EcoLincNZ

Category: student blog

  • Buried treasure: the hidden gems of alpine peatland

    Growing up, I had a fascination with pirates.

    I’m not sure if it was the fact that they stole buried treasure, sailed the seven seas, and broke all the rules or if I liked that they used the term “swashbuckling” to describe themselves. All I know is that I wanted to be exactly like Captain Jack Sparrow. Granted, Johnny Depp does quite well at making Jack Sparrow seem like the best and worst pirate at the same time, which definitely influences the likeability and comedy factor of the character.

    Peat Area in Perigi village, Pangkalan Lampam District, Ogan Komering Ilir Regency.
    Photo by Rifky/CIFOR cifor.org, CC BY-NC-ND 2.0 (Flickr)

    For the majority of the first Pirates of the Caribbean: The Curse of the Black Pearl, Sparrow, with the help of his slightly awkward, bumbling, and unlikely traveling companion, Will Turner (played by Orlando Bloom), attempts to chase down his precious pirate ship and crew of the Black Pearl.

    To steal back his ship and find treasure along the way, Sparrow and Turner must make their way through various tunnels and streams until they finally reach the be-all-and-end-all of all treasure rooms, full of the loot that the pirates have collected over the years.

    Oftentimes, to get to these places of “great treasure”, the pirates would use maps to find the hidden jewels they so desired, and if they were underground, well, they would dig for them!

    But what if hidden gems are not always jewels?

    Even Sparrow, the death-defying pirate who escapes prison, steals ships, drinks copious amounts of rum and loves treasure, says:

    “Not all treasure is silver and gold, mate.”

    Treasure is “wealth stored up or hoarded, something of great worth or value” and “a collection of precious things,” according to Merriam-Webster Dictionary. In terms of natural resources, water is a treasure.

    Water is crucial for humans. Water is also a critical worldwide currency and supports life as we know it. Beyond using water for cooking, cleaning, or washing, water is critical for supporting agricultural crops, farms and, therefore, our food sources. In many communities, water also has a spiritual value, more than a monetary or physical value. In New Zealand, the Whanganui River even has personhood status, highlighting just how important water is.

    Considered a natural treasure, water is extremely precious in dry, arid regions with little rainfall or annual precipitation, meaning plants and animals must adapt to limited water sources. The same applies to agriculture; farmers must adapt in dry regions, using water sparingly and wisely. In these regions, it is essential to understand where water comes from and goes to and how it is potentially stored underground upstream from agricultural land.

    Buried treasure, some might say.

    In the arid Chilean Andes, this treasure is buried in mountain peatland.

    Peatlands are wetlands with layers of compact and partially decomposed plants and organic material (i.e., dead and decaying plants) in water-logged soil. If you’ve heard of the “Tollund Man” (a well-preserved body from the Iron Age), then you’ve heard of peatland. Peatland may have standing water or vast swaths of very soggy ground, as pictured below. This makes it difficult to immediately understand their capacities to hold water.

    Great Kemeri Bog, Latvia. Photo by: Runa S. Lindebjerg, CC BY 2.0 (Flickr)

    Shelly MacDonell (Lincoln University) and a team led by Remi Valois and Nicole Schaffer investigated the ability of Chilean peatland in the Elqui Valley to store water and estimated its role in delivering water to agricultural areas via streams.

    The researchers chose a peatland (bofedal) in Spanish, called “Piuquenes” for their study because of its central location compared to surrounding peatlands and its elevation (approximately 3000 meters above sea level), making it a great representation of other Chilean alpine peatlands. This peatland was also chosen based on a proposal to place a dam at the edge of Piuquenes for agricultural water control downstream.

    To study the inner workings of Piuquenes, the researchers had to look below the surface. Picture someone on the beach using a metal detector to find potentially valuable items under the surface (like a modern-day pirate), and that is a very simplified view of the tools used to visualize the geology and structure of the peatland below the surface. However, using Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), the researchers were able to create a 3D image of what might be under the surface. Through this 3D image, they could calculate the potential storage capacity (volume) of the studied peatland and estimate the role of high-alpine peatland in the area’s water cycle.

    According to estimates by researchers, the peatland itself could hold between 164,000 and 243,000m3 of water. That’s between 66 and 97 Olympic-sized swimming pools worth of water!

    The study found that the Piuquenes peatland can actually contribute water to lower agricultural regions downstream. However, the peatland is also vulnerable to water loss through evapotranspiration, which is a fancy word for water that evaporates and is lost from the vegetation and soil.

    Despite this water loss, researchers determined that Piuquenes was still important for supporting the surrounding ecosystems and could still act as a significant reservoir (i.e., source of water) for downstream agriculture and livestock grazing. They also discovered that the peatland could shield the area from drought impacts because of its water capacity. This means Piuquenes peatland could deliver water to grazing and low land agricultural areas via streams and limit the most severe effects of drought even in low-rain seasons.

    In addition to storing water, the Piuquenes peatland can also help produce soil from the slow build-up of decaying plants, store carbon, help plants grow and provide watered grazing areas for livestock.

    Understanding the inner workings of Piuquenes advances our knowledge of high-alpine peatland and its natural benefits to lowland agriculture. This study also adds valuable information to the discussion of if and how a dam should be built at the edge of this high-alpine peatland.

    Piuquenes, although located in the Chilean Andes, is an excellent example of how critical preserving and conserving peatlands worldwide.

    Studies have further investigated the secrets and treasures of peatlands, such as the carbon storage capacity, internal chemistry and nutrient cycling effects on methane emissions, proving that peatland continues to be a valuable ecosystem and that there is indeed treasure hidden beneath the surface.

    Peatland in Torronsuo National Park, Tammela, Finland. Photo by: Tero Laakso, CC BY 2.0 (Flickr)

    Current efforts have also focused on how to conserve these valuable landscapes and how local management initiatives could be applied worldwide. For example, Global Peatlands Initiative is a group dedicated to informing people about the importance of peatlands and keeping you updated on peatlands around the world.

    I’m pretty sure Jack Sparrow wasn’t referring to peatland as the treasure in his quote about silver and gold, but he was on the right track. If only he had known about the inconspicuous treasure hidden in the high reaches of the Andes!

    So, next time you’re on a swashbuckling adventure, keep your eyes open for what might be lurking under the surface and could be even more precious than silver or gold.

    This article was prepared by Master of International Nature Conservation student Alaina Eckert as part of the ECOL608 Research Methods in Ecology course.

    P.S. Here is a really cool (and short) video about Peatland Protection from the UN!

  • Toxins help rare birds

    As a birder, there is a unique and somewhat pure excitement to seeing a bird you’ve never seen before – at least that’s my experience. Spotting a “lifer” (a.k.a. a species ‘new to you’ in birding lingo) comes with a feeling of accomplishment, especially if the bird turns out to be rare. For example, I could still tell you when and where I saw my first California condor, Great bustard, or Rock wren/tuke. Some birders, or “twitchers” to separate them from more casual birdwatchers, even make somewhat of a sport out of seeing as many rare species as possible. I recommend watching “The Big Year” if you want to learn more about this and have a good laugh while you’re at it.

    As a conservation biologist, spotting a rare bird often brings about feelings other than excitement. After the initial high, it leaves a little bit of a bitter taste behind because, more often than not, there is a not-so-great reason why a bird is rare.

    I feel this particularly strongly when birdwatching in New Zealand, where introduced predators have wreaked havoc on the unique and vulnerable bird life and caused many species to disappear from large parts of their natural ranges. Many native birds now survive in wildlife sanctuaries and are difficult to spot in the wild.

    “Since the arrival of humans, [59 species of bird] have been recorded as lost to extinction as a result of changes to the landscape and the introduction of predatory mammals.”

    Te Mana o Te Taiao – Aotearoa New Zealand Biodiversity Strategy 2020

    While New Zealand’s charismatic rarities certainly are a great addition to any twitcher’s life list, I find it hard to forget that some of these species are on the brink of extinction. The birdwatcher and conservation biologist in me are at odds when I go birdwatching here, and I never know how to feel when spotting a rare bird. When I saw my first yellowheads/mohua near the Blue Pools by Haast Pass, I felt ecstatic and sombre at the same time – it’s quite the dilemma.

    Rock wren in Fiordland. © Antonia Ulle

    The upside is that New Zealanders know the value of their native wildlife and are committed to conserving it. Native birds, along with other indigenous species, are considered taonga and, as such, an important part of the country’s national identity – why else would a kiwi shooting laser beams have been such a popular design for New Zealand’s alternative flag back in 2015?

    Naturally, making rare species not as rare is one of the cornerstones of New Zealand’s Biodiversity Strategy, and protecting native birds is a national priority. This goal goes hand in hand with eliminating the mammals that threaten their existence.

    On a landscape scale, predator control often requires dropping 1080 (a biodegradable poison) from helicopters and planes in the rugged backcountry to target mammals in areas that are otherwise hard to reach. Experts say that for birds with a remote and inaccessible range, such as rock wrens, kiwi, blue ducks/whio, yellow-crowned parakeets or mohua, that this is currently the only practical management tool. Despite research showing that the aerial application of 1080 helps the recovery of native bird populations, this strategy is often criticised by members of the public for being indiscriminate and endangering the very species it is supposed to protect.

    So, how does DOC make sure native birds aren’t dropping dead left, right and centre when they use 1080 for predator control? The answer is research, research and … more research! Preliminary research, follow-up research, and intensive monitoring of bird populations during pest control operations, all help the people in charge understand how 1080 affects native birds with the aim of reducing their poisoning risk is as low as possible during any 1080 drop.

    Some of this important research was done here at Lincoln University when Jakob Katzenberger and James Ross investigated how mohua were affected by a pest control operation using aerial 1080 in the Catlins State Forest Park back in 1999. Intensive monitoring before and after the 1080 drop showed that the control operation didn’t have unwanted non-target effects for mohua. More specifically, the researchers concluded that mohua numbers didn’t differ significantly before and immediately after the control operation.

    While this might not seem like the most exciting result, it tells an important story – that 1080 worked and only killed what it needed to kill. Now, in case you’re wondering if these results still hold true since the research for this study was carried out over 20 years ago – rest assured, they do. Studies conducted in the Landsborough, Dart and Routeburn valleys since then have shown that both mohua numbers and nesting success increased following predator control using 1080. In 2006 and 2009, nesting success of mohua was on average twice as high after 1080 than without it in the Dart and Routeburn valleys, and in the summer of 2015 89% of mohua nests in the area were successful.

    Another key takeaway from the study by Katzenberger and Ross is that the timing of 1080 control operations is critical to maximise the benefits for native species. While the 1080 drop in 1999 did not affect mohua in the Catlins negatively, it could have provided more benefits had it been timed better. Monitoring showed that a predator boom caused by beech masting in the summer after the 1080 drop caused drastic declines in the resident mohua population. Applying 1080 after this masting event could have reduced predator numbers and, therefore, protected mohua more effectively by providing a “predator free” window for them to breed.

    Benefits of aerial 1080 for mohua from the 2014 “Battle for Our Birds” pest control operations in the Dart valley.
    © Department of Conservation 2016

    In 2014, DOC managed to protect mohua and other natives in a year of heavy beech masting with the “Battle for Our Birds” campaign by applying aerial 1080 just before predator numbers skyrocketed. Without predator control, that beech mast and the resulting high predator numbers would have been detrimental for the populations of native animals. This is an excellent example of how protecting native species is a learning process, and how research helps us learn, and improve conservation practices.

    What we can take from this is that 1080 works and that native birds do better where it is used. Researchers don’t just leave it at that though. A lot is still being done to make aerial 1080 baiting as “bird proof” as possible and ensure that birds gain the maximum benefit from it. Baits are improved continuously, sowing rates are reduced, and bird populations are carefully monitored. Overall, 1080 baiting has come a long way since it was first done, and now is an effective tool to protect native species. Some people may always oppose the use of 1080 no matter how loud the science talks, but, to use the words of Dr Nick Smith, New Zealand’s 6th Minister of Conservation, “reason must trump prejudice about poisons when the very species that define our country are at stake”.

    I consider myself lucky to have seen many of New Zealand’s birds, rare or not. Some of the encounters I’ve had here have been quite magical and, to be honest, almost cheesy. Like the time I was hiking Gertrude saddle in Fiordland, wondering if I would get to see a rock wren – only to have one poke its head around a rock to check me out while I was having lunch. Or when a family of mohua landed in the trees right next to me in Hawdon valley and I got to watch them for a good half an hour.

    Mohua in Hawdon Valley. © Antonia Ulle

    With research continuously improving how introduced predators are controlled, I hope that, in the future, encounters like this will once again become the rule rather than the exception.

    This article was prepared by Master of International Nature Conservation student Antonia Ulle as part of the ECOL608 Research Methods in Ecology course.

    Katzenberger, J.K. & Ross, J.G. (2017). Mohoua ochrocephala abundance in the Catlins following aerial 1080 control. New Zealand Natural Science, 42, 1-8.

  • Seed coating: fungi protect maize from disease

    Did you know that seeds can wear coats, just like people? Different kinds of coats can be added to seeds to protect them for improved cultivation. How do seed-coatings work and what are the benefits for seeds wearing coats? There are several distinct strengths of seed coating. You will know a lot more about seed-coating, and a recent discovery that could be applied in maize seeds, after reading throughout this page.

    Recently, Federico Rivas-Franco, with colleages at Lincoln University and researchers around the world, discovered the benefits of coating maize seed with a kind of entomopathogenic fungi (Metarhizium species). Entomopathogenic is a technical word meaning insect killing, so this is a fungus that infects and kills insects. By adding a Metarhizium coating to maize seed, Federico found that maize plants grow taller than the untreated plants, when those plants are in the presence of the plant pathogenic fungus, Fusarium graminearum. That was a useful surprise!

    What’s more, the Metarhizium hyphae (the growing threads of the fungus) were observed growing on and in root tissues in all the Metarhizium treated maize with the coating. This showed that Metarhizium can live together with maize roots and had a consistent effect on defending maize plants from underground pests and plant pathogens (like Fusarium graminearum).

    Fusarium ear rot on maize
    Fusarium ear rot on maize.
    Image CC BY-NC-SA 2.0 by Thomas Lumpkin

    Many of you may be asking, what is Fusarium graminearum? It is a causative agent of several serious plant diseases. Fusarium graminearum can cause a devastating disaster on maize and lead to huge yield losses.

    Maize seeds, roots, stems and ears can all be easily infected by this fungal pathogen, which means maize plants are susceptible to Fusarium infections throughout the cultivation period. More terribly, not only maize, but also wheat, barley and rice can be infested by Fusarium. It is quite annoying, right? It can be expensive for farmers. What if people and stock eat the contaminated crops? The answer is they will get ill, and the symptoms including vomiting, stomach ache and so on. Fusarium infected maize can not be sold as food, so farmers need a solution to protect their crop from this nasty fungus.

    Metarhizium species are a kind of fungus that is generally used to biocontrol insect pests. However, the biocontrol ability of Metarhizium not only works for insects but also against plant pathogens like Fusarium. That’s quite the superpower!

    In 1870s, Metarhizium was first extracted and identified by a Russia scientist Élie Metchnikoff (Илья Ильич Мечников in Russian). He found that there were hypha growing from dead beetles. Initially, the hypha was white, then turned green, and then a darker green. After molecular techniques were introduced at the end of 20th century, new species of Metarhizium species have continued to be identified.

    How does Metarhizium combine with seed coats? In fact, it is microsclerotia, which is a resistant structure grown by the fungus, that is added into seed coats. Over the past decade, it has been discovered that entomopathogenic fungi are able to produce high concentrations of microsclerotia when grown in liquid media.

    Microsclerotia are desiccation tolerant and have excellent storage stability. More importantly, they are capable of producing high quantities of infective conidia (asexual spores) after rehydration. All these attributes make microsclerotia an excellent agent to be used in seed coating.

    Besides preventing plant diseases and pests, different seed coatings can also make seeds grow healthier and improve cold resistance (drought & moisture resistance as well). That’s because commercial seed coatings are composite products made up of combinations of insecticides, fungicides, compound fertilizers, trace elements, plant growth regulators or more other chemical or physical components. What’s more, same size and shape of coated seeds make it much easier for mechanical sowing.

    After using seed coatings, farmers don’t need to use as many insecticides and fungicides to protect the emerging young plants. This reduces the pollution in the environment and the insecticide (or fungicide) resistance of the plant.

    This research demonstrated the excellent potential for adding Metarhizium to commercial seed coatings for maize. We have seen the good outcomes in the experimental field. Let’s wait and see the next step for figuring out how best to do this in commercial production.

    This article was prepared by Master of Science postgraduate student Xiaohan Wang as part of the ECOL608 Research Methods in Ecology course.

  • Small animals show us the value of old natural forests

    Hambach. You are in Germany right now, halfway between Cologne and the Belgian border. I’d like to warmly welcome you to the Hambach forest – an ancient forest that is dominated by oak and hornbeam, representing a rare forest type in modern Germany. The Hambach forest is the last remnant of a forest that ranged over wide flat plains since the end of the last ice age around 12,000 years ago. Regrettably, it has become famous for being gradually absorbed by a vast hole!

    Tree house in the Hambach forest.
    CC BY-NC 2.0 by Tim Wagner, Flickr

    The Hambach forest used to range over an area of around 5 500 ha. During the past four decades, around 90 percent has already vanished. What remains today is not a normal forest anymore – idyllic, undisturbed, and peaceful. The forest is not only threatened by further sliding into the hole. In 2018, the Hambach forest also became the stage for one of the largest major police operations, owing to another curiosity about the Hambach forest: it is inhabited by people, living in tree houses. Occupying the forest, they want to protect what is left of it and demonstrate against the further expansion of the hole. However, since the forest is privately owned by the company that sacrifices it for the hole, activists were forced out of the forest with the help of police power – before occupying it again.

    So what is the gigantic hole? It is the result of four decades of open-cast coal mining in the Hambach region. However, its further growth will eventually take an end. For the year 2038, Germany has committed itself to complete the coal phase-out, a critical step for Germany’s energy transition. Until then, coal power stations in Germany can be fuelled by coal – extracted from German coal mines (“holes”), with a spectacularly bad impact on the climate. Still, based on the coal-phase out, the remaining part of the Hambach forest can be saved.

    Hambach open-cast coal mining hole.
    CC BY-SA 2.0 by Traveling Tourist, Flickr

    Growing up close to the Hambach forest, that received international attention in the environmental and climate movement, I’ve been concerned about one question for a very long time: How can we replace an ancient forest that is destroyed for mining purposes?

    “If we are moving several villages, people, and a motorway for the open-cast coal mining, why don’t we also move the forest?” That is how people in my region would have addressed this question in the past. Believe me or not, that’s exactly what has been done. At one end of the gigantic hole, the largest artifical hill worldwide was created and recultivated with trees. It serves the region now as a recreation area, comprising an about 70km network of hiking trails. “Forest is forest. There is no difference”, people say in my region. So why be concerned?

    But is it really that easy? Are humans really able to shape a new forest within a few years as a replacement for a destroyed ancient forest, that has the same value for biodiversity and people? And will the planted trees provide an appropriate habitat for all mammals, birds, insects, spiders, herbs, lichens and other important life forms that used to inhabit the lost forest?

    In many countries around the world, there are nowadays regulations regarding compensation and restoration measures that mining and other companies have to fulfil when their activities destroy land. However, in reality, is it always possible to restore an ecosystem that has undergone complete degradation from a natural forest to a mining site, back to its original state and biodiversity value? Otherwise, it is possible to shape a new ecosystem with the same values at another site – like it was aimed with the planted artifical hill as a compensation for the destruction of the Hambach forest? Fortunately, there are ecologists who have learned the answers to these questions. Closely monitoring the process of ecosystem restoration they can tell how successful undertaken restoration efforts are for biodiversity.

    So, now that we’ve already practiced thinking in great dimensions, let’s undertake a great jump to another mined forest – we’re jumping off Germany, over Italy and the Mediterranean Sea, crossing the Arabian Peninsula and the Indian Ocean, passing Australia and are finally landing in… Auckland! Well done! We’re standing here at the Hunua Quarry site, near Papakura in South Auckland. It is part of the Hunua ranges that consist of over 20 000 ha of native forest, comprising tawa, podocarp, kauri–hard beech, and taraire forest as main vegetation types.

    The Hunua Ranges.
    CC BY-NC 2.0 by Neil Hunt, Flickr

    The Hunua Quarry is managed by Winston Aggregates, New Zealand’s largest aggregates provider. As a restoration measure, in six years over 140 000 plants have been planted in this highly modified habitat after quarrying. The aim is to provide a new forest as a replacement of the forest area destroyed. Next to the restoration area, you can still recognize unrestored areas of exotic grassland that have established after quarrying, as well as undisturbed mature native forest.

    Researchers from Lincoln University (Mike Bowie and colleagues) studied the invertebrate communities at Hunua Quarry, including wetas, beetles, cockroaches, crickets, spiders, centipedes, earthworms, ants, flies, mites, moths, slugs and snails, amongst many others. Although rather small animals, invertebrates are essential for the functioning and health of ecosystems, thereby making an important contribution to biodiversity. The objective of their study was to develop a better technique for the assessment of restoration success after mining, using invertebrates as bioindicators. Bioindicators are species that react sensitively to changes in their environment so that they can be used to assess the quality of an ecosystem.

    The researchers collected invertebrates in the undisturbed mature forest, in restored areas, as well as in the unrestored exotic grassland. They compared how many and which invertebrates were living in the respective areas. Interestingly, the undisturbed mature forest, the restored areas, and the unrestored exotic grassland were characterized by very different invertebrate communities. The invertebrates found in the six-year-old restored areas were mostly still very unlike those found in the undisturbed mature forest. For instance, the researchers were able to collect eight times more cave weta in their pitfall traps in the undisturbed mature forest than in the restored areas. In addition to cave wetas, the mature forest also harboured many spiders and beetles. Hence, if the forest restoration process is successful, it is expected that more cave weta, spiders and beetles typical for mature forest will inhabit the restored sites in the next years. At the same time, fewer exotic snails, slugs and earthworms that were found to be characteristic for the unrestored exotic grasslands are expected.

    This beetle,
    Holcaspis mucronata,
    was found most abundant in the mature forest.
    CC BY 4.0 by Birgit E. Rhode, Wikimedia Commons

    The study identified several invertebrate species as bioindicators. These can be used in future studies to assess the success of forest restoration at mine or quarrying sites. The study findings have been recognized in several other invertebrate studies of different parts of the world, for example, in a global synthesis on how good forestry plantations are at providing habitats to native beetles in comparison to natural forests. In that study, restoration sites were considered as forestry plantations, being planted by humans for conservation purposes and therefore different from natural forests. Another study dealt with the effect of removing an invasive plant as a restoration measure on an Mediterranean island. It referred to the study at Hunua Quarry for the use of beetles as bioindicators to observe the effects of restoration.

    All in all, the study showed that invertebrates might tell us more about the quality of a forest than you would easily see yourself. Hence, studying invertebrates as bioindicators has great potential for making better decisions in ecosystem management and for restoration projects. I hope that research about restoration will also raise public awareness for the complexity of biodiversity and the needs for appropriate habitats. Perhaps, I will hear many people around the Hambach forest region in Germany say: “Forest is not like forest. We need to consider old natural forests as valuable habitats and save them from vanishing, not only for the sake of spiders and beetles.”

    This article was prepared by Master of International Nature Conservation student Vivien Michel as part of the ECOL608 Research Methods in Ecology course.

    Link to the research article:

    Bowie M, Stokvis E, Barber K, Marris J, Hodge S. 2018. Identification of potential invertebrate bioindicators of restoration trajectory at a quarry site in Hunua, Auckland, New Zealand. New Zealand Journal of Ecology 43.

    Read more:

    Donahue, Michelle Z. 2018. Is Germany’s Hambach Forest Doomed by Coal? National Geographic, April 13. https://web.archive.org/web/20190914181247/https:/www.nationalgeographic.com/news/2018/04/hambach-forest-germany-logging-coal-conservation-science/

    Coal exit will save Hambach Forest: activists. Deutsche Welle, January 27, 2019. https://www.dw.com/en/german-coal-exit-plan-will-save-hambach-forest-activists-say/a-47251256

  • Defend the buffer!

    “Hold the line! The invasives are coming!”

    “Captain, we’re losing ground! The phosphate is encroaching.”

    “Retreat to higher ground! It’s safer up there.”

    “Send in the spiders and beetles! Earthworms, you stay here.”

    “Defend the Buffer!!!” [insert battle cry]

    If the plants and insects at Bankside Scientific Reserve could talk, they would probably sound something like that. While this 2.6 ha protected area is home to important communities of native species, it is under threat of phosphate intrusion and the breaking-up of the local habitat. Humans have greatly altered the lowland Canterbury Plains of Aotearoa/New Zealand. With the recent switch to irrigated dairy farming, very few patches of undisturbed native dryland vegetation are left in the region. This change in land-use has led to a higher reliance on fertilizers as well as water for irrigation, which has come with its own set of challenges.

    Aggressive introduced weeds, pasture grasses and forbs, have also begun to dramatically alter the functioning of native plant communities. Remnant areas are both vulnerable and essential to maintaining native ecosystems (hence the need to defend the buffer). Mike Bowie and his team investigated one of these remnant areas, looking at soil chemistry, plant distribution, and soil invertebrates along transects at the Bankside Scientific Reserve. Their study identified the current conservation value of the reserve, assessed how persistence of native biodiversity changed along the pasture-reserve gradient, and evaluated the effects of the likely infringement of irrigation water and nutrients from adjacent farmland.

    The vegetation of Bankside Scientific Reserve had been studied previously by Malloy (1970), who provided a detailed catalogue of the flora, listing 66 native vascular plant species. Jenson & Shanks (2005 – unpublished DOC Report) also completed a one-day reassessment of the site, but recorded only 14 native species. Today, the vegetation at the reserve can be described as a patchwork of native woody shrubs, made up mainly of makahikatoa, matagouri, and dry grassland. As Mike and his team point out, the modified soil conditions seem to have made the reserve not as well suited for native species, and better for the invasion by exotic plants. Compared with detailed surveys prior to the dairy conversion, only 31% of the original 65 native vascular plant species were found in the current study, and 27 new exotic species had arrived since the original survey.

    As for the underground conditions, soil nutrient concentrations and pH were lower in the reserve than in the surrounding farmland, with peaks of nitrate and ammonium being recorded at the boundary. Meanwhile, soil phosphate was higher in lower-lying areas within the reserve. Four species of endemic (Megasolecidae) earthworms were found in the reserve, but not in the neighbouring pasture.

    Other cool finds included ground wētā (Hemiandrus sp.) and trap door spider (Cantuaria dendyi). A 2011 survey by Emberson et al. (2011) also found the large rare rove beetle, Hadrotes wakefieldi, and several species of long-horn beetles. As opposed to the earthworms, the diversity and abundance of beetles and spiders in the reserve was similar to that recorded at least 10 m into surrounding farmland.

    Another interesting take-away from this research, is the importance of areas of higher elevation. Although elevational differences between highest and lowest contours were <5 m in the study, the higher areas were very important in avoiding environmental change from agricultural drainage and effluents. They helped to maintain environmental conditions that were closest to the original habitat, providing the best-suited habitat for native plants and animals.

    Image created by Catherine Priemer

    The work of Mike Bowie and his team, along with previous studies, points out the significance of small remnant reserves for the conservation of indigenous invertebrates found in these rare dryland ecosystems. Their findings also suggest that lime and phosphate fertilisers may represent the main threats to dryland nature reserves in irrigated dairy landscapes. Above all, their research underlines the importance of the soil environment in sustaining the variety of plant, animal, and insect life in this unique environment.

    Taking the team’s findings into consideration, the maintenance of a buffer zone – a protected zone established around sensitive or critical areas – could be beneficial in lessening the impacts of human activity and land disturbance around remnants, such as Bankside Scientific Reserve. To do this, native species can be planted between agricultural and conservation areas, to help protect sensitive habitat. The key take-away: Defend the Buffer!

    This article was prepared by Master of International Nature Conservation student Catherine Priemer as part of the ECOL608 Research Methods in Ecology course.

  • From stinky van adventures to restoration projects – the unseen potential of wastewater

    Picture this: you’re on a camping trip, enjoying the breathtaking view of one of the most beautiful lakes of Aotearoa New Zealand surrounded by snow-capped mountains, watching the incredible red colours of the sunrise, when suddenly a ghastly smell permeates the air. You quickly discover the source – a full wastewater tank in your camping van that urgently needs to be emptied.

    My friend Julia as she is emptying out the wastewater tanks of her van. Photo by Flora Brumen

    For those who have not experienced the dreadful smell of such a full wastewater tank, know that this is not easily forgotten. Standing in line at a dumping station, waiting to take your turn to get rid of your own disgusting fluids while someone is emptying their toilet container right in front of you, is a situation that brings shared discomfort to campers.

    Now, I may be exaggerating a little now, but you understand my point. Toilet tanks include so many chemicals, that it actually smells better than the tanks that collect just the wastewater from doing the dishes. However, it’s an experience that highlights the less glamorous side of camping but still unites people in their shared discomfort. It reminds us that wastewater is an unavoidable reality that affects us all, every day, not just while camping.

    The impact of wastewater goes beyond our noses. Uncontrolled discharge of wastewater poses a threat to human health, native freshwater species and ecosystems. In New Zealand, treated wastewater is often released into waterways or the ocean. Unfortunately, this can contaminate recreational surface waters with harmful bacteria and viruses.

    The consequences of this pollution are significant. Many popular swimming spots in Canterbury have been ranked unsuitable for swimming due to high levels of bacteria from human sewage found in the water. Last summer, heavy rainfall events worsened the situation, leading to increased runoff of faecal pathogens. Besides creating severe threats to human health and creating unsuitable recreational areas, the pollution also harms freshwater species and degrades aquatic ecosystems. In fact, a devastating 76% of the indigenous freshwater fish species are endangered or threatened, 46% of all lakes have poor water quality and 45% of New Zealand’s rivers are not suitable for swimming activities.

    What if we could turn the tables and use wastewater to actually help save our ecosystems? That’s exactly what a recent study under the direction of Alexandra Meister, a bio-waste scientist from ESR and the University of Canterbury, in collaboration with the Christchurch City Council and Lincoln University, suggests.

    The researchers carried out an experiment on Banks Peninsula, where they irrigated a site with native plant species with treated wastewater from the local treatment plant for three years. The research team made an exciting discovery: the native plants experienced significant growth with this wastewater regime. In fact, their plant height increased by an impressive 10% compared to plants not irrigated with treated wastewater.

    Site of the field experiment on Banks Peninsula, that was irrigated with treated wastewater. Photo by Meister, Gutierrez-Gines, Robinson (Kiwiscience)

    It doesn’t stop there. The soil at the experimental site showed no signs of an increase of potentially harmful elements – beyond what is normal in the soil – that could endanger humans or the environment. There may be exciting possibilities for combining restoration projects with wastewater application to land. By doing so, we could decrease the discharge of wastewater into our water bodies, but also promote the growth of native vegetation, leading to a potential recovery of native biodiversity.

    Of course, establishing native plants in these environments can be challenging if the species are not adapted to highly fertile soil conditions that are created by treated wastewater irrigation. One particular native plant, Mānuka (Leptospermum scoparium), was an obvious candidate for this experiment. This species has the ability to eliminate harmful soil pathogens and reduce the amount of nitrate leaking into water. Even though mānuka is not adapted to such nutrient-rich conditions, typically growing in low-fertility soils instead, the species responded well to irrigation and increased their growth.

    The success and safety of applying treated municipal wastewater to the land depend on two key factors: the quality of the wastewater and the characteristics of the local environment. Due to these unique considerations, it is crucial that each system is designed to specifically address these factors.

    Going forward, the researchers will continue their investigation by exploring various plants and soil types. They will continue to explore different plants and soil types, expanding our understanding of where and how wastewater irrigation can be utilised effectively.

    It’s time to shift our perception of wastewater. Instead of viewing it as something unseemly to get rid of, we need to recognize it as a valuable resource that can be multi-purposes. By finding innovative applications for treated wastewater, we can decrease its careless discharge and contribute to saving our environment and ecosystems.

    The success of using treated municipal wastewater as a valuable resource shows us how even the unpleasant smelling wastewater from our camper van adventures something associated with an unpleasant smell can turn into the sweet scent of environmental protection and restoration efforts.

    This article was prepared by Master of International Nature Conservation student Flora Bumen as part of the ECOL608 Research Methods in Ecology course.

    Meister, A., Li, F., Gutierrez-Gines, M. J., Dickinson, N., Gaw, S., Bourke, M., & Robinson, B. (2022). Interactions of treated municipal wastewater with native plant species. Ecological Engineering, 183, 106741. https://doi.org/10.1016/j.ecoleng.2022.106741

  • Island life, saviour of the wrybill

    I’ve never been so pleased to see the braids of a river than when I finally escaped the jaws of the Waimakariri Gorge in my kayak, as part of the Coast to Coast race. A braided river brings not just relief from roaring bluff corners, and the threat of capsizing my kayak, but a peaceful place that unusual birds decide to call home.

    Rakaia River, NZ (Geoff Leeming, 2006, CC BY-NC 2.0, via flickr)

    One such creature is the Wrybill or Ngutu parore. It’s the only bird in the world with a laterally curved beak (bending to the side)! Sadly, this little bird faces many threats. In 2008 some optimism was found in the research of Duncan, Hughey, Cochrane and Bind (River Modelling to better manage mammalian predator access to islands in braided rivers). The paper explained how particular characteristics of braided rivers could be used to support successful breeding of braided river birds, including our wee friend, the Wrybill.

    Braided rivers are made up of multiple threads of flowing water, with islands found between the threads. The researchers knew that these islands provided a safe place for endangered breeding birds, with the water flowing around them providing a partial barrier to a major threat –

    Wrybill
    (57Andrew, 2007, CC BY-NC-ND 2.0, via flickr)

    introduced mammalian predators, such as hedgehogs, rats, mice, stoats, weasels, ferrets and cats.

    It was already known that water extraction, narrowing and stop-banking of rivers impacted the flow of water in the braids, but little was known about the optimal flow of water or the required characteristics of the islands to support breeding birds. Models were used to determine the number and area of islands needed for successful breeding. The researchers found that certain levels of water flow preserve islands large enough for nesting (larger than 2 hectares) and protect the area from mammalian predators or weed invasion. This information was used to recommend abstraction rates on braided rivers during peak breeding season. They did conclude that using photos in the research would increase understanding of how islands change in different flows.

    One of the authors, Ken Hughey, was from Lincoln University and his PhD, back in 1985, looked at factors impacting the breeding of braided river birds in Canterbury. He studied five different birds: Wrybill, Banded dotterel, Black-fronted tern, Pied stilt, and the South Island pied oystercatcher. Among other things, Ken found that higher levels of predation on birds occur where there were lower flows of water and lower numbers of channels or threads in the river. He recommended that minimum flow levels should be higher during the breeding season to protect the nesting birds. The 2008 study builds on this understanding and provides information not just about the flow of water needed, but also the size of the islands required to protect the nesting birds.

    This study has been used in subsequent research in New Zealand around maintaining river flows in braided rivers. This is unsurprising given braided rivers are rare around the world and Canterbury is known as New Zealand’s braided river hotspot. The themes within the research were around maintaining river flow levels, predator and weed control, maintaining river islands, and water abstraction. Advances since this work seems to be focussed on weed control and the impacts of hydropower to braided river systems.

    It appears that the messages about the importance of minimum flows and island size in braided rivers for breeding birds are getting through. The Regional Council in Canterbury (ECAN) refers to the importance of flows in preserving the ecology of the river for breeding river birds in the Canterbury Water Management Strategy and the Canterbury Land and Water Regional plan. The knowledge that came from the research by Duncan, Hughey, Cochrane and Bind, and subsequent research, has clearly shown how local communities think about braided rivers and informed how they care for them. This is demonstrated by the Ashley Rakahuri River Care Group in 2022, when they made a submission to the ECAN to raise concerns about gravel extraction on the Ashley Rakahuri River and how this will impact the islands needed by birds to breed safely.

    This approach also appears to complement work by the Predator Free 2050 campaign regarding pest control within braided river environments. I was intrigued as to how the authors felt the research was received and asked one of them, Ken Hughey, about the impact. He said it ultimately led to high flows being recommended and resourcing for predator control on the islands. Sounds like a great result!

    New Zealand Map (mhx, 2010, CC BY-NC-ND 2.0, via Flickr)

    Undertaking research consumes your life while you are doing it. It is fascinating to see the journey from conception to the completed work and then how it informs environmental work moving forward.

    The Wrybill is still classed as vulnerable and there is work to be done, but this research has added valuable insight into flow regimes for braided rivers. It has highlighted the importance not just preserving islands for breeding birds, but ensuring they are above a certain size. It has prompted further research, and informed councils and charitable groups on how to best support endangered braided river birds, like our wee friend the Wrybill. I’m sure there shall be some grateful kayakers out there too! I shall sign off this blog with an image of the Wrybill making the most of his unique laterally curved beak.

    This article was prepared by Master of Environmental Policy and Management student Katherine Manning as part of the ECOL608 Research Methods in Ecology course.

    Wrybill/Ngutuparore (Shellie, 2016, CC BY-NC-ND 2.0, via Flickr)

    Here is a full citation for the article:

    Duncan, M.J., Hughey, K.F.D., Cochrane, C.H., Bind, J. (2008) River modelling to better manage mammalian predator access to islands in braided rivers. Exeter, UK: British Hydrological Society 10th National Hydrology Symposium: Sustainable Hydrology for the 21st Century, 15-17 Sep 2008. 487-492

  • Neighbourhood disputes, models, and a harmonious coexistence with elephants

    In my home country, Germany, we have cut down every bit of primeval forest. We hunted aurochs, brown bears, wolves, lynx and even beavers to extinction between the 17th and 19th centuries. After messing it all up like that, we now dare to tell other countries, that still hold on to their forests and wildlife, what to do with their nature.

    “Don’t hunt those animals you used to hunt sustainably for centuries; we think they are so charismatic”. Currently, wolves are slowly coming back to Germany, and immediately people (successfully) changed laws to permit their shooting if they prey on sheep because it is “not bearable” to live in close coexistence with wild animals like that. Apparently, wolves don’t belong to Germany anymore because…yeah, because what? Because humans live here?

    Now close your eyes and imagine you are a subsistence farmer. Oops, don’t close them, rather, continue reading! You can still imagine, though! Every day you’re working hard taking care of all the veggies and crops you planted to feed your family. One day you look up, and what you see is a massive giant, almost as tall as your house. That giant has destroyed everything you ever planted.

    African elephant (Loxodonta africana) drinking. Picture © Severin Racky (used with permission).

    Happily munching on the last corn cob, the elephant greets you with an intimidating “HEI!”. Sounds absurd? Well, this scenario is much more realistic than our Western culture’s perception of African savannas as a vast untouched wilderness with Simba and all his large mammal friends living their best lives, without humans in the picture and without “HEI”, Human-Elephant-Interactions.

    This perception of wild Africa has influenced our approach to mitigating HEI. A common attempt is to build physical barriers, such as fences, to separate humans and elephants, believing they could protect both parties. However, elephants are unbelievably strong and intelligent creatures, and they easily overcome these obstacles, leaving farmers caught in a perpetual battle to safeguard their livelihoods.

    I have personally witnessed elephants knocking over trees onto “elephant-proof” electric fences to get to the other side. No fence can hold back a herd of determined elephants. Fences, therefore, cannot be the only solution when both humans and elephants need to get their food from the same land. It doesn’t stop with crop and infrastructure damage, though; Humans and elephants die through HEI. Elephants are killing around 500 humans per year and humans return the favour.

    After bothering you with way too much bad news, at least I can tell you that science offers a glimmer of hope! Picture a team of brilliant minds huddled around computer screens, armed with data and determination. With powerful tools with mystical names like Agent-based modelling (ABM) and Geographic Information Systems (GIS), ecologists are unravelling the complexities of HEI to help us understand human-elephant interactions better. With these tools, the researchers can simulate scenarios and explore the factors determining conflict incidents, to develop effective measures to reduce the conflicts and to mitigate poaching. The models are needed because, due to plenty of ethical problems, these kinds of experiments could not be conducted in real life.

    In their study from 2021, Abel Mamboleo, Crile Doscher, and Adrian Paterson, from Lincoln University, simulated 18 scenarios, considering things like human population, elephant population, rivers, conservation corridors, and protected areas. They evaluated their impact on different HEI incidents, such as crop damage, human deaths, elephant deaths, and hidden impacts. The term “hidden impacts” refers to indirect consequences of HEI and includes fear restricting movements, missing school, or resulting health issues. For example, their “elephant-effects scenario (ES)” evaluated the effects of varying elephant populations on HEI, the “human-effects scenario (HES)” evaluated the effects of varying human populations on HEI, and the “environment-effects scenario” evaluated the effect of varying environmental parameters (distances to rivers, protected areas and corridors) on HEI.

    Using their models, the scientists identified hidden impacts of HEI (e.g. fear and resulting health issues or restricted movements depending on elephants) as the most challenging incidents to mitigate. Interestingly, maintaining a greater distance from rivers seemed to effectively reduce those hidden impacts. Now who would have thought that?

    Their model also indicated that most incidents of elephant crop damage occur within 1 km from rivers. Therefore, according to the model, it is possible to lower the risk of your crops being eaten and trampled by a grey giant by planting them further away from rivers (Yeah, good news!). Among the incidents studied, human deaths were found to be the easiest to reduce (more good news!). Fifteen out of the 18 scenarios lead to significantly fewer human deaths.

    African elephants drinking and playing at a waterhole. Picture © Severin Racky (used with permission).

    Distancing human activities from rivers, and creating conservation corridors and protected areas, seem to be an effective mitigation strategy. However, challenges remain. Reducing the deaths of elephants seems to be one of the most difficult tasks, with only six out of the 18 scenarios showing significantly fewer dead elephants. The number of elephant deaths was reduced in some scenarios, such as a so-called “ENS-River-Protect-Corridor”, in which the scientists modelled farms to be 7000 m away from rivers, protected areas and wildlife corridors.


    While no single scenario that the scientists played through was able to completely eliminate all incidents, their modelling provided valuable insights and recommendations for potential strategies to reduce HEI. With their models, the researchers showed that HEI is influenced by many different factors beyond the pure numbers of humans and elephants. Geographical and environmental features, such as rivers, protected areas, and corridors, and socioeconomic activities, also play crucial roles. With the approach of creating safe distances between human activities and critical areas, the researchers found practical strategies to minimize the deaths of both humans and elephants.

    The study’s findings, therefore, highlight the need to address the spatial relationship between humans and elephants and promote responsible settlement planning. Successful strategies for mitigating HEI require a holistic approach that balances the needs of both humans and elephants and prioritizes a healthy elephant population as well as the well-being of affected human communities.

    It is important to emphasize that models are just a tool, implementing solutions still needs to be done by our big, juicy human brains. For example, in all scenarios, the model suggested to just lower the population size of humans and/or elephants to mitigate HEI. Fewer humans, fewer elephants: fewer human-elephant interactions. Of course, both options are far away from an ethical or recommendable solution. If the elephant density is extremely high, relocating them to other areas could be a (very complicated and expensive) option.

    Wait a minute! Hey, German politicians, how come you haven’t thought about reducing the population size of humans in areas where the wolves are coming back? I heard many of us would love to live in New Zealand anyway. What about providing a free one-way ticket to New Zealand for every revengeful German sheep farmer who wants to kill wolves as a compensation measure?

    This article was prepared by Master of International Nature Conservation student Ronja Hardener as part of the ECOL608 Research Methods in Ecology course.

    Mamboleo, A. A., Doscher, C., & Paterson, A. (2021). A computational modelling approach to human-elephant interactions in the Bunda District, Tanzania. Ecological Modelling, 443, 109449. (https://doi.org/10.1016/j.ecolmodel.2021.109449)

  • The secret life of elephants: ecological engineers and agricultural pests

    As a Kiwi, when I hear the word ‘pest’ my mind instantly goes to possums, stoats, rats and cats. These are some of the invasive mammals which are killing so many of our native species, most of which cannot be found anywhere else in the world. These lethal pests have turned us into killers as well; we promote and stand by numerous lethal methods for pest management, without batting an eyelid. Whilst some are made uneasy by the thought of trapping, poisoning or hunting these creatures, we still employ these measures as second nature.

    When talking about pest management in the past, I never quite understood the shock or disapproval from visitors from overseas. They get a certain look on their faces when they hear what we do to these mammals, many of which they are trying to protect at home. It seems to them that we have become somewhat apathetic to the lives of these creatures and accustomed to having blood on our hands in the name of pest management.

    Dead stoat, trapped in Fiordland National Park/ Avenue

    The way that I look at it, along with many other New Zealanders, is that I feel a strong sense of responsibility for protecting our native birds, lizards and plants. I do accept that these pests are simply trying to survive, on an island archipelago that they didn’t choose to live on.

    Some parts of the world, have a much larger agricultural pest issue: elephants. Hearing this, helped me to understand what others feel when we talk about pests in New Zealand. How can an elephant, such a majestic creature, be considered a pest?

    Of course, an agricultural pest differs in definition to the introduced conservation pests that we have in New Zealand, although reactions to these pests seem to be the same. In retaliation to the damage caused to local livelihoods or personal safety, some people have been reported to purposefully remove native elephant habitats or even employ lethal methods to control the “problem elephants”. I am now the one in shock, although in the grand scheme of things it’s not so dissimilar to our pest control strategies.

    Abel Mamboleo, as part of his PhD research at Lincoln University, asked the question, published in the Journal of Biodiversity & Endangered Species, of whether elephants were really the most disastrous agricultural pest animals or are they actually the agents of ecological restoration. He reviewed multiple studies and publications to obtain crucial information about elephants, agricultural pests and ecological restoration. All of this helped guide him towards the answer to this big question: are elephants a pest or an ecological blessing? He also wanted to summarise the existing knowledge to help both conservationists and local people create appropriate plans for sustainable management.

    Indian elephant bull in musth in Bandipur National Park/ CC-BY-SA 3.0 Yathin S Krishnappa.

    Human-elephant conflicts arise through any interactions between our two species that have negative impacts on social, economic or cultural life, on elephants, or on the environment. The most common feature of these interactions is crop-raiding. As human populations increase, our demand for land, water and food also increases. Consequently, historical elephant habitat is being infiltrated by human activities through agricultural development, limiting elephant habitats to small “ecological islands”. This means their usual dispersal routes are restricted and the competition for resources with humans increases.

    So, what happens when the natural habitat and resources of elephants are taken away? They search for food elsewhere, with the most abundant source being crops on surrounding farms. Elephants actually prefer agricultural crops to wild plants because they are more palatable, nutritious and readily available. For this reason, local people have labelled elephants as the most disastrous agricultural pests, because of the damage from elephants that they sustain. But is this a fair statement?

    Elephants were compared to the criteria an animal must fit to be considered a pest. These criteria include any animal that feeds on crops, damages buildings or stored food, injures people and kills livestock. When looking at it this way, yes, elephants by definition are pests. They damage stored and field crops, which ultimately affects human food security during drought seasons. However, to be labelled the most disastrous agricultural pest seems a bit extreme. In fact, for this to be the reality they must be causing massive economic damage to crops and property; more than other pests.

    While they do cause some local damage, Mamboleo found that they only cause moderate damage when compared to other pests. The damage inflicted by wild pigs actually far outweighs that of elephants and puts them in first place for the most disastrous agricultural pests. Elephants even sit behind rodents, European starlings, red billed quelea and desert locusts when looking at the line-up for the worst pest offenders in these areas. While it is true that elephants can inflict extensive damage, it is still significantly less than other pests. For local people, it is hard to see it this way as they have entire fields of crops decimated by these giants.

    People are seeing persistent crop damage and associating this with pest behaviour. Because their farms often closely border protected elephant habitats, it means people are seeing more severe crop-raiding and they’re seeing it more frequently. While on the other hand, the elephants just see more food. Naturally, the elephants are getting the blame and inheriting this new title; from a local perspective it is an obvious response.

    On the other hand, elephants are considered as agents of ecological restoration. Much like secret agents, they work inconspicuously to repair and re-establish ecosystem services that may have been damaged by human activities. A successful act of ecological restoration must be effective, efficient and engaging. This is otherwise known as the “triple E” principle, which serves as the guidelines for evaluating environmental restoration processes.

    Elephant in India/ CC-BY 4.0 Sanghavisrini

    Elephants are effective because their natural and physical abilities provide all sorts of environmental benefits to humans and other wildlife. They also have the ability to restructure their environments, sometimes opening up thick vegetation and helping their herbivore neighbours in the process.

    Elephants are also efficient because of their high level of intelligence and behaviours; they are able to perform productive ecosystem rehabilitation activities in a consistent and timely manner. Usually this is without the support of human intervention. Elephants have been branded “ecosystem engineers” or “mega-gardeners” because of their role in dispersing seeds, helping both wildlife and humans. Through ecological restoration, these elephants are replenishing cultural resources and socioeconomic conditions for humans and allowing re-connection with nature. Some would call that engaging. This ecosystem restoration allows humans and other wildlife to reuse otherwise damaged ecosystems.

    So what is the answer to whether elephants are the most disastrous agricultural pests or actually the agents of ecological restoration? This needs to be looked at from two separate viewpoints. Yes, they are pests, but they are not the most disastrous. And, yes, they are agents of ecological restoration. But they are both occurring simultaneously, depending on the perspective you view it. Can’t they be both?

    This article was prepared by Master of International Nature Conservation student Quinn O’Halloran as part of the ECOL608 Research Methods in Ecology course.

    Mamboleo, A.A., Doscher, C., & Paterson, A. (2017). Are elephants the most disastrous agricultural pests or the agents of ecological restorations? Journal of Biodiversity & Endangered Species, 5(185). doi:10.4172/2332-2543.1000185 .

  • Life near the edge: same dung, different day

    Although I was vaguely aware of dung beetles and their role in the ecosystem, I finally became interested in them while participating in giraffe research in South Africa. I’ll never forget the time when I was finishing up my giraffe work for the day and I stopped to watch a couple of dung beetles who were squabbling over a single ball of dung (poop). What I had perceived to be a relatively gentle disagreement escalated quickly when I watched one demolish the other with a long-time favourite move from the World Wrestling Foundation, the Brainbuster. You know the one.


    Dung beetles play an essential role in the environment. However, they fly a bit under the radar, which is why they are often called nature’s “unsung heroes.” There are over 100 species of dung beetle, each choosing one of three strategies: rolling, tunneling, or dwelling in dung. Not only do they eat and live in animal dung, but they increase the freak by reproducing in it and burying it. This ensures their offspring have plenty of food for when they hatch. 

    As gross as it is, this burying behavior strongly limits the growth of vertebrate parasites, which is tremendously helpful to the rest of the ecosystem. They help remove animal dung from the surface environment with incredible efficiency and speed. In some places, the beetles can eliminate a pile of dung in less than 10 minutes, where the ground would otherwise be carpeted with it.

    Dung beetles are very widespread, found in many different habitats across all continents except Antarctica. Like many species, dung beetles appear to be harmed by the break-up of natural environments. This fragmentation reduces the size of undisturbed, or core, habitat in the centre and creates isolated habitat patches. The environment along the edge of a habitat is usually quite different from the core. In forests, for example, it’s typically windier and sunnier at the edge of the forest than in the centre. 

    Edges are not only susceptible to environmental challenges, but also to human impacts. They are more vulnerable to fire, as well as illegal harvesting or collecting of plants or animals by humans, simply because they are more easily accessible. Some of these impacts along the edges don’t stay localized, but can radiate into the core habitat as well.

    Edges are in fact an important habitat, because they support species that like transitions between different habitats. However, as humans continue to break up large habitats, with roads or communities for example, the amount of edge habitat increases, while core habitat shrinks. This challenges the animals that rely on core habitat. Additionally, the edges of habitats typically support fewer species than the core. We don’t want to consistently change habitats around the world to ones that support similar and fewer species. 

    Buffer zones are areas around a sensitive, often legally protected, environment that are typically managed to reduce edge impacts on the borders of a sensitive area. Sometimes buffer zones have methods to exclude humans or livestock, such as fences. Sometimes they are simply designated areas without active protection measures. Relatively little is understood about how effective buffer zones actually are for some species.

    Back to dung beetles, we typically see fewer individuals and a less diverse group of dung beetles along habitat edges than in the core, because they are a group that tends to be quite affected by human activities. For example, because they are in constant contact with dung, they are exposed to pesticides that livestock ingest, which has been causing population declines. But how do buffer zones impact dung beetle diversity and density along the edge of protected habitats?

    Andrew Barnes and his colleagues, including the late Rowan Emberson from Lincoln University, decided to find out. The montane rainforests in Sub-Saharan Africa are shrinking rapidly, largely due to deforestation for agriculture and grazing. There is also nearby habitat decline that often comes with agriculture. The Ngel Nyaki forest reserve in Nigeria is a heavily fragmented area. To test how dung beetles would respond to increasing edge effects, the researchers applied experimental habitat restoration treatments to certain areas along the edges. For the restoration, researchers excluded livestock with fencing, created and maintained firebreaks to help block fire, and allowed passive natural regrowth of the floral community. This combined restoration occurred in 200 metre buffer zones over the course of three years.

    The impact of these buffer zones was remarkable. In the forest next to the restoration area, the dung beetle population size increased by over 50% compared to the unrestored areas. Perhaps more important was the difference between dung beetle populations in the edge and habitats. Before the restoration, there were many more species of dung beetles in the habitat core and relatively few in the edge. After the restoration, that difference disappeared, meaning that the buffer zones successfully mitigated the challenges that are typical of edges for dung beetles. The restoration also led to the return of certain species that had previously locally disappeared in the degraded habitat.

    These changes are incredibly pronounced and occurred after only three years and with small levels of restoration. While firebreaks do require active maintenance, it is encouraging that even relatively minor land-use changes around protected areas can make a world of difference for many species. Relatively few studies have been completed about the effectiveness of buffer zones, so this is a single, but vital, drop in a much larger pot of conservation decisions. 

    After all, we want all dung beetle species to survive, no matter how gross or freaky, to tidy up after vertebrates and perhaps to get more inspiration for wrestling moves.

    This article was prepared by Master of International Nature Conservation student Julia Criscuolo as part of the ECOL608 Research Methods in Ecology course.

    Barnes, A.D., Emberson, R.M., Chapman, H.M., Krell, F-T., & Didham, R.K. (2014). Matrix habitat restoration alters dung beetle species responses across tropical forest edges. Biological Conservation, 170: 28-37. DOI: http://dx.doi.org/10.1016/j.biocon.2013.12.006