Last week this blog concluded with a series of photographs that gave some indication of how the eradication of invasive alien trees can trigger a return of indigenous biodiversity that they have displaced.
This week we take a look at the effect that clearing of invasive plants can have on water availability. I owe a thank you and an acknowledgement to Jonathan Voss for the letter and the photographs that follow.
Jonathan lives at #1 Castle Rock, which is about a kilometre from Blue Gums, making Jonathan one of my closest neighbours.
1 Castle Rock
This is a smallish plot that is very close to the boat club at Miller’s Point. As such it is almost on the northernmost boundary of one of a cluster of conservancies in the deep South Peninsula. The Conservancy is called Castle Rock Conservancy and was officially established in 2009. We will return to the Conservancy in future posts. In the meantime, here are the observations of its Deputy Chairperson, Jon Voss himself. The letter was written in late Summer (Feb 2012), at the driest time of the year and in one of the driest seasons in quite a while. Jon wrote the letter after the Conservancy’s members had agreed to clear the main watercourse in the area, which provides water to several of Castle Rock’s houses.
Hi everyone,
The task has been completed! For the moment anyway.
The cutters and stackers spent 10 days in a grueling battle against the alien infestation.
Dense Stands of Hakea and Port Jackson on the northern edge of the Conservancy
The gully has been cleared from the spring all the way up the mountainside to where the natural vegetation takes over (about 300m). It’s quite amazing how the infestation peters out very quickly at a certain altitude – one moment you’re in a thick impenetrable mass of Hakea, Rooikranz & Port Jackson, the next moment you step into the beautiful indigenous vegetation of proteas and fynbos!
The Thick Impenetrable Mass
The gully is very stark at the moment but indigenous flora should re-establish fairly quickly and we will in any event monitor on a regular basis to ensure that the nasties don’t reappear!
The Gully After Clearing – Looking out to Sea
The Gully After Clearing – Looking up to the Mountainside
I took a walk up to the spring at 15h00 on Sunday to clean the catchment bin and was very pleased to see that the water was gushing from the spring. Normally at this time of year the spring dries up during the day and slowly starts flowing again after sunset. So it really goes to show just how much of our precious water was being sucked up by the aliens.
Water Gushing into the “Heath Robinson” Catchment Tank – 3pm on a Late Summer’s Day
bluegumsfree 
June 22, 2012 at 1:43 pm |
Would love to received updates on this, as we wish to do something similar along the Breede.
Heather