Revegetation, a term that is seeing more use each day, broadly means to ‘provide land with a new vegetative cover’. This article aims to introduce the reader to land rehabilitation methodology and the benefits that accompany revegetating one’s property.
An impactful lesson in conservation and land management is understanding that once an area of remnant vegetation is cleared, be it rainforest or dry coastal grassland, the long-established natural biodiversity of the area disappears, often for good.
As discouraging as this may seem, with planning and implementation of a variety of methods, degraded land can be rehabilitated to represent its former splendour and restore the biodiversity of the area.
Why?
There are multiple benefits to revegetating an area, some more apparent than others. These include:
Increase in real estate value of a property
Revegetation work has the potential to substantially increase the monetary value of an area by improving the aesthetics of the land. A weed-infested property or a property with little or no vegetation will sell for less than a property where attractive native vegetation is present.
Long-term reduction in gardening and maintenance costs
Native vegetation has adapted to the climate and soil conditions of an area and will require less expenses such as water and fertilisers to stay healthy. The initial outlay of conducting any revegetation will over time lead to more affordable maintenance costs.
Soil health and erosion protection
On cleared land or areas with partially barren soil, reintroducing plants with fibrous roots such as sedges tussock grasses can greatly increase the soil stability of the area. Basket grass (Lomandra longifolia) and Tasmanian flax-lily (Dianella tasmanica) are native to most areas of Tasmania and provide excellent erosion protection qualities. Tall shrubs and trees found in native woodlands assist in maintaining a low water table which reduces dryland salinity and planting native legumes including wattles and bush peas can increase nitrogen quantities present in the soil, making it more fertile.
Increasing biodiversity and habitat value
Loss of biodiversity has been a major issue in Tasmania with several species at risk of extinction. Reintroducing native flora to an area encourages native wildlife also return. A current example would be planting Tasmanian blue gums (Eucalyptus globulus) as potential habitat for the critically endangered Swift parrot (Lathamus discolor). Native shrubs and groundcovers are also important as habitat for small marsupials including bandicoots, potoroos and antechinuses.
Potential income
Large scale revegetation opens the opportunity for business ventures including accommodation, seed collection and sales, and harvesting of native bush tucker species including Karkalla (Carpobrotus rossii) and Tasmanian mountain pepper (Tasmannia lanceolata).
Attracting pollinators and long-term regeneration
Native pollinators generally prefer native flora. Plants such as banksias and wattles will attract native bee species and assist bee communities with foraging patterns and establishing a population in the area. There are also dozens of native Tasmanian butterfly species which would be encouraged to frequent areas with native vegetation. An increase in plant pollination will improve natural regeneration of plants and assist in building a healthy, growing ecosystem.
Improving pasture
On agricultural grazing land, reintroducing native grasses such as Kangaroo grass (Themeda triandra) provides increased drought resistance and a valuable grazing food source in summer months. Planting tall shrub and tree species will provide livestock with shade and wind protection whilst not reducing grazing.
Connection to the land
Perhaps the most important benefit of native revegetation work is installing a sense of connection to an area. The natural beauty of Australian landscapes and the feeling that one is doing their bit to improve and maintain native biodiversity is a great reward.
HOW?
Assessing the Area
Prior to undertaking any work in an area, an accurate understanding of the overall condition of the land is required. Along with providing an opportunity to set up the objectives of a revegetation plan and quantifying the amount of work required for the project, a comprehensive assessment will also consider the following:
- Percentage of weed cover
- Soil type and quality
- Size of area
- Water quality if present
- Health of any native plant species
- Native fauna within site
- Presence of rare or threatened flora and fauna species
- Pest species – vertebrate and invertebrate
- Grazing and browsing pressure
- Geomorphology of area
- Native flora and vegetation communities present in nearby reserves or remnant bushland
Develop a strategy
Once the site has been assessed, a revegetation plan can be developed. Having an objective-focused plan will assist in measuring progress and ensuring that any work undertaken is carried out according to schedule and budget. A strategy will also help determine the budget required to undertake the revegetation works as well as the following:
- Weed management program if necessary
- Prioritising objectives
- Site preparation
- Estimation of plant / seed quantity needed
- Erosion and grazing protection, ie. Tree guards, jute matting
- Contractors to utilise
- Constraints
- Timeline
Weed Management
Cleared areas are almost certain to harbour invasive vegetation. Seed which may have laid dormant in the soil for years now had the chance to sprout and new seeds entering the area are free to germinate due to the absence of native vegetation. This is seen all too often when land is cleared and, only a few years later, a dense weed infestation has been established.
Whether an area is overrun with weeds or only sparsely covered, wherever revegetation is planned, a thorough weed management plan is the first step.
There are many weed control options available, and research and professional advice are essential in ascertaining which methods best suit the land. In most cases, several methods are used and integrated to achieve comprehensive weed control in an area. For large revegetation projects, a minimum of two years should be given to weed management, this allows for regular follow-up work to reduce any weed regrowth.
Plants – species selection and quantities
The next step to revegetating an area is to select which species will be planted. Species selection is dependent on the objectives for the area and any constraints which require considering. Constraints may include proximity to infrastructure such as powerlines and dams, livestock presence and physical barriers.
When selecting plants, it is recommended to opt for species which naturally occur in the area. This can be ascertained by visiting nearby remnant bushland areas and identifying the species which comprise the vegetation. Local councils are also an excellent resource for obtaining species lists and professional revegetation companies can best advise on quantities required.
When the aim is to expand or replicate remnant vegetation, a good plant selection list will ideally include species which represent all vegetation strata levels found in an area.
Not all areas will have all strata levels. For example, when revegetating a grassland there may only be mid-stratum and groundcover species to select.
When large quantities of plants are, pre-ordering plants from a native nursery at least six months prior to planting will give the nursery time to collect the seed required as well as grow the plants to a specified timeframe.
Plant selection can easily become a rabbit hole in terms of how many species are chosen for the area. A good suggestion is to keep the initial revegetation to 10 species or less, with two species from each stratum, and focus on correct planting techniques and monitoring. Further planting could incorporate a wider selection of species.
Site Preparation
Once weed control and plant selection has been achieved, the next step to revegetating an area is to prepare the site for any planting or direct seeding work. Preparation work may include the following:
- Tilling of the soil – this is done primarily to loosen and work organic matter into the soil and can be achieved manually with a rake, or mechanically with designated machinery attachments. Tilling, though not always necessary or possible, is a great way to prepare degraded soil for planting or seeding.
- Rubble and waste removal – cleared land often contains discarded fencing, building and waste materials. Removing any unwanted material will assist in accessing the site, decrease breaks in vegetation and improve the aesthetic value of the area.
- Spot-spraying – if there is any thick grassy groundcover present in the area, it may prevent any revegetation work from being successful by competing with and choking any work undertaken. Spot spraying an area with a non-specific herbicide two – three weeks prior to planting will increase the survival rate of any revegetation work.
- Installing erosion protection – when planting along river banks or floodplains it may be necessary to install erosion protection such as rock walls or jute matting.
Planting and seeding
Once the hard work is done, the fun can begin. Planting and direct seeding is recommended to start from mid-Autumn and can continue throughout Winter. Generally, the first heavy rain of this period is a good natural indicator that revegetation can begin.
Planting is ideal for reintroducing native species to the area. Though straightforward, care should be taken to ensure plants are not pot-bound when going into the soil, and that the plants are placed securely in the ground. Augurs may be required to drill holes into rocky, compact soil and tree guards are highly recommended to protect the plants from grazing and browsing animals.
The more plants go into the ground, the higher the chances of a successful revegetation program are. In areas with poor soil conditions, adding a few handfuls of fertilised soil will give the plant the extra nutrients needed to survive the first year, which is often the hardest. If planting in dry conditions, thoroughly watering the plants in is recommended.
For barren areas in which the soil has been tilled, direct seeding is recommended to kickstart the revegetation process. Direct seeding of native grass seeds and groundcovers will translate to a healthy low vegetation stratum which will compete with any emerging weeds in the area.
Monitoring and Maintenance
One often overlooked factor in revegetation is the importance of regular monitoring of the area and conducting any follow-up maintenance required. This includes:
- Regular watering if necessary or the installation of an irrigation system
- Surveying for any new weed infestations
- Monitoring plant health and looking for signs of dieback
- Monitoring grazing pressure
- Installation of fencing or possum guards
- Replacing broken or displaced tree guards
- Removal of tree guards when plants are of a satisfactory size (minimum 6 months)
- Replanting plants if necessary
- Weed control with minimal disturbance to native plants
- Expanding area of revegetation
How we can help
Tasmanian Tree Care are highly professional arborists that value honest advice and a holistic approach to land management. We believe that trees add value to your property, and that proper management can boost the biodiversity, amenity and monetary value of your asset.
If you’d like to have a chat about holistic land management, complete the form below or contact us on 0428 997 068.