Example: sand dune community Temperature & Water Foredune—very hot in summer, little water ▪ Grass adapted to conditions ▪ Long roots find water; leaves can curl to save water and resist heat Mature dune—much cooler, more moist ▪ More species diversity ▪ Example –“forest” floor--ferns (low light, moist conditions)
Light Grasses in high light ▪ Thin leaves reduce water loss, withstand heat Ferns – low light ▪ Wide leaves capture the small amt light / shade Soil pH pH varies among dune regions Yellow dune- soil pH 7.5 (grass here too, pH) Grey dune-decomposition of lots grasses, soil more rich, more acidic (acid-loving heathers here)
Salinity Foredunes get salt spray ▪ Grasses can tolerate it Grey dune less salty ▪ Small shrubs, mosses, lichen Mineral nutrients Grey dune – diversity of plants, older region, has mineral content to support shrubs, etc. Mature dune – way inland, lots of nutrient-rich soil, oldest region (soil building up 100s yrs), can support large trees (ash, birch, oak)
Example: Indiana Dunes, Lake Michigan Temperature Animals adapted for hot/cold temps Sand wolf spider: foredune dweller, extreme high temps—lives in deep burrow (behavioral adaptation) Woodland spider: live in trees (shade, cooler)-mature dune Water Water for eggs, aquatic animals for food Heron-catches fish/frogs, lives near water Woodpecker-eats insects in trees, lives in mature dune
Breeding sites Nesting sites Protection from sun, wind; mature dune, wetlands Habitat loss! Food supply Generalists, specialists Raccoons, skunks, foxes-move to where food is located; nocturnal Rabbits-burrows in foredune, near grass (food) Territory Packs of coyotes, scent to mark space May or may not overlap