Bringing resilience back to its ecological roots

Resilience, along with its sister term, resistance, is among the first ecological concepts taught to ecology undergraduates and remains central to conceiving how ecosystems cope – or do not – with environmental change. Despite its potential importance to conservation decisions and environmental management, confusion about how to define and measure resilience has impeded its application.

In an effort to reclaim the utility of resilience, Rachel Standish (UWA), Nancy Shackelford (Victoria Uni., Canada) and I brought 20 community ecologists together with the aim of quantifying ecosystem resilience and identifying the characteristics associated with it. Using experimental data gathered from around the world, we will compare the extent and speed of recovery of different ecosystems from different types of disturbance.  In doing so, we intend to learn more about resilience and make its application to ecosystem management more feasible. More information. 

Working hard at Rottnest Island, December 2013
Working hard at Rottnest Island, CEED Workshop, December 2013

The divine glory of our nation’s capital

It may come as a shock to some people, but I am delighted to say that Canberra is now my home.

For those who aren’t so familiar with Australian snobbery, Canberra (along with our South Australian sister, (R)Adelaide) tends to get a pretty bad rap. Boring; nothing to do; weird; where are the milk bars?!

While I nod my head appreciably at the last comment (and, dare I say, groovy wine bars?!), the first few seem to come from people who a) have never been to Canberra, b) came once during primary school to visit Parliament House or c) have very poor taste.

My response to this:

  • fast, flowing mountain bike trails winding through beautiful grassy woodland all of ten minutes from Canberra’s CBD;
  • Two hours to the coast, two hours to the mountains;
  • And then there are the after work strolls with kangaroos, kookaburras, cockatoos, wallabies, rosellas…

    What I did at the weekend: Canberra to Kosciuszko by bike. Photo by Milly Brent

Clearly, I am a “nature lover” (surprising, I know) and Canberra offers “nature” in droves. As well as being great for one’s physical and mental wellbeing, this also presents some great work opportunities as the field really isn’t that far away. To illustrate, I’ll briefly introduce a couple of the field sites where some of my colleagues in the Fenner School of Environment and Society work.

Mulligans Flat–Goorooyarroo Woodland Experiment

MulligansExperiment fig
Response variables being studied in the woodland experiment: 1 Dead wood; 2 Birds; 3 Invertebrates; 4 Vegetation; 5 Reptiles; 6 Fungi; 7 Bettong reintroduction; 8 Brown Treecreeper reintroduction; 9 Kangaroos; 10 Small mammals; 11 Litter, soil and soil microbes; 12 Exclusion of feral pests. See link to the left for source info.

Located in a couple of nature reserves 15 km north of central Canberra, the Mulligans Flat–Goorooyarroo Woodland Experiment is a partnership between the Australian National University, the ACT Government and CSIRO. The aim of the project is to find ways of improving box-gum grassy woodland for biodiversity and the experiment manipulates and monitors a whole raft of factors (see figure above).

One of the many exciting aspects of this experiment is the reintroduction of the Tasmanian Bettong (Bettongia gaimardi) – it has been extinct from the mainland of Australia for 80 years.  Regarded as an ecosystem engineer, it will be interesting to learn what effects the Bettong has on the ecosystem.

Tumut Fragmentation Study

Based in the Buccleuch State Forest 100 km west of Canberra, the idea for the Tumut Fragmentation Experiment was sparked when David Lindenmayer was flying from Canberra to Melbourne. Peering out of the plane window, David saw an area of native forest that had been cleared for a radiata pine (Pinus radiata) plantation. Rather than just bulldozing the whole lot of it though, patches of native forest had been left. Representative of the original forest, these patches varied in size from half a hectare to 200 hectares thus providing a great way to study effects of forest fragmentation on biodiversity.

The Tasmanian Bettong (Bettongia gaimardi). Photo by JJ Harrison (jjharrison@facebook.com)
The Tasmanian Bettong (Bettongia gaimardi). Photo by JJ Harrison (jjharrison@facebook.com)

In all, the Conservation and Landscape Ecology group at Fenner run seven large-scale longitudinal field studies, all located in south eastern Australia. Long-term, large-scale ecological studies are pretty rare in Australia, yet provide incredibly valuable insights because many ecological processes occur at the landscape-scale, it can take a long time for ecosystems to respond to certain actions and it can also be very hard to detect ecological responses when background levels of variability are so high (just think of weather patterns versus climate change). A major impediment to establishing long-term studies is the fact that most grants last for only a few years. While there is increasing support and appreciation of long-term studies (the merits of which are nicely illustrated by the Long Term Ecological Research Network in the US), many researchers rely on passion, strong working relationships and cheap labour (i.e. their own) to maintain such research.

I have been in the Fenner School at the Australian National University for a few months now and I am just loving it. Although I am still employed by the University of Melbourne and retain strong links with the Quantitative and Applied Ecology research group, I will be based here for the duration of my grant and hopefully, fingers crossed, beyond that.

If you are ever in town, or are keen to visit, please drop me a line. We could even go to Parliament House.

Parliament House. Source: Milly Brent
Parliament House. Source: Milly Brent

Managing the Murray’s water to combat invasive species

An invasive exotic species, Sagittaria platyphylla, dominating a wetland in Cobrawonga, Victoria (2008)

About this time last year, I wrote an article for H2O Thinking, a water management magazine published by eWater (until recently the eWater CRC). While the turnaround time is nothing to envy, the piece found its place on the web earlier this week.

In the article, I focus on two questions that anyone* who has spent any time along a river will surely have asked:

Why are river banks, floodplains and floodplain wetlands so susceptible to alien species invasion?

And what can we do about it?

Well, I’m not going to give the game away, but lets just say that the words “flow” and “regulation” do make an appearance. Click here for more scintillating reading (?!).

A very nice wetland near Cobram, Victoria (2007)

*OK, anyone like me would surely have asked…

Land of 10,000 Lakes

Located on the Canadian border, smack bang in the middle of the US, Minnesota is indeed a land of many lakes. While this  postcard does sell them a bit short (there are in fact about 15,000 lakes and that doesn’t include those with more pond-like dimensions), it communicates the basic facts: there are a LOT of water bodies in this part of the world. And for someone who is partial to water, that is a pretty cool thing.

As part of my DECRA research, I am spending a couple of months in Minnesota this year.  I am planning to conduct an invasion-style experiment at Cedar Creek Ecosystem Science Reserve in 2013 and 2014, so this is the essential reconnaissance trip.

So, what have I discovered so far?

1). My University of Minnesota mentor (Dave Tilman), his lab and the Dept of Ecology, Evolution and Behavior (EEB) are all tops. Widely recognized as a place of (i.e. people that do) cutting edge ecological research, it is also proving to be a really fun and dynamic place to work.

Me obscuring a beautiful Bur Oak (Quercus macrocarpa) in sand savanna. Sand savanna now only makes up 0.00005 of its former range, so this patch of habitat is pretty precious.

To illustrate: within 10 days of arriving, I have had dinner at Dave’s house with his lab group and Simon Levin (another super high-echelon ecologist visiting from Princeton), gone to an EEB summer barbeque, spent a day out at Cedar Creek and to top it off, I’ve just returned from a “lab get-away” at the Tilman family cabin that is situated on a lake (of course!) ~3 hours north of Minneapolis. A pretty good start, I would say. 

2). A staggering amount of high quality research has taken place at Cedar Creek. Owned and operated by the University of Minnesota in cooperation with the Minnesota Academy of Science, Creek Creek is a large ecological research station that is part of the Long-Term Ecological Research Network that exists in the US. Established in 1940, Cedar Creek is located in central Minnesota and contains natural habitats that represent the entire state. To cite Nee and Lawton’s (1996) Nature paper, Cedar Creek “is rapidly becoming one of ecology’s classic localities” (p. 672). Well, not wanting to assume that I am qualified to make the call, but I would say that Cedar Creek is one of ecology’s classic localities. If you’re in any doubt, then check out the publications that have been generated from work at Cedar Creek (be prepared to scroll!).

Dave Tilman chatting to some interns who are weeding a plot of the big Biodiversity Experiment at Cedar Creek

Like all things that work well, the strength of Cedar Creek comes down to its workforce. 24 Faculty members work at Cedar Creek, as well as 15 support staff, 10s of postdocs and postgrads and even more summer interns. This summer there are about 60 people working at Cedar Creek and – in two days time – I’ll be one of them. Yippee!

 

3). As an upshot of (1) and (2), some incredibly exciting opportunities are available for my research. I can take a fresh look at past experiments and surveys, tweak experiments that are already up and running and then there is the option of setting up an experiment myself. The world is most definitely my oyster – I can hardly believe my luck!

While being completely spoilt for choice is a wonderful situation to find oneself in, it does present the inevitable challenge of narrowing things down. So, in the next little while I plan to do some general reading, some Cedar Creek-themed reading, some Cedar Creek fieldwork and then a generous dose of coffee-fuelled and bike-inspired thinking. At the end of that, and the end of my two months here, I hope that some sparks will have flown, some light bulbs lit and some cool ideas arisen. Exciting times!

And now, off for a bike ride and a swim… You probably have an inkling where those activities will take place!

My ride home from work: Lake Calhourn with downtown Minneapolis in the background

New paper: Predicting novel riparian ecosystems in a changing climate

Image
A bit of a stretch, but I couldn’t resist including this image!

I was fortunate to attend a workshop hosted by the National Climate Change Adaptation Research Facility last year that focused on riparian ecosystems under climate change. Among the various discussions at the workshop, some colleagues and I started discussing how riparian ecosystems might be affected by climate change and ways in which their abiotic and biotic characteristics are likely to change. It soon became clear that envisioning future ecosystems is no easy task, so we set about trying to come up with an approach by which to do so. 

We present our approach in a paper that has recently been published in the journal Ecosystems. Based around four recommendations, we present the approach in the first part of the paper.  We then use four case studies from contrasting environments to illustrate the approach and to determine:

–        Whether certain characteristics make some ecosystems more susceptible to climate-induced shifts in community structure than others; and

–        Which aspect of climate change seems to have the greatest effect on community structure and therefore should be a research priority.

Focusing on changes in community structure, we use qualitative process models to predict likely abiotic and biotic changes in four case study systems: tropical coastal floodplains, temperate streams, high mountain streams and urban riparian zones. We concentrate on functional groups rather than individual species and consider dispersal constraints and the capacity for genetic adaptation.  Our scenarios suggest that climatic changes will reduce indigenous diversity, facilitate non-indigenous invasion (especially C4 graminoids), increase fragmentation and result in simplified and less distinctive riparian ecosystems.

Compared to models based on biota-environment correlations, process models built on mechanistic understanding (like Bayesian belief networks) are more likely to remain valid under novel climatic conditions. We posit that predictions based on species’ functional traits will facilitate regional comparisons and can highlight effects of climate change on ecosystem structure and function. Ecosystems that have experienced similar modification to that expected under climate change (e.g. altered flow regimes of regulated rivers) can be used to help inform and evaluate predictions.

While the paper centres on Australian riparian zones experiencing climate change, the approach can be applied to ecosystems in other biomes that are subject to environmental change.

The paper is now online early; you can find the abstract and link here.

Please drop me a line if you’d like a copy.

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