Our research focuses on the population dynamics of plants and how they are influenced by impacts of natural disturbances and global environmental change. We are particularly interested in the interactive effects of fire, grazing and drought in grasslands and woodlands in southern Australia, and how climate change, fragmentation and shrub encroachment affect ecosystems.

Monday, 24 October 2011

Science and land management

I'm a plant ecologist partly because it allows me to understand the natural world. But I'm also an ecologist because I want to see the management of that natural world done with the best possible scientific knowledge. This not only promotes the wise and sustainable use of natural resources, but ensures that appropriate management occurs in those areas where nature conservation is the primary aim.

Some of the best understanding of natural ecosystems in Australia can be found in the alpine grasslands, wetlands and heathlands of the Eastern Highlands. Scientific research has a long history in alpine Australia (dating back almost a century) so you'd think land management decisions would be informed by this research, i.e. the level of uncertainity about management actions is much lower there than elsewhere in the landscape where much less scientific research has been conducted.

The high mountain grasslands and wetlands of Victoria are most
extensive on the Bogong High Plains. This is where most of the scientific research
on impacts of disturbance have been conducted.
(Photo: John Morgan)
Cattle grazing impacts on range condition of high mountain ecosystems is one research area that has been particularly prominent. 

Maisie's Plots - started in 1946 by Maisie Fawcett from the School of Botany at Melbourne University - has been a pioneering study examining the effects of cattle grazing on alpine ecosystems. It shows clearly that bare ground is highest in grazed areas, which is not good news for erosion, and that bare ground favours regeneration of shrubs > forbs. The plots continue to be monitored till today, giving new insights on vegetation change in reponse to infrequent fire and climate change.

Maisie's Plots in 2005.
On the left, the area grazed by cattle for 100 ys.
On the right, the area unavailable to cattle since the 1940s.
Note the contrast in vegetation - composition and abundance is
very different inside the fence
(Photo: John Morgan)

More recently, Dick Williams and others tested the hypothesis that "alpine grazing reduces blazing" - in response to the idea that cattle are necessary to reduce fuel loads in alpine areas and prevent mega-fires. There wasn't much evidence that cattle grazing impacted on the extent and severity of landscape fires in 2003. Rather, the patterns of burning were mostly a consequence of fuel type. These studies (and many others), give managers, policy makers, and society a very solid basis on which to make informed decisions about the management of alpine lands. And it was such science that swayed governments to phase out cattle grazing from high mountain catchments over the last 30+ yrs - because of their detrimental effects of wetlands, vegetation cover, soil erosion potential and biodiversity values. Such rigorous assessment should be the standard for all land management activities.

But just last week, the Mountain Cattlemen's Association of Victoria trotted out their oft-stated claim that ''arguably suspect science'' surrounded the decision to remove cattle from the high mountains of Victoria. This is a baseless accusation given the science that has occurred there over six decades has followed normal scientific practices (development of hypotheses, replication, controls, rigorous measurements, etc), as well as being peer-reviewed before publication. Such statements need to be held to account - because without challenge, they can gain some level of credibility and undermine / erode confidence in the scientific process.

 What's often not understood is that scientists are inherently conservative beasts - before proclaiming "effects" of X on Y, they have tested their ideas through replicated observation and experiment, considered alternative hypotheses, and  used statistical inference to interpret their findings. They do this because they want to make sure that they don't proclaim significant effects when none occur - a false positive. This is called a Type 1 error in statistical terms.

Statements like those of the MCAV highlights a mis-understanding of how science works and, more generally, its role in society. Science is an evidence-based discipline, and allows degrees of 'certainty' to be proclaimed - e.g. we are 95% sure that adding nitrogen to native grasslands in Australia promotes invasion by exotic species. Hence, it's generally not a good idea to spread nitrogen around if you want to conserve diverse native grasslands. There will be exceptions to this (in our field, we talk about how effects may be 'contingent' on site factors), but this should not undermine the general confidence we have in making these predictions.

However, in society, people are often inclined to believe what they want, with or without evidence. This is because religion, politics and upbringing all affect the way that people view their world. It makes the likelihood of a fruitful scientific debate on sustainable land management difficult. And how might we argue the case for acting on climate change in such an environment? Discussing the environmental impacts of an increasing population size in Australia (predicted to hit 35 million by 2050) is another topic that springs to mind where science should have an integral input into the debate.

More than 300 years after the Enlightenment ushered in the Age of Reason, superstition and belief still vie with rationality; the scientific method remains ill understood and we are as likely to believe what our peers say as our scientists. In debates we pick sides and become entrenched in positions, rather than weighing up the evidence. So how do we change this idea that our science is peripheral to good management when (I'd argue) it should be front & centre?

Certainly not by giving up! One of the best things we can do, as scientists, is to point out errors of fact and logic that may be promoted in the mainstream media cycle. And, crucially, to accept that conservation biology is not purely a scientific endeavour. [Read John Lawton's excellent article on "The science and non-science of conservation biology" in Oikos 79: 3-5 for an interesting take on this]. It involves society and we need to much better engage with that society (i.e. the users and decision-makers of the land) if we are to convince them of the methods (and merits) of informed land use. It won't be as simple as that, but I've found that if you take the time to explain your science to the average man on the street (or land manager), he's usually really quite receptive. In many cases, it's about making science (and nature more generally) relevant to people who might not really understand how and why we do what we do.

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