EcoLincNZ

Category: student blog

  • PredatorFreeNZ 2050: fantasy into reality

    High in the treetops of a lush forest, a group of native birds gathered together, their vibrant feathers glinting in the dappled sunlight. Excited chirps and melodic trills filled the air as they engaged in a lively conversation. Their voices carried the hopes and dreams of a restored ecosystem.

    Koru, a charismatic Tūī with iridescent feathers, fluttered his wings and cleared his throat. “Have you all heard the latest? The Humans are determined to make New Zealand predator-free by 2050!”

    The cheeky Kākāriki, a lively parakeet, interjected. “Can we truly reclaim our forests from the claws and jaws of those invaders?” A wise and observant Morepork owl, Ruru blinked his large, round eyes. “Is that so? Quite a lofty goal, but can they really do it?”

    Photo credit: CC BY-NC-ND 2.0 Simeon W Flickr
    Red-crowned Kakariki, Photo credit: CC BY-NC-ND 2.0 Simeon W, Flickr

    With its unique biodiversity, New Zealand is home to a huge array of species found nowhere else on Earth. However, many of these treasures face an existential threat from invasive predatory mammals, such as rats, stoats, and possums, introduced by human settlers centuries ago. These voracious predators ravage the native bird populations. Many species are now extinct, and more are now on the brink of extinction.

    Predator-Free New Zealand 2050 (PFNZ2050) was initiated in 2016 with an audacious aim of eradicating the most destructive trio of predators: possums, stoats, and rats; from New Zealand. This call for action echoed through the mountains and valleys, inspiring conservationists to make New Zealand, once again, a land of breathtaking beauty and thriving unique biodiversity. The ambitious aim of Predator Free 2050 is not without precedent. To date, New Zealand has successfully eradicated invasive mammals from 105 (admittedly much smaller) islands.

    In 2020, a journal article was published that assesses the feasibility and steps needed to achieve Predator Free 2050. it was written by James Ross, from the Centre for Wildlife Management and Conservation (CWMC) at Lincoln University, Grant Ryan from The Cacophony Project, Merel Jansen from the Department of Applied Biology, HAS University of Applied Sciences, Hertogenbosch, The Netherlands, and Tim Sjoberg, from the Taranaki Mounga Project. Together, these researchers have decades of experience controlling and monitoring pest mammals in New Zealand.

    The first step, removing predators with aerial 1080 poisoning and ground-based resetting traps, will help remove the majority of predators. A modified aerial 1080 approach, developed by Zero Invasive Predators (ZIP), can result in localised eradication. This was first tried in a 400-ha area at Mt. Taranaki in 2016, then at a 2,300-ha site in South Westland, using ground-based resetting traps. Regular servicing of resetting traps also gives better ground-based control results.

    Once pests have been eradicated from an area, the next big challenge is to defend the area from invasion. ZIP demonstrated how to defend predators from re-invasion in two sites using a “virtual barrier” of traps. A 2 km wide barrier of traps protected a 400-ha peninsula at Bottle Rock in the Marlborough Sounds. Using this virtual barrier of traps, ZIP prevented predators from re-invading at two sites, in the short term.

    Australian brushtail possums, initially introduced into New Zealand for the fur trade, and now one of the major pest mammals in New Zealand.
    Photo credit: CC BY-SA 2.0, Gnu Chris, Flickr

    Detecting the survivors is the next crucial phase for eradication, as any survivors can build a new population. The CWMC and Cacophony Project found that thermal cameras are 3.6 times more sensitive than trial cameras in detecting possums. Whilst trail cameras appear to improve detection rates, they do not always trigger when a small, fast-moving animal moves in front of them. These cameras also use infrared illumination at night, which may deter some animals.

    Thermal cameras are a new advanced technology that shows high sensitivity in detecting both small and large pest mammals. Because the motion detection is done using software, the sensitivity can easily be adjusted. Unlike trail cameras, thermal cameras do not require infrared illumination to operate at night.

    Videos collected by the thermal cameras are classified using AI technology (machine learning) trained on a library with more than 50,000 tagged videos. The AI can identify the animal species and only keep recordings for the target pests, which can be stored on-board the device or sent out using the cellular network.

    To achieve the PFNZ 2050 goal, detecting the last few individual pest mammals is complex and expensive. As a technical improvement in detection, ZIP has made an AI network of over 500 cameras across the Predator-free South Westland project area. The AI cameras use LoRa (low-powered radio technology) to send the information to solar-powered mini-satellites. The information is transferred to a web server that checks the information the next day. The AI cameras only need to be serviced twice a year to change the batteries. The AI cameras have reduced the time to detect one predator from around six weeks to just one day and have reduced the cost significantly.

    PFNZ2050 will require more innovative strategies, control tools, and wider public support to be successful in its ambitious challenge. Future control work will increasingly take place in and around urban areas. As such, the next most important advancement needs to be construct control tools that community groups can use. There should be a bottom-up-driven approach to community engagement in conservation so that as new technologies become available, the number and size of invasive mammal-free publicly and privately managed reserves can increase. In a recent study, people showed high support for species-specific toxins, but there is a shortage of funding for registration of these toxins.

    NZ has a 60-year history of eradicating pest mammals, from tiny 1-ha Maria Island to more than 11,000 ha Campbell Island, with suitable techniques and public support. This is an example of how the impossible becomes possible when passion, science, and community unite.

    With a final chorus of their harmonious calls, the native birds took flight, their wings carrying their hopes and aspirations to the corners of the land. From forests to cities, their songs echoed, touching the hearts of all who listened.


    This article was prepared by postgraduate student Mohamed Safeer as part of the ECOL 608 Research Methods in Ecology course for his Master of Pest Management degree.

  • Farming and biodiversity: what’s on 0.5% of Canterbury Plains?

    Imagine the Canterbury Plains blanketed in tall trees interwoven with small hardwoods. This beautiful, unique landscape is then singed into dry grassland with the arrival of Māori. Continue to imagine European settlers introduce weedy exotics that infest the landscapes, once again modifying the region. Now, picture the current landscape – a monotonous cover of dairy farms. Which of these images would you think is best for our native and endemic species?

    Prior to humans or today? (Think from an insect’s perspective)

    The plains have been a dynamic landscape ever since humans stepped foot in our vulnerable country. They will continue to experience dramatic changes in the future with the ever growing population leading to climate change, urban expansion and agriculture intensification.

    The 1940s saw the commencement of irrigation on the plains so that farmers could have a reliable water source to enhance the production of pasture and crops. Water facilitated the development of dairying from sheep farming, into the landscape we see today. Between 2002 and 2012, the Canterbury herd increased by 115%, accounting for 13.5% of the Aotearoa dairy herd.

    These drastic landscape changes have been detrimental to many of our precious native species by creating unfavourable conditions and habitats, species such as the bellbird (Anthornis melanura) have suffered. Some species, such as paradise shelducks (Tadorna variegata), have exploded in population numbers due to the favorable wet conditions caused from irrigating.

    Within the Canterbury Plains, less than 0.5% of this area is still the original remnant forest. Canterbury has been described as the most biological deprived and most modified environment in Aotearoa due to the intensification of agriculture. However, agriculture is a big portion of the country’s economy, bringing in approximately $10.6 billion (5%) of the country’s Gross Domestic Product (GDP).

    The food and fiber sector are major employer, providing jobs to over 359,000 people. Not only does it feed New Zealanders, it is also a big player in the global food market. in order to come to terms with this environmental dilemma, farms need to incorporate more sustainable agricultural practices, to feed the world and to support biodiversity. Currently through education and awareness this is already becoming a point of discussion.

    There has been a push to introduce native vegetation into farming systems. Several studies have examined the impacts of intensive dairy farming on soil health, vegetation, and life below ground. Farmers are now starting to see the benefits of even simple things, such as planting native vegetation. Such plantings not only positively impact farms, but also our are good for our native species, from small bugs to cryptic skinks and chatty birds.

    Mike Bowie from Lincoln University, like me, grew up on a family farm, and went on to tertiary education in ecology. This brings a helpful perspective to topics around the interaction of agriculture and ecology. It led Bowie to check out the biodiversity in the Bankside dryland remnant that is surrounded by an intensive dairy farming landscape. The Bankside Scientific Reserve in a 2.6-hectare area established in 1969. Mike wanted to know how adjacent agricultural land impacts the soil composition and fauna in this reserve area.

    Aerial photograph of the Bankside Scientific Reserve with kānuka and matagouri dotted throughout. (From Bowie et al., 2015)

    In 1970, an initial vegetation survey was conducted by Molloy within the new reserve. Bowie’s survey in 2015 found that only 31% of plants that Molloy surveyed still remained and that 27 new exotic species were present. The fauna found in the remnant were different to that of the neighbouring agricultural land. Bowie discovered the presence of four native earthworm species along with six exotic species. The number of the exotic worm species decreased with distance into the reserve.

    Bowie and his fellow researchers found 112 specimens of invertebrates, including many beetles as well as a significant native species, the ground weta! Soil pH, nitrate, and phosphate levels were all lower in the reserve compared to the surrounding paddocks.

    These observations highlight the need to retain existing dryland remnants and to establish other reserves throughout the plains. A diverse landscape will support a diverse range of species. I think farmers and the community are now starting to see the value of incorporating native vegetation and agroecological principles into their system, such as mixed species pasture systems.

    We don’t all need to put three hectares away into a reserve. Even small steps, such as planting a row of diverse natives along a fence line or waterway, will make a huge difference, if many farms join in.

    One thing that is highlighted in this study is the need for continued maintenance of restoration and remnant projects. It is not a plant and leave situation (no pun was intended…). Weed and pest control should be continually applied in these areas to prevent exotic weeds and animals from becoming established and smothering and displacing the natives.

    An example of this is in practice Te Ara Kakariki group that is establishing green dots (tiny native areas) from the Southern Alps to Lake Ellesmere/Te Waihora on private properties. This increases the connectivity of native planting, further increasing the power that these small areas can make overall. Animals and invertebrates will be able to spread throughout these dots and over the region.

    Farming has transformed the landscape of the Canterbury Plains. Image from Adrian Paterson.

    Farmers are becoming more aware of sustainable principles through education from organisations such as Te Ara Kakariki, DairyNZ, Landcare trust, and councils. Through education, ecology is becoming more interwoven into their practices. It will be a trick balancing the need for feeding the world and protecting the environment. Ecology is an excellent way to find this balance in agriculture, it can be adapted to any farming system to suit their needs and desires.

    Mike wants to help bridge this gap, not only in this study, but also others that he has conducted throughout his time at Lincoln University. Mike has examined how native plantings encourage native and beneficial invertebrates on Canterbury dairy farms, plus many more. I too believe that ecology and agriculture can work together to create a more sustainable agriculture sector that can efficiently produce food and improve food security, whilst supporting the health of the soil, water and biodiversity.

    This article was prepared by Master of Science postgraduate student Sam Fitzgerald as part of her ECOL608 Research Methods in Ecology course.

    Further reading

    Practical guide for landowner and farmers for landcare

    Improving biodiversity – Beef + lamb

  • Remove one NZ invasive mammal predator and another steps into its place

    Invasive species are a major concern for ecosystems worldwide, causing significant disruptions to native flora and fauna. Some mammals can have particularly devastating effects on local ecosystems due to their predatory nature. In the Hawke’s Bay, New Zealand, a recent study titled “Niche Partitioning in a Guild of Invasive Mammalian Predators” sheds light on the dynamics of invasive mammalian predators and their impact on the region’s native biodiversity.

    I’ll walk you through the key discoveries and explain why they hold immense importance in our understanding of niche partitioning and its implications for ecosystem management.

    Niche partitioning refers to the process by which species with similar ecological requirements coexist within an ecosystem by utilizing different resources or occupying different ecological niches. Niche partitioning reduces direct competition, promoting the coexistence of species that would otherwise struggle to survive in the same habitat.

    In Hawke’s Bay, a guild of invasive mammalian predators has established, comprising three key species: stoats(Mustela erminea), ferrets (Mustela furo), and feral cats (Felis catus). 

    These predators were introduced to New Zealand and have since wreaked havoc on many native bird populations. Recent studies have revealed an intriguing pattern of niche partitioning among these invaders, suggesting a potential balance within the guild.

    Camera traps were deployed in three seasons. Credit by Albert Salemgareyev/ACBK

    Researchers have observed distinct differences in the dietary preferences and hunting strategies among these invasive predators in Hawke’s Bay. These variations have allowed the species to exploit food, reducing direct competition and encouraging the peaceful coexistence of individuals.

    Stoats, being the smallest and most agile of the three predators, specialize in hunting rats, mice, and birds. Their slender bodies and keen sense of hearing enable them to pursue their prey with stealth and precision. Ferrets, on the other hand, are larger and more versatile, adapting to different types of prey or using various hunting techniques. Ferrets tend to target larger prey, such as rabbits and small hares, which they capture using their strength and speed. Feral cats, similar to stoats and ferrets, are solitary hunters, exhibiting a broader dietary range, preying on both small and medium-sized mammals, birds, and reptiles.

    While the predators may occasionally target overlapping prey species, they generally exhibit distinct foraging preferences and occupy different microhabitats. Stoats predominantly inhabit forested areas, where their excellent climbing abilities give them an advantage in pursuing prey in trees.  Ferrets, with their larger size and ground-based hunting strategies, are often found in open grasslands and shrublands. Feral cats, being highly adaptable, can exploit a range of habitats, from dense forests to human settlements.

    The phenomenon of niche partitioning among invasive predators in Hawke’s Bay has important implications for native species conservation. By occupying different ecological niches, these predators help reduce the burden on specific native animals in an indirect manner, allowing them to persist despite the presence of invaders.

    Bird species, in particular, have been heavily impacted by the invasion of mammalian predators. Native birds, such as kiwi, weka, and tui, have experienced population declines due to predation. However, the niche partitioning observed among invasive predators offers a glimmer of hope for the survival of some native bird species. For example, stoats target ground-dwelling birds, while ferrets focus on larger prey, like rabbits. This division of labour reduces the overall predation pressure on specific bird species and allows them to maintain a foothold in their respective habitats.

    Stoats are tricky to study. They are hard to find in the field and difficult to keep in captivity. Image from Adrian Paterson.

    Understanding the dynamics of niche partitioning among invasive mammalian predators can inform targeted conservation strategies. By recognizing the specific resources and habitats favored by each predator species, conservationists can create plans for managing natural areas that utilize the division of habitats to safeguard endangered native animals.
    Implementing effective trapping and removal programs, focused on the specific predators posing the greatest threat to certain bird species, can help alleviate their population declines.

    Habitat restoration initiatives aimed at enhancing native bird habitats, while creating barriers for invasive predators, can further support the survival and recovery of endangered species. For instance, Wellington, Zealandia is a 225-hectare fenced sanctuary dedicated to protecting and restoring native wildlife. The sanctuary is predator-free and provides a safe haven for endangered bird species like the tīeke (saddleback), kākā, and hihi (stitchbird). Zealandia also conducts active predator control outside the sanctuary to create a buffer zone for native birds.

    The study on niche partitioning among invasive mammalian predators in Hawke’s Bay offers valuable insights into the complex interactions within ecosystems and the potential consequences of invasive species on native biodiversity. These findings provide a foundation for conservation efforts and ecosystem management strategies aimed at mitigating the negative impacts of invasive predators on native flora and fauna. By understanding the dynamics of invasive species, we can work towards restoring and preserving the delicate balance of ecosystems, ultimately fostering a more sustainable future for our planet.

    Removing cats and ferrets from an ecosystem often has unforeseen consequences, as evidenced by the subsequent increase in site use by stoats. Stoats, cunning predators known for their ability to adapt to changing circumstances, have exploited the absence of cats and ferrets to their advantage. In the absence of these competitors, stoats have become more active during the day, closely following diurnal bird activity. This behavioral shift has raised concerns among conservationists, as it highlights the need for predator control measures to account for the specific hunting patterns and preferences of different predators.

    Failing to address this issue adequately could lead to a worse outcome for daylight birds, whose vulnerability to stoat predation may increase if their activities are not considered in predator control strategies. Therefore, it is crucial for ongoing conservation efforts to not only focus on removing invasive predators but also to consider the complex interactions among species and the potential cascading effects that may arise.

    This article was prepared by Master of International Nature Conservation student Albert Salemgareyev as part of the ECOL608 Research Methods in Ecology course. Albert won a prestigious Whitley Award for Conservation in 2023.

    Garvey, Patrick M., Alistair S. Glen, Mick N. Clout, Margaret Nichols, and Roger P. Pech. 2022. “Niche Partitioning in a Guild of Invasive Mammalian Predators.” Ecological Applications 32(4): e2566. https://doi.org/10.1002/eap.2566 

  • Tricks of the underground trade: networking below the vines

    Life in the soil can be a tricky business for plants and microbes. Nutrients are a limited commodity for some, and competitors may swindle and cheat to gain the upper hand. Strategic partnerships are highly sought after enabling exchange of one commodity for another within elaborate networks.

    In a tough economy, well-connected networks promote resilience, sharing of ideas and opportunity to those participating in mutual exchange. However, an efficient network should be an intentional one. Making simple connections is one thing, but choosing the right friends and trade partners is another.

    Although it may not appear that obvious on the surface, most land plants are proficient networkers. Below ground, plants form selective partnerships with microorganisms in the soil to access nutrients, water, and protection from pathogens. Those with strong networks are favoured in times of scarcity and change.

    Fungal mycelium consisting of thread-like hyphae. Photo by Lex vB at Dutch Wikipedia, (CC0 1.0)

    Within soil communities, fungi known as mycorrhizae play a major role in the growth and survival of plants. It is estimated that more than 80% of vascular plants form partnerships with mycorrhizae, an ancient evolutionary network approximately 450 million years old.

    Mycorrhizae are of particular importance in the viticultural industry as grapevines are highly reliant on these partnerships for growth and nutrient uptake influencing grape composition, vine health and occurrence of disease. In fact, grapevines form associations with entire communities of mycorrhizae known as arbuscular mycorrhizal fungi (AMF).

    AMF form close associations within the root tissue of plant hosts through specialized tree-like structures called arbuscules. These allow exchange of mineral nutrients from the soil for carbon fixed by the plant host which is transferred through the extensive hyphal network in the soil. These hyphae form interconnected “superhighways” within the soil, linking neighbouring vines and nearby crops transferring nutrients, such as nitrogen, from one host to another.

    Arbuscule of Rhizophagus irregularis colonising a plant root. Photo by Hector Montero, Flickr (CC BY-SA 2.0)

    AMF are highly diverse and have different effects on nutrient uptake and growth on grapevines. Depending on the situation, AMF can have positive, neutral, or negative effects on plant growth and stress resistance. However, under field conditions, plants are selective in the networks they build. These communities perform a diverse range of functions which collectively contribute to plant health and characteristics. Therefore, investing in the right trade partners is crucial.

    Until recently, the effects of whole AMF communities on grapevines had been largely unexplored. A research project at Lincoln University lead by Dr. Romy Moukarzel sought to understand how AMF different communities influence nutrient uptake and growth of different grapevine rootstocks. 

    In other words, who are the trade partners behind the vines and what is the return from these communities?

    To answer these questions, AMF communities were recovered from the roots of three different grapevine rootstocks across three different vineyards. Each rootstock was inoculated with its own (“home”) community or communities from other rootstocks (“away”) within three different vineyards. Vine growth, nutrient uptake, and chlorophyll levels were measured to find out if different communities had positive or negative effects on the different rootstocks.

    Consistent with previous work, different vineyards and rootstocks had their own unique communities. Growth and nutrient uptake differed depending on the composition of the community and rootstocks responded differently to the same communities. While some species in these communities improved nutrient uptake, others improved growth. In particular, a diverse community with a large representation of AMF of the Glomeraceae family resulted in the greatest increase in grapevine growth.

    In one vineyard, home advantage was also evident with “home” communities having greater increase in vine growth compared to “away” communities. Interestingly, when the amount of each AMF inoculum was equalised, home advantage was no longer observed.

    By changing the community composition, the positive effects on plant growth were reduced.

    New Zealand vineyard. Photo by Jorge Royan (CC BY-SA 3.0)

    Moukarzel and colleagues suggested that altering the composition may have resulted in competition between AMF leading to reduced positive effects on the host. AMF are known to compete for host resources, soil nutrients and colonisation sites. As a result, cooperation, and rivalry between AMF within different communities may have major implications for vine productivity.

    So, what can grapevines teach us about networking?

    Basically, choose your trade partners wisely. Identify friends and adversaries within the network and invest in those relationships with the greatest return.

    As proposed by marketing expert, Porter Gale: the so-called ‘new model’ of networking should focus less on ‘handing out as many business cards as possible’ and more on making connections based on how you want to grow. In other words, efficient networking should focus on investing in specific needs and interests. A well connected network with diverse partners offers wide opportunity and stability if components are co-operative.

    Overall, the findings generated from the study will be an invaluable insight towards leveraging AMF communities to target specific growth and nutrient requirements of grapevines. This is of particular importance to the viticultural industry as the composition of these communities play an important role in determining vine health, yield, nutrition, grape composition, and wine characteristics.

    Featured image: vineyard inter-row by rawpixel.com (CC0 1.0)

    While this study has provided a step towards understanding the communities below the vines, soil is a complex system with a wide range of players and there is much to learn about the orchestration of these networks. There are likely many more tricks of the underground trade to uncover.

    Moukarzel, R., Ridgway, H. J., Waller, L., Guerin-Laguette, A., Cripps-Guazzone, N., & Jones, E. E. (2022). Soil Arbuscular Mycorrhizal Fungal Communities Differentially Affect Growth and Nutrient Uptake by Grapevine Rootstocks. Microbial Ecology. https://doi.org/10.1007/s00248-022-02160-z

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

  • Detecting eDNA: everything, everywhere all at once

    Let’s say you want to know what animal species are present in a forest. You could walk along line transects and record the species visually observed. You could set up trail cameras to take pictures of passing animals for as long as there is enough space in the memory card and battery life in the cameras. You can use the acoustic survey method to study bats, birds, frogs, and even some monkey species, as they can be distinguished based on their sounds and calls.

    Depending on the size of your study area, making a list of the animal species present might take a several hours to several months because you will need to carry out various methods to identify them, which may also require species experts.

    These are well-established conventional methods for biodiversity monitoring, but is there no single method to find all the species in a given area at once? A one-size-fits-all t-shirt?

    There is a rapidly developing method that can identify a good portion of species in a given study area, including those living on the ground, in the ground, in the water, and even those flying in the air.

    Every organism contains genetic material called deoxyribonucleic acid (DNA), passed down from parents to children. All organisms from the same species have very similar DNA.

    An illustration of the double-helix of the DNA molecule. Original public domain image from Wikimedia Commons

    This technology takes advantage of the traces that organisms leave of their DNA in their environment, whether feathers, skin, scales, urine, or faeces. These traces, known as environmental DNA (eDNA), can be found in soil, water, and air.

    This shiny new method is called DNA metabarcoding. Simply put, it identifies organisms by matching their DNA with reference DNA from the gene database or library. It is like matching the barcode of products when you check out at the supermarket.

    The process begins with collecting water or soil, or even air, samples from the study area. These samples typically contain genetic material from diverse organisms, including bacteria, plants, and animals.

    Once samples are collected from the field, they are brought to the laboratory. DNA is separated from the samples, amplified, and sequenced to generate vast amounts of genetic data that can be compared with existing DNA databases and reference libraries such as GenBank for species identification.

    Environmental DNA – An emerging tool in conservation for monitoring past and present biodiversity – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/The-overall-workflow-for-environmental-DNA-eDNA-studies-with-examples-of-organisms-that_fig1_269724781 License: CC BY-NC-ND 4.0

    DNA metabarcoding can detect a broad range of organisms at once, providing a snapshot of the species diversity within the study area. That way, you can avoid performing various sampling methods. How convenient is that!

    Of course, no method is perfect, even DNA metabarcoding. Since it is still developing, there are limitations. The public gene library has the DNA references of many species but this is still a small fraction of all the species on earth, so far. There can be contamination in the samples, which could disrupt the results. Errors can occur not only during sample collection in the field but also in the laboratory.

    Compared to DNA metabarcoding, conventional methods have stronger standardised techniques for sampling and for interpreting the datasets. Besides, in the context of biodiversity monitoring, conventional methods can provide detailed information, such as abundance, age, sex ratios, and individual animals’ special characteristics, such as colours and conditions, which DNA metabarcoding cannot tell us.

    Conventional methods are like pictures with tiny pixels portraying good resolution, but their taxonomic scope is limited, whereas those of DNA metabarcoding cover a broad range of species, but the resolution is coarse.

    Is there the best of both worlds?

    Yes! Robert Holdaway and colleagues, including Ian Dickie working at Lincoln University, suggested that combining DNA metabarcoding with conventional monitoring methods will benefit scientists in many ways.

    Using them together will enable scientists to test and improve the reliability and accuracy of our still-developing DNA metabarcoding method. Moreover, combining them will result in a higher chance of detecting species from the same lineage.

    Robert and colleagues provided three case studies in New Zealand that can benefit from the dynamic duo.

    First, the duo can be of advantage to the nationwide measurements of New Zealand’s biodiversity. They can provide greater taxonomic coverage and more thorough information on the relations among biodiversity, ecosystem functions, and services.

    Second, integrating DNA metabarcoding with Māori biodiversity monitoring approaches will bring more understanding to the Māori worldview of interconnections among living and non-living beings. Metabarcoding can enhance biodiversity inventories, identifying species important and relevant to Māori which are rare or hard to find using conventional methods.

    Third, combining DNA metabarcoding with traditional surveillance in detecting pest species at the early stage will secure native species and landscapes from harmful biosecurity threats, such as harmful pests and diseases.

    In addition, DNA results shared from various surveys using the dynamic duo will be added to the reference libraries making them more resourceful and convenient for future research. Having more reference DNA sequences of species in the reference libraries, like GenBank, will make biodiversity monitoring much easier by identifying species with just a few clicks.

    DNA metabarcoding is a rapidly developing and powerful tool for monitoring biodiversity. Integrating it into conventional methods will lead to a stronger method to get plausible results. Overall, as Robert and colleagues indicated, not only will they add value to New Zealand’s biodiversity and Māori culture, but they will also protect the native natural environment and species through early detection of pests.

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

    Together, they will indeed make the best of both worlds for conservation.

  • Make boysenberries juicy again: the fight against downy mildew

    “Yes, why not!! Hi! I am Boysenberry. I will tell you the whole story, how I fight this destructive fungus. Before delving into the subject, I just want to tell you a little bit more about me.”

    Boysenberries Photo by simplyAutumn 2009 from Flickr

    I am a rich source of micronutrients and have great health benefits. My origin was in California, USA and I was introduced to New Zealand in the early 1940s. New Zealand has become a major producer and exporter of my fruits. The fruits are produced on the second-year canes ‘floricanes‘, whereas the first-year canes that only possess leaves known as ‘primocanes’. Those that grow quickly are known as ‘hurricanes’. Hah – an old joke amongst us boysenberries.

    Propagation of my plants is done either by cutting or tissue culture. Sadly, there is a fungus, Peronospora sparsa, who is my enemy and develops a disease, known as Downy mildew, systemically in tissue cultured plants. It causes huge damage and is will often cause losses of 50%, when I am grown with conventional management methods, to 100 %, when grown organically. It produces symptoms of mycelial growth of fungus, on my leaves in early spring and then later then premature reddening, shriveling, and hardening of my fruits and ultimately, the leaves become dull. That’s why it is sometimes called “Dry berry“.

    Downy Mildew of Boysenberry by Jones and other researchers

    “Unfortunately! I was struggling with this disease when some traditional methods, like removal of leaf litter, rooted ends of primocanes, and root suckers besides the fungicide sprays, that were being used to fight against it, but those were unfortunately not enough to beat it. I know, you are thinking, then how do I overcome this disease?”

    Some scientists from Lincoln University; Anusara Herath Mudiyanselage, Hayley Ridgway, Monika Walter, Marlene Jaspers, and Eirian Jones, came up with some solutions and experimented on me. They thought that heat and fungicides could help treat and stop the growth of the disease.

    To test if these ideas could work, fifteen symptomatic plants (2-year-old) were selected, repotted and cold stored at freezing temperature for 6 weeks to induce dormancy in them. Dormancy is a state where my plants hang tough and save their energy without undergoing their active growth. Dormancy allows my plants survive on their reserved food as they are cut off from the supply of food. The plants were transferred to a greenhouse until 2-3 primocanes developed. Thereafter, the plants were divided into three groups with five plants in each and given three different treatments to each group.

    The first group remained in the greenhouse for a month and was then given a heat treatment by being placed in a growth chamber at 34°C for 4 more weeks. The second group was sprayed twice with phosphoric acid and mancozeb (fungicide), the first spray was given two weeks afterward in greenhouse and second was given two weeks after the first spray. Plus, this group was also heat treated for a month. But the last group was left untreated and remained in the greenhouse for two months.

    Well! The main reason for giving the heat treatment with or without fungicide spray was to check the ability of my propagation material to limit the systemic infection of fungus prior to tissue culture to produce fungus free plants with verification done by PCR.

    Tissue Culture grown plants. Photo by EcoFert Inc. 2010 from Flickr

    After each of the treatments were complete, the plants were ready for the next step: propagation.

    “Do you remember how I am propagated? Yes, the tissue culture.“
    The single-bud stem cuttings from each plant were washed in antimicrobial soap, followed by surface sterilisation and washing in distilled water. These steps were followed in order to make my cuttings free from any contamination and washed with water to remove excessive chemicals/disinfectants. The cuttings were then placed in a liquid medium that made it possible for them to grow and multiply in a sterile condition.

    “You know what!” 125 plants survived in total and were potted after this. The largest group of survivors were from the heat treatment group.

    Cuttings/plants with roots were placed in the greenhouse for a couple of weeks where they were misted to maintain moisture. Afterwards they were shifted to the shade house and were kept for about five months under conditions that favor systemic symptoms. As the cool and wet conditions induce the growth of fungus, these conditions were provided to check the ability of my plants to resist it after given treatments.

    “Are you curious, to know what happened next, then?“

    Polymerase chain reaction machine Photo by USAID Laos 2020 from Flickr

    Twenty-two weeks after potting, all the untreated plants become sick with the disease. However, the other two treatments gave phenomenal results. Only 13 % and 17 % of plants showed visible symptoms, treated with heat only and fungicide + heat, respectively. The seventy-six plants (of 125) from both treatments (Heat and Fungicide + Heat) survived well without any symptoms several weeks after potting.

    Because some plants could have the fungus but not show any signs of infection, the researchers used the modern molecular technique (PCR) to confirm that there were no asymptomatic plants. This test was carried out regularly at certain interval for about a year and all of the tests gave a negative result. Fortunately, only a few plants with heat and fungicide + heat treatments got infected as compared to 100 % infection in untreated ones.

    “Well! this was my story, and now I can say that I can fight against this destructive disease, if I am given heat treatment with or without fungicide. I think you are also curious to know how the heat treatment affect the fungus.“

    The answer is the high temperature. The higher temperature destroys the essential chemical activities and inactivates micro-organisms like viruses. Similarly, this fungus has the nature of only being rely upon the living matter to eat and survive like the viruses. Therefore, the high temperature restricts the growth of fungus into the shoot tips and stops the infection.

    This is the first time that researchers have found a solution to a key challenge in managing dry berry disease. This opens the door to disease free propagation of my plants in nurseries with the uptake of heat treatment and without fear of fungicide resistance to fungi.

    “So now we can all be happicanes!”

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

    Reference: Herath Mudiyanselage AM, Ridgway HJ, Walter M, Jaspers MV, Jones E. 2019. Heat and fungicide treatments reduce Peronospora sparsa systemic infection in boysenberry tissue culture. European Journal of Plant Pathology. 153: 651–656.

  • 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