The Terrestrial Environment Terrestrial Environment Physical environment of

The Terrestrial Environment

Terrestrial Environment • Physical environment of land dwelling organisms. • ECOSYSTEMS are interactions between: – Physical environment (Soil, air) – Living things • Producers (plants) that make their own food during photosynthesis • Consumers – organisms that eat other organisms (plants and animals) • Decomposers (bacteria/ fungi) - organisms that decay remains of dead organisms.

Feeding Relationships • Food chains- feeding sequences amongst organisms in ecosystems. Producer Primary consumer Secondary consumer tertiary consumer Herbivore carnivores/ omnivores • Food webs are several food chains interlinked

SOILS • Formed from weathering of rocks by environmental factors: – Rain – Wind – Freezing – Thawing • Weathered rocks form small particles called rock waste. • Plant need soil for: – Anchorage – Nutrient minerals – Water – Air

SOIL COMPONENTS • Soil consists of 5 main components: – Mineral particles • Small rock particles – Air • Air spaces between particles with a mixture of gases – Water with nutrient ions • Found in spaces between particles – Humus • Organic matter or dead remains of plants and animals • Coats mineral particles so soil particles clump together. • Provides food for living animals within the soil. – Living organisms • Animals, plants and microorganisms (fungi, bacteria)

Soil Types Gravel Sand Silt Clay Particle size Bigger than 2 mm 0. 02 mm 0. 002 mm Less than 0. 002 mm Water drainage Very Free poor Poor Water retention Very Poor Good (waterlogged) Air spaces large medium small Very small

Discussion • Use the results to compare the soil types. Which soil type was the most abundant and which one was the least abundant? • What type of drainage do you expect this soil to have? Why? • How could the drainage be improved? • List some limitations or sources or error.

SOILS Physical weathering Chemical weathering • Temperature changes • Rock and mineral • Rain water particles dissolved by rain • Root action water

Soil Types • Sandy – Drain easily – Warm up quickly • Clay – Do not drain easily (waterlogged) – Do not warm up quickly • Loam – Mixture of sandy and clay – Drain freely but hold enough water for plants – Best type for gardens

Soil Types • Soils differ because: – It is formed by different rocks – Particle sizes vary • Water drainage and air spaces will vary – Humus content varies • Fertility depends on the amount of humus or organic matter in soil • Humus – Provides mineral ions for plants – Binds soil preventing erosion – Helps soil warm up quickly so seeds grow – Allows free drainage while keeping in some water

Soil Fertility and Crops • Soil must provide enough Minerals, Water, Air • Fertility is how well a soil can grow crops. – Constantly improved by • Adding natural, organic (manure) or artificial, inorganic fertilizers • Using good farming practices – Balance organic and inorganic fertilizer use – Crop rotation – Hedgerows ( mixture of large and small fields) – Liming soils (addition of Calcuim to improve p. H and soil structure)

Soil erosion • Removal of soil particles by wind, water or human activities (agriculture or development) Caused by coastal development… & removal of coastal trees

Caused by land clearing…

SOLUTIONS Build walls & silt traps Maintain vegetation

SOLUTIONS • Use good agricultural techniques – Contouring, benching or terracing – Wind breaks