25 July 2014

Biological Warfare! Organic Management of Pests 101

This blog post was written by postgraduate student Andrew Kirk in the course, Research Methods in Ecology (Ecol608). Andrew revisits a Lincoln University research area that looks at managing insect pests in organic crops from 2007.

 
Organic visions in Tuscany, Italy courtesy of Chavelli
on Flickr creative commons





Interested in organic agriculture? You're not alone. Many of us were drawn to agriculture somewhere along the line by visions of warm summer days, rolling hills, and pesticide-free produce. However, if it were that simple, everyone would grow crops organically. No 20th Century farmer would have ever abandoned the traditional practices for the forbidden fruit of the synthetic chemical. Alas, organic agriculture is tough and it most definitely is dirty.

While the challenges faced in an organic production system are numerous, we will focus here on the strategies available for the management of arthropod pests. A tremendous resource is available on this topic in the 2007 work of Zehnder, Gurr, Kuhne, Wade, Wratten, and Wyss. That review will serve as the foundation for my discussion.

The framework outlined by these authors is based on the idea of Integrated Pest Management (IPM). As the name indicates, this type of regime incorporates preventative measures, instead of simply relying on reactive measures such as the application of agrichemicals. Most conventional agriculture systems would fit the latter description, leaning heavily on agrichemicals to solve a problem after it has taken hold. However, most farmers are intelligent, practical people. Synthetic chemicals, pesticides in our context, are often very cheap in the short-term compared to the cost of integrating Ecosystem Services into every level of production. There is no doubt, on the other hand, that pesticide residue is everywhere in our world, even on organic produce that we would like to assume to be safe. For instance, have a quick look at the toxicity report for copper sulphate, one of the most widely applied organic pesticides. With that in mind, what steps can be taken to minimise the use of chemicals on our crops?

The first phase of organic pest management includes the cultural practices that can help regulate pest populations. Most basic among these is site selection. An interesting example here is the geographic distribution of fruit production in the United States. 65 per cent of this production can be found in Western states with an arid summer climate that is inhospitable to many of the devastating insect and fungi pests of horticulture. Anecdotally, much of the fruit grown in other highlighted areas of that map is native to its respective location and has internal mechanisms for dealing with pest problems. On a more local level, many "old-timers" in an agricultural community will often gladly impart some knowledge about the best site for a particular crop.

Isolation and rotation are also of particular importance in devising a strategy for cultural management of pests. Essentially, the idea is to disrupt the spread of a particular pest by limiting the area in which it thrives. One can achieve this by planting a diverse range of crops, or rotating them, to create a wider range of environments for a pest to deal with. One can easily see how this idea conflicts with the monoculture situation found in many developed countries. On the other hand, veering away from monoculture will increase the cost of management in many instances. Proponents of an IPM system will probably counter-argue that this investment will be returned through reduced input costs and spillover benefits. So maybe we'll keep moving!

Inter-row and under-vine cover crops are often used as a
substitute for crop rotation in Viticulture, for the purpose
of attracting beneficial insects to compete with harmful
insects. Photo by Bela Hausmann on Flickr creative
commons.
Next, we turn to the ecological engineering to initiate our second phase of pest management. At the centre of this idea is the encouragement of ecosystems that allow the natural enemies and competitors of a given pest to thrive. This practice, known as conservation bio-control, is a relatively new idea in the applied ecology field. It requires one to do more than introduce a natural enemy as a bio-control agent, but to also manipulate its surroundings to create the desired result. It's sort of like being the referee of the football match and giving one side water breaks while the other team runs laps around the field. This is somewhat of an indirect approach to ecological engineering, though.

A more direct route might be found in intercropping, which works similarly to crop rotation. The core of both strategies is to make it as difficult as possible for the pest to establish a large core population. A variation on these is what is known as trap cropping. As the name indicates, this entails the luring of a pest species to a more attractive plant than the commercial crop in question. Zehnder et al. mention a classic example in New Zealand sweetcorn production, where the southern green stink bug is cleverly lured to the black mustard plant, instead.

The southern green stink bug is exhibit A of
effective trap cropping. Apparently it is
very fond of black mustard. Photo from Marcello
Consolo on creative commons via Flickr.
As alluded to before, the introduction of bio-control agents can be an important part of an organic pest management system.There are two types of bio-control releases and it is important to understand the difference. Inundation bio-control relies upon the released organisms, themselves, to alleviate the pest situation. An inoculation bio-control release takes a long view, one where the progeny of the inoculation group are expected to provide relief from the pest well into the future. Of particular note among the bio-control agent success stories is the development of Bacillus thuringensis, a fungi that is pathogenic to many arthropod species of insects. If that seems like biological warfare, it's because it is. Nevertheless, the track record of bio-control is decidedly mixed. Biological systems are complex, after all, and trying to manipulate them can be very tricky. For that reason, most researchers do not recommend bio-control agents by themselves, but rather as part of an IPM system.


Photo by jetsandzeppelins on Flickr
creative commons
Last comes the part of organic pest management that everyone likes to forget. That, of course, is the fact that some pesticides are permitted in an organic management regime. These chemicals are required to be biological or minerally-based, a definition that can seem quite arbitrary to those on the outside looking in. Rememember our old friend foe, copper sulphate! With regard to insects, though, a number of organic insecticide and pheromone products are available, but individual countries have different laws regulating their use. One interesting case is an insecticidal agent formed by the bacterium Saccharopolyspora spinosa during fermentation. This insecticide is thought to be environmentally safe in the long run, but is only permissible in the EU when obtained directly through fermentation, as opposed to a purification process. According to Zehnder et al. Discrepancy over regulation of organic insecticides represents one of the major challenges to the international trade of organic goods.
Organic reality courtesy of Antony*** on Flickr
creative commons
In truth, the organic management of pests is a challenge that deserves a review much longer than this. However, with some key concepts emphasised, you can branch out into a more detailed study of these strategies. Perhaps the most important thing to remember is that pest management starts on day one, not the day after the rains and humidity come. By understanding the life-cycle and tendencies of the pest, a grower can (try to) stay one step ahead of the pest. While that goal sounds like hard work and means less time for the enjoyment of sunny days and rolling hills, it is probably a more accurate depiction of the organic dream.


References

Zehnder, G., Gurr, G. M., Kühne, S., Wade, M. R., Wratten, S. D., & Wyss, E. (2007). Arthropod pest management in organic crops. Annu. Rev. Entomol., 52, 57-80.

22 July 2014

Which wine to take home? Sensory analyses of wine regions provides a clue


This blog post was written by postgraduate student Yunxuan Qin in the course, Research Methods in Ecology (Ecol608). Yunxuan revisits a Lincoln University research area that looks at how the region of origin affects wine traits from 2013.

Walking through wine aisles in a supermarket, different brands of wines fill the shelves. Besides all the appealing labels, there must be some inherent differences hidden within the bottles. Unless opened and tasted, the characteristics of the wine remain a secret. However, there is always a clue on the label, indicating where the grapevines were planted and the wine region of origin. Indeed, the expression of regionality is an important part of the philosophy of winemakers in all parts of the world.

Wine shelves in a French supermarket. Photo by christine592, CC BY-ND 2.0. 
That philosophy about regionality is based on a concept, "terroir", which has long been recognized but is difficult to interpret. Terroir itself includes many factors, such as climate, soil type, and topography. The common understanding of terroir is "a sense of place" that wines from specific geographic locations can be perceived as different. According to Patrick Iland's, past Senior Lecturer at The University of Adelaide, book The Grapevine: from the science to the practice of growing vines for wine, terroir modifies the flavor shape of wines from different sites within a region, sub-region and even within a vineyard block. Sometimes, the soil characteristics became the predominant factor impacting on vine growth, berry composition and wine style and quality, as indicated in the figure below.
A "vine to wine" web showing vine, berry and wine characteristics from terra rossa and deep black cracking clay soils. Adopted from The Grapevine: from the science to the practice of growing vines for wine, page 287. 
If we knew the differences in wine characteristics between regions, we could easily make the purchase decision by personal wine tasting preferences, instead of standing in front of wine shelves making a hopeful selection.

Another question is how to measure wine characteristics between regions? Wine characteristics are measured by sensory attributes, which are difficult to measure. Indeed, everything related to human sensation is hard to interpret. Variables such as personal odor threshold, physiological status (with perceived astringency by saliva as an example), psychological status (with emotional attributes and wine perception as an example) and descriptive vocabulary are examples. Thus, these variables are the reason why human perception of wines will vary from person to person, which makes it difficult and impossible to establish a standardized wine tasting note for every individual wine.

A recent study from Elizabeth Tomasino and co-workers aimed at measuring the differences in Pinot noir wine according to their sensory attributes (e.g. aroma, in-mouth flavor, mouthfeel) from four regions in New Zealand. Pinot noir, one of the noblest red grape varieties, is now the most widely planted red grape variety in New Zealand with these wines frequently compared to those from Burgundy. Several degrees of latitude were covered, including Central Otago, Marlborough, Martinborough, and Waipara. These regions were studied as Pinot noir is a locally important wine variety in these places.

How did they determine wine characteristics according to different regions? Elizabeth and co-workers did a preliminary tasting by six panelists who afterwards, listed wine aroma and palate descriptors for each of the wines. Combined with previous sensory work, a final list came out, including twenty-five attributes (fifteen for aroma, four for in-mouth flavor, six for mouth-feel). The formal tasting then conducted by asking twenty-one panelists to rank the intensity of each of the twenty-five attribute.

As customers, which Pinot noir wine shall we choose from the four regions? According to the results from Elizabeth and co-workers, you can have following options. If you want something red and fruity, you'd better choose Marlborough Pinot noir wine. It was characterized by greater raspberry and red cherry aromas, a red fruit in-mouth flavor, and longer finish length with a more harmonious balance. If you prefer a note of dark fruits and oak, Martinborough Pinot noir wine should be your first choice. Greater black cherry, oak, and spice aromas and oak tannin mouthfeel describe this wine. If you desire a herbal note in your "glass of wine", then the Waipara Pinot noir will be recommended for greater barnyard with violet aromas and a decent in-mouth fruit density/concentration. If you want something neutral, choosing Central Otago Pinot noir wine would be wise. It was the intermediate one and had fuller body.

The sensory table, filled with many of the aromas wine may possess.
Photo by H. C., CC BY-NC 2.0CC BY-NC 2.0
Based on the knowledge of wine characteristics upon corresponding regions and your own preference, followed by checking the region on the label, it won't be hard to make a decision. Indeed, you already establish an expectation before opening the bottle. Another choice is doing a blind selection, and having fun to discovery the secret hidden in the bottle.

Nevertheless, nature plays a magical role on wine sensory profiles/styles according to different regions. We often address "terroir" to roughly explain the cause, but which factor of the terrior contributes the most to the differentiation remains to be discovered by scientists. Actually, one of my colleague is currently working on it (check the wine research topics in Lincoln University).

How reliable is Elizabeth research results? You have to find out by yourself. Enjoy your wine. Cheers!

Reference
Elizabeth Tomasino, Roland Harrison, Richard Sedcole, and Andy Frost,(2013) Regional differentiation of New Zealand Pinot noir wine by wine professionals using canonical variate analysis. American Journal of Enology and Viticulture.64, 357–363.

Iland, P. and Promotions, P.I.W., (2011) The grapevine: from the science to the practice of growing vines for wine. Patrick Iland Wine Promotions.



21 July 2014

The Lord of the Rings: how dendrochronology leads to a better understanding of climate dynamics


This blog post was written by postgraduate student Stefan Unterrader as part of the course, Research Methods in Ecology (Ecol608). Stefan revisits a Lincoln University research area that looks at historical climate data taken from tree rings in 2010.

Previously... on the global climate change show - It is well understood that we are facing ongoing warming of our planet's climate. Whether or not we are responsible for this process (and we are), rising temperatures around the globe have been observed for at least the last couple of decades. Although our behaviour is recognized today as a significant influencing factor for Earth's climate, it is not the only driver for today's changing climate. To get a grip on these drivers scientists often use little helpers, such as tree rings, that carry astounding potential for this task. Richard Duncan, a former professor at Lincoln University, and Pavla Fenwick, a former Lincoln PhD student, are among those scientists who are hot on the scent of such internal climate drivers using tree-ring dates from a native New Zealand tree, the pink pine. Their team of dendrochronologists - scientists who date tree-rings - pursue a promising lead which links internal climate variation to regional temperature patterns and try to explain phenomena that do not match the general global warming trend.

Residents of the Arctic Circle are concerned about rising
temperatures (Photo by Payton Chung). Tree rings can help
to better understand who's behind global warming and
how to mitigate its consequences.

Climate Change in a nutshell: Greenhouse gas concentrations were on the rise throughout the 20th century and global temperature mainly followed this worrying trend. But the devil is in the details: local and even regional temperature patterns around the globe had the cheek to behave differently. And as if this isn't enough, some cooling periods in the northern hemisphere have coincided with some rapid increases of temperature in New Zealand during the same period  (for instance, from 1940-1975). So what’s behind all this? Have New Zealanders been polluting the air to such an extent that they generate their own little hot spot? Well, chances are that humankind isn't alone being in the driver's seat to this mess. 
 


Climate proxy: extracting tree rings
 from a slice of wood (Norway spruce) and
plotting its biological growth-curve.
(Figure from the author's thesis.)

Back to the Future: In general, global climate is known to be driven by both natural and anthropogenic external forcing as well as by internal dynamics. In order to get a glimpse of Earth's climatic behaviour climatologists can use what are known as climate proxies: preserved physical characteristics of the Earth's past and present climate. Such proxy data allow for a reconstruction of climatic conditions from periods where no instrumental or historical records are available. Tree-rings can be used as such proxies because some trees, such as conifers growing in a temperate climate, will build up one tree-ring each year to grow in both size and rigidity. Based on adequate temperatures and moisture the duration of each growing season will determine the widths of tree rings: high temperatures will generally allow for wider tree-rings, and vice versa. And since many NZ tree species are climatically sensitive enough to temperature for this to be seen in their tree ring widths, we can use their tree-ring sequences as a substitution for instrumental climate records. This is actually quite useful as instrumental coverage here in New Zealand only goes back to about 1850. 

The hunt for understanding internal climate variability: Because of its isolated location and exposure to considerably high mountain ranges, New Zealand's climate is highly sensitive to variations in atmospheric circulation, the movement of air and thermal energy across the globe. With its native forests that contain many long-lived tree species, NZ is the perfect dendrochronology-lab for investigating changes in such climate circulation patterns. In their 2010 study, Duncan and his colleagues established a tree-ring chronology (a timeline based on a great number of connected, dated tree-ring samples) for Halocarpus biformis, a tree species endemic to NZ and commonly known as pink pine. Duncan's team was able to gather samples whose tree-rings were strongly influenced by temperature and significantly corresponded to instrumental temperature data in NZ. Based on this chronology they could reconstruct the mean annual temperature in NZ since the 14th century. Apart from verifying NZ's instrumental records the authors also observed several departures from a global trend of rising temperatures. On top of that, the behaviour of NZ temperatures is not in line with northern hemisphere temperatures. In fact, they appear to be sometimes directly out of phase with those in the northern hemisphere.
 
Who's in charge? Differences in climate patterns between the northern and southern hemispheres have typically been explained by the spatial variation of "radiative forcing": the effects of solar radiation, volcanoes and aerosols on Earth's climate, which all vary both in space and time. In contrast to such a global forcing, scientists identified phases when the southern hemisphere began to warm more rapidly while parts of the northern hemisphere experienced cooling temperatures. Since previous studies already identified regional climate drivers as strongly influencing large-scale temperature variations across the globe, Richard Duncan and his team took a closer look on the main modes of such internal variation: the Interdecal Pacific Oscillation (IPO) and the Atlantic Multidecadal Oscillation (AMO) which can both be derived by measuring the sea surface temperature.
 

Pink pines on Waharoa Saddle, Arthur's Pass National Park,
New Zealand (Photo kindly provided by Chris Morse).
One Pine to rule them all:  Through comparing the variations in the Pacific and Atlantic Oscillation patterns with their pink pine tree-ring chronology, Duncan and his colleagues were able to link New Zealand's temperatures to these internal oscillations for the past 550 years. At the same time they identified time intervals where NZ temperatures follow northern hemisphere temperatures and therefore a global warming trend more closely. To make a long story short, these opposing climate states (in-phase or out-of-phase with global warming) recur on a more or less regular basis and can hardly be explained by us polluting the air alone. While our influence on Earth's climate is beyond doubt, this study reinforces previous research where natural climate variation on a more regional scale still plays a powerful role in controlling New Zealand's temperatures! The story of this NZ pink pine chronology not only shows how valuable tree-rings can be for reconstructing past temperatures but also reminds us that the term "global warming" may only tell parts of the story.  


...to be continued: The study by Duncan and his colleagues is not the last piece of work in this area. The University of Auckland's dendrochronology-lab, for example, is primarily investigating kauri trees and has built up kauri tree-ring records for the last several thousand years. Tree-ring records stretching over such long time scales have been related to El Niño/Southern Oscillation  (ENSO) activity which is another key climate driver for New Zealand and likely to be more dominant in the decades to come. A current overview of what has already been done with tree-rings and other climate proxies on the southern hemisphere was given by Neukom and Gergis shortly after the release of the pink pine study. And there's definitely more to come - I wouldn't wonder if tree rings will stay a key indicator for understanding New Zealand's past and future climate. 


16 July 2014

Illuminating Behaviour


This blog post was written by postgraduate student Davena Watkin as part of the course, Research Methods in Ecology (Ecol608). Davena revisits a Lincoln University research area that looks at a study of how possums respond to moonlight in 2011.


The moon has a face like the clock in the hall;
She shines on thieves on the garden wall,
On streets and fields and harbour quays,
And birdies asleep in the forks of the trees.

The squalling cat and the squeaking mouse,
The howling dog by the door of the house,
The bat that lies in bed at noon,
All love to be out by the light of the moon.

 excerpt from The Moon by R. L. Stevenson

For our species, the moon is a theme of many literary and cultural ideas. And it's more than just waxing lyrical; we also have a long history of attributing human behaviour to moon phases. Calling someone a lunatic’ is a reference to the historic belief that prolonged exposure to moonlight caused insanity and epilepsy. In folklore, a full moon in some instances could also mean turning into a hairy, rampaging beast; lycanthropy is popular in many modern fictions.

Morepork: a native nocturnal predator.
Photo by russellstreet
As it turns out, ecologists are similarly fascinated with the effects of lunar light on behaviour, though for more down-to-earth reasons. Light, including moonlight, is an important regulator of the circadian rhythms of animals. Nocturnal animals are known to alter their foraging behaviour under higher levels of illumination, and such studies have their own moon-related jargon. Animals that avoid moonlit nights are known as ‘lunar phobic’, while animals that are more active on moonlit nights are known as ‘lunar philic’. 

Typically, small terrestrial mammals that are preyed on by higher-order nocturnal predators exhibit lunar phobia, while the opposite is usually true of their predators. In fact, contrary to Robert Louis Stevenson’s poem, mice and some bats are both lunar phobics. Lunar phobia is thought to be a form of predator avoidance, as more light increases the ability of visual hunters to detect prey.

The Ecology Department at Lincoln University have their own literary works on such behaviour. A recent example is a study that was undertaken by University of Göttingen masters student, Jessica Parisi, in 2011. The research sheds new light on the activity levels of brushtailed possums (Trichosurus vulpecula) in New Zealand under full moon and new moon phases. 

Brushtailed possums are native to Australia, where they are preyed on by snakes, eagles, foxes and dingos. As such, Australian possums display anti-predator behaviour by avoiding well-lit open areas. It was expected that the possums in Jessica's study would therefore be more active during new moons

New Zealand possum nocturnal behaviour:
a dramatic re-creation of the study findings.
Picture from Jeff Carter (modified)
In fact, Jessica found the opposite: that possum activity was lessened during new moons in forested areas. Possum activity was also still high in open scrub-land even during full moons.

Possums are perfectly capable of clambering around tree tops in the dark, so possum foraging strategies must have changed since their introduction into New Zealand. Jessica's results suggest that New Zealand possums don't need to be lunar phobic to avoid predators. Possums don't have many predators in New Zealand, but young possums are sometimes preyed on by feral cats. The feral cat is an ambush predator. It is likely that a preference for high visibility prevents a possum from being attacked out of the black by feline foe.

Caught on camera trap: possums 
interacting with wax tags, which
are used to monitor possum density.
Photo from Parisi, 2011
Brushtailed possums make regular appearances on this blog for one big reason: they are a notorious pest in New Zealand. As opportunistic omnivores, they cause significant tree defoliation and pose a threat to large endemic invertebrates and native chicks. Their widespread distribution also facilitates the spread of bovine tuberculosis. Hence, a great deal of research goes into finding the most effective ways to control possums in New Zealand. Pest management policy mandates that possum density is kept below a certain threshold and, as such, continual monitoring of possum numbers is required to show how effective ongoing control methods are and when further control needs to be undertaken. 

This research has important implications for the timing of possum control. Poisoning and trapping during times of greatest activity will conceivably increase possum encounter rates with control measures. Control operations may therefore achieve threshold values faster if populations are targeted during peak lunar phases. Similarly, monitoring using indirect measures should achieve greater precision if standardised to particular times of the month. Focusing control on open areas may also be particularly beneficial regardless of moon phase. 

More than anything, the study highlights the importance of behavioural studies for applied ecology. "Unless we fully understand pest animal behaviour, how can we effectively manage them?" asks James Ross, the supervisor of the study. Spoiler alert: we can’t. Behavioural ecology is essential for informing conservation and pest management, and helps us sort fact from fiction. As such, it is a valuable scientific pursuit. To believe otherwise is lunacy.


"AWOOOooo!" 
Picture by DCW
For more works from Lincoln University on the effect of the moon on behaviour, including the one discussed here, see:

Lennon, J. S. (1998). The Effect of Moonlight Intensity and Moon Phase on Feeding Patterns of Common Brushtail Possums. (Master's thesis, Lincoln University, 1998.) Retrieved from http://hdl.handle.net/10182/3062
 

Parisi, J. D. (2011). The Influence of Lunar Phase on Indirect Indices of Activity for the Common Brushtailed Possum (Trichosurus vulpecula) on Banks Peninsula, New Zealand. (Unpublished master's thesis). Lincoln University, Lincoln, New Zealand.

15 July 2014

Bartering Biodiversity - Offset or Upset?

This blog post was written by postgraduate student Cathy Mountier as part of the course, Research Methods in Ecology (Ecol608).
Cathy revisits a Lincoln University research area that looks at the value of biodiversity offsets published in 2008.

I love a win-win approach to problem solving. Wouldn’t it be great to have win-win outcomes where development projects could go ahead, creating economic benefits for local communities, and at the same time protect and enhance natural assets, including native biodiversity? (Native critters and organisms such as plants, birds, fish, insects, and fungi).

Biodiversity offsetting is designed to meet these win-win goals. Offsetting trades biodiversity loss caused by development, for a biodiversity gain elsewhere. For example the construction of a new road may require diverting a stream into a covered drain, and the offsetting might involve riparian planting and restoration of another stream in exchange. Or if a new subdivision involved bulldozing some native vegetation, this damage might be offset by planting a reserve with native trees.

In principle offsetting sounds really good - aiming for no net loss or even a net gain of biodiversity while promoting development. However, researchers looking at the mechanisms and outcomes of biodiversity offsetting concluded that in practice the outcomes for biodiversity are rarely good.

So what are the problems? For starters, there is the issue of “currency”. To do a deal, to trade or barter or “offset”, the parties involved need to have some kind of agreed system of valuing the objects of bargaining, in order to come up with a fair deal. It’s an apples and oranges problem. Is one bulldozed hillside of established vegetation equivalent to another newly planted “restored” hillside?


Biodiversity offsetting - a balancing act.
Is the goal of no net loss of biodiversity really being met?
(picture modified)

Biodiversity assets do not lend themselves easily to interchangeability. Enhancing habitat for one species is not necessarily a good exchange for destroying habitat of another species. And species don’t exist alone anyway - ecosystems are complex and interwoven. There have been many suggested improvements to the way “currencies” are calculated and assessed, along with other proposed improvements to the offsetting system.

But Susan Walker, Ann Brower, Theo Stephens and William Lee researched biodiversity offsetting and discovered more fundamental reasons why offsetting is very unlikely to succeed in delivering its stated goals. In their paper “Why bartering biodiversity fails” they draw a picture of a triangle of players in the potential offsetting deal, and show that the goals of just one of these groups is likely to dominate the outcomes.

First, there are traders - the developers who want to invest in a new project, which requires damaging or destroying some natural habitat. I was surprised to see that restoration/offset providers are also included as traders, but of course they also stand to gain from the business created if an offsetting project goes ahead. Second, then there are the biodiversity protection interests, which are typically members of the public who care, local community groups, such as “friends of ……”, and broader based advocacy groups, such as Forest and Bird. Third, there are regulatory officials. These are the people in government departments and local government offices who are charged with facilitating these negotiations and making sure the agreed outcomes are followed through.

This system of three types of players, unfortunately, always tends to tip towards the traders interests. The traders have a vested interest - they stand to gain financially from the proposed development. They have money to invest in the project, and are motivated to spend some resources on getting the project off the ground.

‘Biodiversity protection interests’ people, on the other hand, do not have vested interests. They are often people who recognize the intrinsic values of biodiversity and want to protect the bits that we humans haven’t yet destroyed. They do not stand to gain financially, nor typically do individuals or community groups have a lot of funds to work with. Larger groups, such as Forest and Bird, do have infrastructure and more financial resources, but because they are national organisations it is difficult for them to focus efforts on specific concerns at a case by case, local level. Whereas the developers interest is concentrated on the specific project, environmental protectors interests are often spread wide and thin.

Regulatory officials are required, under the RMA (Resource Management Act 1991) to take care of biodiversity in their region on behalf of all of us - the citizens and taxpayers of NZ. This includes ensuring follow-through, as in compliance with agreed conditions and monitoring of outcomes. But because of the nature of bureaucracy, the pressure on these folks to tick boxes and serve the system may at times override or obscure the impulse to serve the greater good.




Ann Brower at Lincoln University is one of the authors of the bartering biodiversity paper mentioned above. She has highlighted the triangle of players described here, several times, first and most famously in her book “Who owns the high country?” - an exposé of the tenure review process for South Island high country stations. And then, together with other authors, in a paper about the assessment of significant natural areas under the RMA. In all three of these studies, the dynamics between the three groups of “players” follow a similar pattern - traders, biodiversity protection interests and regulatory officials, and all result in less than satisfactory outcomes for biodiversity.

Basically it is a competition between the motivated few and the disorganised many, refereed by the bureaucratically hamstrung, some of whom seem to forget that they are supposed to be looking after the public good and the unique indigenous biodiversity of this country. A study of biodiversity offsetting in Canada, the USA and Australia, by Joe Bull and others, also found that the challenges of ensuring compliance and monitoring, and “conceptual flaws in the approach”, often prevent biodiversity offset schemes from meeting conservation objectives. The concept of offsetting suggests that almost anything is negotiable and unfortunately both the traders and officials have more incentive to facilitate a deal than to ensure biodiversity protection. Hmmm.

Offsetting has the potential to “legitimise” biodiversity loss, and allow developers to skip the steps of looking for ways to completely avoid, or minimise damage or loss and go straight to the trading option. Walker, Brower and colleagues conclude that “while compensation and no net loss are worthy goals, and bartering biodiversity might appear more promising than simple and weakly enforced prohibitions…..policies that enable biodiversity trading may perversely yield worse biodiversity outcomes”. Frankly, it is looking a bit grim.

Some biodiversity offsetting outcomes are undoubtedly better than others, but Walker, Brower, Stephens and Lee argue that overall, simple prohibitions to protect biodiversity, even if imperfectly enforced, would be more effective than biodiversity offsetting.

There is an ongoing discussion about biodiversity offsetting and other forms of ‘compensation for ecological harm’ in New Zealand, and around the world. This Bartering Biodiversity paper has been cited in many other papers (See links to a few at the bottom of this page). The team that wrote "Why Bartering Biodiversity Fails" are a mixed bunch, blending their various fields of expertise, from ecology and conservation to economics and political science. Awesome! They have shown that "tweaking" the offsetting system is unlikely to create the desired outcomes for biodiversity, because of the underlying dynamics between the groups involved.

Biodiversity loss may look like an ecological problem, but ecology alone is not enough to deal with the reality of politics, bureaucracy and human behaviour. Collaboration between ecologists, social scientists, and policy makers is the way forward.


Some other papers about biodiversity offsetting and other forms of ecological compensation:

Biodiversity tradeoffs and offsets in impact assessment and decision making: can we stop the loss?
Susie Brownlie, Nicholas King; Jo Treweek

Ecological compensation: an evaluation of regulatory compliance in New Zealand
Marie A. Brown, Bruce D. Clarkson, Barry J. Barton; Chaitanya Joshi

Is there any empirical support for biodiversity offset policy?
Michael Curran, Stefanie Hellweg, and Jan Beck

Compensating for ecological harm – the state of play in New Zealand
Marie A. Brown, Bruce D. Clarkson, R.T. Theo Stephens and Barry J. Barton

11 July 2014

Future agriculture: what we gain and lose with organic farming

This blog post was written by postgraduate student Yuan Amata as part of the course, Research Methods in Ecology (Ecol608). Yuan revisits a Lincoln University research area that looks at soil quality from organic farming in 2010.

Tuner Organic farm
Photo by Paul Hamilton

Organic farming is on the rise around the world as it is considered a better alternative to conventional farming. However, problems with organic farming have also been reported. How does organic farming influence the environment? Is it possible for us to make improvements?

You may be wondering what the problems are. Before we talk about this, let's first clarify what organic farming is because I've found that many people are confused about the concept. So, what is organic farming? I found this to be a really tricky question. Lots of people have different ideas about organic farming, and what kinds of "organic" should be marketed as organic. As a result, organic standards have been created  by many countries and regions. If farms can meet the requirements of the standard, the products can be marketed as organic. Generally, these standard include the regulation of site selection, cultivation methods and crop condition. Synthetic pesticide and fertiliser are not allowed, but some pesticides can still be used under certain conditions.

Then, let's look at what we have gained and lost by growing crops organically according to a recent research. Leo Condron and his colleague in Lincoln University studied the environmental effects under organic farming systems in New Zealand. They started by investigating 'soil health' in organic farms. To evaluate 'soil health', some determining factors such as soil quality, nutrition dynamics and balance were tested.

Many problems from organic farms were reported in the research. Their were imbalances of phosphorus (P) and sulphur (S),  two essential nutrients for plant growth. This is because many native soils are low in P and S in New Zealand and synthetic fertilisers are forbidden in organic farming. Organic fertilisers, however, have relative low nutrient concentrations and, therefore, large amount of organic fertiliser may be needed to meet the nutrient needs of crop plants. In addition, it is also hard to control the degradation of organic materials. Because of these issues, organic farming can lose nutrients from the soil. For example, an organic farm in Canterbury was found with lower "Olsen P" and "phosphate-extractable S" than equivalent local native soil. Even even worse P and S budgets were found to be negative on biodynamic farms. In other words, the nutrients in soil cannot be kept in balance with ongoing cropping. Without intervention, the soil nutrient conditions will get progressively worse.


Soil in organic farm
photo by Amber Case
Organic farming is seen as better for the environment because of its lower nutrition losses. However, the authors also challenged the environmental benefits of organic farming. It is true that organic farming generally has a low nutrition loss especially in N and P. However, they pointed out that N losses may only depend on the quantity of N rather than the form. If the nutrition inputs are equal on an organic farm and a conventional farm, their impacts on environment are likely to be same.

Organic farming systems normally require more frequent soil cultivation to control pests and weeds. However, this practice can also damage soil aggregates and increase N loss by leaching. There is currently no strict standard to regulate the practice.

It is noticeable that certified/modern organic farming does not mean chemical free. Some chemicals are permitted to be used in organic farming system. Although these chemicals are regulated, many of them were still reported to have negative effects on the environment. For example, copper (Cu) compounds used for pest control will affect soil organisms under high concentrations. Rotenone is toxic to fish. Pyrethrum will kill some beneficial organisms. The fine dust of diatomaceous earth is a lung irritant. And so on. All of these could be a hidden danger for human health if the usage is not carefully managed.


Organic Berry Farm - Yakima
An Organic berry farm.
Photo by Mark Davis. CC BY-NC-ND 2.0

Despite there are problems, researchers also confirmed that organic farming has some advantages, such as improved soil structure and quality, especially compared to conventional farming. Therefore,  organic farming is still, typically, a better alternative to conventional farming. What I am trying to say is that organic farming is not a perfect option. Organic farming could have negative impacts on the environment if it cannot be well managed. However, the question can be raised about whether it is necessary to be organic if we just want cleaner products and less environmental impacts when natural fertilisers and pesticides could also generate environmental and healthy outputs? It is my view that we should focus more on how to produce healthier plant products with minimal impact on the earth rather than dogmatically believing all natural ingredients are best. I think it is better for future agriculture to use organic fertiliser as fundamental inputs combined with integrated pest management (IPM), but chemical fertiliser could also be used to keep the balance among soil nutrition, biological activity and plant growth. Pesticides should be avoided or only used in some limited conditions. In short, I think further agriculture should more focus on reducing negative environmental impacts. Chemical fertilisers and some pesticides could still be used, but should be treated as "medicine" rather than "food" for plants and soils.

I just hope future farming can be better for both the environment and people.


Reference:
Condron, L. M., Cameron, K. C., Di, H. J., Clough, T. J., Forbes, E. A., Mclaren, R. G., & Silva, R. G. (2010). A comparison of soil and environmental quality under organic and conventional farming systems in New Zealand. New Zealand Journal of Agricultural Research, 43(4), 443-466.

Chatting about prehistoric couch potatoes


Maybe we are not as inactive as we think
Our hunter-gatherer ancestors may not have been much more active than we are. Allison Ballance from Radio NZ interviewed Mike Hamlin and I about this idea this evening. You can hear the conversation by here. For more read about it here. As a bonus I talk about the evolution of penguin behaviour as well! For more on this read about it here and here.