Why is Casey special?

 

  • Less than 2% of the Antarctic continent is ice free rock or soil and therefore suitable for plants to grow.
  • The plant life at Casey is as good as it gets - Casey has the most extensive and best developed plant communities in continental Antarctica.
  • Mosses and liverworts are the highest plant form occurring naturally in continental Antarctica.
  • Although no large animals rely on moss for food, moss is home to many very small animals (invertebrates).
Bryum

What is here:

The plants at Casey can be divided into three groups:

1. Mosses and liverworts

During evolution these were among the first plants to inhabit the land. Unique characteristics enable them to survive drying and freezing. Very few plants can cope with these stresses which is why the Casey vegetation is so special.

Although mosses are really tough, they can only grow in the relatively wet areas around melt lakes and streams. Small moss patches also inhabit cracks in rocks and other sheltered areas where melt water is available.

Mosses and liverworts together form the group of plants called bryophytes. There are three species of moss in the Casey area –

Grimmia antarctici

Bryum pseudotriquetrum

Ceratodon purpureus

And one liverwort –

Cephaloziella exililflora

Click on image for enlargement
 
Ceratodon

2. Lichens

Some lichens are often mistaken for mosses. They can survive in very dry areas and are therefore widely distributed. Lichens are even found on exposed rocksurfaces close to the South Pole.

You can easily see lichens in the rocky areas around Casey. They can grow on most surfaces (e.g. rocks, soil and moss) and can survive on water in the air. Like mosses, lichens can survive long periods of desiccation. This is how they make it through the severe Antarctic winters.

3. Terrestrial and snow algae

These plants belong to the same group as seaweeds. You will often see them in the nutrient rich areas around penguin colonies.

Terrestrial algae thrive in the salty coastal areas where mosses and lichens cannot grow. Prasiola crispa (a species of terrestrial alga) grows as a green mat and is often mistaken for moss. It looks like sea lettuce.

Snow algae are similar to the algae that cause blooms in river and marine systems. They are colonies of microscopic algae, which reproduce rapidly in the snow when nutrient and temperature conditions are right. Snow algae come in both attractive (red and green) and unattractive (grey and yellow!) colours and occur in different places each summer.

All line drawings by Garry Mayo.
Grimmia

Where are the plants?

Mosses and lichens grow on rocky outcrops, although mosses are more common in lower lying regions which receive melt (e.g. along melt streams and on the edge of melt lakes).

Where possible, keep to snow covered areas. Avoid edges where snow is thin as you may break through to underlying moss.

Don’t drive on rocky areas. If on foot stand on clear rocks. Avoid lichen covered rocks and be careful not to step on moss growing between rocks.

LICHEN MOSS
Distribution of mosses and lichens at Red Shed site.

How to avoid damaging the plants:

Lichen species are often more visible than the mosses because they inhabit rock surfaces. Moss is more likely to be hidden under snow BETWEEN the rocks.

ON FOOT:

As a general rule when walking in rocky areas, stick to clear rock surfaces. Moss growing between rocks may be damaged if you step in such places (even when there is some snow around).

IN VEHICLES:

Whenever possible, always stay on the snow, never drive over rocky areas. Stick to the deepest snow areas, avoiding snow edges and slushy areas where tyres may break through and damage the moss below.

WORKING IN MOSS HABITATS:

It is obviously harder to avoid damage to plant life when working in lush areas (such as out the back of the red shed, Robbos and the SSSI’s) but it is definitely worth the extra effort. Try to avoid entering over moss beds, stick to the areas of thickest snow cover. Be careful not to leave any off-cuts lying around.
INDEX | DIARY 98 | SCIENCE 98 | MOSS HABITAT | MONTHLY UPDATES

Disclaimer
 
November 1998
Direct site & design comments to:
Andrew Netherwood