Canterbury University scientists involved in intermittent rivers study

University of Canterbury scientists are part of a global research collaboration into the environmental impacts of dry riverbeds, with their findings published today in a new paper in one of the world’s top scientific journals (see AgScience report HERE).

New Zealand researchers, Professor of Freshwater Ecology Angus McIntosh and Dr Catherine Febria, of the School of Biological Sciences, UC College of Science, have been part of a global team from 22 countries evaluating what happens to plant litter that falls into in river beds when they are dry (i.e. not flowing).

They co-authored the paper titled ‘A global analysis of terrestrial plant litter dynamics in non-perennial waterways’ which was published today in Nature Geoscience.

“People might feel that a pile of plant litter accumulating in a dry river bed couldn’t possibly contribute to global climate warming, but the surprising reality is it very likely is,” Professor McIntosh says.

The contributions of drying rivers haven’t been included in global carbon accounting previously and their CO2 effects  could be significant.

“This is especially important because, surprisingly, intermittent streams and drying rivers are thought to include more than 50% of the river length world-wide,” he says.

Dr Febria says it is known that when rivers dry up fish and insects die, and the whole food web of the river collapses.

“However, we haven’t previously appreciated the significance of all the decomposition that happens when the water comes back. The amount of carbon dioxide released in many cases is huge,” she says.

“We should all care about this because carbon dioxide in our atmosphere is the driver of global climate warming.

“Our research indicates that increasingly drying rivers, along with other land use changes, are contributing to global climate warming. Moreover, climate warming in many places like Canterbury is predicted to increase the frequency and magnitude of drought which could also cause more river drying.

“That is a really worry because that could form a positive feedback cycle by releasing even more carbon dioxide.”

This is the first piece of research published from this collaborative study involving 94 international partners from 22 countries studying the dry beds of 212 rivers from round the world, including Canterbury.

Until recently, drying and intermittent rivers had been largely ignored. This global study is beginning to reveal they really are very important and should not be ignored.

Such extensive global research efforts have traditionally been rare. That a very large group of researchers from around the world, led by a group in France, have come together to contribute is really quite significant, Professor McIntosh says.

He didn’t expect the magnitude of emissions to be so high. Therefore the findings should force a rethink of how the global carbon models are made so that they include CO2 emissions from intermittent rivers.

Source: University of Canterbury


Farming leaders and Govt make progress towards Mycoplasma bovis decision

Farming leaders and the Government have met again today to discuss ways to combat Mycoplasma bovis, says Agriculture and Biosecurity Minister Damien O’Connor.

All those involved understand that farmers need certainty about a future plan and are committed to make a decision about the next steps in the biosecurity response next week, he said.

Two key options are on the table –

* Getting rid of the disease from New Zealand over time (phased eradication), or

* Long-term management (how we can all manage the disease, protect farms and slow any spread of it).

The decision will be taken jointly by the Government and farming industry representatives.

“Today’s meeting was constructive with all participants, including the Prime Minister Jacinda Ardern, updated on the known extent of the disease, the effects it’s having and the costs, both social and economic, of dealing with it,” Mr O’Connor said.

“Farmer, rural community and animal welfare is at the heart of the difficult decision. Clearly we want to make the best decision for farmers and the country.”

Organisations represented at the meeting were DairyNZ, B+LNZ, Federated Farmers, Rural Women New Zealand, Dairy Companies Association of New Zealand and the Meat Industry Association.

Source: Minister of Agriculture and Biosecurity

Dry riverbeds release CO2 when the rain comes

Dusty, dry riverbeds accumulate all manner of leaves, wood and other plant material, but when water starts flowing again it significantly speeds up the microbial breakdown of this plant matter and the release of carbon dioxide, according to a study examining 212 ‘intermittent’ rivers around the globe.

Several rivers in New Zealand and Australia are included in the study.

The authors say the findings change how we think about rivers contributing to CO2 emissions – accounting for intermittent rivers could increase estimates of daily CO2 emissions from inland watercourses by up to 150 per cent.

Intermittent rivers are rivers which sometimes stop flowing and can dry completely.

They are studied much less than permanent rivers but could represent half of the world’s river network. In response to climate change and increasing water demands, they may come to dominate the landscape in some regions.

Because little is known about their role in the global carbon cycle, a collaborative study involving 94 international partners was led by IRSTEA.

The research, published on May 21 in Nature Geoscience, represents the first global study of the contribution that intermittent rivers make to carbon cycling.

Quantification and analyses of the plant litter deposited along the dry beds of 212 rivers distributed across the globe showed high levels of O2 consumption and CO2 emissions upon short-term simulated rewetting events.

Associated drivers including climatic variables, flow regimes and geomorphological variables were also identified.

These results highlight the need to incorporate intermittent river ecosystems into further studies exploring the contribution of inland waters to carbon cycling at the global scale.

When a river ceases flowing, terrestrial plant litter, mostly leaves and wood from the adjacent riparian zone, falls and accumulates in dry river beds. The type and amount of litter varies, depending on climate, riparian vegetation, the width of the river channel, the duration of the dry period and the river’s flow regime.

To shed light on what happens to the litter during rewetting and to explore the contribution that intermittent rivers make to the global C cycle, the 1000 Intermittent Rivers project2 -a collaborative network – investigated the quantity and quality of terrestrial plant litter that accumulated during dry periods in 212 intermittent rivers across 22 countries.

Sub-samples of leaf litter collected by this international research consortium were analysed at Irstea’s DYNAM laboratory following standardised assays to simulate short-term (24-hours) rewetting events.

High respiration rates were measured, reflecting the reactivation of microbial communities within the litter. In turn, this activity released substantial quantities of CO2 into the atmosphere.

A rough extrapolation indicates that estimates of daily CO2 emissions from inland watercourses could rise by between 7 and 152% if data from intermittent rivers are added to existing data from perennial rivers, and one rewetting event could contribute up to 10% of this increase.

The results suggest that the exclusion of intermittent rivers leads to notable underestimation of the contribution of the world’s river networks to the release of CO2 into the atmosphere. The next step is to incorporate intermittent rivers into global models of litter decomposition and global carbon cycling in inland waters.

The study can be found HERE.

Source: scimex


Reducing greenhouse gas emissions on Māori-owned farms

Scion, in partnership with AgFirst, is undertaking a research programme funded by the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) looking at GHG mitigation options for Māori-owned pastoral farms.

The research programme is led by Dr Tanira Kingi (Scion), based in Rotorua, and managed by Phil Journeaux (AgFirst) out of their Hamilton office.

It is aimed at understanding how diversified Māori farms like Te Uranga B2 can improve their carbon profile further with changes to the management system and land use diversification.

The programme will develop a carbon and economic profile of the current operation of the incorporation’s dairy, sheep & beef and forestry operations and then model hypothetical changes that the Committee of Management want to explore, to see the affect on carbon emissions and profitability.

The programme is collaborating with DairyNZ, B+LNZ, Federation of Māori Authorities and Te Tumu Paeroa to share the findings with the wider agribusiness community.

While this study is carried out on Māori-owned farms, it is the first research programme in the country that is modelling both farm management mitigation options and land use changes and is therefore relevant to New Zealand’s entire agricultural industry.

This news orginally was included in the Autumn 2018 newsletter of Te Uranga B2 at 

Source: New Zealand Agricultural Greenhouse Gas Research Centre


iHemp Summit aims to kick-start industrial hemp economy

New Zealand’s first iHemp Summit will be held in July with the aim of kick-starting a home-grown iHemp (industrial hemp) economy.

Building on global interest in hemp business opportunities and fuelled by changing legislation, the summit will explore the potential for New Zealand to be the best in the world at growing and using hemp for food, fibre and medicine.

The iHemp Summit is open to companies, farmers, scientists, funders, community leaders, economic development representatives, regulators and others wanting to look at opportunities to collaboratively develop the New Zealand industrial hemp economy.

Richard Barge, chairman of the summit and Treasurer of the NZ Hemp Industries Association Inc (NZHIA), says New Zealand has a fantastic opportunity to create a brand new primary industry based on hemp and now is the time for an informed discussion.

“iHemp is being recognised as a sustainable source of food, fibre and medicine and this creates opportunities for companies to make it part of their future business plan and be part of what is projected by some analysts to be a $NZ75 billion global industry by 2025,” he says.

At the summit experts will share local and international knowledge on hemp, identify the local and export opportunities available to companies entering the industry, highlight the barriers to success within the market and develop strategies and relationships that will help the industry to overcome them.

The lineup of speakers an be found HERE.

New Zealand food safety authorities are considering following Australia by allowing hemp seed to be used in food by changing regulations under the Food Act, the Misuse of Drugs Act and the Medicines Act. These law changes, expected later this year, will allow hemp seed to be sold as a food in New Zealand, in addition to the current legislation allowing the local sale of hemp seed oil.

Andrew Davidson, Director of Midlands Seed and Midlands Nutritional Oils, says:

“Demand for our Cold Pressed hemp seed oil is being fuelled by interest in its beneficial health properties. It’s rich in essential fatty acids such as Alpha-linolenic acid (ALA, Omega 3) and Gamma-linolenic acid (GLA). These are the sort of speciality products that are also attracting the rapidly growing market of vegetarian and vegan consumers looking for new protein sources.

“There is enormous potential in hemp food products and the market is growing around 25% year on year. Legislative changes that will allow other hemp seed based foods will open up new sources of income and markets for the crop, potentially tripling plantings in the next few years.”

The summit is being co-ordinated by the NZ Hemp Industries Association Inc, which has been promoting the iHemp industry since 1997, with sponsorship and support from Midlands Seed/Midlands Nutritional Oils, Agmardt, Hemptastic, Hill Laboratories, Ligar, KiwiNet, Nutrient Rescue and Plus Group Horticulture.

The inaugural iHemp Summit will take place at in Wellington on July 5 and 6.

Details can be fund HERE.


Red Zone project aims to boost the endangered bee population

The Minister for Greater Christchurch Regeneration, Megan Woods, has announced that the Residential Red Zone will become the new breeding ground for the embattled global bee population.

May 20 has been declared World Bee Day by the United Nations.

Dr Woods used the occasion to announce the initiative to protect and grow native bee stocks.

Land Information New Zealand (LINZ) has created a trial in the Residential Red Zone after an extended search for appropriate and safe areas to place and grow beehives.

The first trial involves 10 beehives with around 600,000 bees at a Dallington location, but that number of locations can be increased in the future.

“This trial is another wonderful example of a transitional project to use the red zone effectively and created eco-friendly activities in this area until the final regeneration plan has been formed,” says Dr Woods.

“The Government recently extended the amount of time red zone land can be used for community projects.”

Christchurch beekeeper Simon Phillips, who manages the hives on behalf of LINZ, says declining bee numbers are a worldwide problem. “

It is a constant battle, with new diseases appearing every month, so we constantly have to develop new treatments to deal with each new virus.”

Jeremy Barr is General Manager of the Canterbury Recovery Group of LINZ, responsible for managing the red zone areas.

“It is only a small first step, but with this trial LINZ wants to do its bit to protect and grow the local bee population,” he says.

Mr Phillips has timed the introduction of bee hives with the end of the honey season, before splitting his strongest hives in two new hives.

“We then introduce a new queen from our breeding programme and hope the new hive will grow to house around 60,000 bees each by next year.”

Mr Phillips says the red zone is the ideal area to grow bees.

“Normally we would have the hives on farms or in open fields where there is not always much for them to feed on, but the red zone is full of fruit trees that will be able to sustain the bees.”

Despite the large open spaces in the red zone, Mr Barr says that the project team had to be careful in deciding on the location for the hives.

“We are trying to keep them out of sight of the public and places with no traffic and little pedestrian traffic,” says Mr Barr.

The hives will be well sign-posted and fenced off after LINZ conducted a robust health and safety assessment.

Mr Phillips says that the hives only need 10 to 20 square metres. “But we wanted to make sure there will be no safety concerns, for the public, and the bees.”

A video interview with Mr Phillips can be seen HERE. 

Source: Minister for Greater Christchurch Regeneration 

Owl Farm is going strong in the face of challenges

A focus day at a dairy demonstration farm this week will reflect on the standout progress the North Island farm has made during “an incredibly challenging season”, says Demonstration Manager Louise Cook.

A 16 per cent lift in standardised profit shows the strength of journey Owl Farm is on, despite milk production being lower than the year before, she says

The demonstration farm, located in Cambridge, is a joint venture between St Peter’s School and Lincoln University and aims to help build a profitable and sustainable dairy farming future.

Ms Cook says the focus day will include a discussion on how the farm’s use of plantain has improved operations over the past 12 months.

“One year on, we’ve learned a number of things about integrating plantain into our dairy farm.

“We’ll also talk about how we’ve been supported to optimise soil fertility levels and ensure we use the right product at the right time to get the best out of our fertiliser inputs.”

The focus day will conclude with a review of the changes in the Waikato River Plan change variation and what this means for Owl Farm.

The event is open to the public.


Wednesday, 23 May, 10.15am-12.30pm, followed by lunch

1716 Cambridge Road, State Highway 1, Cambridge (3km north of Cambridge on SH1)

Source: Lincoln University