Monday, 31 December 2012
The EBB and Flow: blogging all things ecology and evolutionary biology. This is a really neat Blog. It's big on reporting about papers that focus on ecological theory (which we should use as the basis for all our investigations) - under the 'Research Focus' tab. The most recent Blog on a new paper by Jonathon Levine about how coexistence theory can help inform community assembly makes a difficult/challenging topic palatable.
EBB and Flow also has excellent sections on 'Conservation Focus', 'Academic Life' (which PhD students will find really informative, 'Career Corner' (ditto), 'Meeting Dispatches', 'Recent Papers of Interest' and the excellent 'Researcher Spotlight' that send the reader off into weird and wonderful (and more importantly, relevant) ecological territory. It's well worth bookmarking!
Happy New Year!
Saturday, 22 December 2012
But, I've bitten the bullet. One of the reasons was that Nick Bell, a Summer Research Student working on our long-term ecological plots examining alpine vegetation change, recently showed me how useful smartphones can be for the average field ecologist. While he was talking to me about technology stuff that seemed to be based on the English language, he showed me two simple Apps that I might find useful.
|Nick talking to John|
(thanks to Calvin & Hobbes)
One was an app to help measure tree heights (Smart Measure). Having recently done this with Nick in the field the old fashioned way - tape measure, compasses, pythagoras' calculations - this seemed really simple and effective. Then, he showed me how you could ghost an image on the screen while trying to re-take the same image. This would be awesome for my re-photography work that I am currently undertaking, comparing photos from the 1930s with the current day.
|Measuring tree height is easy. Right?|
I went away and started to do some research. Not on getting a smartphone, but on the apps that I could use in ecology. Very quickly, I was thinking "hmmm, there's a lot of technology available that is cheap, accessible, and that I've totally overlooked".
One of the sites I found was Emilio Bruna's excellent 'Mobile Ecology' webpage. This page lists a bunch of apps for research, teaching and outreach (with a US emphasis, so I guess I'll have to look for the Australian equivalent). If you're interested in such things, it is well worth a look. My favourite was the app called RInstructor - this looks like something that will really facilitate my learning and use of R, particularly how to customise plots.
So, with Christmas coming up, I might just have to treat myself and upload (or is that download) a couple of these apps to see whether my investment in a new phone was actually worth it! In any case, I can see great potential in this technology to help me facilitate my data collection and efficiency in the field.
Merry Christmas, and best of wishes for the New Year. I look forward to writing more about plant ecology in southern Australia in 2013. JOHN
Friday, 7 December 2012
One thing that struck me was the number of talks I saw on fire. There was a whole symposium dedicated to fire, which was very well-attended. I also saw talks scattered through the programme that dealt with the impacts of individual fires, the regeneration biology of key species, the importance of fire return interval, why fire severity matters, etc, etc.
This is not surprising given that south-eastern Australia is one of the most fire-prone areas on the globe. It is a recurrent feature in many ecosystems, and is projected to increase in frequency because of climate warming over the coming century. Additionally, it is also a contentious issue - the management of bushfire threat in SE Oz revolves around policies that mitigate risk by hazard reduction burning.
Two important issues arise - how often should it occur in an ecosystem (both as a tolerable event and as a desirable disturbance to cue important ecological processes such as seed germination). Second, what type of fire event is likely to have positive or negative impacts on these outcomes.
I've been musing about these questions for the last few weeks, but from a different perspective. And it returns me to one of my favourite pasttimes: observations in ecology.
While fire is a recurrent event throughout much of SE Oz, there are indeed very long fire-free intervals for some parts of the landscape. We intuitively know this. In the rainforests of eastern Victoria, fire is probably fairly rare - perhaps in the order of hundreds of years apart. But what is probably less appreciated is that in the drier, less productive parts of central Victoria, perhaps fire is also equally as rare.
How can I make such a statement? What evidence do I have for one of the most fire-prone areas of the world having very long fire-free intervals. Well, that is where observation comes in. In the dry, eucalypt-dominated woodlands of north-central Victoria, around Rushworth to Wangaratta, there is a clue on the upper slopes and rocky outcrops. It's a pretty obvious clue when you think about it.
Here, there is a plant that is born to burn (or so it would seem). Grasstrees, in the genus Xanthorrhoea, are arborescent monocots, developing tall stems that allow them to grow to great heights. We know they grow very slowly. Let's focus on X. glauca. For the first 50 yrs, plants consist of leaves but no stem. The stem then emerges and height growth is about 10-25 mm per annum. My old PhD student Peter Curtis measured growth rates over 10 years, so this seems a pretty reasonable estimate. So, a plant 3 m tall might be anywhere up to 350 years old. Each year, the leaves die but are held appressed to the stem rather than shed. In unburnt grasstrees, this 'skirt' can extend all the way along the 'trunk' to the ground. When a fire occurs, the 'skirt' is a ready-made fuel source to rapidly burn the plant - a quick fire where most heat is carried rapidly away from the meristem by convection. Plants generally survive burning, although Peter's work does show that mortality of grasstrees can be quite substantial in the decade after fire. But that is another story..........
|Burnt Grasstrees, Rushworth State Forest, October 2012|
(Photo: Michele Kohout)
Well, old photos tell us so! Here are some images of grasstrees in the Warby Ranges - taken in the early 1980s by the well-known fire ecologist David Cheal - that are notable for (a) their enormous height (up to 8 m perhaps) and (b) the fact that they have grass skirts that extend all the way to the ground. This suggest that this part of the landscape has not been burnt for upwards of 600 years. Hence, we are not talking about fire suppression since european settlement. And it is not just one or two individuals, but entire slopes, suggesting that fire is very uncommon here. On recent inspection, it is hard now find examples of these great unburnt plants. Low intensity fire has seen to that.
|Grasstree in the Warby Ranges, 1983. Note the scale (approx. 1.75 m)|
and dead leaves all the way to the ground. The trees in the background
have not been burnt. Rather, they are dying from intense drought.
(Photo: David Cheal)
|Grasstrees, all with skirts that indicate long intervals between fires, across a slope at |
the Warby Ranges, 1983. Plants are approx. 2.5 m tall.
(Photo: David Cheal)
|Long unburnt Grasstrees, Rushworth State Forest, 2012. Scale approx. 40 cm.|
(Photo: Michele Kohout)
The lesson here, if there is any, is to observe patterns in nature. The simple observation that grasstrees in some parts of the range (low productivity, rocky) have not experienced frequent fire is probably very important, particularly when thinking about fire return intervals. While low intensity fires may seem ecologically benign, this needs to be put in the context of the fire history of the site.
It also challenges our notion that dry forests burn frequently simply because they occur in a part of the continent where fire is known to occur regularly!
Monday, 5 November 2012
What is great about old photos is they convey information about the historic state of systems, well before many of us were involved in management and research, and they potentially allow current condition to be compared to prior states. Clearly, this grassland had a high cover of forbs in 1979. The silver coloured vegetation is probably the Lemon Beauty Head (Calocephalus citreus), the yellow flowing daisy is Chrysocephalum apiculatum, while the white sprays are mostly Bracyscome dentata in the background, with Stackhousia (Creamy Candles) in the foreground. While tussock grasses (Themeda triandra) are obvious, they certainly don't dominate. You get the impression this was much closer to a herbfield than a grassland.
|Truganina Cemetery, spring 1979 |
(Photo: Neville Scarlett)
I thought it would be great to take an up-to-date shot of the same location to see how things have changed over the last 30 years. Truganina Cemetery is well-known as an important grassland remnant (it has two nationally endangered species present) and it is managed by irregular burning, while vehicle access is prohibited. Armed with a tripod and digital camera, I went out a few weeks ago to capture the same shot. Below is my effort to replicate Neville's original shot.
|Truganina Cemetery, spring 2012|
(Photo: John Morgan)
Two things are obvious. Firstly, and probably most obviously, it is clear that much of the colouring afforded by forbs in 1979 has dramatically declined, indicating their cover and abundance has likely diminished by an order of magnitude or more. All four species that I mentioned as obvious in the original shot are still present, so what we are looking at is a dramatic change in species evenness rather than local extinction. We could visualise these changes by constructing a rank-abundance curve, plotting the percent cover of species from most common to least. This would hint that dominance has shifted completely from a multitude of forb species to one native grass, and that forbs are mostly now at very low cover.
Secondly, I found it really hard to re-take the orginal shot. In this case, I don't think it mattered hugely because the magnitude of the change is so great. But, it got me thinking about how I might go about doing this better next time. Using old photos to assess environmental change is becoming increasingly popular in environmental science. Part of this, I suspect, is that old photographs are now being scanned and stored in archives such as the excellent one called TROVE (curated by the National Library of Australia). Hence, how might one go about doing this accurately?
The field is called "repeat photography" or "re-photography". It seems that a pretty common method is indeed just walking out to the same spot and taking the same photo. But then you want to match the conditions as well as possible. There's a lot going on with seasonal variation and time of day in terms of shadow length. Visual parralax is the key to the basic technique; you can get pretty close to the same location by comparing rocks and details that are partially obscured by objects in the foreground... but this does not give you exactly the same picture, just something that is clearly the same viewpoint of the same landscape. Part of the problem here is that an oblique perspective creates a continuously varying scale and this makes it hard to link landscape features in the photograph to absolute spatial co-ordinates.
A good starter is Methods in Re-photography: A Research Method for Amateur Researchers. This has some really excellent background on the scientific relevance and utility of the technique, and a very quick'n'dirty guide to the fundamentals. Apparently the bible on the method is called Repeat Photography: Methods and Applications in the Natural Sciences,edited by Webb et al..
It is pretty clear that matching photos can be a powerful means of comparing local changes in vegetation, particularly when photographs extend well back in time. Aerial photographs are great for the same reason, but most don't extend beyond the 1940s in Australia, so repeat photography has great merit to address small-scale, long-term change. I'll leave you with the nice example below by Roush et al. (2007) that compares the alpine treeline ecotone in Glacier National Park in 1930 with that in 2003. Note the massive invasion of trees across the entire landscape!
Wednesday, 24 October 2012
|Planting Buloke trees on the heavily cleared Wimmera plains |
of western Victoria. (Photo: John Morgan)
The two most common explanations that are used to justify / defend this approach are that (i) local seed produces plants that are best adapted to the revegetation site (the 'local adaptation' hypothesis) and (ii) using local seed reduces the risk of causing outbreeding depression (i.e. the introduction of novel genes that will swamp the local genotype). I, too, have tended to use these concepts to underpin my thinking on this issue. But, on reflection, I've started to change my mind on this, for two reasons.
|Swainsona spp. are now extremely rare in grasslands.|
(Photo: John Morgan)
Recommendations for provenancing based on dispersal distance from parental plant (Figure 3 from Sgro et al. 2010)
Sunday, 14 October 2012
This project now has >60 sites in grasslands across the globe (see http://nutnet.umn.edu/), with four in Australia: Kinypanial (a semi-arid grassland in southern Australia that I manage), Bogong (alpine grassland managed by Joslin Moore and myself), Mt Caroline in Western Australia (Suzanne Prober) and Burrawan in Queensland (managed by Jennifer Firn and Yvonne Buckley).
|Bogong NutNet site|
|Burrawan NutNet site|
|Silwood Park NutNet site, England|
Our main questions are:
- 1) what are the relationships between diversity and productivity? This is an old question in ecology, with much hot air generated in the process about humped-back relationships, that we have addressed using our observational data. This resulted in the paper by Adler et al (2011) in Science.
- 2) are grasslands limited by multiple nutrients or one? This is being addressed by factorial field experiments where we add N, P and K singularly, and in combination. At Kinypanial, productivity is definately co-limited by N and P. Each nutrient, when added alone, has rather minimal impacts on productivity and diversity, but when added together, leads to a profound shift. Indeed, most of these plots (and the NPK plots) have been transformed from a native system to one dominated by the exotic annual grass Avena barbarta after 5 yrs of nutrient addition. Plots sown with N, P and K alone have a remarkable resilience to change. I was not expecting this.
- 3) is diversity controlled by nutrients (bottom-up processes) or herbivores (top-down processes)? In my sites, it definately seems that bottom-up processes rule, probably because native herbivores have been lost from many Australian grasslands (e.g. kangaroos, bandicoots, wombats) and hence, their current impacts on vegetation are minimal. This is not so true elsewhere in the world where large animals are still part of the natural system and they eat most of the biomass.
Eric Lind, the post-doc on the project, has just been interviewed on the Journal of Ecology Blog and explains the process of running a multi-site, global project with common aims. It's a good explanation of what we are doing and how NutNet can be (potentially) seen as a great model for successfully running such meta-analyse projects with standardised protocols. And the fishtank in the background is a nice touch!
You can see Eric at http://jecologyblog.wordpress.com/2012/10/12/interview-with-eric-lind-on-the-nutrient-network-nutnet/
In the current climate of declining research funding in Australia, multi-site network studies enable me to contribute to some of the big questions in ecology. The opportunity to ask 'big picture' questions, and collaborate with lots of smart people, has really opened my eyes as to the way I do science.
Wednesday, 12 September 2012
And thinking. And observing some more. These are the fundamentals of doing ecology - figuring out the patterns in nature and the mechanisms/processes that underpin them.
And, it's the reason I got interested in ecology in the first place. Long before I knew anything about a GPS, or a Mixed Effects Model, or a molecular phylogeny, or a Powerpoint Presentation, I was interested in plants - their form and function (we'd now think of that as plant functional traits) - and their capacity to grow in interesting patterns (we'd probably call that species coexistence) and the controls of their seedling recruitment (that has always been called the regeneration niche). And, in many ways, that is still what drives my curiousity. Of course, that is now underpinned by ecologial theory and experience.
But the basics remain the same. A few days ago, I spent some time looking at semi-arid woodlands in northern Victoria in an area I'm not all that familar with. I visited a new Trust for Nature conservation reserve - Wanderer's Plain. And I was struck by how little I knew about the vegetation patterns in this area. There were stark changes from grassland, to woodland, to forest but I wasn't quite sure what was going on.
So, I made some notes and, married with photos, started to unravel the story.
At any new site I visit, I have a little checklist of things I ask myself: how does the topography change? How does the overstorey change? How does the understorey change? How does the soil change? By running through this list, I can start to arrange the components of the landscape into some sort of order. My geomorphologist friend Neville Rosengren calls this 'being able to read the landscape'. While he's looking at rocks and landforms, such a concept is equally applicable to the vegetation.
There were very subtle rises in the landscape, many no more than 100 cm above the surrounding plain, forming ribbon-like bands at semi-regular intervals. Here, the soils were sandy, a sure sign of some aeolian deposition from soils brought from the desert country to the north-west. On top of these rises grew Acacia melvillei (in full flower), but it was largely restricted to this area. Presumably the drainage here is excellent, and the fertility low.
|Acacia melvillei in full flower, September 10 2012|
(Photo: John Morgan)
|Fringing the Acacia is Buloke and tall native grasses|
(Photo: John Morgan)
Fringing the Acacia band was an interesting zone of Buloke trees and tall C3 grasses. This occurs at the base of the sandy rises and a short distance into the plains, and I presume is a sort of run-on zone where water and fertility are both more readily available. Soils are likely to be better drained here than on the plain which appears to be composed of clays with very little topographical relief.
Away from the trees are native grasslands - flat and relatively featureless. But there is something going on. The grasslands here were looking spectacular. In large areas, the white-flowered Minuria leptophylla was the dominant herbaceous species. And, in other areas nearby, the yellow flowered annual daisy Hyalosperma semisterile was the dominant species. And rarely was there any co-dominance.
|Hyalosperma semisterile - wildflower heaven!|
(Photo: John Morgan)
|Hyalosperma in the foreground, Minuria in the background|
(Photo: John Morgan)
(Photo: John Morgan)
It suggests the way forward is an experiment. Another of my favourite ecological activities. Perhaps a seed sowing experiment, crossed with resource manipulations, to get to the heart of the patterns I've seen. And, undoubtedly, this will raise even more questions!
Friday, 24 August 2012
|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.
Tuesday, 31 July 2012
At each site, there were six grazing treatments, each replicated three times. Apart from continuous grazing, and grazing exclosure, the other four treatments tested for the effects of (a) season and (b) duration of grazing. You can read about the results of the initial findings (to 2007) in Zimmer et al. (2010) Forb responses to grazing and rest management in a critically endangered Australian native grassland ecosystem. The Rangeland Journal 32, 187-195.
|This grassland is not grazed in spring ('spring rest'), June 2012|
(Photo: Michele Kohout)
|This grassland is never grazed ('always rested'), June 2012|
(Photo: Michele Kohout)
|This grassland is always grazed ('never rested'), June 2012|
(Photo: Michele Kohout)
I'm lucky enough to be using the study at 10 years after the plots were established to look at longer-term impacts of manipulating grazing regimes on native grasslands (with my new student Kaitlin Wright). The plots are the longest running trials in southern Victoria addressing the question: can strategic grazing improve/restore threatened native grasslands? At 10 yrs, the plots have been through one of the longest and most intense droughts in Australian history, and plant community dynamics that were not evident in the first 4 yrs (the funding cycle) are likely to be much more apparent now.
My first task is to figure out what indices I would use to describe the changes that have occurred over the last decade.
Traditionally, you would monitor species richness (more correctly, this is species density - the number of species per unit area). Ecologists call this alpha diversity. You might specifically want to know about native species (hopefully they wouldn't go down) and the number of exotic species (hopefully they wouldn't go up). This seems (to me) to be one of the major objectives of the use of conservation management by grazing. So let's state it here: grazing maintains (or enhances) native species richness at the expense of exotic species richness/cover.
But what else matters. How might grazing be used to effect other (positive) change in grasslands?
It's clear to me that we could enhance the understanding of vegetation change through time by grazing if we consider aspects of spatial heterogenity and spatial and temporal turnover. Do certain grazing regimes enhance spatial heterogenity? If so, you might think that beta diversity might increase. Hence, let's state this hypothesis: grazing (either duration or season) can be used to enhance spatial variability, leading to positive outcomes for native plant diversity because it enhances niche variability. By enhancing variation in structure (with consequent effects on nutrient fluxes, light and moisture), deterministic processes may have greater impacts on species patterning than currently operate on grazed grasslands.
I've been giving some thought about what you'd really try to achieve by shifting regimes or disturbance types. And I've come up with three motivating questions illustrated in the slide below. I can't take credit here - my NutNet collaborators in the USA (Ellen Damschen, Peter Adler and others) are asking similar questions about grassland response to nutrient addition and grazing, but their approach seems relevant to grasslands in western Victoria too! In all cases, I think there is more to be gained than just looking at the number of species. Does continuous grazing homogenise grasslands and can we manipulate aspects of variability (in space and time) to promote positive community responses. If not, why not? Does grazing reduce exotic species cover regardless of richness responses? What do you think is important?
Sunday, 15 July 2012
Germination of semi-arid plants is usually cued to rainfall which is unpredictably distributed across years. Plants must cue their germination to rainfall events that are heavy enough to ensure sufficient moisture for seedling emergence and survival; hence, it is thought that this cue is moisture availability. In variable environments (i.e. drier systems with a large coefficient of variation in mean annual rainfall), it is predicted that a smaller fraction of seeds from a population will germinate at any one timeafter rainfall compared to species whose populations have evolved in more mesic or predictable environments (i.e. systems where the mean is higher and the coefficient of variation is lower). Despite this fairly simple hypothesis, it has not been well studied in Australia, reflecting the gap in fundamental autecological research that exists.
I am starting a project to determine whether seeds of semi-arid shrubs (in the genera Atriplex and Maireana) sampled from populations in xeric environments have lower germination fractions (at all moisture regimes) than seeds sampled from more mesic populations.
To do this, we will study the lab germination of several populations of semi-arid shrubs that have been collected across a strong climate gradient from southern NSW. This climate gradient represents a temperature, rainfall and evaporation gradient.Seeds will be counted into replicate seed lots and exposed to a range of experimental conditions to see if (a) xeric populations exhibit lower germination fractions than more mesic populations and (b) whether variability in germination is most affected by population differences or is outweighted by environmental conditions.
If you are interested in bet-hedging and seed germination, these paper give a nice entry into the field:
Friday, 29 June 2012
Thesensitivity to temperature at the germination phase will likely be one important predictor of a species' ability to respond to a rapidly changing climate.
The underlying assumption here - about climate change and the temperature sensitivity of seed germination - is, in part, a question about niche breadth.
By contrast, species with "broader" niches have germination that occurs over a greater range (i.e. the mean has a large standard deviation around it). Hence, if we identify species which possess narrow temperature germination ranges, we may be able to identify those species more susceptible to rapid environmental change.
Seems simple - develop a screening protocol, use a temperature gradient plate to quickly assess germination niche breadth for a large number of species, and identify species with narrow versus broad temperature germination sensitivity.
|Temperature Gradient Plate - capable of 192 temperature combinations!|
At the edges of the temperature range for germination is where niche expansion is most likely. New sink populations are much more likely to develop from source populations from individuals at the extremes of the niche space (as defined by temperatures) than from optimums. Hence, whilst we might find that species germinate less well at higher (or lower) temperatures than some optimum, the interpretation about temperature extremes for germination should take on more than just statistical significance to us; germination at these extremes of the temperature range is the raw material for future niche expansions. Most authors tend to ignore this and still focus on identifying optimum germination temperatures.
Two papers recently caught my eye and serve as good examples of how we might study fundamental germination processes to help understand potential responses to climate change. The paper by Ooi et al (2009) Climate change and bet-hedging: interactions between increased soil temperatures and seed bank persistence is one of the few I have seen that explicitly tests whether warmer soils will have implications for germination and the persistence of soil seed banks. It's worth reading if you're interested in how plant population processes underpin responses to climate change. You should also check out the excellent paper by Cochrane et al. (2011) on germination in restricted rocky outcrop species from Western Australia as a good example of narrow versus broad germination strategies, and what this might mean for responding to a warmer world.
Saturday, 16 June 2012
But this isn't the case everywhere across the range of native grasslands in southern Australia. In the more xeric areas (300-400 mm rainfall), native grasslands are still a feature of the landscape, e.g. the Riverine Plains grasslands of northern Victoria. In part, they survive because agricultural use has been of lower intensity, i.e. sheep grazing has been rather conservative and cropping largely unsuccessful. Additionally, perennial exotic grasses are absent (it's too dry) meaning that the integrity (if not composition) of the native grasslands remains largely intact.
For many years, however, the extent of xeric grasslands in southern Australia was overlooked. The conservation imperative first focused on the mesic C4 grasslands on volcanic soils near Melbourne. Xeric grasslands protection was so poor that by the early 1990s, none of the ecosystem was under conservation management.
Thankfully, this has changed - reservation has increased the area of xeric native grasslands in the National Reserve System from zero hectares in 1995 to an estate now in excess of 10 000 ha. This is a remarkable achievement. This increase has been driven, to a large extent, by government land purchase coupled with private conservation agreements. I, for one, have much greater hope that grasslands in these areas can now be conserved in a meaningful way. The challenge now will be to manage them for their biodiversity and ecosystem processes in the face of a changing climate. Understanding the factors that affect the resilience of these systems to change is a pressing research need.
I recently undertook a tour of some of the new conservation reserves protecting grasslands in northern Victoria and I thought I'd share some of these sites with you. While it's mid-winter here (and not the best time to see the diversity and colour of grasslands), I was impressed by the scale of grassland protection being achieved.
|In some areas, it is obvious that overgrazing in the past has|
led to dramatic soil loss. Large, bare scalds result and there is almost
no recolonization by native species from the surrounding grassland.
Thursday, 31 May 2012
No matter what people say, doing ecology is hard! Natural systems are, after all, complex. There are lots of factors that affect ecological processes, and teasing them out can be a challenge. Hence, trying to decide what to study can be a daunting task for any new grad student. Funnily enough, however, modern ecology is not data (or technique or computation) limited – it’s often ideas limited. If you are lucky (like I was), you get to study the "low-hanging fruit" - the questions that need to be answered first before you can move on to deeper understanding. Do grassland plants have soil stored seeds? Is germination stimulated by fire? How big does a gap in the grassland canopy need to be for recruitment of forbs? Once these questions have been picked off, you'll have to think more critically about the next round of obvious things to ask. And this is the challenge.
Hence, when choosing a research project, it's advisable to first read widely, see what’s going on in your field (and related fields), and identify some general question or idea that you can address in your own system? This means being inquisitive and wanting to know where the field is at and how you might contribute meaningfully.
So, how important should this question be?
That is a difficult question to answer. Publishing metrics (Impact Factors, H-scores, etc) and funding trends mean that you should have your eye "on the game" if you want to make ecological research your career. But this doesn't guarantee you'll do good science. Good science involves carefully thought out hypotheses, and well-designed tests of these hypotheses. And to succeed, I think it is critical that you passionately believe in the research you are doing - you own it! Hence, jumping on the latest "hot topic" in ecology (think the productivity-richness debate) might make your research seem current, but it is just as likely to move quickly on. Good ecological science, however, will stand the test of time.
There are two general observations I'd make when it comes to developing research questions:
First, avoid testing poorly developed hypotheses / theories with data you really don't understand and which wasn’t collected for the purpose. Trying to make your data fit a question isn't good science. That said, the recent surge in meta-analyses shows that when such data do exist, they can provide powerful insights that site by site studies just can't achieve.
Second, selecting a topic based on the choice of tool, not because of the question, is a no-no in my opinion. I’ve seen papers that seem to imply their study is important simply because they used [insert latest fad or bandwagon here]. Bandwagons that depend heavily on technical proficiency might make your research look great, but from my perspective, it is much easier to learn a new skill than to do original, ground-breaking science.
Of course, this is my personal view on the matter and you may disagree. There is no one or right approach here. That said, I'm a question-driven person. Tools are just that: tools! Good luck navigating a research thesis - it really is one the best things you'll ever do - particularly if you find a topic that grabs you and acknowledges those who came before you!!
I'll leave you with a recent comment I saw from Steve Packard (in Ian Lunt's excellent blog) - I thought it was apt (he was talking about the early days of restoration ecology):
"restoration was in the early Wright Brothers stage of flight. We were barely getting off the ground, but we were tackling the most fun and fundamental questions...............in the Wright Brothers’ day, learned academics were also trying to explore flight, but the Wrights made the key discoveries because they had the hammers and wrenches in their own hands and did their own flying."
Friday, 11 May 2012
|Cooper Street grassland, dominated by the C4 grass Themeda triandra|
| Grazed grassland on the Northern Plains. |
How many of the 18 golf balls can you see?
What does this tell us about biomass and the need for biomass reduction?
(Photo: John Morgan)
|The Plains Wanderer|