland which typically has widely scattered trees either low rainfall or seasonal rainfall with prolonged dry periods - often 85 to 150 cm (34 to 60 inches) Temperature doesn't change much - often in 80's or 90's Savanna soil is low in mineral nutrients Savanna found in Africa, South America and northern Australia

Tropical rainforest

Tropical rain forest occurs where temperatures are high throughout the year and precipitation occurs almost daily - annual precipitation may be 200 to 450 cm (80 to 180 inches) - much of the rainfall is locally recycled as water that enters atmosphere from transpiration quickly falls out again Soil is usually very old and nutrient poor, low in minerals and organics - decomposition and recycling is very quick due to high temperature and high availability of water extremely diverse forests

Distribution of Biomes in Current Climate

Possible Distribution of Biomes in Climate with CO2 Doubled