Adaptations to environment

habitat

• the place in which an organism, a community or a population lives

  • refers to the geographical location, the type of ecosystem and physical location

adaptations to abiotic environment

• all organisms are adapted to their abiotic environment, seen clearly in plants that live in extreme habits e.g sand dunes and mangrove swamps

• grass & sand dunes

  • has rhizomes (underground stems) that grow deep into the dune to obtain water

• trees & mangrove swamps

  • swamps are flooded w/ seawater at high tide

  • as a result, trees have salt glands on leaves to secrete excess salt

  • cable roots grow close to the soil surface, where there is the most oxygen

species distribution and abiotic factors

• distribution of a species (where it lives) can be limited by abiotic factors

• factors affecting plant distribution:

  • temperature

  • availability of mineral nutrients

  • soil pH

• factors affecting animal distribution

  • water availability

  • temperature

• adaptations of a species give it ranges of tolerance

measuring ranges of tolerance of abiotic factors

• if a species is unable to grow in an area because the level of a variable is outside the range of tolerance, that variable is a limiting factor

• to measure this, transects are used:

  • measure the abiotic variable

    • using electronic sensors or data loggers

  • measure species distribution

    • number of individuals touching the transect are recorded

formation of coral reef

• coral reefs can only develop where conditions are suitable for hard corals,

  • depth

    • less than 50 m, so light penetrates for zooxanthellae photosynthesis

  • pH

    • alkaline, so CaCO3 can be deposited in skeleton

  • salinity

    • between 32-42 parts per thousand of dissolved ions

  • clarity

    • clear water to allow light penetration

  • temperature

    • 23-29 C so coral and zooxanthellae remain healthy

terrestrial biome distribution

• with given combinations of abiotic factors (usually temp and rainfall), a particular time of ecosystem is likely to develop

• all ecosystems of a specific type are biomes

biomes

• groups of ecosystems that resemble each other, due to similar communities because of similar abiotic conditions and convergent evolution

• major biomes:

  • temperate forest

    • temperature moderate with cold winters and warm summers, medium rainfall

  • grassland

    • medium/high temp in summer, cold in water, moderate rainfall w/ a dry season

  • taiga (boreal forest)

    • low temps with short summers, medium/high rainfall

  • tundra

    • very low temps with very short summers, more snow than rainfall

adaptations to life in hot desert

• hot desert

  • very high daytime temp and colder nights

  • little rainfall, long droughts,

  • very little soil development

• adapted species: fennec fox

  • nocturnal so avoids high daytime temps

  • long thick hair for insulation in cold nights and hot days

  • pale coloured cot that reflects sunlight

  • longer loop of henle to reabsorb more water

adaptations to life in tropical rainforest

• tropical rainforests have:

  • high light intensity

  • high temps

  • much rainfall

• adapted species: yellow meranti tree

  • grows over 100 m tall to avoid competition for light

  • smooth trunk to shed rainwater rapidly

  • trunk thickened at base to support against shallow soil