Rabbits compound the problem by preventing the natural regeneration of trees. In the past decade the return of Wallabies (whose prefer shrubs to grass have also made it harder to establish vegetation.
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Always More to learn |
| As with most things in life creating a
National Park ain't easy. Its far better to leave things the way they are
than to try to fix them up later! One of the big problems the Organ Pipes
is facing at the moment is dying trees. The unfortunate fact is that most
of the species of Wattle tree have a life span of up to 20 Years. Large
areas of the park were planted at the same time and subsequently many of
the trees in the park have reached the end of their life span.
Rabbits compound the problem by preventing the natural regeneration of trees. In the past decade the return of Wallabies (whose prefer shrubs to grass have also made it harder to establish vegetation. |
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This is a common site in the park. Note the cancerous
growths on this sickly looking tree. This tree is infested with galls, in
this case of the fungal variety. Unfortunately these galls have taken hold
on the majority of Acacias in the park. What impact this may have on the
nectar dependent birds and Sugar Gliders in uncertain.
Activity: Have your students examine a tree infested with galls. Ask for theories on what is causing these mysterious lumps. |
| Another concern is the band of
Allocasuarina trees (common name - She oak) that occur on the top of the
escarpments. It is thought that they were planted in the park more densely
than they would have occurred naturally. The problem is (as with many
species in the park) that they are not reproducing naturally. Having a
stand of trees the same age will mean that they all reach the end of their
life at the same time. Trials have been undertaken by the Friends group to
see what is preventing the natural regeneration of these trees. Activity: Have your students design a trial to test what factors are preventing the regeneration of she oaks, make sure they include and experimental control. |
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This Photo on the left shows the abundance of cones that
the Allocasuarina trees drop on the ground. Surely it cannot be lack of
viable seed that prevents them from reproducing.
Exclusion fencing like that shown on the left has been used to see if that can help explain the lack of regeneration! |
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This Photo is of the main flat, an alluvial plain. The trees here were
most likely planted too close together as well and need to be thinned out.
It was unlikely that the forest would have looked like this originally.
Part of the problem is that the previous under-storey of Acacia trees
recently had a mass death when they all reached a certain age.
Activity: Summarize some of the problems that are faced with recreating an ecosystem after it has been destroyed. Suggest some ways that re-vegetation practices used at Organ Pipes could be improved. |