Biomes and Ecosystems Flashcards
Broad categories of living systems
defined mainly by climate
Biomes
what do biomes vary in
biodiversity, productivity, structure
vegetation zones defined by altitude
Vertical zonation
what are communities shaped by
temperature ranges, availability of moisture (precipitation)
biome with abundant rainfall; warm and hot temperatures all year
tropical rainforests
soil in tropical rainforests
thin, acidic, nutrient-poor
90% of nutrients in organisms
Distinct wet and dry seasons
drought-deciduous trees/shrubs
More agriculturally productive than moist forests
highly endangered
tropical seasonal rainforests
trees that lose leaves and cease growing with low water availability
drought-deciduous trees
grassland with sparse tree cover
savanna
rainy season- less abundant/dependable
dry season- risk of fires
plant adaptations- deep, persistent roots
threat- grazing from livestock
Tropical savannas & grasslands
extreme hot and extreme cold temperatures
low and sporadic precipitation
plant adaptations are drought-deciduous
animal adaptations- nocturnal; concentrated excrement
deserts
biome with enough rain to support grass; not enough for a forest
deep, persistent roots (like plants in the savana)
produces thick, organic-rich soils
main threats: agriculture, overgrazing
temperate grasslands
broad-leaf forests
trees lose leaves in winter
dense canopy in summer; diverse understory in spring
Greatest threat: rapid deforestation
deciduous forests
evergreen forests
often occur with limited moisture
in pacific coast: known as temperate rainforests (cool, rainy, fog)
pines, spruce, fir, etc.
coniferous forests
dominated by conifers w some deciduous trees (low species diversity due to allelopathy)
extreme cold, short summer (limit growth rate of trees)
boreal forests
below freezing temperatures most of the year
high latitudes or mountaintops
low productivity (short growing season, frost any month of year)
low diversity
not directly threatened (indirectly affected by climate change and air pollution)
tundra