B4.1 - abiotic variables and adaptations (5n) Flashcards
what is a habitat?
a habitat is the place in which a community, species, population or organism lives, including both geographical and physical locations as well as the type of ecosystem
what is a geographical location?
a geographical location is a point, line or area on the Earth’s surface, described by it’s site (physical characteristics such as topography (landforms), climate and vegetation) and situation (description of a places features by relating it to what’s nearby)
what is a physical location?
a physical location is the tangible place represented by the co-ordinates or the address
what are abiotic conditions on sand dunes?
dry and sandy
how is marram grass adapted to sand dunes?
- deep roots to reach damp soil at the bottom of the sand dune
- high salt tolerance
- wide temperature range
- horizontal roots (rhizomes) to stabilize the sand
- waxy cuticle on upper epidermis to prevent water loss
- hairs on leaves to reduce air flow near leaf and trap water vapour
- stomata in pits to trap water vapour
- rolled pits
how is marram grass adapted to prevent water loss?
- thick waxy cuticle on upper epidermis to prevent water loss
- hairs on leaves to reduce air flow near leaf and trap water vapour
- stomata in pits to trap water vapour
- rolled leaves
how do the rolled leaves in marram grass prevent water loss?
- it protects the lower epidermis from the wind, trapping water vapour
- this increases humidity, reducing the diffusion gradient and reducing transpiration rate
what are abiotic conditions that Red mangroves are adapted to survive?
red mangroves are adapted to survive with their roots in salty water that contains low concentrations of oxygen
what is a mnemonic for remembering adaptations of the Red mangrove?
SCOFS:
S - secrete salt from leaves
C - compartmentalise salt into leaves which drop
O - oxygen taken in by roots
F - filtering of salt out of water absorbed by roots
S - Seeds germinate and grow into a root before dropping
how are Red mangroves adapted to mangrove swamps?
Adapted roots:
- prop roots filter salt out of the water when taking water in.
- stilt roots have pores that take in oxygen at low tides.
Adapted leaves:
- salt-secreting glands form salt crystals on the leaf surface.
- salt is compartmentalised in older leaves that turn yellow and then fall.
Adapted seeds:
- seeds germinate while still on parent tree, growing a long root.
- this means that when the seed falls, they float until the root digs into the soil, ensuring they grow in shallow water.
what abiotic factors affect the species distribution of plants only?
- light intensity
- light pH
- light duration
- soil mineral ion concentration
what abiotic factors affect the species distribution of animals only?
- oxygen concentration in aquatic ecosystems
- breeding sites / territory
- food resources
What abiotic factors affect the species distribution of both plants and animals?
- water availability
- temperature
- wind intensity
- salinity of water in an estuary affecting water uptake
what is a zone of stress?
zones where species can survive the abiotic condition, but in lower numbers and often with lower biomass than within the optimal range
how do adaptations of species impact the range of tolerance?
the adaptations of a species give it a range of tolerances, meaning the species will be present in different numbers at each value in a given abiotic variable.
