When I use the Austral Ecology citation style that I installed I get this:

Cornelissen, J. H. C., Lavorel, S., Garnier, E., Díaz, S., Buchmann, N., Gurvich, D. E., Reich, P. B., Ter Steege, H., Morgan, H. D., Van Der Heijden, M. G. A., Pausas, J. G., Poorter, H. (2003) A handbook of protocols for standardised and easy measurement of plant functional traits worldwide. Aust. J. Bot.. 51, 335–380. 


But the correct citation style for Austral Ecology is as follows:

Cornelissen J. H. C., Lavorel S., Garnier E. et al. (2003) A
handbook of protocols for standardised and easy measurement
of plant functional traits worldwide. Aust. J. Bot. 51,
335–80.


Note that there are several differences between these two versions:
1) there should be no comas between the authors' last names and initials. 
2) when there are more than six authors only the first three should appear in detail and the rest should be refered to as "et al."
3) the name of the journal should be in italics
4) there should be only one full stop between the name of the journal and the volume number
5) the volume number should be in bold.

More changes based on more feedback from user:

I've been taking a look and there is still three minor (but probably more complex) details to correct. I really don't want to mess with the code, so I would really appreciate of you could take a look at it.

1) When there is between two and six authors (if there is more only the first three appear and the rest is "et al.", you already fixed that), there should be a "&" sign before the last author. For example: 

Lawes M. J., Richards A., Dathe J. & Midgley J. J. (2011) Bark thickness determines fire resistance of selected tree species from fire-prone tropical savanna in north Australia. Plant Ecol. 212, 2057–69.

2) Whenever "et al." is used in the list of authors, there should be no coma between the third author mentioned and "et al.". For example: 

Cornelissen J. H. C., Lavorel S., Garnier E. et al. (2003) A handbook of protocols for standardised and easy measurement of plant functional traits worldwide. Aust. J. Bot. 51, 335–380.

Note that there is no coma between "Garnier E." and "et al."

3) There should be a space bewteen the name of the journal and the volume number (see example above). In the current version there is no space.