|Cape Conran, August 2012|
(Photo: John Morgan)
I find teaching in the field, in small groups, a really satisfying way to train budding plant ecologists. I'm of the opinion that most undergrads learn through their eyes, and by getting their hands dirty! So, last week, I split the students into groups of six, and posed each a research question related to fire ecology. The aim was to make some observations that inform a question, make some predictions, design a study, collect data, collate and interpret that data, and make some statements about what had been found. This is something many of us do every day, but clearly it has to be taught (and learnt!) by students new to the field.
|Happy students in recently burned sandplain heath|
(Photo: James Shannon)
One of the biggest challenges our discipline faces is to develop generalities that might apply across taxa, communities, ecosystems. We've all conducted research where the results are contingent on the study system under examination. Or where opposing results are found across sites due to unknown site history factors. This might be something we accept as the 'norm' and keeps us endlessly asking questions about the natural world. But, it is a major challenge for students trying to understand the contribution they might make to the field, and to managers needing advice about the conservation management and restoration concerns that occupy them daily.
As an example of the challenges faced by my undergrads, one project looked at serotiny in the genus Banksia (Proteaceae) with an eye to thinking about the implications for fire management. Serotiny is the term used for seeds that are stored in fruits for extended periods of time (usually years) and then released spontaneously by an event. Triggers for this release include:
- Wetting (hygriscence)
- Warming by the sun (soliscence)
- Drying atmospheric conditions (xeriscence)
- Fire (pyriscence)
- Fire followed by wetting (pyrohydriscence)
|This is what happens when you heat Banksia|
infructescences at 500 deg C for 2 mins.
From top: B. serrata, B. spinulosa, B. marginata.
(Photo: Susan Hoebee)
To me, one way to bridge this 'uncertainty' about data and, why it varies, is to emphasise and adopt proper sampling design in all our studies. This is not a new idea but rather, a call to remember what constitutes sound, evidence-based research. This may reduce some of the uncertainty that is generated by conflicting ecological studies - are the differences due to poor experimental design or real population differences? I recommend you read the essay by Downes (2010) to brush up on sampling design and its importance in ecology, as well as how to deal with questions that aren't always amenable to experimentation.
Downes, B. (2010) Back to the future: little-used tools and principles of scientific inference can help disentangle effects of multiple stressors on freshwater ecosystems. Freswater Biology 55, Supplement s1, 60-79.