Terrestrialo Flashcards
Describe how animals may be adapted to cold environments:
Thick fur/ fat layers (arctic wolves, polar bears)
Torpor (temp hibernation) (leadbeaters possum)
Hibernation (burramys)
Behavioural patterns (penguins huddling)
Describe how plants may be adapted to cold environments:
Low streamlined shape (cushion plants)
Hairy leaves
Deciduous leaves (oak)
Describe how animals might be adapted to hot, dry environments:
Aestivation (desert frogs)
Life cycle with resistant stages during the dry season (many insects)
Burrowing (frogs, lung fish, bilby)
Migration (bogong)
Nocturnal activity, crepuscular activity and day time torpor (kangaroos)
Concentrated urine (reptiles)
Describe how plants may adapt to hot dry environments:
Annual life cycle (everlastings) Small leaves, leaves with thick cuticle and rolled edges (Triodia) Hairy leaves (banksia) Succulence (Crassula) C4 photosynthesis (portulacca) Thick cuticle (hakea) Stomata in grooves (casuarina) Resurrection properties (moss)
In an arid area what are the advantages and disadvantages of a succulent growth verses a twiggy shrub?
Succulent: advantages - stored water allows metabolism to continue in dry weather (if linked to C4 photosynthesis enables stomata to be closed during the day)
Disadvantages - attractive to herbivores
Twiggy shrub: advantages - low surface area, small leaves/low evaporative surface, unattractive to herbavores.
Disadvantages - small photosynthetic area to use when growing conditions are good
Biomes are described as discrete entities in the world. Is that justified?
Yes. Biomes provide a useful classification of vegetation types, although drawing the exact boundaries between them can be difficult as there is rarely a sharp boundary, more often a gradation between types.
How can population viability analysis be used to assist in the management of a threatened species?
PVA (population viability analysis) modelling is a system that integrates demographic, genetic and environmental data to predict the likely future population size under different management options. In setting up the model often gaps in knowledge are identified.
What limitations are there to using only a threatened species approach to conservation?
Critical components or interactions in the community may be missed such as pollinators or seed dispersal agents for plants. The same conservation effort might be more usefully applies to conserving a community with acceptance that loss of some species may occur.
What issues must be considered in setting size and shape of conservation reserves?
Only large areas that can support sufficient numbers of large, wide ranging, low density species to maintain long term population and that they can also support large numbers of species. Large reserves also minimise the ratio of edge to total habitat. Species averse to conditions at the edge will have more habitat available to them in large reserves. On the other hand, the rate at which the number of new species is added to a reserve tends to decline as total area increases. The optimum shape is rounded, rather than a long linear reserve because this maximises the ratio of the area of the reserve to its perimeter and minimises edge effects.
How does the conservation of Leadbeaters possum illustrate the need to understand thoroughly an organisms basic biology before recommending conservation measures and the importance of legislation to encourage and enforce conservation action?
It was incorrectly assumed that possums would recolonise regenerated logged areas as their food was available in those regions. It was found that nesting hollows in old trees are essential so areas must be protected from logging to provide suitable hollows. Similarly post fire logging should be restricted as fires help to create hollows. Corridors of undisturbed vegetation are necessary to link sites together.
Legislation was necessary to protect the areas needed from logging.
What evidence is now available that outbreaks of crown-of-thorns starfish on the GBR are encouraged by human activities?
High nutrient load in runoff from agricultural areas encourages algal growth on coral reefs which in turn supports higher survival of starfish larvae.
