Ferns are a vital component of a number of the vegetation communities (EVC’s) that exist in our district e.g. Wet and Damp Forests. However when an area is being replanted ferns are often left out of the mix, mainly because they are tricky and more expensive to propagate and may also struggle with being transplanted. The upside is that given the right conditions ferns can easily come back eventually by themselves over time.
A fantastic example of ferns ability to spread can be found in my own garden. I live on a property which is next to farmland and a dry schlerophyll forest, the rainfall average is about 700mm a year and the nearest fern gully would be around 6km away as the crow flies. Over the last year or so I have been amazed at the ferns that have been popping up in my , garden. The first one I noticed was growing in a protected spot next to some tea tree, initially I had assumed it was just a bracken fern (pterdium esculentum) which is common here (like everywhere else). I was in the process of learning to identify my ferns better and one day while walking past this fern I realised it was in fact a different species, which turned out to be pteris tremula (Tender Brake).
My next and biggest discovery came when I noticed to my surprise some ferns coming up in a corner of my vegetable patch where I have a row of citrus trees planted in large pots. I have now had at least 4 different species of fern appear, all of which you would not expect to find anywhere near where I live. In this area as well as Tender Brake, I have found Histiopteris incisa – Bats Wing-fern, Hypolepis rugulosa – Ruddy Ground-fern and what I am fairly sure at this stage of growth are 3 separate Dicksonia antarctica (Soft-tree ferns). With close inspection I can still see some young sporophytes (baby ferns) that are too small to identify the species. I also discovered another spot in the garden where a Pteris tremula has popped up next to a raised garden bed.
The key thing about all the sites where ferns popped up was that they were shaded and sheltered and they had good moisture, in this case as a result of both artificial watering, but also probably because of the milder and wetter summers we had had over a couple of years. Having bare soil would have also been a factor, prior to finding that the ferns were growing I was periodically spraying the area where they were with Glyphosate (Roundup) to keep the grass at bay. A key way to promote the regeneration of ferns on your site may be to provide some sheltered micro-climates where ferns can develop. Logs and rocks not only provide potential habitat for animals to shelter they can also provided a moist shaded environment suitable for ferns to recolonise your site.
The spores responsible for the appearance of these ferns were either possibly brought in to my place via me (off my shoe or clothing) but also possibly by the wind as they are so light that they are thought to be able to carry many kilometres.
If you are wanting to restore native vegetation, you can save a lot of expense and wasted effort by working with nature as much as possible. Different sites will require different actions to get the desired results. The following examples show some of the different possibilities for action.
The overstorey trees in this gully, (mainly Blue Gums) are regenerating strongly, There are also plenty of understorey plants including various species of native daisy bushes coming back.The main threat to the site is destruction of the recovering vegetation by stock and weed invasion by transforming weeds. Some annual weeds such as Thistles are very common here now but as the trees and understorey grow back they will be shaded out. The real threat is weeds that will potentially outcompete the native plants and reduce the quality of the habitat for animals, in this case Blackberries are the main issue and a high priority should be to establish a plan for their control. There should be no need for any replanting of vegetation, because it should all be able to recover naturally, in order for this to happen the main priority should be to ensure that a good quality fence is built to keep stock away from this sensitive area.
The site above is a completely different story. This area is on an exposed west-facing ridge, it is steep, erosion prone and unproductive so the landholder has wisely decided to re-vegetate it.There are virtually no native species found on this site and given its position in the landscape and the history of grazing, in the near future there is not likely to be any appear on their own . This site needs a long process of rehabilitation it first needs to be fenced out from stock then planted with as many species as possible from its original vegetation type, so that it can eventually become a diverse and valuable habitat for native species. Ongoing control of high threat weeds will need to continue, especially in the first few years after planting to ensure that they do not get a stranglehold on the site and restrict the growth and development of the new plantings.
The above site along a small creek is in a degraded condition with a cover of exotic grasses and weeds and some dead trees present. On a positive note the site does have some surviving overstorey trees as well as some thickets of native understorey present. Again the first priority for this site will be to fence it out from stock. This will give any regenerating trees a much better chance of survival and allow the understorey to spread. Also again weed control of high threat weeds is a high priority. Once fenced is site can be monitored for the appearance of regenerating native plants that may come from seed stored in the soil, blown in by the wind, washed down the gully or dropped on the ground via birds. If regeneration is not occurring you may have to consider other control measures. Rabbits or other browsing animals could be killing new seedlings, you could build a rabbit proof area on the site to see if that makes a difference. Or perhaps thick grass is stopping germination, you could spray an area with herbicide or scalp off some topsoil to see if that helped trigger new plants to sprout. If all else fails you may go back and resort to planting out the open areas of the site with tube-stock.
The site above is quite a difficult one, It is steep, highly exposed and has poor soil. It formerly had pines growing on it before the fires. It has been sprayed for Blackberry but there are still plenty of Blackberry canes re-sprouting and other weeds such as Variegated Thistle covering the site. the other side of the ridge does have some native scrub growing on it which could provide a source of seed, but it also harbours plenty of Swamp Wallabies which will be keen to eat any newly planted seedlings. Turning this site back to native vegetation will probably be a slow process. One strategy may be to fence the site out from stock and replant the site with overstorey eucalypt and wattle species. The site is likely to be too exposed and weedy for understorey plants to survive. If a canopy can eventually be achieved (maybe up to 10 years later), Shade and protection will provide a better opportunity for understorey and a greater diversity of plants to be established.
This site above is typical of many in the Strzelecki Ranges. It is a very steep slope that was cleared for farming, although hindsight tells us that this was a bad mistake. Since given up for agriculture this gully has seen species such as Blackwood and Silver Wattle come back via soil stored seeds and root suckers, and daisy bushes blow in via their wind-blown seeds. The Eucalyptus overstorey however has disappeared, with no hope of natural replacement. The answer is to once again fence out the site from any stock that may be keen enough to wander down into the gully. Attempts to establish carefully selected Eucalyptus species can then be attempted, this will not be simple as Swamp Wallabies are again sure to be common at this site. One common (but expensive and labour intensive) option is to install mesh wire guards at least 1.2m tall around any plantings to allow them to grow above the height at which Wallabies can graze them). Another issue on this site is the large established Pine trees, Pinus radiata, the simplest way of dealing with the Pines may be to poison them.If they are allowed to persist they will reduce the habitat value of the site and regularly drop seed and produce new wildlings.
This last site on this post has seen a mass regeneration of some species after the fires. No stock on the site has seen thousands of seedlings emerge. The landholder is fencing, what is a very long gully, some areas of the gully have recovering remnants, other bits were formerly pasture with a thick carpet of new Wattles and other species coming up and other bits are bare. The uneven regeneration at this site means that planting may be necessary in some parts and not others. Carefully selection of species to plant is also necessary. There is no point wasting time and effort planting when thousands of plants of that species are already coming up on their own. Spots where overstorery trees are missing are probably the highest priority because unlike species that can be spread by wind-borne winged or fluffy seed or berries carried by birds Eucalyptus seed is only spread by release from its capsules.
This site is all about restoring the vegetation in a steep gully that runs through a grazing property in the upper catchment of Flynn’s Creek and contains some remnant vegetation. The steep gully land has relatively low productivity; given its difficulty to manage and access it is also an area of the property that is vulnerable to erosion and weed infestations. Fencing to exclude stock and re-vegetation of the cleared areas will have multiple environmental benefits and provide a valuable habitat link for scattered patches of remnant forest. The total area involves 1.3 ha and 2000 indigenous tube-stock plants are being used for the re-vegetation. It is anticipated that stock exclusion will also allow natural regeneration of plants from the pockets of remaining vegetation contained in the gully as well as from the newly planted species when they are established enough to start reproducing. Other native species will also be re-introduced to the site via movement of seed and spores. There is a narrow stock crossing across the site where access can be gained to the other side of the gully; this will allow access for maintenance of the boundary fence-line and for weed control.