Category Archives: Riparian & stream ecology

Restoration after pipeline installation: Pimpama Northern Gold Coast, Queensland.

Posted on 21 June 2012 | Comments Off

Key words: Assisted natural regeneration, topsoil transfer, Wallum Froglet, Regional Ecosystem 12.3.5, pipeline construction.

Mark Bibby

Revegetation works were carried out in 2009-10 to accompany a civil construction project in the northern Gold Coast, Queensland, where a pipeline was being laid through a natural area.

The Regional Ecosystems on site included palustrine wetland (12.3.5), which is habitat for threatened flora species including Phaius australis, P. bernaysii and Schoenus scabripes and the Wallum Froglet (Crinia tinnula).

The goals of the project were to: reinstate vegetation on site after the construction of the pipeline; minimise weed establishment and other maintenance issues; to ensure that no canopy species were replaced over pipes (to avoid root damage to the pipes); and to achieve an optimal  outcome for local biodiversity, including the Wallum Froglet.

Summary of works.  The native vegetation in the path of the pipeline was removed from wet areas with excavators and a crew of regenerators (Figs 1a and 1b). As much as possible of the macrophyte vegetation from the watercourse area was temporarily moved to ‘holding’ trenches, created to allow for a variety of soil moisture levels. (These were lined with plastic and then filled with water).

Some 600 specimens of other plants were removed to a nursery for later replanting. The top 200 mm of topsoil and site litter from the remainder of the site were stripped and stockpiled on site for later replacement.

Fig 1a: Macrophyte holding trenches before replanting.

Fig 1b: Macrophyte holding trenches providing temporary habitat during works.

Following civil works (conducted 8 months after the topsoil stripping) the stored topsoil and litter was replaced (at 30-50mm depth) and plants from the holding trenches replanted in their original positions. Spaces were left between the patches of litter to allow for regeneration from the replaced topsoil. Stumps were replaced on site as habitat.

The 600 nursery-spelled plants were reinstated on site and further planting of tubestock was undertaken, with grasses and sedges translocated from nearby at the site. Seed was collected nearby and spread on site when available. The site was regularly visited by skilled bush regeneration weed control staff members for 12 months.

Results. A high level success was achieved with the translocation of holding trench stock following inundation of the site during summer rains.  After replacement of the topsoil, vegetation and litter, the watercourse and surrounding fringes established well and natural regeneration from the replaced topsoil and germination from the seed dispersed by hand occurred. One year after the completion of works, the site was recovering well (Fig 2a-c) and recent inspections showed that vegetation cover and diversity in the watercourse area is consistent with the pre clearing condition. The terrestrial restoration area is showing good recovery with 15 species (that were not planted on site) observed regenerating. The native to weed ratio is 9:1. Conversely in the area of disturbance (adjacent the project site) without restoration the native to weed ratio is 1:9.

Fig 2a: The watercourse after removal of the vegetation.

Fig 2b: The watercourse upon reinstallation of topsoil and stockpiled plants

Fig 2c: The watercourse after the completion of the contract.

Lessons learned.  The joy of this project was being able to convince the the civil engineers if not also ecologists that a more natural regeneration-style approach could offer preferable outcomes to a standard civil landscaping approach.  Particularly interesting was the need to convince them not to be afraid of some short term ‘mess’ to ensure a good result for a natural area.

Contact: Mark Bibby, Gecko Regen, / 139 Duringan Street,Currumbin, Qld, Australia. Tel:  +61 (7) 5534 6395. Email: admin@geckoregen.org.au ; http://www.geckoregen.org.au/

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Posted in Bush regeneration, Fauna & habitat, Queensland, Riparian & stream ecology, Techniques & methodology, Wetland

Evans River catchment to coasts corridor – Northern Rivers CMA

Posted on 28 May 2012 | Comments Off

Key words: Riparian restoration, weed control, landholder engagement, community training, Erythrina x sykesii

Maree Thompson

The project. A three-year bush regeneration and weed control program was conducted (from June 2009 to March 2012) along nearly 15km of Evans River in north coast NSW. Carried out byEnviTE Environment, the works were designed to meet priority targets of the Northern Rivers Catchment Action plan. A range of weeds degrading vegetation communities were controlled along 61 ha of native vegetation (20 ha of wetland, 31 ha riparian and 10 h of upland native vegetation). This particularly involved the control of Coral Tree (Erythrina x sykesii).

Evans River catchment to coasts corridor drill injecting Coral Trees. Photo: Maree Thompson

Eight of the ten land managers along the river were private landholders, with one parcel of land being part of the NSW National Parks and Wildlife Service (NPWS) estate. Private landholders were engaged in the project through Landholder Management Agreement commitments and worked alongside professional bush regenerators, gaining skills and knowledge in weed control techniques and bush regeneration strategies. They saw positive changes in riparian vegetation as a result of the works and through this have increased their understanding and support of environment restoration efforts.

In the case of the NSW NPWS estate, significant areas of primary weed control were undertaken in the last two years of the project. This included control of major infestations of Ochna, a difficult weed requiring further follow up in this area to ensure sustainable environmental outcomes.

Live Coral Tree, Evans River September 2010

As well as on-ground works, the project involved a workshop held in Evans Head with attendees learning how to effectively kill Coral Trees. Project promotion through local media and landcare networks, as well as at the local Evans Head markets, helped to raise awareness in the local community Wider community participation included employment of a member of the Bandjalang people, who are traditional owners of the area.

Its outcomes. Contribution to targets of the NR Catchment Action Plan has far exceeded contract requirements. The Coral Tree infestation in the Evans River Catchment has been reduced to minimal levels.

As future reinfestation will occur due to spread of seed, particularly in floods, from the Richmond catchment – on-going, low level, maintenance is required to gain greatest benefits from the investment to date. 

Poisoned Coral Tree

Lessons learned. This project ran over three years, which to date has been uncommon for projects funded by Northern Rivers Catchment Management Authority (CMA). This allowed us to work across the full cycle of seasons over three years, timing treatments for their optimum time for both the species and OHS requirements. This time period proved highly advantageous as it allowed the achievement of sustainable environmental outcomes and reinforced investments for the Evans River Catchment. As a result, we strongly recommend that the duration of restoration projects be three years or more.

Partners and funding.  The project cost $183,230 over the 3 years, over half of which came from the NSW Environmental Trust, about a quarter came from the Northern Rivers CMA and the remainder was contributed mainly by the EnviTE Jobs fund bush regeneration team, with some contributions from NPWS and Richmond Valley Council.  Landholders’ in-kind contributions was valued at an additional $24,790.

Contact: Mike Delaney, Environment Manager, EnviTE Inc, 56 Carrington Street (P.O.Box 1124), Lismore NSW 2480; Tel: +61 2 6621, Mob: 0429 968 070, Email: miked@envite.org.au.

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Posted in Bush regeneration, New South Wales, Riparian & stream ecology, Weed issues & solutions

Planting for success – using long stem plants

Posted on 6 December 2011 | Comments Off

Key words: restoration, planting, riparian,  revegetation

Leah Andrews

Development of the long-stem planting method in Australia has seen an increase in the survival rates of seedlings of a range of species planted in many different environments.  While research to test the value of the method for a broader number of species is currently ongoing (see Trials and Results below) the technique has now been successfully used on subsets of species in riparian, rainforest, coastal and saline environments.  The advantages of this method are no post-plant watering, increased growth and increased survival rates.

The approach. The long-stem planting method is a way of planting that can result in enhanced survival with minimal post planting care.  Seedlings are grown in pots for 10-18 months so that they develop long woody stems.  These seedlings are then planted with about three quarters of their long woody stem below ground.  Once planted the buried stem develops roots and leaf nodes resulting in the development of a robust root network which gives the seedling a greater chance of survival.  This method challenges two long held horticultural practices: (i) that large plants should not be grown in small containers as they will become root bound and will hinder full growth of the plant; and (ii)stems of seedling should not be planted below the surface of the soil as it subjects them to fungal attack and disease.

Cover of the Long-stem Planting Guide

Trials and results to date: The method was originally pioneered by Bill Hicks in the Hunter Valley to reduce the use of willows in the riparian environment and has now expanded and proved successful in a range of environments and with a variety of plant species. Experimental field trials on the application of the method on particular species have been carried out by researchers at the School of Environmental and Life Sciences, University of Newcastle, and Gosford City Council since 2005 Knowledge of the species that suit this technique is building as more bushcare groups and individuals across Australia continue to trial the technique.

The Environmental Trust funded Gosford City Council and the Australian Plants Society to pull together the current anecdotal and researched information on the use of this technique into a Guide for use by practitioners.  (See full Guide at: www.environment.nsw.gov.au/grants/dissemination.htm#longstem).  This project found that the main benefit within the riparian environment is that the roots of the seedlings are planted deeply in to the river bank making it harder for them to be washed away.  Eucalyptus camaldulensis is one of many species that has show enhanced performance in this environment.  In rainforest environments, the long-stem seedlings will often not grow to the suggested one meter prior to planting,  but  a range of plants such as  Glochidion ferdinandi show increased growth once planted.

In the coastal environment this method has shown promise, possibly due to the potential for  the deep rooting to reduce root competition, provide additional anchoring (therefore reducing the impacts of sand movement), greater access to soil moisture and reduced impact from heat.  Acacia longifolia is one example of a species that has been successfully used in coastal environments.  With regards to the saline environments, again the deep rooting is a major advantage as the plants roots are below the salt encrusted upper soil layer.  A large range of species have been found to successfully grow using the long-stem technique in this environment such as: Eucalyptus botryoides, Eucalyptus tereticornis, Eucalyptus robusta, Melaleuca styphelioides, Melaleuca linarifolia, Melaleuca quinquenervia, Acacia binervia, Acacia saligna, Casuarina glauca and Casuarina cunninghamiana.

Lessons learned and future directions: Plants need to be grown in pots placed in potting racks so that the roots are air pruned if they protrude from the pot. This will allow the roots to spread out in to the surrounding soil when planted.  Soaking the seedlings the night before you intend to plant out the long-stemmed plants assists with their survival. Whilst the long-stem planting technique has been shown to be successful particularly in environments where the surface soil conditions are not favorable for planting, the costs of this technique do need to be considered. Long-stem plants are kept in the nursery for longer than traditional tubestock or direct seeding so there is some increased cost per plant.  However, if balanced against the other advantages in environments where establishing vegetation is more challenging, the additional costs can be minor when offset against increased survival.

Stakeholders and Funding bodies: NSW Government’s Environmental Trust, Australian Plants Society – Central Coast Group, Gosford City Council

Contact: Leah Andrews, Senior Project Officer, Environmental Trust 02 8837 6081

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Posted in New South Wales, Riparian & stream ecology, Techniques & methodology

Eels on Wheels – An evaluation of the trap-and-transfer method of Long-finned Eel (Anguilla reinhardtii) at the Ross River Dam, Townsville

Posted on 26 October 2011 | Comments Off

Key words: fish barriers, fish passage, migration, fishways, eels, Anguilla reinhardtii

Carla Hutchinson-Reade

Freshwater eels, like many other species, need to migrate to and from marine environments to complete their lifecycle. Throughout Australia large dams are restricting the migration success of native eels contributing to the overall decline of eel numbers. NQ Dry Tropics (the natural resource management body for north Queensland’s dry tropics) is conducting a project focused on removing fish barriers which will help to reverse this trend. An Eels on Wheels device is a simple yet effective method that can be employed in many locations that are impassable to eels. The device facilitates upstream migration of eels during the early stage of their lifecycle.

NQ Dry Tropics commissioned a study Eel passage over large dams of their catchment region in the dry tropics in Queensland, Australia. During the study no eels were recorded above the Burdekin Falls Dam while many were recorded below. This suggested a very real problem. The study identified the Ross River Dam as a major barrier to the Long-finned Eel (Anguilla reinhardtii), as several thousand elvers were observed attempting upstream migration by climbing dam wall abutments without success.

Elvers scale the blue netting up the sheer wall to get to the Astro Turf

To overcome this barrier an eel trap-and-transfer trial was established on 17 December 2010 prior to wet season rainfalls. (Local knowledge of previous migration history gave NQ Dry Tropics insight into migration events.) Since then around 3000 upstream migrants have been captured using a custom-designed trap we call Eels on Wheels and safely relocated within 48 hours. Trapping went on for 3 months.

Entry ramp lined with Astro Turf leads to a modified wheelie bin. The bin is filled with water and contains a live adult eel whose scent attracts elvers. The bin is then wheeled by project staff to the upstream side of the barrier.

The trap consists of a wheelie bin fitted with an Astro Turf-lined entry ramp which delivers a flow attraction fed from the upstream storage. The main drivers for trapping success and retention are in the level of attraction flow and trap accessibility. Once the elvers are in the wheelie bin they are transported and released by the project staff on the upstream side of the barrier. The Eels on Wheels device is a low cost and effective option to assist eels to overcome dam barriers. The same device can be replicated by natural resource managers around the country.

Contact: Paul Duncanson, NQ Dry Tropics (07) 4724 3544 or email paul.duncanson@nqdrytropics.com.au

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Posted in Fauna & habitat, Queensland, Riparian & stream ecology