Monday, May 16, 2016

Natural resilience

We live in a moderate to high bushfire area. There are still remnants of the last bushfire, all around our property. Many burned out tree stumps and fallen trees, belies the truth of our landscape. The last bushfire came through in 2003, but it would be another two years, until we purchased the property.


Fire scorched tree, down


So when it comes to building bushfire resilience into our landscape, we went looking for answers in the unconventional. "Natural" resilience, in other words. It may seem contrary to standard practice of clear and burn, but we use all our vegetative matter (fresh and dried) as moisture and silt traps.

Because if there isn't the constant rainfall to hydrate slopes regularly, the only kind of vegetation to grow, will be leggy, brittle and fire prone. To change the kind of vegetation that grows here, we first have to address the way we manage the vegetation.

If you want to read an extensive view on how David Holgrem, has approached bushfire resilience in his districts of Daylesford and Hepburn, please read this informative paper on the matter. I read this paper, many moons ago, which got me observing vegetation in my landscape, in a more appreciative way. It wasn't something to be feared, it was something to be used, to build resilience instead.


Lower Gully ~ or Dragon, as we've nicknamed it


Seeing our lower gully transformed, with its seasonal water flows, retained in the landscape for longer, has really convinced us "natural" resilience, was indeed the way to go. It wasn't just a theory in a paper any more, because it was actually emerging in the landscape as a result of our intervention.

To demonstrate the difference, I would like to show our southern slope. What is so different about this area, to the lower gully is, we haven't actually managed the landscape since moving here. It's actually how nature is working on the slopes with zero intervention from us.


Looking up the southern slope


This southern slope, is quite degraded. It's mostly dried mulch for ground cover, all falling naturally from the eucalyptus scrub. There is grass growing, but mostly in sporadic, dried clumps. The nature of a slope is to run everything down hill, so as you can imagine, the ground is somewhat hydrophobic. It takes quiet a lot of consistent rain, to get moisture down into the soil.

Because of this, its extremely difficult to grow GOOD vegetative matter. Nothing but the hardy eucalyptus trees, lantana bushes and a few leggy acacias survive. Sadly, this is prime bushfire fuel, especially when it hasn't rained in a while.


Prickly pear


Which is why we've noticed the prickly pear emerging up here too. A true desert survivor. It lives off the moisture in its succulent pads, as there's nothing in the ground to hydrate it.

What this area really needs, and we're looking into rectifying, is swales. More like modified swales, by using branches, twigs and any kind of vegetative matter, and laying on the surface - across the slope. This will help catch water and debris, from going down hill and in turn, will grow better vegetation.

With better vegetation, comes the potential for more moisture to be contained on the slopes. It's all about defying the laws of gravity, with intelligent intervention.


Deliberately placed horizontal saplings


We have started this process already, at the lowest point of our southern slope. This is close to our lower gully work. When we manually cleared some small saplings, we started laying them across the slope. It got them out of the way, but also stopped things going down hill too.

What we find emerging near these debris piles we're laying, are native grasses. They are the strappy leaf variety, which aren't really edible. Grasses like lomandra; niche plants, which pop up in the right conditions.


Native grass in seed


They prefer locations near depressions in the ground, where it catches rainwater, or near where debris lodge, accumulate and get wet. These clumps of native grasses are the biological filters, which specifically emerge where they can exploit a niche of seasonal moisture and nutrients, in other words.

When you see these living biological filters on your landscape, observe the features around them. Then attempt to duplicate what's happening, somewhere else on your property. Because they're great indicators for what's working in your landscape. I can show you what works here, but where you are, will have different conditions and features. But it is the plants which tell us, what's working.


Earthworks


Higher up on our southern slope, the plumbers dug some spoon drains to divert water away from our septic run-off area. It no longer works, since being clogged up, with tree roots. Unfortunately, this spoon drain wasn't built on contour though, so it can't retain water. It diverts straight downhill again.

David and I plan to tweak it gradually with manual digging, as well as placing vegetative matter as modified swales. This is what we do, when we don't want to involve machinery. Not only does it give us time to observe carefully any changes we make, but it takes a certain degree of skill to operate machinery to the benefit of the landscape, on a slope. We've seen some shoddy workmanship before - cutting land for the benefit of machinery, rather than what's best for the landscape. We don't have to worry about that, when we work at the manual pace we do. 

But the reason the septic run-off area got clogged in the first place, is due to the weedy nature of the eucalyptus trees. Specifically to this region, the spotted gum. These can grow up to 45 metre giants, which drop some large branches. They have their good points and their bad ones.


Weedy trees


The problem with the spotted gum is, they're really good at dominating the landscape, quickly. So they are, in fact, a weed, nature has selected to stabilise these slopes. But I will emphasis, while nature will always attempt to cover the soil with what WILL grow, it doesn't mean, just because its "native", this monoculture is actually healthy for this environment.

As you'll see a little later, "mature gums" still have an important part to play in our system. They can be, effective and intelligent management tools as well.


Natural soil condition


Because to build natural resilience into our landscape, we have to change the dead and lifeless soil on these slopes. The key components are (1) identifying where the water flows across the landscape, and (2) marrying that to plants which will capture moisture and fertility. We're the third component though, because its our job to observe the interaction, cut down vegetative matter when it will feed the soil, and assist in restoring an ecological improvement to fertility.

These key components will then generate a lot of "edges" to exploit. A lot more than exist now. Hopefully over time, it will change how the soil retains moisture and what vegetation can grow. It's a gradual process and its one best navigated, utilising what's already in the system. It won't grant immediate success, but we've learned nature's pace is also a good pace for us to work, as well.


Ground litter


As gums dominate, we'll be using a lot of their dropped material in our modified swales. Branches and limbs, don't have to be spread around the base of the trees, like confetti. The trees don't need them to grow. But we can collect and position them across the slope instead, to capture water and debris travelling downhill.

In theory, it will act somewhat like a hugelkultur bed over time - once the seasonal rains arrive, for all those soil critters to get to work again.


Large termite mound


Speaking of which, I've mentioned the dreaded termite before, but they really compliment this ecosystem perfectly. They break down all those hardwood trees, in short order. Which favours the fungi and microbes to move in next, creating friable humus. So its important to acknowledge the role they play, improving soil fertility. A termite mound, is part of the natural resilience at work in this landscape.

In suburbia a termite mound means a completely different thing, than where they emerge in a food chain of endless hardwood trees. So if you hear me singing their praises, don't think I've completely lost my senses. They just have an important job to do, and its my job to acknowledge that, for our land's sake.


Another gully


Onto something a little scary and a little disappointing, further up the hill though. This is one of the gullies, much higher up the slope, than our lower one (Dragon). We have several gullies crossing our land, and the ones higher up, are in poor shape. All that spindly scrub, is prime for burning. These gullies have no plugs to slow the flow of water, and are designed to simply run water down hill, as quickly as possible. Which is part of the reason why everything is so brittle.

It's not the scary or disappointing part though - neither is the 90 degree turn downhill, despite the fact, you can see the erosion caused by the 2011 Queensland floods.


Click to enlarge


Imagine a cute little gully, running gently with water, after a large rain event, for many days. Unfortunately the force of water involved in the 2011 flood, chewed out part of the slope and will simply keep eroding, without some kind of intervention. It was always our intention to work our way back up here, and modify this area.

However, the intervention which came, wasn't something we had planned for. Which is actually the disappointing part.


Spot the gully


The gully was filled with trees, so you cannot see it any more. It was done by our neighbours about 26 months ago. While part of this gully comes out on their property, the part I'm photographing now is on our land, higher up.

I would have liked to be consulted, before this specific strategy was done. I was told they were going to do some clearing on their land, and might encroach a little on our side, because its difficult to tell the property boundary. I imagined a downed tree here and there, crossing into our property, but I didn't imagine a concerted effort to fill the gully, with some of our own trees.


Scenic but potentially dangerous


The reason I would like to have been consulted specifically on this strategy, is they didn't fill the gully with the debris properly (see above). Dumping large vegetative matter indiscriminately, creates caverns, which ultimately allows the water through. Only they've narrowed the pathway of the water even further.

This will force any increase in water flow, into the side of the gully wall, taking soil with it. I thought it was accidental at first, because I concede the difficulty with property boundaries when dealing with scrub. Until I realised, the only downed trees on our side of the property, were directly adjacent the gully.


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Follow the grass straight up the slope, in the image above, to determine the real boundary between properties. The clump of trees on the left, are on our side. So they only scraped back the trees on our land, that would fill the gully.

It shouldn't bother me, but the reason it does is because all care and consideration should be taken, when attempting to manage seasonal waterways. The force of water which travels down them in a wet year, are phenomenal. All the plugs we make are from vegetative matter which is small, and breaks down into a mat. It won't take out soil, if it gets dislodged by the force of water.

Any trees which end up in our waterways, are the ones nature has felled, naturally.


Very edge of our lower gully


As you can see in the image above, there's a tree tilting forwards behind the log. This path becomes a waterway, in heavy rain, and so any trees which grow in it, are destined to eventually (with enough size) topple over. Their roots cannot handle the water-logging, the bigger they get. But we didn't plant it here, the tree came up of its own fruition. There's also another tree, coming up on the other side of the log, to replace it. This is the cycle of nature at work. Something is dying, while something else is getting ready to replace it.

Understanding how native vegetation is operating in your neck of the woods, is important for understanding how you can use it to create natural resilience. While we may not deliberately drop a tree into a gully at this point, I'm happy for nature to decide if it will. We work together for the same cause. Resilience. But if we are going to do anything on purpose, we ought to comprehend the effects of such.

Trees in waterways are one thing though - trees growing out in the open, are quite another.




This is looking onto our neighbours property, which was partially cleared about 26 months ago. They haven't managed this landscape, since scraping back trees and burning them off.  While this is considered the conventional approach to bushfire mitigation, it does require maintenance on behalf of land owners. Because opening the canopy up, without managing the land, has created opportunity for prolific new seedlings to sprout.

If they don't mow, they could end up with replacement trees, in another 26 months. Which brings me back to the subject of mature gums, as management tools in the landscape.

Mature gums are the ones most useful for native animals, to nest in the hollows, once large branches fall off. But mature gums also make it difficult for establishing seedlings to emerge too. The only ones to emerge around mature gums, are the ones they throw up from their roots, at the drip line. These suckers will be thick and moist, because they'll partially feed from the parent roots.


Note the distance between the mature gum,
and where the saplings are growing


In effect, having mature gums around, thins unwanted seedling growth for you, and only allows strong saplings to emerge on degraded soil. If its not a wet year, for several seasons, saplings emerging from seed, can grow leggy and be fire prone. More so, than the ones emerging from the roots of a mature gum. Its important to remember not all gums sprout suckers, but the ones in our area do. Even still, mature gums can hold back seedlings emerging from seed, at least to their drip-line. Often smaller trees, like acacias can emerge closer to a mature gum, but they're smaller and can help to fix nitrogen.

On the downside though, you have to watch the drip-line of the mature gums, and thin some of the suckers which come up from the roots. Which is easy to do when they're small. So its not all tea and crumpets with mature gums. But at least sapling numbers can be controlled with a set of hand tools, rather than spending a few thousand on machinery for a weekend. Plus you've left those tree hollows for native animals to use.

Unless the intent is to move into a cleared area, and use it for pasture, access roads or other features in the landscape which will be used frequently, its best to leave established vegetation alone. Because there's still a semblance of balance at work, in favour of stabilising the environment. This can be hard to appreciate, when everything within that environment looks so degraded though.


Gold nuggets


Speaking about degraded, this is kangaroo poo, on impoverished soil, with eucalyptus leaves everywhere. It looks to be a truly sad image. Who would want this kind of soil on their land? However, this is precisely what its all about. Right here, is an opportunity to take what's pre-existing in the landscape (free manure supply) and find a way to use it.

We can't keep livestock on these slopes in their present state, but we can find ways to entice the local inhabitants to continue foraging for food. Leaving their little nuggets of manure on our land, as way of thank you. Which is also part of the strategy of leaving some elements of nature in place, rather than removing what we think is a problem. Animals will feed and raise their young where they can appreciate some protection, so we keep strategic stands of bushes, for them to move around the landscape safely - seeking food and water.

We aren't particularly enamoured with mowing ourselves - we do what's in our interests to control. Which is why having those unruly bands of vegetation spotted around the landscape, works both in the animals' interests and our own. We only have to control the areas we use, which tend to be the footpaths. The animals can still have the protection of bushy cover elsewhere.


Maturing female brush turkey


We are always excited to see new animals, which haven't appeared on our patch of land before. Such as the clutch of baby brush turkeys, which hatched in our area recently. Their appearance signals, some aspects of our land are now habitable enough for them to emerge.

When I was up on the southern slope a few days ago, I noticed all the holes they've dug out, around the mature gums, to get at beetle larvae. They've also scratched open an emerging termite mound. As these brush turkey's seem to favour the land around the house the most, they may actually become a natural deterrent to termite mounds, where we don't want them in future.


 Signs of a brush turkey at work


So when I talk about natural resilience for the environment on our property, I'm talking about a host of different elements, accumulating something better, out of something degraded. If I'm tempted to believe, anything is out of alignment with my personal vision for the land, I just have to watch nature's clues, for why they might actually be the perfect fit instead.


Even this large prickly pear is struggling


Prickly pear may not be my desired plant up here (we're working on it) but they're just filling the niche, created in the landscape. A lot of emphasis is placed on weeds being an issue, needing to be controlled - when its really the degraded "environment" which needs dealing with. Measures which require more placement of people, rather than machinery and poisons, as a form of control.

Because its the people with the intelligence to figure out, what the landscape actually needs. If our vision is merely short term, focused on immediate solutions, then we will never allow ourselves to look beyond what we're doing, to the potential consequences - good or bad.


The dragon sleeps for now


We want to work more on this...more vegetation which brings comfort to the environment it grows in. That sandpit caused by human induced erosion, due to land clearing, which we were first introduced to - is no longer radiating heat up to our faces, and we can visit it more than just in the cool of the morning and the afternoon.

I'm not suggesting we have the perfect system or solutions, but when I see the difference between the southern slope, and the lower gully, the change is enough to warrant continuing with our interventions. Which is really the desire to farm natural fertility for the cause of resilience in nature.

Bush fires will always be an ongoing concern here, but so should the lack of healthy vegetation. For healthy vegetation, doesn't burn as readily. So somewhere, a compromise needs to be found in between. Which is why I'm not entirely against the conventional approach, of clear and burn. But it does require more ongoing maintenance of vegetation afterwards, than perhaps is fully appreciated. It's up to everyone to find their own balance.

Perhaps where we all struggle, is learning to appreciate what actually is an asset to the landscape, instead of what's perceived as a detriment.


5 comments:

  1. Great post, Chris. I'm learning so much from this type of thoughtful post from you. That last line is a doozy. I will print it out in large letters and put it in my permaculture course notebook (why did I miss something so obvious? Must be getting old :-(

    I am definitely going to look at my land with new eyes.

    Just by way of explanation....the bush part of my block is on flat land with very well-drained sandy soil. I don't get water flows across it that I need to capture with swales and debris. The rest (where the food gardens are) is on a slight slope and is heavy, poorly-drained soil (some of it is fill, done when the property was subdivided from 10 acres to 4 x 2.5 acre lots, in order to provide driveways to the 2 rear blocks). This is where I have dug swales behind each fruit tree which are capturing runoff very nicely. I had initially kept them free of debris (nicely formed and raked....aesthetically pleasing), but the rabbits kept digging into the soil and disturbing the swale mound so that water escaped. Now I have filled them with debris and leaves and the rabbits leave them alone. The water still collects under the debris and causes it to slowly rot down. I rake the rotted material up onto the swale mound and under the fruit trees and fill the swales with more debris. It's working well.

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    1. Excellent interventions there Bev, with the animals, swales and vegetative matter. Sometimes, what we try the first time, doesn't necessarily work - but then we can always come back with new eyes to develop a new approach.

      Which is what you did, filling the swales with vegetative matter and cycling it. Low maintenance compost making in other words, and you always had to do something with that vegetative matter. So you found the perfect niche, to connect a lot of different elements together. The swales are the "edges" where it all happens.

      Thanks for sharing your own little discoveries. I'm happy to share mine, finally, after nine years of experimenting and seeing what happens. Nature's pace is slow, but then, it's the perfect pace for what needs to happen.

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  2. Very interesting post, Chris. We are slowly creating modified swales down the back of our property, too, for pretty much the same reasons although we probably get more rainfall than you.

    Your point that it's the environment rather than the plant growth (weeds) which needs to be dealt with is a good one. That's constantly on my mind too as I try to deal with vegetation that is difficult and what I see as counterproductive to what we're trying to do. I don't always know the answer though, except to continue to work on soil fertility, which will change growing conditions, which will in turn change vegetation. It's a slow process as you know! And it takes "slow thinking" to find permanent solutions rather than they typical fast-thinking quick fixes people want to use.

    When I lived in the Ozark Mountains the Army Corp of Engineers would come through every so many years with bulldozers to clear and flatten out the creeks and small rivers in an attempt to control flooding in those areas. The resulting erosion was terrible. But I think it takes living on and observing the land to understand there are alternatives.

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    1. Nice to hear others trying out the modified swales. It all contributes to putting more moisture in the ground, which is a plus. You just never know when the next extended dry period will come.

      Slow is definitely nature's pace, isn't it! You need to invest in a lot of fossil fuels to get more immediate results, which isn't an option for a lot of people. So we just keep tending to the dirt, hoping it will do some good. When we start to see new species emerge however, that's when we know, its working.

      Some local Councils (County for US equivalent) in Australia, destroy creek beds, just to remove the noxious weeds, such as Willow. The result is the same though, soil erosion, because the Willows were the things holding the banks together in the first place. Its a case of cutting your nose off to spite the face. Crazy stuff!

      Give me time honoured, slow observation, any day. It's less lethal. ;)

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  3. Hi Chris, I couldn't find contact details here so would you be able to contact me via the contact form on the sidebar of my blog as I have something to ask you. Thanks heaps. Chel

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