phyllode Posted December 21, 2011 (edited) it is true that they probably did effect some ecosystems in a negative way by drying up some of the less arid environments, causing certain animal and plant species to be come extinct. I don't have references handy, but the extinction of the megafauna by humans has been discounted by most scientists, and is now attributed to climate change. Recent CSIRO investigations showed that 'burning off' by indigenous australians was far less frequent than europeans had assumed, and serious bushfires increased dramatically after european arrival. I say humans generally are the problem. Weeds are guarding the soil. It's us who let them and the environment 'go'. Edited December 21, 2011 by phyllode Share this post Link to post Share on other sites
Quetzalt Posted December 21, 2011 (edited) OH, has the forum stoped emailling and forwarding topic discussions? I didn't realise the discussion had been going on and was still expecting someone to identify for me the invasive acacia photo I posted (anyone?)... Anyways, we all know what an invasive species can do and all is well while the 'system' manages to balance itself naturally... There are many choices and I could even go for all I 'm just trying to weight them and choose the appropriate/ best. I'm a perfectionist but so far form perfection... Hurray, PD is sending me some phlebs, lets see if I've got green hands (and if I found another invasive sepcies:) Lol E.Genius, so full of seeds it almost fell over That's "The" reproductive power. I remember a friend who when he was a kid used to plant weeds and crazy plants/ flowers all over his unfriendly neighbour's front gardens Maybe you've got kids like that in Germany? Edited December 21, 2011 by Quetzalt Share this post Link to post Share on other sites
phyllode Posted December 22, 2011 Your "invasive" acacia appears to be A. auriculiformis. Web search for interesting tentative contents found by Trout. It is quite "invasive" in it's native habitat. Share this post Link to post Share on other sites
Quetzalt Posted December 30, 2011 I had a look and A.Auriculiformis has quite a diferent seed pod.... Thanks anyway Share this post Link to post Share on other sites
phyllode Posted January 3, 2012 (edited) Have you got a better photo? How are the pods different? They can vary in twistedness. The other similar candidate would be Acacia aulacocarpa. Edited January 3, 2012 by phyllode Share this post Link to post Share on other sites
Synthase Posted January 4, 2012 I don't have references handy, but the extinction of the megafauna by humans has been discounted by most scientists, and is now attributed to climate change. Recent CSIRO investigations showed that 'burning off' by indigenous australians was far less frequent than europeans had assumed, and serious bushfires increased dramatically after european arrival. According to Professor Roberts of Wollongong University, "There are two theories. One is people came in and did so much burning of vegetation and that caused hardship and the megafauna died of starvation. The other is they (humans) only had to eat a very few each year and they still would have driven the species to extinction." The study is "damning evidence" that humans were involved in megafauna extinction. This is one of the studies from 2008, the qoute above is from a 2010 study by Professor Roberts. (Turney, C.S.M., Flannery, T.F., Roberts, R.G., Reid, C., Fifield, L.K., Higham, T.F.G., Jacobs, Z., Kemp, N., Colhoun, E.A., Kalin, R.M. & Ogle, N. (2008). Late-surviving megafauna in Tasmania, Australia, implicate human involvement in their extinction. Proceedings of the National Academy of Sciences of the USA 105, 12150–12153.) Those scientists make up a large proportion of respected Australian naturalists, so not sure who 'most scientists' are. I've been under the impression that most of Australia was a rainforest before humans arrived, and that eucalypt's were not the dominate tree. I've heard gymnosperm forests were more widespread, with fire being the key element in there retraction (climate change and humans). Share this post Link to post Share on other sites
phyllode Posted January 5, 2012 About a year after the Victorian fire storm disaster the CSIRO did the most detailed soil layer investigation ever undertaken of the history of fires on the East Coast for the past several thousand years. They concluded what I said above, and that massive fire events dramatically increased after the European arrival. When I get time I will find link. It would be an extreme exaggeration to blame the general drying out of the continent 15-20,000 years ago as due to humans. No, I don't have refs handy, but I say this is outdated 20th century thinking. Share this post Link to post Share on other sites
Quetzalt Posted January 5, 2012 Thanks Phylode, sorry I haven't got any better photos. You're probably right, I can't find any better Tax. Ref. , it's just that I never had heard of these species around here before. Share this post Link to post Share on other sites
phyllode Posted January 7, 2012 (edited) Yeah Quetzalt, there's maybe one or two closely related species it could be, but not many. Would be good to know what's 'invading' europe. Regarding the extinction of the megafauna, from the Australian Museum: The extinction of megafauna around the world was probably due to environmental and ecological factors. It was almost completed by the end of the last ice age. It is believed that megafauna initially came into existence in response to glacial conditions and became extinct with the onset of warmer climates......Worldwide, there is no evidence of Indigenous hunter-gatherers systematically hunting nor over-killing megafauna. Trueman et al. 2004 found evidence to.. ...effectively refute the rapid-overkill model and necessitate reconsideration of the regional impacts of global climatic change on megafauna and humans in the lead up to the last glacial maximum. Here, we present geochemical evidence that demonstrates the coexistence of humans and now-extinct megafaunal species on the Australian continent for a minimum of 15 ka. The latest CSIRO study 2010 is not linked yet, but CSIRO 2003 estimated pre-European fire events to be 1/7 the level of after arrival. Edited January 7, 2012 by phyllode Share this post Link to post Share on other sites
Tryp Posted April 18, 2012 I'm a huge fan of acacias but if theres something I've noticed wandering around the west, its that Saligna, and the three mentioned by Quetzalt are rampaging while the more beautiful variants are becoming harder to find even in nurseries. It's been a long time since I've stumbled across a wild acuminata and in the past year I've only seen 3 podalyriifola (mt morgan wattle) Btw has anyone else noticed the list of active acacias has disappeared from wikipedia? i just realised. Should've screen-capped it Share this post Link to post Share on other sites
applesnail Posted April 18, 2012 http://en.wikipedia.org/wiki/List_of_Acacia_species_known_to_contain_psychoactive_alkaloids heres a wiki list! Share this post Link to post Share on other sites
