Living World Flashcards
Ecosystems, Tropical Rainforests, Hot Deserts
Ecosystem
An environment in which a community of plants and animals (biotic) interact with non-living (abiotic) things (eg, soil). Large ecosystems are called biomes (eg, tundra, desert, coniferous forest).
Producers/plants
Green plants that use photosynthesis and take nutrients from the soil, using their roots
Primary consumers/herbivores
Plant-eating animals
Secondary consumers/carnivores
Animals that feed on herbivores
Top carnivores
Animals that hunt and eat other carnivores in the ecosystem, as well as herbivores
Food chains vs food webs
A food chain shows only one path. A food web shows many food chains.
Weight of biomass decreases at each level in the food chain
- Animals don’t eat all parts of a plant or animal (eg, bones and roots)
- Much of what the predators eat is excreted
- 10% energy is lost at each level —> hunters use kinetic energy to chase and catch their prey. Herbivores search for plants to eat. Energy is also constantly used for respiration.
Decomposers
Decomposers return nutrients to the soil in the form of an organic substance called humus
Physical factors affecting balance of ecosystems
Imbalanced food chains; Hurricanes; Forest fires; Coral bleaching; Desertification; Climate change
Human factors affecting balance of ecosystems
Hedge row removal;
Eutrophication;
Deforestation
When one species increases or decreases in population…
When one species decreases in population, the population of its predator will increase because it is eating more of its other prey. The species’ prey increases because the prey has no predator. Vice versa occurs for increase of population.
Distribution and Characteristics of Tropical Rainforests
Located on the Equator between Tropics of Cancer and Capricorn —> Central America, northern South America, West Africa, South East Asia;
High temperatures (25º+) and heavy rainfall (2000mm+/year);
Humid, dense forest, rich in biodiversity —> half of world’s species
Distribution and Characteristics of Mediterranean
40º-45º North of Equator —> Italy, Spain, California, Morocco;
Temperatures range from 10ºC (in winter) to 30ºC (in summer), rainfall of 200-500mm;
Hot, sunny/dry summers, mild/moist winters;
Shrubs, low-lying vegetation —> adapted to drought conditions (eg, olive trees, dry herbs — rosemary)
Distribution and Characteristics of Deciduous Forests
25º-50º N/S of Equator —> Eastern USA, Western and Central Europe, North East Asia;
Temperatures range from -10ºC (in winter) to 20ºC (in summer), rainfall of 700-1500mm, well-defined seasons;
Broad-leaved trees, fertile soil enriched by decaying litter, trees lose their leaves during winter months, animals hibernate
Distribution and Characteristics of Coniferous Forests
50º-60º North of Equator —> Canada, Scandinavia (largest biome on earth);
Temperatures range from -50ºC (in winter) and 21ºC (in summer), snowfall of 100mm;
Evergreen trees, predators (eg, lynx, wolverines, minx)
Distribution and Characteristics of Savanna Grassland
40º-60º N/S of Equator, away from coasts/sea;
Dry for half the year;
Flat plains, limited vegetation, close to desert
Distribution and Characteristics of Deserts
15º-30º N/S of Equator, near Tropics of Cancer and Capricorn —> Africa, South West USA, Mexico, and India; Temperatures range from 50ºC (at day) and 0ºC (at night), rainfall less than 250mm/year; Little vegetation (can survive drought conditions and retain water, small animals that bury themselves in the sand
Distribution and Characteristics of Tundra
55º-70º North of Equator, coldest and driest biome;
Temperatures range from -70ºC to -28ºC, very windy;
Barely any vegetation, except for grass, bushes, no trees, some wolves, deer, hares, insects
Distribution and Characteristics of Alpine
North and South Pole;
Temperatures ranging from -40ºC to 10ºC, little precipitation, mainly as snow;
Most of ground is permafrost, creatures have thick layers and white fur
Why ecosystems are distributed globally
- Altitude — as altitude increases, temperatures drops
- Relief rainfall — windward side of mountain is wetter, leeward side is warmer as air is falling, ie. no clouds
- Ocean currents — warm ocean currents create evaporation and condensation, cold currents don’t, so it’s dry
Tropical Rainforest Examples
Amazon Rainforest, Congo Rainforest, Borneo Rainforest, Madagascar Rainforest, Queensland’s Tropical Rainforest, Ecuador’s Cloud Forest, Monteverde Rainforest, Sinharajin Forest, Sumatra’s Rainforest
TRF Climate
2000mm+ rainfall/year;
Average daily temperature of 28ºC;
Humid and hot atmosphere;
Climate is consistent all year round (no seasons)
TRF Soil
Not very fertile;
A thin layer of fertile soil where dead leaves decompose;
Red in color because it’s rich in iron;
Lots of leaching of the nutrients from heavy rainfall
TRF Plants and Animals
Warm, wet climate perfect conditions for plant growth;
Wide range of plant species supports many different animals, birds, insects;
Species have adapted to conditions
Structure of TRF
Emergent
Canopy
Under canopy
Shrub level
TRF Plant Adaptations: Lianas
Roots in the ground, climb up trees to reach sunlight, in the canopy
TRF Plant Adaptations: Tall Trees
Reach sunlight, bark is smooth to allow water to easily flow to roots
TRF Plant Adaptations: Drip Tips
Waxy surface, pointed tips to allow water to easily run off, prevents growth of algae which would block out sunlight
TRF Plant Adaptations: Buttress Roots
Shallow roots, expand surface area to get more nutrients, large roots also provide support for very tall trees
TRF Plant Adaptations: Stilt Roots
Shallow roots, provide support for tall trees
TRF Plant Adaptations: Leaf Angling
Leaved arranged as different angles to prevent shading its own leaves