Extending your woodland
In the following series of articles, we will showcase some of the techniques we use for increasing tree regeneration across the landscape. We will dive into the details of how to stimulate and support natural tree regeneration and discuss the methodologies and implementation strategies so as to get the most return on investment when performing this restoration activity.
It is not always obvious why increasing tree regeneration is of direct benefit to your landscape, as the presence of a Eucalypt tree is often seen as secondary to the management of stock and the growing of grass, complementary but not essential. Although the view that trees shade pasture is commonly held, it is not always applicable on the New England Tablelands. In fact, more often than not, we can find open woodland happily co-occurring with a grassy herbaceous layer.
It is within this type of vegetation structure that we as land managers can use its benefits to produce both better products, but also increase the health and biodiversity of the local ecosystem that supports us. When we increase the spaces of native woodland, we attention both of these requirements in an elegant and simple solution.
Integrating woodland regeneration directly into your production system has shown to be effective in providing a set of short and long-term benefits to the health of your animals, soil, and local biodiversity, which make up the foundation of your farming landscape.
Some of these short-term benefits include immediate erosion control that keeps nutrient within the soil profile, supportive habitat for beneficial local fauna such as parasitic wasps, dung beetles and micro-bats, and most important of all, increased infiltration of groundwater. If we aim to increase the areas of woodland regeneration within our landscapes, the intrinsic effects that come with the re-introduction of trees to the landscape quickly follow.
When thinking further down the track, future generations, which are likely to encounter greater and more frequent weather extremes, will appreciate the long-term benefits that a treed landscape offers. Some of these long-term benefits we can look forward to include shade for stock, stabilising of waterways, improvement to water quality, cooling of the landscape, improvements to soil-stability with increased organic matter and carbon, buffering of desiccating winds, increasing pollinators for diverse pasture, and an overall increase in biodiversity across the landscape. Starting now is the best time to work towards this future!
In this article we will discuss the easiest and most straightforward way of promoting trees on your landscape: extending a pre-existing woodland edge. We will run through the process of how we do this, from identifying the best spots to perform regeneration, to getting crafty with fencing techniques, and finally, managing your regenerating woodland.
Identifying your woodland edge – the best spot to promote regeneration – the best time to start
Right now is a great time to start promoting the regeneration of trees. The long drought that had oppressed much of the Tablelands over the past few years has recently released its grip, with an onset of favourable rainfall. We have seen many areas of regeneration naturally kicking off, with rapid germination and growth of new trees. Eucalypts are advantageous in this way, and will try and make the most of these conditions to get a leg up on becoming established, knowing very well that the future likely will again present unfavourable conditions.
When you drive across the New England Tablelands, a common pattern emerges across the landscape. In most localities, we can find regenerating woodlands of various sizes bordering paddocks managed for grazing stock. You probably have a section of your land that has a small regenerating woodland that sharply transitions to a cleared paddock. If so, you’re in luck, this is often the easiest place to start promoting new tree recruitment. You may even have a few regenerating trees having a go at getting established. It is within this zone that we will focus our attention.
Although not essential, sites that are particularly effective at promoting regeneration will include those that either receive surface flows of water, or are within close proximity to a creek or depression within the landscape. While young regenerating eucalypts are incredibly hardy, they will benefit greatly from available water and initial shelter, whether that be surface water or water permeating through the landscape. It is for this reason we commonly find eucalypts regenerating along creek lines or in low lying areas in close proximity to stands of mature trees. In fact, it may be highly likely that you have species regenerating that are classified as threatened on the New England Tablelands, such as the New England Peppermint (Eucalyptus nova-anglica). If you happen to have one of these threatened ecological communities (TEC) on your property and would like to support it’s regeneration, we can help you get started via an on-site consultation that will cover the technical aspects of performing regeneration. Also, there are many grants available to support local landholders in promoting the regeneration of these threatened ecological communities, particularly in riparian areas. If you are interested, please get in contact with us.
Next time you’re out and about, investigate these small patches of woodland! Is there regeneration happening? If so, this is a fantastic place to start. At this very moment, due to the recent rains bringing good surface flows and wetted soil profiles, along with low stock numbers post-drought, we are seeing new saplings in places there previously were none. Where mature trees were able to set seed, the adjacent zones 5 to 50m from the base of the tree will very likely have some regeneration taking place. From our research, we have found that the two key factors required to produce seedlings are the presence of mature trees, and the health of those mature trees.
Transition boundaries, or ‘edges’, are ubiquitous throughout natural or modified landscapes. They are often the most effective place for landscape managers to begin work. In this instance, we are using the edges of pre-existing woodland, ideally composed of mature trees producing seed to kick start the next generation of saplings. There is a ‘sweet spot’ for germinating seedlings – they need to be far enough away from the base of the tree to avoid thick bark and branch debris (usually greater than 5-10m) and ideally, have access to sufficient light along with minimal competition from other plants. With a little bit of encouragement, we can give these seedlings a greater chance of surviving through challenging conditions by limiting the encroachment of weeds and reducing the amount of disturbance through grazing or trampling. By softening the transition from paddocks to a forested canopy, we improve the health of mature adults, and in turn, the success of future seedling recruitment.
Crafty fencing – doing more with less
The key to extending your woodland edge is through the use of semi-permanent fencing. Fencing can reduce the disturbances commonly caused by grazing stock, which inhibit the establishment of new trees. This does not necessarily mean that we need to lock up entire paddocks to achieve tree recruitment! The ideal long-term goal is to continue expanding our woodland, without having to reduce our ability to graze the land. In fact, we want to improve our production systems by strategically introducing trees so they can provide inherent benefits to managing our farming business, all the while improving biodiversity across the greater landscape. Furthermore, it is rarely necessary to invest in expensive new fencing materials, as the fencing we use to section off regenerating patches will be removed in coming years when the trees are established. The view we must keep front and center is that we are working towards a landscape primarily consisting of open woodland with a thick grassy understory composed of both improved pasture and native species. Sounds nice?... here’s how we do it.
Extending your fence line
Stock love shade. You will have seen this on any hot day, the first place they go to is water, the second place they go to is shade. The New England Tablelands are renowned for their dry, hot, windy summers, and we have had our fair share of them over the last few years. By promoting tree regeneration, you can improve the shade available to your stock and protect our pastures from drying out as quickly.
In the image below (Figure 1) we see a common example of paddocks adjacent to regenerating and remnant woodland and planted tree lines on the New England tablelands. The aerial view depicts a set of adjoining paddocks laid out so as to make the most efficient use of space (existing fencing is indicated as pink lines). On the far right of the image is an intact remnant woodland set higher in the landscape on steep country. On the far left of the image, three paddocks contain dams open to grazing stock (green stripes indicate low depressions within the landscape where water collects or runs). The landholder has successfully extended his woodland by opening a section of perimeter fence from the existing woodland, and in doing so has increased connectivity of his woodland from one side of the farm to the other.
Figure 1: Current fencing of a landholders revegetating paddocks. Pink lines show current fencing, green stripes indicate areas that are low-lying or where water flows and accumulates. Far right of image is a regenerating woodland. Note the belt of regenerating woodland that increases connectivity across the farm, and provides habitat for fauna and flora.
A few simple extensions of this system could be made so to increase the reach of the woodland areas and their benefits for supporting the health of the landscape. In the top right of Figure 1, it is evident that erosion is taking place where water moves frequently. With this left unchecked, it is likely that this will move further up the hill, what we would commonly describe as a ‘head cut’. By extending portions of the perimeter fence line (Figure 2, extensions are shown as blue lines) to enclose these low-lying areas where water moves and stock create erosion, one could reduce erosion across the landscape, and extend our woodland at the same time. Down in the lower paddocks on the far left of the image, we enclose our main water sources with some simple fencing extensions, further extending the connectivity of our woodland, at the same time improving the water quality by excluding stock. So that stock continues to have access to water, we can run a short water line from each dam down-slope to terminate at a trough.
Figure 2: Suggested fencing in blue showing how existing woodland can be expanded while beginning to repair erosion (section A). Low lying areas with dams or depressions indicate where water flows and are marked as green stripes. Keyhole paddocks (section B) and enclosed paddocks (section C) indicate areas where stock will benefit from shelter and where future regeneration can be expanded. Areas that are most likely to undergo natural tree regeneration are indicated in orange.
Parallel/Adjacent extension.
The above examples of fencing techniques to expand your woodland are using a number of best practices. Parallel or adjacent extension is visible within the top right of the image where a fence line has been extended directly adjacent to an existing woodland area. This is particularly effective where mature fertile trees are producing seed that will be cast within the drip line, or up to 5 to 50m beyond with the aid of wind or slope. Simply by increasing the distance that your stock have access to the regenerating trees through the running of a new fence line parallel to the original fence will be enough to give those volunteer saplings a fighting chance (Figure 2, area labelled A). Where mature trees are scarce and up to 50m from where you would like regeneration to occur, it may be necessary to transplant tubestock (far left of section A).
Keyhole extension.
The use of fencing techniques that create a ‘keyhole’ type space within an existing paddock bordering regenerating woodland can be quite effective for both creating a small refuge for cattle from weather extremes but also the conditions suitable for regenerating trees (Figure 2, area labelled B). When the extended trees reach maturity, they will provide shade for the center keyhole and also any stock seeking refuge.
In using this fencing technique, we are actually expanding the edge of our forest woodland that in turn generates favourable conditions for our production system. As is shown in Figure 2, the actual length of woodland edge adjacent to our pasture has increased significantly from the original fence line, allowing for the beneficial properties to feedback directly onto our production system and pasture.
Enclosed paddocks within regeneration belts.
Within the above example, we have aimed to take care of some erosion by strategically allowing our woodland to extend into a paddock space, but in doing so we are also improving our grazing spaces by creating sheltered spaces for our stock. A paddock space that is enclosed on all sides by regenerating tree belts is less likely to dry out in strong prevailing winds (Figure 2, area labelled C). Stock benefit greatly from shelter and by giving them areas to seek refuge when weather becomes inclement, we are improving the quality of our farm products. It is often we see this behaviour of stock finding shelter either under a tree within a paddock or often, higher in the landscape to avoid the frost, or in the corners of paddocks to camp in the evenings.
Getting support for fencing creek lines & woodlands.
It is worthwhile checking in with your local land services (LLS) group for advice and support for performing extensions to local woodland areas. LLS often has grant funding available for fencing creeks from stock and can advise on the use of fencing techniques when erecting new fences. If you want more on-ground help or require the planting of seedling trees, Armidale Tree Group offer some great options for doing so.
How to manage the space.
Depending on your site and its prior history of use, there is a chance that weeds may recruit in areas that have been fenced off. The use of herbicides or strategic grazing to control heavy persistent weeds such as Ox-eye Daisy or Blackberry may be necessary. A technique that may assist in the suppression of weeds is the strategic planting of low-growing shrubs common in the eucalypt forests of the New England Tablelands. A familiar example of this is acacias such as Acacia filicifolia (Fern Leaved Wattle), which will grow quickly in the available space and potentially out-compete weeds that are encroaching on the now undisturbed ground. Planting plugs of Acacia along a fence line and managing them with the use of spot spraying glyphosate can be a simple strategy to keep broadleaf weeds from taking control of the regenerating site. A combination of both of these techniques may be necessary for highly disturbed or degraded spaces so to control grasses and weeds that will slow the pace of regeneration. Each season, cutting back the planted Acacia and dropping the cut branches around the base of eucalypts (the chop and drop technique), can help control light resources necessary for the regenerating Eucalypt seedlings, provide habitat for fauna, and control any potential weeds that may be limiting the development of the saplings. Although this is an extra piece of work, there is something quite satisfying about actively managing your woodland.
Acacia filicifolia (Fern Leaved Wattle)
Acacia filicifolia (Fern Leaved Wattle)
The long-term goal in using these techniques is to gradually increase your woodland edge by extending the reach of the tree line along paddock divisions, fence lines, across contours, or adjacent to creeks or waterways. Facilitating this expansion with incremental extensions of fencing infrastructure, allows both for more effective maintenance of each extended area, and enough flexibility for the woodland to grow with your production system. Given sufficient time, an alley grazing environment will emerge, where we have belts of trees dividing our paddocks with grazable land in between and plenty of refuge within the woodland for stock to intermittently take shelter and continue grazing when conditions are unfavourable. Furthermore, by extending our woodland in initial belts, as trees mature over time, we increase the probability that regeneration can occur within paddocks (Figure 2, B & C) if desired.
Given suitable conditions, Eucalypts can grow at an astounding pace. In many cases, a small canopy can be obtained within 3 to 4 years. We have found from investigating the threatened eucalypt communities of the New England tablelands that these trees can begin flowering and setting fruit with tree diameters as small as 5 to 15 cm. This is not surprising as eucalypts are renowned for being able to withstand unfavourable conditions, and in some cases re-sprout after physical disturbance such as fire, drought, or even trampling. If provided with conditions where disturbance is reduced or eliminated, we are giving them the highest probability of survival and growth into adult trees.
For more information
If you have a site you would like consultation on so to get started with promoting natural or assisted tree regeneration, please get in contact with us via our contact page.
Alternatively, if you have already started, we would love to hear about it. Share your adventure with us on Facebook or twitter and tag us at #SOSgrowingtrees
