In issue 2: Kaipara hill country erosion project, poplar & willow nursery and wetland condition monitoring.
View this email in your browser
ISSUE 2      
Welcome to the second issue of our e-newsletter to keep you in touch with Northland Regional Council’s Land Management and Biodiversity teams. We’re often so busy with new clients and new initiatives that we don’t have time to reconnect with landowners we’ve worked with in the past. This newsletter will help keep you updated with news and events happening in the land management scene at the council and beyond.

Focus on soil conservation

Introducing the Kaipara hill country erosion project in Northland

In 2015, Northland Regional Council was awarded 15% ($650K) of the Ministry for Primary Industries (MPI) hill country erosion fund, for work in the Kaipara Harbour catchment from 2016-2020.

Northland’s part of the Kaipara Harbour catchment covers over 442,000 ha, with 23% (102,280 ha) identified as having high erosion risk within hill country. Through the use of sediment modelling tools, we have estimated that this 23% of the land area could be producing as much as 72% of the sediment that reaches the catchment as a result of hillslope and surface erosion (this modelling doesn’t include streambank erosion).

The land management team at the council feel we can really make a difference in soil conservation by supporting landowners and by allocating council resources into these hill country areas.

We hope to help farmers apply sustainable practices that increase the productive capability of their land and ultimately reduce sedimentation of the Kaipara Harbour. By talking to landowners involved in erosion control projects in Northland over the past 40-50 years, we’ve gained invaluable information about the success of those earlier projects.

It appears that a major reason that previous soil conservation projects didn’t reach their full potential was a lack of long term maintenance of the trees. Our investigations suggest that old, large, unmaintained poplar and willow trees unable to serve their original purpose is a recurring problem. New soil conservation projects will have a strong emphasis placed on the maintenance, senescence and replacement of previously planted trees.

By collaborating with local landowners and other interested parties, we aim to compare the economic returns from marginal grasslands (hill country/ grazed forest mosaics) with alternative hill country land use options, such as pine forestation or manuka stands. We’ll use this information to help provide sound advice and economic data to landowners on changing land use from highly erodible pastoral land to more sustainable, economically viable options.

For more information about this project contact:

  • Paul Sorensen (Dargaville area): 470 1052 | 0274055338
  • Mike Mitchell (Whangārei area): 470 0250 | 0274055336
An emerging issue: early soil conservation poplar tree plantings in Northland are reaching the end of their use and falling over, causing more issues
Areas of high erosion risk identified as part of the Kaipara Hill Country erosion project

Poplar and willow nursery project

Nursery expansion

This year the council will be expanding our existing 6.3ha poplar and willow nursery operation by an extra 2.2ha to meet expected increased demand for poles.  Material planted this year will not be available until 2020 as it takes three years to establish the growing beds.

Rows of poplars at our Flyger Rd nursery, ready for harvest this winter

Winter 2017 supply
Orders are being taken now for winter (June – August 2017) supply.  This year we aim to supply 6000 3m ‘Kawa’ and ‘Otahoua’ poplar poles. A selection of tree willows will also be available, including ‘Matsudana’ and ‘Tangoio’ clones, along with small volumes of shrub willow for stream and gully plantings.

Smaller grades of both poplars and willows are also available (2.5m, 2.0m, 1.5m and 1.0m). Talk with your land management advisor who can help tailor a planting plan specific to your site.

Get in early as demand usually exceeds supplies available
We’ll be allocating poles in March / April and properties with existing Farm Water Quality Improvement Plans, or hill country properties in the Kaipara catchment will be given priority.


Currently a subsidised 3m poplar pole will cost the land owner $5. Tree protector sleeves are available at cost for $6.40 each, which may help with establishment in the presence of small stock.  Please indicate your requirements with the order.

Plant materials can be collected from our Flyger Road nursery by arrangement or delivered at a cost of $20 per order (early June to late August). When ordering please state your preferred collection method.

NRC has a few poplar pole rammers available for loan for a maximum of one week. Talk to your land management advisor to reserve one today.

Poplar poles stacked ready for delivery

Free poplar poles in the Kaipara hill country erosion fund area
This year as part of our hill country erosion fund partnership with MPI we will be making a number of fully subsidised 3m poles available, targeting areas identified as having a high erosion risk within the Kaipara Harbour Catchment.  If you live in this area, talk with your land management advisor to see if you qualify for the fully subsidised poles!

We want to hear from you
Please let us know how your previous plantings have gone, including successes or failures. This information can help us improve our advisory service for other Northlanders.

Fencing and planting transform an eroding gully on an Arapohue farm

Environment Fund case study: Gary Watkins

Young manuka, kanuka, flax and cabbage trees are taking hold in an eroding gully on an Arapohue dairy farm run-off.

Gary Watkins has a vision that the two-hectare site, recently harvested of 50-year-old pines, will be transformed into a rich stand of native bush resembling the land as it was before native trees were felled to make way for pasture.

A grant from the council’s Environment Fund of just under $5,000 has helped meet the cost of approximately 1.5kms of fencing around the gully to allow the new plants to establish.

The grant also included $1000 to kick start the planting project, with Gary providing about 4,500 extra trees at his own cost. All the trees were supplied and planted by Babylon Coast Gardens and Gary is very happy with their work.

“There was massive erosion there, so we’ve also planted 210 shrubby willows, subsidised by the council to stabilise the land until the young trees get a foothold,” Gary says. “The plan is to remove them once they’ve done their job and the natives are fully established. Some of the new native trees are already up to knee-height.”

More than 4000 new natives, mainly manuka and kanuka, will be planted this year and Gary is keen to plant kauri groves when the conditions are right. Stabilising the gully with the planting will help stop the gully eroding further uphill.

Gary says there was “no hassle” getting the funding with the help of the council’s land management team.

"I think it’s great that the council can help with this sort of project,” he said.

The council’s Environment Fund contributed to this fence which will keep stock out of the eroding gully while the willows and native trees establish
Some of the native trees Gary has planted within the fenced gully

Biodiversity feature – wetland condition index monitoring

Historically, over 20% of the Northland region was covered with wetlands, with vast swamps and gumland heaths extending from the edges of the Kaipara Harbour to Spirits Bay.  However, less than 5.5% of original freshwater wetlands now remain, which is roughly half of the national average. Most of these losses have come from drainage for pasture development.

Wetlands are important and worth protecting for many reasons.  They help to improve water quality in a catchment by acting as the ‘buffer zone’ between our land and water areas.  They act like sponges and are able to absorb large quantities of water, filtering out nutrients and sediments to improve water quality before directing it downstream.  This isn’t the only benefit – wetlands also absorb enough water to significantly reduce flood peaks in heavy rain, and provide an important habitat for many plant and animal species, many of which are threatened. 

Wetlands vary and can be divided into different classes, largely dependent on how they receive water and nutrients.  Rain-fed wetlands such as bogs, gumlands, peat lakes and dune wetlands are usually lower in nutrients. Wetlands which receive water from groundwater or surface flows include fens (‘drier’ wetlands), swamps (‘wetter’ wetlands), and marshes (often found alongside rivers and lakes and in coastal areas).

Because of the importance of our remaining wetlands, and as a way to help measure their health, the Northland Regional Council assessed a selection of wetlands across Northland in 2012, using a system developed by Landcare Research and NIWA called the Wetland Condition Index (WCI).  This index provides three separate scores that we and owners can use to track the condition of a wetland.

These include a ‘plot’ score for one or more plots within the wetland that measures the plant health, a second, ‘total’ score which takes into account the current condition of the whole wetland and a final ‘pressure’ score which analyses pressures being placed upon the wetland which may affect its future condition.

Twenty-six wetlands were identified as being good candidates for this monitoring based on a range of factors.  Firstly, a group was picked as being ideal reference wetlands, being in good condition and functioning well.  These were spread over a range of wetland types, such as fens, swamps and seeps. The second group was then selected over the same wide range of wetland types but in various degrees of degradation.  Having landowner interest in the project and being covenanted by QEII was also looked upon favourably in terms of ongoing monitoring.  

Jumping forward five years, we have just completed our reassessments of these 26 wetlands and are pleased to be able to present some positive results, with the average total, plot and pressure scores improving across the group.  This was especially evident in the sites where fencing to exclude stock has happened since the initial monitoring – this seems to be one of the best things we can do to improve wetland condition and function. Funding help for fencing stock out of wetlands is available through the council’s environment fund (phone 0800 002 004 for more information).

Results from the assessments of the 26 wetlands show that 21 improved in the total score by an average of 4.4%, while five retained the same score and none showed any regression.  In terms of the pressure score, half of the wetlands retained their original score and the other half improved by an average of 4.2%.  Because some of the wetlands had multiple plots within them, there was a total of 49 plots assessed.  Of these, 61% showed improvement on their previous scores, largest improvements being up to 30% in some plots, 14% of these plots remained unchanged in score whilst the remaining 24% showed some degradation.  Despite this, the average change was positive.  The degradation was from increases in the number of introduced plants or their spread in the plot, and in a few cases, continued grazing of stock in the wetlands.

These results are important as with so little of Northland’s wetlands remaining and even fewer still in good condition, we can begin to analyse trends in wetland health and start to understand what we can do to improve wetland health throughout our region.  For more information about Northland’s wetlands, see our website:

One wetland in 2012
The same wetland in 2016

Focus on our team

Each newsletter we will profile one of our team members – please say gidday when you see us out and about!

Duncan Kervell – Land Manager

Duncan Kervell is a Scottish tuechter (meaning a Highlander, pronounced chookta) who has been in Whangarei since 2009. He has barely left sunny Northland since, with his Scottish wife Julie and 2 Whāngārei-born kiwi kids.  Duncan is the Land Manager in the Environmental Services Department at Northland Regional Council (NRC), forming part of a team of 15 completing farm plans, catchment management operations, biodiversity and soil conservation plans and other land science / soil projects.

Duncan started with NRC as a land management advisor in 2012, following a fun and exciting three-year stint working for the Department of Conservation. He worked in stunningly beautiful places (e.g. Poor Knights Islands) doing normal DOC ranger tasks such as cutting bait lines and killing pests and weeds while wearing far too short and tight green shorts.

Duncan has been scrambling up hills planting trees (i.e. ecological restoration) since he left school. He followed this up with a degree in pure soil science and postgrad in forest management.  From 2001 Duncan ran a “kitchen benchtop” woodland restoration consultancy and contracting business, restoring the badly denuded native woodlands (less than 5% land cover of native forest) in Scotland. In 2009, he jumped on the waka to New Zealand to follow the sun and soon to be wife.

Duncan has an interest in sediment modelling, especially for farm plans, and the use of mobile mapping and online tools for farm planning.

Duncan and a dairy farmer sharing a joke

Contact us


Copyright © 2017 Northland Regional Council, All rights reserved.

Want to change how you receive these emails?
You can update your preferences or unsubscribe from this list

This email was sent to <<Email Address>>
why did I get this?    unsubscribe from this list    update subscription preferences
Northland Regional Council · 36 Water St · Whangarei, Northland 0110 · New Zealand

Email Marketing Powered by Mailchimp