Tuesday, July 5, 2016

What’s Good about Lantana?


It’s easy enough to list the things we Australians DON’T like about that invader from South America, Lantana camara. Alas, that we inflicted it upon ourselves, with our careless gardening habits!

1. It colonises disturbed soil with dense shrubbery, 2-4 metres tall, crowding out smaller plants and preventing regrowth of native trees.
2 As the native vegetation is lost, so is the wildlife that depended on it.
3. Lantana behaves as a nurse plant to privet, an even worse, tree-sized weed, enabling it to establish a virtual monoculture on what was previously rainforest land. The privet forest on the Eastern slopes near Toowoomba, is a classic example of this.
4. Lantana has huge economic impact, reducing the productivity of pastoral and forestry land.
5. Its leaves are poisonous to stock, (some varieties more than others).
6. It’s a prickly, scratchy nuisance to bushwalkers.

Lantana has some Good Points Too
Whenever a super-weed like lantana creates a new environment, some native animals will find a niche to their liking, and thrive.

1. Small birds like wrens find lantana thickets an ideal place to live, eating the succulent fruits, and building nests in the scratchy thickets.
2. It shelters small mammals, such as antechinus, bush rats, and bandicoots.
3. Reptiles, especially small skinks, make use of the shelter.
4. Butterflies love the nectar-rich flowers, which provide them with food over a long season (albeit while slowly exterminating their species by crowding out their host plants).
5. The pithy stems are used as homes by the primitively-social reed bees (Exoneura species). These bees are important pollinators of native plants.
6. It improves soil quality, and controls erosion on slopes.

Does this mean we should love lantana, after all?
Well, no. Not really.
A natural mixture of native plants is the basis for a richer, more varied ecosystem. It hosts more kinds of birds, mammals, reptiles, and insects than lantana ever could, and stabilises the soil just as well.
But lantana’s good points can be a reason for avoiding the “bull at a gate” approach to removing it. We have to keep in mind that clearing weeds is not a beneficial environmental activity in itself. It’s what comes after the clearing that matters. If no thought is put into where they are to go, those little creatures which managed to make lives for themselves among the weeds, then clearing them only causes a net loss of biodiversity.
“Softly, softly”, is the answer.
If we’re hoping that natural regeneration of plants will provide for the displaced wildlife, we need to clear in small doses, and monitor whether regeneration, of the kinds of plants we were hoping for, is really happening.
Were our expectations unrealistic? If clearing doesn’t result in a cheering surge of new growth - and it often doesn’t in our dry and erratic climate - then active revegetation is needed. Plants must be planted, and tended until their survival is assured, and meanwhile, the cleared area will need constant weeding of lantana (and other weed) regrowth so the carefully-planted seedlings aren't lost to shading and root competition. Too many bushcare projects have been sent back to square one by lack of follow-up!
Working with nature is the way to go, when revegetating. A half-and-half approach, blanket planting planting pioneer species to modify the environment, can provide both fast shelter for wildlife and a suitable mileu for natural regeneration of  longer-lived species. This only works if there is a natural seed source nearby, of course. Revegetation of rainforests and scrubs, on the other hand, can be slowed down by mistaking fast-growing dry sclerophyll plants such as wattles and eucalypts for pioneers, though. These greedy plants rob the soil of moisture, slow down the growth of other plants, and simply establish themselves as the dominant vegetation.
Sometimes, the best approach to clearing lantana consists of leaving it alone for a few years, and getting on with planting, instead. Once refuges for wildlife have been established, the clearing can go ahead - but always in proportion to the shelter available.
Now is the time to be planning it. The frosts will be over before very long.


Anonymous said...

You are one of the first people I've seen to say that Wattles are not pioneers and that they are greedy. I respectfully disagree in that regard. I do agree that incorrect placement or lack of management could possibly swamp other plants, but in a successional system, they are excellent for shade, leaf litter and inground biomass and help quickly create the humus that rainforest plants so crave.

Someone like Ernst Gotsch, who is pollarding Eucalypts that are growing with bananas would probably also disagree. If you can manage for transpiration and cycle the biomass from the Eucalypt, they are, by definition, a good pioneer. Example here: http://i.imgur.com/ywOIsuM.jpg

Eucalypts are also grown for 3 years over hardpan in places like Africa. They are harvested for firewood or poles, biomass left behind and then cropped over the roots that have cracked the soil open. This is also a pioneer behaviour.

Eucalytpus grandis (Flooded Gum)/Eucalyptus pilularis (Blackbutt) as 2 examples would probably also disagree as they co-exist with rainforest as a pioneer to this day. They are unlikely to be replaced as the rainforest will fulfil that role. Also a pioneer behaviour. Mary Cairncross Reserve, a rainforest, also has E.grandis as a climax species left over from indigenous management: http://i.imgur.com/7JWbycA.jpg

Ernst Gotsch also has a video regarding the use of exotic Acacia as a pioneer that you may want to watch: https://vimeo.com/118802811

I believe Eucalypt and Acacia are excellent pioneers *when managed*. If you are regenerating by a single planting, then not managing and want a rainforest assemblage at the outset, then you are correct; they are not a good choice for the rainforest or there are better options. They will work fine when you use decades as your baseline.

SNB at Crystal Waters Theatre said...

Thanks Patricia I enjoy all the info and tips especially ideas about trees on your archived pages, dry rainforest, as that is what the kind of environment I have here on Lot 14 at Crystal Waters Eco Village on Sunshine Coast hinterland so I hope you will always be posting such ideas and pictures too are helpful. Have planted many native trees in 3 years since moving here, making use of your enthusiasm, so a good new interest and hobby for me, and our body corporate setup broadly encourages native bush regen work.

Patricia Gardner said...

I wasn't sure whether or not to allow this comment through, SNB. It does sound like advertising, and we bloggers get a bit defensive about having our sites used for advertising!
However, I am glad to hear that my site has been useful to you, though I would think its usefulness must be rather marginal to anyone in a coastal area who wants to plant indigenous species.
There is a lot of species overlap, of course, but all the same, my site is more geared towards people who are dealing with the special plants and conditions of the inland, and some of my advice would seem like overkill to people who are growing plants in the softer conditions of the coastal strip.
One thing we try to do here, for example, is to get our plants from inland sources wherever we can. Even though a plant may be of the same species, having inland parents does increase the likelihood that a plant will be more drought and frost resistant.
I am also glad to hear of yet another development which encourages buyers to grow "natives". (I do hope this actually does mean indigenous plants, not just Aussie plants of widespread origin?)
We could do with more of this kind of thing hereabouts.

SNB at Crystal Waters Theatre said...

Advertising yikes, yes fair enough, I didn't think of that and no intentions along that line.

I had been intending to write a comment expressing appreciation for your contagious enthusiasm and info about trees for quite awhile now,and didn't know about exposing email addy, whether it is safe or not, and didn't want to merely choose the *anonymous* option,
and I don't know what the OpenID option means,
so the remaining option/choice in the comments dialog box is *name/URL* so I used that one, thinking a url would show some kind of indirect identification.

Well anyway, tips like planting close:

So within a few weeks I did that very thing, got 2 x Cupaniopsis parvifolia in tubes from a natives nursery and planted them quite close approx 45-50 cm. apart.

And I do mention/link your site on our local body corp social forum for there are a bunch of enthusiasts for indigenous trees hereabouts, not least because they should be the less trouble to grow I believe.

The village here was designed to be a permaculture village too and some are proponents of that hereabout but I am nearly 60 years and don't care about theory systems so much as actual experience with particular plants and photos which you provide in spades, though I can always do with more ideas, the internet so useful when new enthusiasm aflame.

PS. I see the URL is optional in name/url option so I will skip the URL this time.

Sowhat said...

Hi Patricia

I've found your "place' just today snooping around and find the Blog extremely well written in content, quality and quantity.

I know it doesn't mean anything but I do endorse your Article about the Lantana in full.


Patricia Gardner said...

Thanks for the thumbs up!

Patricia Gardner said...

My apologies to SNB.
Your comments disappeared into my spam box, and I have only just thought to check it.
I will admit that a comment signed with your actual name (first name only is fine), and something that indicates where in the world you are, does tend to influence me into believing that a comment is "real" rather than spam. There's a lot of spam out there.