Unearthed Gems – EcoLincNZ articles from the last two decades see the light again! From 2008…
The blue penguin (Eudyptula minor) is found around New Zealand’s coastlines and in many parts of south-eastern and western Australia (where they are sometimes known as fairy penguins). Over the years there have been many different suggestions put forward to explain the regional variations seen throughout the range of this species.
Early researchers hypothesised that each geographical region of New Zealand contained a subspecies of blue penguin. Molecular data from gene regions is often ideal for examining these kinds of hypotheses. A study in 2002 found only a little support for regional differences but a lot more support for major differences between blue penguins in New Zealand and Australia.
Image by Julie Paterson.
In a follow-up to this study Adrian Paterson, Rob Cruickshank, Gabby Drayton (Lincoln University) with Jonathan Banks (then University of Waikato) examined the regional genetic variation of blue penguins across Australia. Samples were taken from a western Australian and Victorian populations (which are thousands of kilometres apart).
The team examined the fast evolving control region and the slower evolving cytochrome B gene regions of the mitochondrial DNA from each penguin sample.
The western Australian individuals were found to be the same as the Victorian samples implying that there is a high level of gene flow between east and west Australia (more than from the east and west coasts of New Zealand, for example).
The study also confirmed that Australian and New. Zealand blue penguins are very different genetically and may warrant becoming recognised as separate species in the future.
Curiously, this study also agrees with the earlier study by placing the birds from Otago, New Zealand with the Australian birds rather than the other New Zealand populations. This result is hard to explain at present and will provide impetus for further studies.
This was the second EcoLincNZ article uploaded and was written by Adrian Paterson. In upgrading to a new site it was lost. I am uploading some of these old articles to let new readers access them. Adrian is currently working on little penguins for the first time since this time in 2008!
Unearthed Gems – EcoLincNZ articles from the last two decades see the light again! From 2008…
Tuatara, leiopelmatid frogs, weta (Orthoptera), peripatus (Onychophora), southern beech (Nothofagus) and kauri (Agathis australis) and other New Zealand species are often referred to as Gondwanan taxa. What does this mean? Gondwanaland was a large landmass made up of the southern continents that slowly broke apart through Jurassic and Cretaceous time. The New Zealand area began to break away from Eastern Australia and Antarctica around 83 million years ago in a large chunk of land the size of India, called Zealandia. Slowly this landmass sank. All that remains of this small continent are New Zealand, New Caledonia, Norfolk, Chatham Islands and the subantarctic islands. The term ‘Gondwanan’ is given to species whose distribution recalls this ancient history.
The living species of penguins. Art by Julie Paterson.
First, a taxon is Gondwanan if its lineage has been continuously present in New Zealand since Zealandia broke away from Gondwanaland.
Second, a taxon is Gondwanan if it is descended from a lineage that was present in Gondwanaland prior to break-up but arrived in New Zealand after Zealandia broke away from Gondwanaland and sank (dispersed and colonised).
Third, a taxon is Gondwanan if species are currently found in former Gonwanaland landmasses – but with no expectation of a common historical process to explain different instances of this pattern (which could be because of either of the two meanings above).
For example, penguins are found in New Zealand, Australia, southern Africa, South America and Antarctica and certainly demonstrate a Gondwanan distribution (third meaning).
Penguins have a fossil history to at least 62 Myr ago and molecular analyses suggest a much earlier origin in the Gondwanaland landmass, implying that they are found in the New Zealand region by virtue of having been in Gondwanaland when Zealandia rifted away (first meaning).
Fossil and molecular data all suggest that modern living penguin species all share a recent ancestor from about 25-30 million years ago. Living penguin genera of Eudyptes, Eudyptula and Megadyptes may have colonised New Zealand from other former Gondwanan landmasses since that time (second meaning).
Indeed, Eudyptula, the blue penguin, is found in Australia and New Zealand with molecular evidence for recent contact between these populations. Thus, the modern distribution of penguins could be described as Gondwanan in all three senses.
Does it really matter; it’s all Gondwanan isn’t it? Science is about being precise, removing ambiguity and these three meanings suggest different things. Meaning three simply acknowledges that there is a group of species that share a certain southern hemisphere pattern. Meanings one and two provide different explanations for the origin of this pattern with meaning one implying species have been continuously in New Zealand for 80 million years and meaning two implying that the species could have arrived at any time over the last 80 million years.
Understanding the difference will allow biogeographers (scientists that study where species are found) to be better able to tell the complicated story of the history of the New Zealand’s biota.
This was the very first EcoLincNZ article from 2008, written by Adrian Paterson. In upgrading to a new site it was lost. I am uploading some of these old articles to let new readers access them. Adrian is still bothered by how we use Gondwana.
Being a born and bred southern man from South Otago, crying is not something that I do much (or was encouraged to do).
There are some things that make the eyes prickle, though. Movies can certainly do it. Aragorn telling the hobbits “My friends, you bow to no one” in The Return of the Kingis certainly is up there. The last “That’ll do pig” from Farmer Hoggett in Babehas always gotten me. The final soaring ending of The Last of the Mohicans as Hawkeye and Cora gaze out over the forest clad hills brings the shiny eyes. The speech from young Paikea about her grandfather in Whale Riderwas emotional enough in 2002, now that I am a koro myself with a granddaughter, I can only imagine it would be even more devastating.
In reading books I am a lot more immune to tears. There are, however, a few passages in The Lord of the Rings that will make the eyes water. One of them is in my most favourite section in the trilogy.
Tucked in towards the end of The Two Towers is the chapter Journey to the Crossroads. The last section, just over a page long, tells how Frodo, Sam and Gollum finally arrive at the crossroads. They have been sneaking through the gloom of Ithilien for the whole day, in an absolute unnatural quiet, broken occasionally by distant thunder or drums. They are scared and dejected. They arrive at the crossroads where, once they pass them, they will be committed to walking past Minas Morgul and into Mordor.
An old statue and surrounding walls have been vandalised by orcs at some point and all is in disrepair. Everything is sombre and Frodo is filled with dread.
The King at the cross-roads (Darrell Sweet)
At that moment the sun drops below the ash-cloud cover and shines a light on the scene, picking out the fallen head of the statue and the pretty flowers encircling it like a crown.
“They cannot conquer for ever!” said Frodo. And then suddenly the brief glimpse was gone. The Sun dipped and vanished, and as if at the shuttering of a lamp, black night fell.”
Cue the lump in the throat. It’s the hope that gets you.
There is another reason why I like this chapter so much. The hobbits are travelling through Ithilien, a beautifully lightly wooded region next to the Mountains of Shadow. Mostly the malign influence of Sauron has been kept to a minimum. There are always signs that Orcs have been up to mischief and that the local environment is beginning to suffer from Orc impacts. As the trio move closer to Minas Morgul, a source of orcs, pollution of the local rivers, and general environmental callousness, we start to see greater impacts on nature.
In my humble opinion, one of the best and most moving passages in the Lord of the Rings.
And then the sun shines for that brief moment and the Hobbits see that there are still beautiful plants growing and flowering, even in these areas of high impacts. Nature can persist in the face of ongoing Orcanisation.
Over the last few years, much of my research has involved looking at the impacts of anthropogenic (human) impacts. These impacts are often through urbanisation – building suburbs everywhere -and on local species in the environment. Research has ranged from how blackbird behaviour changes from the town to the country, to how kea and black-fronted terns respond to farming-use changes in the environment.
While we have a focus on impacts on birds in New Zealand, bats are a group that are often looked at in other parts of the world. Bats move around the landscape and will almost always come into contact with anthropogenic impacts in their travels. Bats are often a good indicator species for any local problems caused by humans.
Much of the work on bats has been done in Europe and often around major cities, typically in low altitude flat areas. Lincoln University Master of International Nature Conservation student Quinn O’Halloran had the opportunity of collecting data on bats in the South Tyrol landscape of the northern Italian Alps. Quinn joined a long term data collection project in the EURAC Institute for Alpine Research.
After a summer spent surveying for bats (using bat detectors that can record their calls) Quinn was given access to six years of data from 320 sites, focussing on 32 urban settlement sites and spent her thesis time analysing this information. Quinn wanted to find out how bats responded to urbanisation of these alpine valleys where the human population has grown over a large area in the last few decades.
Image from Valentin Heimer (EURAC Research)
Quinn was interested in how variables impacted the activity and diversity of bats in these areas. She looked at the influence of factors like the amount of hard surfaces and woodlands, distance to woody patches and rivers, access to old buildings and so on.
Typically, urbanisation has a big impact on bat diversity and numbers. There are a few bats that do well with human changes but most don’t and so there is a clear signal that cities are not great for bats.
Image from Andrea De Giovanni (EURAC Research)
In the South Tyrol this was not the case. Quinn found that bat diversity and activity was much higher than expected, even with bats that typically don’t do as well in urbanised environments in other parts of Europe. It seemed that there was enough access to woody patches, water and green areas in these alpine environments for the bats to be less impacted than in other places.
It is likely because of the three dimensional landscape of the alpine environment. The South Tyrol has a landscape of deep glacial-cut valleys (flatfish bottoms and steep sides). People live and build in the valley bottoms but they don’t make it far up the sides (even to farm) as they are very steep.
For a flying bat this is not such a problem and so they have access to somewhat wild areas not too far way up the valley walls. This access is enough to counter some of the urban impacts that are problems for bats living in cities on open plains where there are few wild areas. Quinn was able to show that bats and human changes in the environment respond in different ways depending on the landscape.
Image from Harriet Taylor.
So, much like Frodo and Sam at the crossroads, there is always hope. Urbanisation can seem like an overwhelming problem for our native diversity, and it often is. But we also need to remember that not everywhere is the same and that species are often more resilient than we think (or at least better at finding and using resources in the local environment than we expect).
Nature is robust, and, sure, it will accept help where we give it. But nature is not just a victim, it can also help itself as well. And that’s a hopeful message.
Now, if that doesn’t bring a tear to your eye then I don’t know what will.
When Adrian isn’t choking back the tears he is a lecturer at Lincoln University.
Social wasps work together well in a group. Each wasp has a role, and together they act almost like a single living organism. While weather, food, and other environmental conditions, such as human disturbance, can affect how wasps behave, researchers wanted to know something different: can entire wasp colonies have their own personalities?
This question was explored by a team led by J.M. Jandt, from the University of Otago, and Mateus Detoni, then a PhD student at Otago and now a lecturer at Lincoln University. Their study was published in the scientific journal Insectes Sociaux.
Why study these wasps?
Vespula wasps are well known for defending their nests aggressively when they feel threatened. However, we still know relatively little about why some colonies seem more aggressive than others. The researchers wanted to find out whether different colonies consistently behaved differently, just as people can have different personalities. Importantly, wasps are recognised as pests and have major ecological and economic impacts in New Zealand. Understanding aggression will help us to manage wasps better.
What did the researchers do?
The study was carried out in three different locations in New Zealand’s South Island, observing three main behaviours. They recorded how wasps actively foraged for food, how aggressive the colony was when not disturbed, and how aggressive the nest became when disturbed. These assessments were measured over three periods: one day, one week, and over a month. Mateus and colleagues also recorded other information, such as nest size, weather when the colony was breeding, and temperature around the nest.
Copyright 2026 Tom Bentley. Vespula germanica adult male walker wasp.
What did they discover?
Some colonies were consistently more aggressive than others, no matter when they were tested or how the tests were carried out. In other words, colonies appeared to have their own behavioural “personalities”
Some colonies were naturally more defensive and aggressive, while others were calmer. Differences in aggression could not be explained by factors such as nest size or temperature. Other factors, such as genetics or colony development, may play an important role.
Why is this important?
The study shows that wasp colonies are not all the same. Just like people and other animals, groups of insects can behave differently from one another. In this case, a colony in which the individual wasps are genetically similar to one another, whole colonies can share the aggression. This is of importance to New Zealand because more aggressive colonies may compete with native wasp species, a threat to other insects and birds and pose a greater risk for people who accidentally disturb their nests.
How can this help control wasps?
Pest control methods assume that all pest targets in a population will behave the same. However, this study suggests that some wasp colonies are naturally more aggressive than others. If these colonies can be identified easily, then control efforts will be made easier, targeting the highest risks nest first, making management programs more effective.
Research into social wasps has continued. Scientists are now investigating how genetic differences within colonies affect behaviours such as aggression, foraging and the ability to survive environmental challenges.
The bigger picture
It is known that individual animals can have consistent personality traits. This study has expanded the idea by showing that the entire wasp colonies may also have stable behavioural characteristics. Some researchers describe social insect colonies as “superorganisms” because thousands of individuals work together so closely that the colony behaves as a single living thing. From this perspective, a colony’s level of aggression can be viewed as a trait that evolves just like traits in individual animals.
Questions for future research
The study raises several new questions relating to what causes colonies to stay highly aggressive, and when is aggression helpful or harmful to a colony. Do other social insects, such as ants and bees, show similar colony personalities? This opens doors for further work.
All is all
The research by Jandt, Detoni, and colleagues showed that wasp colonies do not all behave the same way. Instead, each colony can have its own consistent pattern of behaviour, much like a personality. This discovery has changed how scientists think about social insects and may help improve future management strategies of this social wasp.
As science continues to study these remarkable insects, one message is becoming clear: Understanding the personality of a colony may be just as important as understanding the behaviour of individual wasps.
This article was prepared by Master’s of Bioprotection student, Richard Dikrey, as part of the ECOL608 Research Methods in Ecology course.
Aotearoa’s nature is defined by its iconic species like kauri and pōhutukawa, kiwi and kea, and even insects like wētā. These species are undeniably important, but it’s now time for some credit to be given to a less visible group – arbuscular mycorrhizal fungi (AMF).
Little known to most, AMF have been an important part of the Earth’s ecosystems for 450 million years. Around 80% of all plant species live in symbiotic relationships with AMF.
AMF colonise plant roots and support the host plant by extending fine filaments, called hyphae, into the soil. These tiny hyphae can access water and nutrients that would otherwise be missed by the host plant’s roots. This gives plants a major boost. The extra intake of limited nutrients, like nitrogen and phosphate, enhances the plant’s resistance to environmental stressors – such as disease or climate change.
Native Forest, Tauranga. You can’t see them, but AMF are in this photo! Photo by Ngaire Ferriss
But it’s not all one-sided. AMF benefit too, receiving carbohydrates and fatty acids from the plants in return for their work.
It’s no secret that native Aotearoa ecosystems are struggling. Anthropogenic challenges, like climate change, deforestation, invasive species, and soil depletion (I could keep going), make it difficult for our native plants, and the fauna which they support, to thrive.
The same goes for our valuable agricultural systems, which struggle with similar challenges. Luckily, a recent review of AMF in Aotearoa’s ecosystems suggests that these fungi may be able to help us out.
Aotearoa is home to 38 identified species of AMF. It is thought that there is functional specialisation across species, meaning that each species can offer different benefits to its host plant.
Kānuka forest, Paparoa. Kānuka commonly interacts with AMF. Photo by Ngaire Ferriss
Studies show that AMF have the ability to improve plant growth. For example, kānuka and mānuka growth was significantly enhanced when AMF was added to the soil. Another study showed an increase in root and shoot growth in the sample apple trees. These benefits can assist with disease resilience, as greater size means greater defence.
Crop plants can also benefit from this growth. When New Zealand-made mycorrhizal products were applied to plants like lettuce and plantain it increased the size of the crops. Other plant species saw an improved nutrient uptake, which can assist with carbon storage in soils. Aside from helping plant health, this is a global warming win, locking carbon away and preventing it from accumulating in the atmosphere. And unlike chemical fertilisers, mycorrhizal products don’t contribute to soil depletion. While a great temporary solution, crops relying on fertilisers lack many of the components soil needs to thrive. On the other hand, AMF add organic matter, nutrient availability, and long-term soil health.
So far, it’s sounding pretty good. However, AMF isn’t the solution to all our problems yet. Research is expensive, and we currently lack knowledge on AMF species, functions, and relationships with plants. The next steps in advancing AMF research include increasing AMF culture collections, characterising communities at a precise level, and discovering associations with plant species. If this can happen, a whole world of benefits could be unlocked. Native plant diversity and abundance could shoot up with specific applications of AMF – increasing resilience to stress, enhancing growth, improving soil quality, and improving competition with invasive species. Agriculture could also be supported by these fungi, using crops which support diverse AMF communities. By making use of the skills of different AMF species, crop plants could enjoy increased nutrient uptake and resilience, creating more productive and sustainable farms.
It seems our secret weapon has been beneath our feet all along. Now that AMF have had their big introduction, perhaps they can help forge a new path toward healthier soils, healthier ecosystems, and a healthier Aotearoa.
Imagine a typical stream or river running through farmland. It looks clear enough at first glance, but you start to notice something is not right. Algae begins appearing over time. The water quality gradually declines. Something is leaking into the ecosystem and altering the natural environment.
So the question becomes: what is responsible?
For a long time, scientists suspected a single culprit. But, in the early 2000s, soil scientist Andrew Sharpley and his colleagues, including Lincoln University researcher Professor Richard McDowell, set out to investigate why water quality problems persisted even when nutrient management practices were in place.
Instead of one obvious offender, the evidence pointed towards two main suspects: nitrogen and phosphorus.
Solving this mystery changed how we manage nutrients within agricultural landscapes.
Scoping the area over Waitaki River at Ikawai, Canterbury. Photo taken by author. CC-BY-NC
Suspect #1: Nitrogen- a.k.a ‘the quiet traveler’
Nitrogen moves easily through soil, making it difficult to trace back to its source.
Unlike phosphorus, which tends to stick to soil particles, nitrogen is highly mobile. It likes to dissolve in water and travels easily through the soil profile into groundwater systems, ultimately reaching streams and rivers. Because of this MO (Method of Operation/ Modus Operandi), nitrogen losses often occur out of sight below the surface, making them harder to catch and manage.
For a long time, nutrient management strategies focused heavily on the reduction of nitrogen loss. That made sense. If nitrogen moved easily through soil and into waterways, then controlling it should have solved the problem, right?
Well it didn’t.
Even when nitrogen losses were reduced and put under house arrest, freshwater quality issues often remained. This meant something else was involved… nitrogen had an apprentice picking up the slack.
Suspect #2: Phosphorus- a.k.a ‘the one hiding in plain sight’
Phosphorus has a different MO to nitrogen. Instead of traveling through groundwater channels, phosphorus often attaches itself to soil and sediment particles and is transported during rainfall and runoff events. Although dissolved phosphorus can also contribute to eutrophication, most phosphorus losses are strongly linked to surface processes, such as erosion and overland flow. It, essentially, disguises its movements during significant events, helping to evade detection.
Sharpley and colleagues showed that this difference between nutrients matters. Managing nitrogen alone was not enough, because phosphorus followed different pathways through the landscape.
Even more interestingly, strategies that were designed to reduce nitrogen loss sometimes came with unintended consequences. In some cases, the application of manure that was applied based on the crops nitrogen requirements, had repercussions that caused phosphorus to accumulate in soils, increasing the risk of phosphorus loss during runoff events.
So the investigation suddenly became more complicated.
It wasn’t just about catching one suspect anymore.
An event that our suspect uses to disguise its movements while being attached to soil particles. This example is the Leith River, Otago, in flood. Photo taken by author. CC-BY-NC
A breakthrough clue: location matters more than we thought
By this point, researchers realised that nitrogen and phosphorus behave differently, travel through landscapes in different ways, and require different management strategies.
One of the most important insights from this research was that nutrient loss doesn’t happen evenly across farms. Instead, it tends to occur in specific areas where high nutrient availability overlaps with the active transport pathways, such as runoff.
Not every paddock contributes equally to nutrient loss. Some areas of the farm are more prone to loss than others, especially where saturated soils, slopes or drainage pathways allow for nutrients to move quickly into waterways.
This changed the way scientists and researchers approached nutrient management. Instead of trying to control the nutrients everywhere at once, the attention shifted towards identifying the places where interventions would make the biggest difference.
Following the evidence: the phosphorus index
Once researchers realised that location played such an important role, they needed a way to identify where losses were most likely to occur. This led to the development of tools like the phosphorus index.
Rather than simply measuring how much phosphorus was present in the soil, the phosphorus index combines information about soil phosphorus levels with landscape features, such as slope, runoff risk and transport pathways. Together, these factors help identify where phosphorus is most likely to leave the farm and enter waterways.
Instead of treating entire farms the same way, the phosphorus index helps target management practices to the places that matter most.
Almost like predicting the potential next target location.
Example of potential critical source area where nutrient runoff and drainage pathways overlap. Photo CC BY-SA 2.0 by Doug Kerr.
Plot twist: solving one problem can create another
One of the most interesting outcomes from this research was the discovery that managing nitrogen and phosphorus separately can sometimes create trade-offs between them.
Practices that were designed to reduce nitrogen losses can increase phosphorus accumulation in soils simultaneously. At the same time, strategies that reduce phosphorus runoff can increase nitrogen losses through drainage pathways.
This meant nutrient management couldn’t focus on just one suspect anymore. Both needed to be considered together.
That shift in thinking helped to reshape how scientists and land managers approach water quality protection today.
Despite these advantages, the case is far from closed. Excess nitrogen and phosphorus continue to enter waterways in New Zealand and around the world, contributing to algal blooms, reduced water clarity, oxygen depletion and the degradation of freshwater ecosystems. While researches now have better tools to identify and manage nutrient losses, protecting water quality remains an ongoing challenge.
Why does this case still matter?
The work by Sharpley and colleagues helped move nutrient management away from simple nutrient solutions towards more integrated approaches that recognise how nitrogen and phosphorus interact across landscapes.
Instead of asking how many nutrients are present, researchers began asking: Where are they most likely to move to?
That question led to better tools, better targeting of mitigation strategies and a stronger understanding of how agricultural systems influence freshwater quality.
By recognising that both nitrogen and phosphorus contribute to eutrophication through different pathways, scientists and land managers are better equipped to reduce excessive algal growth and protect the health of rivers, streams and lakes.
The mystery of nutrient loss is far from completely solved. But thanks to research, we now know where to look and which suspects deserve the most attention.
This article was prepared by Master of Science student Emma Meikle as part of the ECOL608 Research Methods in Ecology course.
Sharpley, A. N., McDowell, R. W., & Kleinman, P. J. A. (2001). Phosphorus loss from land to water: integrating agricultural and environmental management. Plant and Soil, 237(2), 287–307. https://doi.org/10.1023/a:1013335814593
Just before Christmas in 1999, Dr. Eric Scott collected an unusual ground beetle from the Wangapeka Track, in Kahurangi National Park. His wife also suffered a broken arm after a bad fall along the track and Eric safely supported her through the tough walk out for medical care. You will also be pleased to know that the beetle specimen was safely delivered to the Entomology Research Museum at Lincoln University. All in a day’s work for an entomologist!
At that time, no one knew that this tiny beetle would become crucial evidence in a controversial biogeographical debate years later.
Classification work
The scientific name of this newly discovered ground beetle species was Orthoglymma wangapeka (there is no common name). This species belongs to the ground beetle family (Carabidae, Coleoptera). It is quite small, with a body length about the size of a fingernail. The beetle is elongated and narrowed at the ‘neck’ position. Its entire body is covered in a dark brown, polished exoskeleton.
It looks like a normal brown beetle at first glance. However, careful examination of both its external structure and internal reproductive organs, led an international research team, including John Marris and Rowan Emberson from Lincoln University, to discover that this was a new species, different from any other known Orthoglymma species.
Dorsal View of Orthoglymma wangapeka, Scale bar: 1 mm. Photo Citation: Lincoln University Living Heritage: Tikaka Tuku Iho (6th Mar 2023). Coleoptera Orthoglymma wangapeka Holotype. In Website Lincoln University Living Heritage: Tikaka Tuku Iho. Retrieved 17th Apr 2026 12:00, from https://livingheritage.lincoln.ac.nz/nodes/view/36272, used under CC BY 3.0 NZ
The research team placed the newly named Orthoglymma (from Ancient Greek for straight carved lines – referring to the lined on the abdomen) wangapeka (from the locality of collection) in a tribe called Broscini.
They obtained data on 73 physical traits and compared with closely related beetles. The closest relatives of this species are all found only in New Zealand, Australia, and southern South America. This suggests that the ancestor of these Orthoglymma species was found in these areas. Fossil evidence of Broscini ground beetles in other research suggests that this group originated before the Gondwana breakup.
Ancient biota debate
What is the Gondwana breakup? Based on earth science research, Gondwana was a supercontinent that formed around 600 million years ago. It included many of the current continents, such as South America, Africa, Antarctica, Australia, and our homeland, New Zealand. The supercontinent Gondwana began to break apart around 180 million years ago.
The continent of Zealandia started separating from Gondwana about 85 million years ago, becoming isolated around 70 million years ago, leading to the formation of the Tasman Sea.
The long process of the fragmentation is known as the Gondwana breakup. This history explains why New Zealand’s biology shares high similarities with other southern landmasses, like Australia, South America, and Southern Africa, which were also part of the original landmass and neighbours to New Zealand.
A map of the supercontinent Gondwana. At this stage in the earth’s history, Zealandia had not formed a distinct continent yet. Photo Citation: Mikocheung, CC BY-SA 4.0, via Wikimedia Commons
A second critical event occurred in New Zealand after the Gondwana breakup. New Zealand experienced a significant rise in sea level due to the sinking of the Zealandia continent around 25 million years ago. This is known as the ‘Oligocene Drowning’ theory.
There has been a heated debate about the extent of this drowning in the academic world. Some experts argue that New Zealand was completely submerged under the ocean during the Oligocene Drowning, which would cause all local terrestrial organisms to go extinct. From this perspective, our current animals and plants would have had to colonise New Zealand by crossing the sea after the drowning. On the other hand, the opposing experts claim that parts of New Zealand must have remained above the ocean, providing a refuge for ancient species to survive.
Beetles and land
Orthoglymma wangapeka is a tiny ground beetle that belongs to an ancient branch that evolved before the Gondwana breakup began. These beetles are flightless, lacking the obvious ability to disperse long distances across oceans. Their ancestors almost certainly were present in the pre-break up New Zealand region of the supercontinent Gondwana. Their presence is a powerful piece of evidence suggesting that New Zealand was not completely submerged in the ocean during the Oligocene Drowning.
The area where Orthoglymma wangapeka was collected belongs to the Buller Terrane, which is one of the oldest rock formations in New Zealand and originated on the eastern margin of Gondwana. The species may be a Gondwanan relict, a survivor of extreme environmental change in this area.
Other ‘living fossil’ are also found in this area suggesting that the Nelson area might have been an island that provided insects, including ground beetles, wētā, and micropterigid moths, with dry land to avoid extinction during the Oligocene Drowning.
View of Wangapeka Track, where Orthoglymma wangapeka was collected. Photo Citation: Michal Klajban, CC BY-SA 4.0, via Wikimedia Commons
Summary
As an ecology student, I am deeply drawn to this story because it is remarkable that a newly discovered species could play a vital role in a long-standing unsolved debate in earth science.
It fascinates me how a tiny organism can carry such a wealth of information about our country’s ancient past. This case demonstrates how biodiversity research connects with other subjects and provides a priceless value in broadening knowledge and highlights the importance of environmental conservation.
Without conservation of the habitat, this new species could have gone extinct before it was collected, and we would have missed a critical piece to the puzzle to understand the ancient geographical secrets of our country.
Next time you walk a trail in New Zealand (first watch where you are walking – don’t break and arm!), keep in mind that everything that exists in the environment might carry some undiscovered secrets of the earth’s history, even a tiny ground beetle.
This article was prepared by Master’s of Bioprotection student, Ethan Harland, as part of the ECOL608 Research Methods in Ecology course.
References
Liebherr, J. K., Marris, J. W. M., Emberson, R. M., Syrett, P., & ROIG‐JUÑENT, S. (2011). Orthoglymma wangapeka gen.n., sp.n. (Coleoptera: Carabidae: Broscini): a newly discovered relict from the Buller Terrane, north‐western South Island, New Zealand, corroborates a general pattern of Gondwanan endemism. Systematic Entomology, 36, 395-414. https://doi.org/10.1111/j.1365-3113.2011.00569.x
Mildenhall, D. C., Mortimer, N., Bassett, K. N., & Kennedy, E. M. (2014). Oligocene paleogeography of New Zealand: maximum marine transgression. New Zealand Journal of Geology and Geophysics, 57(2), 107-109. https://doi.org/10.1080/00288306.2014.904387
You stride through lush grasslands. The scenery seems perfect. But lurking just below your feet is a battlefield.
It’s not an obvious one, of course. There are no bombs going off or explosions or yelling; but there are millions of tiny creatures locked in battle for resources and life. And whoever wins determines whether the plant life above it survives.
This blog post has been inspired by research published in 2015 by scientists of Lincoln University, AgResearch, and their international colleagues. They examined whether soils from different pastures in New Zealand naturally inhibit soil-borne plant pathogens.
Figure 1. Grass roots penetrating the soil. The majority of activities that affect plants occur below ground level. Source: iStock/Getty Images
The Invisible Threat
Many important plant diseases originate underground rather than from the aerial parts of plants, such as leaves. They attack plant roots and stems before visible symptoms appear above ground. By the time one notices any symptoms of disease, the damage may already have been done.
And here is the scary part: these silent killers can reduce pasture productivity by 40–50%. Can you imagine how devastating it is to lose nearly half of your production to something unseen? Such is the case in pastures where crop rotation and chemical controls cannot always solve the problem.
Instead of asking the conventional question, scientists started to wonder:
What if the soil could defend itself?
Soil Is Not Just Dirt
It is easy to think of the soil as lifeless material, but this is far from the truth. Soil is one of the most biologically diverse ecosystems on Earth. A complete microbiota lives within it: bacteria, fungi, and other microorganisms interact continuously. While some assist plants in absorbing nutrients, others … kill them.
Some soils inhibit diseases. Such soils are referred to as disease-suppressive soils, and their action falls into two categories:
General suppression: the microbiota competes with the pathogen, Specific suppression: some microbiota attack the pathogen itself.
Soils with high plant diversity likely contain more diverse microbiotas, which suggests a high disease-suppression capacity.
But how can one measure such a phenomenon?
A Clever Way to Test Soil
The researchers developed an interesting experiment to test the soil under examination. Rather than using conventional grass or legumes that can be found on pastures, they opted for something completely out of the ordinary: kale.
And why kale? This plant is not usually used on pastures. If disease does not occur, then it shows that the soil is pathogen-resistant in general.
Furthermore, they exposed the plants to a well-known pathogenic fungus named Rhizoctonia solani. And this one leads to a specific disease called damping-off. Plants affected by the disease exhibit dark lesions near the base of the stem which cause plants to fall, like broken wires.
So, basically, the process works as follows: Introduce the same plant into different soils; Infect the plant with the same pathogen; Observe the results.
The experiment was conducted using four New Zealand pasture soils, including Lincoln, Eyrewell, Rotorua, and Kurow soils.
Same plant. Same pathogen. Entirely different results.
Some soils promoted rapid spread of pathogens; others reduced their effect considerably. There were significant differences between disease levels in the various soils.
Final disease levels were highest in Rotorua soil.
Disease progression rate was highest in Kurow soil.
Lincoln soil displayed maximum resistance, with minimal disease levels in the control.
Same experiment. Different soil. Entirely different results.
And here comes the moment when it all becomes evident:
Soil is not just a neutral element. It actively influences the experiment.
If a soil keeps plants healthy, it’s suppressive. If plants collapse… not so much.
Without even having introduced the pathogen, some soils exhibited symptoms of infection. For instance, in Kurow soils, damping-off disease symptoms appeared in the control group as well. This indicated that the pathogen was already present but dormant until the required environmental conditions prevailed.
It could be termed an underlying threat embedded in the soil. Furthermore, pathogens, such as Rhizoctonia solani, can survive between successive cropping seasons, affecting both pastures and future agricultural crop growth.
It’s Not Only “How Many” but Also “How Quickly”
Besides assessing how many of the plants became diseased, the authors also took into account the dynamics of disease development. Why does this matter?
This is important because a slowly developing disease will allow the plants to develop properly before being affected. The faster moving disease will kill them much earlier.
Two metrics were used to assess this: Disease Incidence (DI) – number of infected plants at the end; Area Under Disease Progress Curve (AUDPC) – a measure of disease development over time. Imagine that: DI is the final result AUDPC is the whole game And often, their narratives may be very different.
Why It All Matters
It isn’t just scientific research for research’s sake. With knowledge of how soils resist disease, we could:
Improve our soil management techniques,
Cut down on chemical use,
Increase productivity from our crops and pastures,
Create a more sustainable agricultural process.
Rather than battling pathogens directly, we could fortify our soil against disease.
That’s where it gets revolutionary.
The Bigger Picture
Agriculture of the future may rely less on adding things to soil… And more on what is already thriving beneath its surface.
When you look at a flourishing farm, remember this: It is not only the plants that prosper. There is an entire ecosystem underground, sustaining all life. And in this unseen world, each microbe counts in the battle beneath our feet.
This blog was prepared by Vikram Shankar Malagi, a Master of Bioprotection student at Lincoln University, as part of an assignment for ECOL608 Research Methods in Ecology.
Bellbirds love to sing; they sing for everything that they do. Communicating, courtship, foraging, defending their homes, it’s almost like they’re living in a musical. I’ve always been captivated by the song of bellbirds. Whether I’m on a walk in the Port Hills, or at Willowbank Wildlife Reserve looking at the capybara and otters, I hear bellbirds singing in the background.
The New Zealand Bellbird, or Anthornis melanura, is a honeyeater species and a close relative of New Zealand’s Tūī (Prosthemadera novaeseelandiae). They have a variable diet, feeding primarily on nectar, but also fruits, insects, and scale insect honeydew. In Christchurch, bellbirds spend their summers in the Port Hills, feeding from the large nectar supplies that come from flowering native vegetation. Then, in the winter, some move to the city, where urbanisation creates a warmer environment, and sugar feeders and exotic plantings provide food.
In 2019, PhD student Jennifer Dent studied foraging and migratory patterns of bellbirds in Christchurch for her thesis, using their calls to determine where different groups were. Bellbirds in different areas make different calls, basically a different accent, language, or singing a song in a different key, and this is referred to as dialect.
For this, Jennifer placed DOC AR4 audio recorders at 59 locations. 29 locations were in the Port Hills, where recording took place in autumn. Sites were everywhere from Rapanui Bush in the east to Ahuriri Reserve in the west, totalling 15 km around the Port Hills. The other 30 recording locations were in Christchurch city during winter, from as far north as the Groynes, as far east as Sumner, and as far west and south as Lincoln. From this, Jennifer matched dialects in the Port Hills in autumn to those recorded in Christchurch city in winter.
Christchurch dialects
Jennifer found four different bellbird dialects in Christchurch.
Dialect A was the most common dialect. It was spread across the northern region of the Port Hills, as well as in more central areas, such as the Botanic Gardens.
Dialect B was the next most common. In the Port Hills, it was found in Kennedy’s Bush, and in the city, it was in south-western areas, such as Halswell and Hoon Hay.
Dialect C was the least common dialect that Jennifer observed. In the Port Hills, it was found in Omahu Bush, and in Christchurch, it was found outside of the city, but only as far as Tai Tapu and Lincoln.
Dialect D was the last dialect. This pattern is unusual because it was not found in the autumn Port Hills recordings, but was found in the winter Christchurch recordings around the eastern and northern parts of Christchurch, such as Sumner, the Groynes, and Riccarton Bush, but because it was not found in the autumn recordings, it is not known where they went after winter.
It’s surprising that four different dialects were found both so close together and with very little overlap, especially since there are no geographic barriers stopping members of one group from flying to another. Jenny suggested that there could be two main reasons for this: limited dispersal and vocal imitation.
Limited dispersal, or philopatry, is the theory that states that birds remain in the areas where they were born and raised perhaps because it is harder to survive outside their own groups. A second theory is that vocal imitation by bellbirds occurs when birds move between groups, but we don’t notice it because they are so quick to pick up on the new dialect. It is possible that both of these theories are occurring simultaneously.
Following bellbirds into the city
The presence of all Port Hills dialects in the Christchurch recordings suggests that seasonal dispersal from the Port Hills to Christchurch is a shared behaviour among all populations. Furthermore, as shown by the map, dispersing to the nearest suitable location rather than spreading across all of Christchurch also seems to be a shared behaviour.
Bellbirds in Christchurch likely remember foraging areas for different times of the year, but rather than remembering many locations across Christchurch, they remember only a few patches that are close together. This is referred to as patch-scale resource tracking, and it has been shown to be a low-work, high-reward technique for foraging by bellbirds.
Next time you hear a bellbird singing, you aren’t just hearing background noise, you’re hearing a local neighbour. That bellbird might be a Cashmere regular or a member of the Tai Tapu community. It makes Christchurch a more lively city, as it’s not only just a place for us, but for birds following their own routines, singing their songs as they go about their day.
This article was prepared by Master of Science student Max Mulvihill as part of the ECOL608 Research Methods in Ecology course.
In New Zealand, these organisms range from burrowing animals, to soil-dwelling invertebrates, to fungi, to microscopic bacteria and much more. So next time you walk on soil, think about how much life is beneath your feet.
For plants, a major component of successful growth and survivability is the soil microbiota, such as bacteria, fungi, viruses, nematodes (tiny worms), and many more. I have much love for fungi in the soil microbiota, especially mycorrhizal fungi that are essential for plant growth.
Mycorrhizal fungi form mutualistic relationships (beneficial for both organisms) with plant roots. The fungi extend their network to increase the nutrient intake in exchange for carbohydrates that the fungi cannot produce itself.
I did a project on ectomycorrhizal fungi abundance on red beech tree roots for SCIE393 where I took this photo of an ectomycorrhizal fungal fruiting body (mushroom) under the microscope (which I thought was very cool). This is really where my love for mycorrhizal fungi started to blossom.
Ectomycorrhizal fruiting body under the microscope – Photo by Lucas Watkin (CC-BY-NC)
Exotic plants are strong invaders
That’s enough about me for now, time to talk about invasions from non-native plants. As I’m sure everyone who lives in New Zealand is aware, we live in an invaded country, full of exotic predators, pests, and weeds.
From grassland to pineland: The rapid invasion of black pine into well grazed high country pasture – Photo by Jon Sullivan (CC BY-NC 2.0)
One of the worst exotic plant species are wilding pines, such as lodgepole pine and radiata pine. Lodgepole pine was introduced into New Zealand in 1880 to combat erosion. Burning of forests, overgrazing, and introduced browsers, such as deer, goats and rabbits, were clearing the hillsides of our native plants, leading to more slips. The New Zealand government decided to plant exotic plants, specifically Douglas-fir and lodgepole pine to cover the hillsides and reduce erosion.
These pines did stop the erosion, however, what was not anticipated was the enormous dispersal ability of these wilding pines. Seeds of wilding pines can survive for a decade in their cones, grow roughly anywhere, and can travel kilometers from their parent. There is now roughly 800,000 hectares of wilding exotics in the South Island alone, two thirds of which is lodgepole pine!
Wilding pines of Flock Hill Station: The very many wilding pines coming out from the experimental forestry plots in adjacent Craigieburn Forest Park – Photo by Jon Sullivan (CC BY-NC 2.0)
Be careful what you plant!
This paper headed by Joanna Green has contributions from my lovely thesis supervisor Lauren Waller. In it they describe the effects of planting non-native plants on the soil microbiota, and how that can impact what grows there afterwards. They were specifically looking at how well lodgepole pines grow in soils that have been used and conditioned by exotic plant species.
Joanna and Lauren started by using soils that had already been conditioned by 19 native and 20 exotic plant species from another two experiments by Warwick Allen and Lauren Waller. The soil microbiota, the nutrients in the soil, and other factors, like the pH of the soil, had been changed to best suit the plant that had been grown in that soil.
An example of part of the soil microbiota that was conditioned were the ectomycorrhizal fungi. These fungi are required for successful growth by some of our native species, such as our beech, mānuka, and kānuka species. However, exotic species use different species of ectomycorrhizal fungi than our native species. Therefore, when exotic species are grown in soil they will grow well with their species of ectomycorrhiza.
Basically, think of it like this. If you owned a garden and really liked roses, you would grow a lot of roses. You might grow some other plants but the focus of the garden would be on roses. Now, if someone else came in and took over the garden for themselves, they might not like roses as much but might really like petunias. They will then plant petunias in place of where the roses used to be, altering the state of that garden.
In terms of ectomycorrhiza, they require associations to survive, so the native ectomycorrhiza species that were in the soil will die after their native plant partners are gone. Exotic ectomycorrhiza species associated with exotic plant species will then survive. Due to this, it will become a lot more difficult for our native species to grow back in that soil due to a lack of ectomycorrhiza that they can grow with. Conversely, it will be a lot easier for exotic plant species to grow in partnership with a large number of exotic ectomycorrhiza.
Anyway, back to the paper. The researchers found that lodgepole pine grew better in soils that had been conditioned by exotic species, such as black alder, cocks-foot, spear thistle, gorse, and many more. And this was regardless of whether pines had been planted there or not! Lodgepole pine will have a much easier time establishing and invading into areas that have previously had exotic species growing there.
Lodgepole pine tree near Lake Benmore – Photo by abcdefgewing (CC-BY-NC)
So why does this matter?
To conserve our native plants, sometimes we must plant them in areas that have previously grown exotic species. Joanna and Lauren’s research shows that the soil will be conditioned to favour growth of exotic species, and so growing native plants will be more difficult. It will also be a lot easier for exotic species, such as lodgepole pine, to re-invade and take over the conservation site. Therefore, conservation managers must be aware of this soil legacy and decisions must be made in order to manage this re-invasion potential.
So, next time you want to plant an exotic plant, think about the soil, and whether you would rather plant a native instead.
This article was prepared by postgraduate student Lucas Watkin, Master of Science in Conservation and Ecology, for an assignment in ECOL608 Research Methods in Ecology.
Green, J. L., Waller, L. P., Allen, W. J., Orwin, K. H., Pelser, P. B., Smaill, S., & Dickie, I. A. (2025). Plant-soil feedback from non-native communities increases pine invasion and re-invasion potential. Plant Soil, 514(2), 2461-2474. https://doi.org/10.1007/s11104-025-07528-x
Featured image: Did somebody order pines? The rapid invasion of black pine into well grazed high country pasture – Photo by Jon Sullivan (CC BY-NC 2.0)
