|Changes in Yorkeys Knob Beach 1952-2015 (click here to enlarge)|
The growing width of Yorkeys Knob Beach provides more than a happy story of how a beach was saved, it is a chance to answer a swag of questions about how coastal features form as they have literally been forming in front our photographic eyes. These questions are important to land management as well as being scientifically interesting. Developers like to claim that dense coastal vegetation is just regrowth and that they should be able to remove some of it to create views. Dense vegetation developing where previously there was open sea could affect the public by blocking cooling sea breezes and possibly by allowing increased mosquito activity. Conversely, a wider beach with dense vegetation provides a much better buffer against storms. Scientifically interesting aspects include the development of landscape features such as chenier ridges form and how and why some areas become impoverished grassland yet metres away a ferny rainforest is created. Topics of scientific interest will be covered in future posts.
In overview, it appears that between 2002 and 2008, the beach got wider by approximately 5 metres per year. From 2008 to 2016, the position of the beach has been stable as sand is now able to escape around the rocks at the northern end of the beach. Recently the beach has been getting higher rather than wider, with the foredune growing about one metre in height. As the beach grew, a series of small ridges and swales were created that are now stabilised by dense grass and herb cover. In places trees colonised, mostly in lines that were probably created by high tides washing seeds up onto the foredune. Many of these seedlings have grown to become trees that are approaching maturity. In places the dense wall of regenerating trees is lifting off the ground and an open understorey is developing where is breezy and open but shady.
|2010 (left) and similar 2016 views (right). The foredune has become much higher and has continuous vegetation|
|Top: Tridax daisy and Mossman River Grass (the nasty one)| Bottom: Singapore daisy and Hyptis|
|Coverage of geotagged photos - you can never have enough|