When a blessing becomes a curse…. A case of invasive Prosopis juliflora

Posted by Tshego Chilume @tschilume

When you live in an arid environment with temperatures that can go up as high as 47oC the prospect of the introduction of any tree into your area is music to your ears. This was the case for the people of Kgalagadi Desert when Prosopis juliflora and Prosopis grandulosa were introduced into the desert to control desertification and the constant moving sand dunes. For the first time large trees were seen around the district and communities had natural shade, fodder for their livestock and kids had playgrounds covered from the scorching sun. It was all merry; what could go wrong in such a beautiful scene? You would think nothing!


Except Prosopis is one of the worst invasive plant taxa in the world, it is capable of eradicating all woody plant species in its invaded habitat. Because there wasn’t much woody vegetation in Kgalagadi District, I figured there was no need to worry, however Kgalagadi Desert is known for its shrubs, cactus and grasses that have adapted to the harsh environment of their native ecosystem and are a valuable source of water and food for the locals, their livestock and wildlife. Forty years ago, the introduction was apparently met with dancing, celebrations and slaughtering of cattle (something Batswana do a lot when they have something to be happy about). But as time went on, a massive commotion has started between the relevant government agencies and communities. The impact of Prosopis is becoming increasingly apparent and difficult to ignore and everyone needs someone to blame for this. Prosopis is perceived to have caused the loss of native grasses, shrubs, reduction in borehole water yields, poisoning livestock and causing allergies to people. The communities blame the department of forestry for the introduction, forestry blames political pressure while the politicians blame the communities for insisting on a quick solution and the department of forestry for not doing enough research prior to the introduction.

The situation is that a solution to this social unease was necessary and back then there was very little funding available for research in issues of environmental issues. Even today, funding for research in environmental issues comes from donors outside Botswana. While this bickering continues, the impacts of Prosopis in Botswana have never been quantified and the current control practices were brought about by the public outcry.

This brings me to my current research on quantifying the ecological impacts of Prosopis juliflora in Gantsi District, the most ecologically and economically valuable district of Botswana. Gantsi district is home to one of the largest wildlife management areas in the world, Central Kalahari Game Reserve and in close proximity to the Okavango Delta (a world heritage site). This research will provide the impacts associated with Prosopis juliflora on the soil chemical variables and vegetation of Gantsi District. The research will improve our understanding of the effects of Prosopis and enable government to make informed decisions on the control measures and development of Prosopis management programmes.

tshegoTshegofatso Sputnik Chilume is an MSc student in the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. She is supervised by Cate Macinnis-Ng and Keotshepile Kashe (Okavango Research Institute, University of Botswana) quantifying the ecological impacts of Prosopis juliflora in Gantsi District, Botswana.

Diversity on our doorstep

Posted by Darren Ward @nzhymenoptera

New Zealand is a weird place for biodiversity. When discussed, perhaps most often mentioned is the ‘high degree of endemism’. This is the proportion of species found only in NZ and nowhere else in the world. Overall, about 90% of insect species in NZ are endemic. Along with endemism, the “total number of estimated species”, or the “number of undescribed species” are also often mentioned. An estimated 20,000 invertebrate species live in New Zealand and about 50% are undescribed.

But what is almost never mentioned is the number of undescribed species that are literally at your doorstep. You don’t have to go to remote field locations to find new species. Even in Auckland, NZ’s biggest city, there is a massive number of ‘undescribed’ and ‘unknown’ species.

Kuschel (1990) perhaps first bought this to our attention with his long running survey during the 1970s-1980s, literally in his backyard. In the Auckland suburb of Lynfield, he collected 130 species of beetles that were undescribed. In total >700 endemic beetle species were found.

Recently, we have been studying the diversity of parasitoid wasps in the Waitakere ranges, a large forest on the doorstep of Auckland city. Our study discovered 136 species of parasitoid wasps from ten locations (Kendall & Ward 2016). 80% of them are undescribed.

Just last week, a new species of parasitoid wasp, Synopeas motuhoropapense Buhl 2016, was described from Motuhoropapa Island (one of the small islands in the Noises Island group in the Hauraki Gulf). It was described along with 14 other species of micro wasps (<2mm in length) from around New Zealand. What is remarkable is that these 15 new species were described from <100 specimens in total, that’s a new species for every ~6 specimens.

Such biodiversity projects are an important part of understanding how the world works, but also give a sense of wonder about how we live with a massive diversity of weird and wonderful little critters.


Darren Ward is an entomologist in the New Zealand Arthropod Collection at Landcare Research, and a senior lecturer at the School of Biological Sciences, University of Auckland.

Buhl PN. 2016. Keys to species of Ceratacis and Synopeas from New Zealand, with the description of new species (Hymenoptera: Platygastridae), International Journal of Environmental Studies. http://dx.doi.org/10.1080/00207233.2016.1205916

Kendall L, Ward DF. 2016. Habitat determinants of the taxonomic and functional diversity of parasitoid wasps. Biodiversity & Conservation. 25(10), 1955-1972i

Kuschel, G. 1990. Beetles in a suburban environment: a New Zealand case study. Auckland: DSIR Report No3.

50 by 50? Yeah…nah

New Zealand’s climate change targets

Posted by Alice Baranyovits @ABaranyovits

New Zealand has a lot to be proud about, it’s an absolutely fantastic country, in fact according to the Telegraph it’s ‘the best country in the world’ and has been for the last 4 years. It’s also a bit of a world leader; in 1893 it became the first self-governing country to give women the vote, it was the first country to introduce the 8 hour working day, zorbing and bungee jumping and need I mention rugby?


New Zealand – the best country in the world

But there is another area where New Zealand is one of the world’s leaders and for once it’s a bad thing (and I’m not talking about the ridiculous house prices) and that’s in greenhouse gas (GHG) emissions per capita. In 2011, New Zealand was the fifth highest GHG emitter per capita out of 40 Annex 1 countries (listed here). New Zealand’s emissions per capita, whilst below countries such as Australia and the US, are well above most European countries, China and the world average – check out this graph. This was one of the points brought up during an excellent Royal Society talk I attended on Tuesday night at the Auckland Museum entitled ’10 things you didn’t know about climate change’.

Now I’m not going to go into everything Prof. Tim Naish and Prof. James Renwick discussed during their fascinating but somewhat depressing talk. One of the key take home messages was something I would have hoped everyone is already well aware of, and that’s climate change is happening, its human induced, and it will have impact on the way we live our lives sooner rather than later.

What I do want to talk about is something else that was mentioned during the presentation and that’s the idea of a GHG emission free New Zealand by 2050.  We will already hopefully be celebrating being Predator Free that year so why not go two for one and make it an even more momentous year by becoming GHGs free as well? Imagine the celebrations!

Unfortunately New Zealand’s current climate policy is well off that – with a proposed reduction in net emissions of 50% below 1990 levels by 2050, the ‘50 by 50’. A 5% reduction is proposed for 2020 and then an 11% reduction by 2030. Sadly, things don’t seem to be heading in the right direction; as of 2014 New Zealand’s gross GHG emissions had reached 81.1 million tonnes, that’s a 23% increase on the 1990 levels. Even if the 2050 target of a 50% reduction is reached that’s still well below the targets set by many other countries (e.g. Denmark, & the UK) and the targets proposed by the UNFCCC – an 80-95% reduction for Annex 1 countries, which includes New Zealand.

Both the Royal Society and organisations such as Generation Zero think New Zealand can and should do better. That we should be striving to be a world leader in this too and proving once and for all that New Zealand truly is clean and green. In a recent report the Royal Society highlighted the many advantages that New Zealand has, such as its wealth of renewable energy options, that leave it well placed for the move into a greener economy. They stated that to be successful, there would need to be sound policy, investments and incentives, along with the willingness of New Zealanders to make some lifestyle changes. Tackling the emissions from the agriculture sector (New Zealand’s biggest GHG contributor) will probably be the biggest challenge but not one that can be avoided – check out my previous post.

New Zealand may be small but it’s proven again and again that it can punch above its weight on the world stage and I can’t think of anything better than being a world leader in the fight against climate change – so let’s try and make 2050 a year to remember for all the right reasons.

For more information, check out Generation Zero’s ‘Zero Carbon Act’ and the Royal Society’s reports ‘Facing the future: towards a green economy for New Zealand’ and ‘Setting New Zealand’s post 2020 climate change target’.


Alice Baranyovits is a PhD student at the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. She is researching the movements of kererū in urban areas. She is supervised by Jacqueline Beggs, Mick Clout, Todd Dennis & George Perry.


At risk of catastrophic failure: relying on others in urban research

Posted by Ellery McNaughton @EJ_McNaughton

Recently, in a conversation commiserating research woes, one of my colleagues described the main part of my project as a “huge risk”. My most memorable line of feedback from my first annual review stated that my project was in danger of “catastrophic failure”. Welcome to the risky but rewarding world of urban research. In my case, the portent of research doom was the fact that my project’s success is largely reliant on other parties.

My 18 month project is based around an initiative undertaken by a large, council-controlled organisation (Auckland Transport), and requires the cooperation of multiple individual volunteers. These supposed harbingers of failure are by no means only found in urban research, but one does frequently come across them when working in such a populated and people-centric environment. Part of the issue with relying on other parties is differing priorities and perspectives.

While a researcher who has spent an inordinate amount of time living, breathing and planning The Most Important Research Project of All Time™ may think their requests are reasonable, a large organisation may not share the same enthusiasm and sense of importance. From my experience, while these organisations can be very accommodating, informative and helpful, at the end of the day they are subject to financial and political pressures that a lowly researcher cannot hope to contend with.


A metaphor. Hint: the dog is the ecologist

At the other end of the scale is dealing with individuals. One of the rewarding aspects of my urban research is the incredibly generous people who volunteer their properties to use as study sites. Understandably, they too have their different priorities. In an ideal research world where everyone appreciated the momentousness of The Most Important Research Project of All Time™, study properties would remain in the same state as you found them. In the real world, trees are cut down, fences are erected, cats are bought, yards are remodelled, and houses are sold and renovated.

All of which is to say that reliance on other parties can lead to complicated stats at best and catastrophic failure at worst. However, when it goes right, it can lead to some fascinating research that would otherwise be unachievable – a result that is worth the risk.

Ellery McNaughton is a PhD student in the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. Her project will investigate the effects of a city-wide changeover in streetlight technology on urban bird behaviour and ecosystem function. She is supervised by Margaret Stanley, Jacqueline Beggs, Kevin Gaston(University of Exeter, UK) and Darryl Jones (Griffith University, Australia).