Ecological succession simplified

One thing you looked at was how ecosystems recovered or failed after disturbances.

Yes. There is plenty of good raw material for that in Australia. In ecology, frequently you just don’t have the time to run experiments. You have to look for either natural, or human induced, perturbations which have done your experiment for you, or have applied the treatments. Then the answer should be there and the challenge is to see if you can validate it. So disturbances associated with overgrazing or the effects of fire were very important perturbations by which to test the theories.

That was the challenge I set the group. I got pretty heavily involved in it myself, with Ian Noble – a remarkable, very impressive person who came from Adelaide to work with us. (He is now leader of the ecosystems group at the Research School of Biological Sciences. The Environmental Biology group did get to be beyond talking distance and so two separate groups were established, but still with a lot of interactions between them). In the mid-1970s Ian and I began to develop what you might call a phenological basis for understanding whether a plant is likely to persist through a disturbance or to arrive at the site of the disturbance afterwards. And then whether it can reach reproductive age and produce viable propagulus. In other words, whether it is going to be in with a chance in the subsequent series of events that lead to the redevelopment of a community.

Also, I had established a close working relationship with Joe Connell, at Santa Barbara. In about 1973 or ’74 I began working with Joe on major mechanisms involved in ecological succession, the temporal change in species composition. The work was intermittent, with ideas, manuscripts and so on going backwards and forwards across the Pacific – plus periods of time in each other’s labs. We didn’t even have faxes then and telephone calls were too expensive, and neither of us were terribly good correspondents, nevertheless we gradually got our ideas together.

We proposed that the complex array of mechanisms that were involved in ecological succession could be seen as just three basic mechanisms: a community acts in such a way as to facilitate the entry of a new species – and there is evidence for that – or to inhibit the entry of another, new species, or to tolerate the entry of a new species. That seemed to sum up, to a considerable degree, the controlling mechanisms for the temporal variation in composition. It took us two years to put together a paper on this proposition, together with the experimental tests that we thought people could apply in assessing whether these mechanisms were operational or not. In about 1975 we sent the paper to  American Naturalist, which was rather slow in refereeing it but published it in 1977.

Your proposition simplified a great problem area. People could now devote their attention to three mechanisms, instead of looking at a massive multifactorial array.

Well, it seems almost self-evident now, but it didn’t seem so simple or obvious when we were involved in it.

A total commitment to cooperative research

As you have probably gathered, I am totally committed to cooperative research. I know that a lot of people like to work away almost monkishly by themselves, but I’ve been so stimulated by interaction with colleagues through my research career that I feel quite unhappy about people depriving themselves of that opportunity and that great experience.

The paper that Joe Connell and I wrote became a citation classic, as did my plant/water relations monograph – that’s always a bit of a thrill. When you get a citation classic you are asked to write a little essay as to how it happened. As Joe and I thought about our work, I realised that the successful ingredient was the interaction of our backgrounds. Joe is a great conventional naturalist who knows the names of all the shells on the seashore and stuff like that, and he brought a broad naturalist, community ecologist view of the world to our association. I’m the world’s worst taxonomist, but I brought a more physically rigorous background. I am more mathematically inclined, more inclined to look at the physiological mechanisms underlying behaviour or performance rather than simply the manifestation of the performance itself. It was perfect that we should have worked together, although when we started we didn’t realise that; it just became apparent to us that we always threw sparks off one another.

Focus questions

• What events give rise to an ecological succession? Can you identify any instances of ecological succession near your school or home environment?
• Slatyer points out the cooperative nature of the research discussed in this section of the interview. Why might cooperative research approaches be of special value in ecological research?