advice on regenerating a pine/eucalyptus plantation

Hey everyone,  long time reader first time poster here looking for some advice.

I've recently bought a little2 hectare mixed plot with 3 separate small pine, eucalyptus and small oak forests on it.

Being in Portugal that means massive fire risk and depletion  of soil life. The pine forest is maybe10 years old and much too dense in my opinion and the eucalyptus is nearly monoculture.  I've been considering cutting out the medium sized trees and maybe saplings to make space for other trees and grasses but my research on regenerative silviculture has not been very fruitful.

What would your recommend? Major use of the forest will hopefully be as a source for both food and wood,  more the former than latter and I just need want to decrease the chance of our land burning down entirely.  It's on a hilkside and I'm keen to either dig swales or majorly make terraces because it doesn't rain here for up to7 months a year.

Any help would be massively appreciated thanks everyone!

I would remove the pines entirely, I find their leaf litter to be too acidic, and the foliage too dense to grow anything under them.

Do you know what species of Euc you've got? There is a huge variation in competitiveness between species. The best Eucalyptus trees are essentially rainforest trees and allow a dense stand of understorey vegetation, others kill everything around their root zone. Knowing your species is the first step.

Eucalyptus litter is very high in Carbon. My approach is to plant a lot of N-fixing trees with them. Getting a good C/N ratio in the leaf litter allows the high C euc litter to break down and form soil easily, this also helps reduce the fire risk both by recycling the litter and building moisture-retaining soil. I use Alnus and Acacia trees here, these should be suitable for you as well. Eucalyptus trees actually improve soil if managed correctly, the litter can create good humus in a short time if conditions allow. However there seems to be a definite moisture tipping point at which this occurs, often around 800-1000mm rainfall. If your dry season is too long, and your wet season too dry, you might find it is better to remove the trees completely.

Eucalyptus trees are built to compete strongly for moisture and nutrients. I had a euc shelterbelt around my orchard but ended up removing it. A friend in Australia had a line of E. pilularis down his driveway, and the neighbour had an avocado orchard alongside. The neighbour complained that every time he put fertilizer on his avocado trees he got no response from the crop but the Eucs next door suddenly grew 2m! I think there is a very good chance your best bet would be to move your food producing area away from the forest, or remove the forest and utilise the higher organic matter forest soil for your food production, and replace the trees with something more friendly, such as alders.

Swales and terracing are great ideas.

Here's some of my euc forests, showing the dense regrowth of native rainforest trees that come up in their shade. Eucs can be very good, but they can also be very bad if used inappropriately.

Ben's advice seems stellar. My experience is that pine and eucalyptus seize and don't easily give up land. They are also both very combustible trees. I also really like his advice about n-fixing trees heavy around eucs. Maybe start most aggressively removing pines, and thin euc grove heavily, replanting with n-fixing trees/shrubs/bushes. Maybe even work to turn the pine space into open field. Best of luck and please share pictures for posterity

I don't know a lot about what you would need specifically in terms of regeneration(complicated), but, in term of fire control, here are four simple steps to take that would VASTLY reduce the chance of wildland fire spread and reduce the chance of total tree loss:


Limb up all trees from the ground up to standing height at least;

Clear woody underbrush/vines/fallen limbs from around the trunks of trees (not counting mulch or leaf litter, or annual crops where you remove/mulch the plant matter after each harvest);

Remove dead and diseased trees, and cut out deadfalls/dead limbs when possible;

Trim/selectively fell trees to make sure tree drip edges(outermost edge of branch coverage) don't overhang each other.


Taking these steps will allow your mature trees to potentially survive IF a wildland fire travels through your forest.
The next, more drastic steps include firebreaks, roads for fire crew access, and clearing "defensible space" which, here in burn-prone California, means 100 feet of land devoid of plant life surrounding any structure (which, in terms of permaculture, I do not endorse).

In terms of what I would personally do, after completing the 4 fire-control steps on whatever I would want to save:

Harvest the existing Eucalyptus stands for firewood (either personal use or sale) the allopathic tendencies and aggressive spreading will mean that it will always be monoculture, and, it isn't even native to your area, so no loss in terms of nature conservation, either if you clear the entire area completely. Use area for whatever you wish to grow(will take a lot of work)

Thin Pine and Oak forests and develop edible understory guilds for each (mushrooms, shade tolerant greens, berry bushes, herbs, etc; (in terms of Zones, these can be your two outermost (Minimal/No Development)
(Do your pine species produce economically viable nuts? your land may already be productive without knowing it!)


Swale uphill and downhill edges of each forest (putting swales in the middle may be too labor intensive, even after thinning.

Develop the edges and cleared spaces to suit your needs (fruit or nut orchards, vineyards, Hugels, whatever you want)



If you do decide to clear-cut,  save at least a few for shade and beauty - for me, cleared land needs at least a LITTLE variety of form.

Enjoy!

I'm astounded and humbled to the degree that my chest and stomach are full of excitement. I've been looking for this information for months and all it took us1 day on premises, you guys have just changed my life and probably drastically improved the way I would've managed my forests. This is so much more sound than just thinning the weak trees or cutting clear circles and replanting.

The pines are pinas pinaster maritime pine so only wood producers and no idea about the eucalyptus, but it seems to shed a lot of bark which looks different to your picture posted.

I will probably need to take my time with clear cutting the forest for a moment as replanting in the heat of summer seems untenable and chainsaws are banned until October.

I will most definitely post pictures for sure,  thanks again guys keep it coming!!! If there's anymore you'd please do share!

Hi again Teaoh Be,

Dustin said Eucs are always monoculture and I post pictures of my eucs starting a rainforest succession, so our advice seems contradictory but in fact we are both correct, given the context. Dustin in San Diego sees only 20-25% of the rainfall I get here (and I am in a dry part of New Zealand!), so we are looking at this from very different perspectives. If you are in a rainfall zone less than 800-1000mm I would agree, remove the eucs, but also the pines. Finding the identity of the eucs has to be your first step though, the best species have extremely useful strong, super-durable timber that is good for building, fencing etc.

The thing we all neglected to ask is what is the surrounding land use? I lived in Australia long enough to develop a fire paranoia,  and if your neighbours land use is pine and euc forests I think the best advice is to remove every fire-loving tree from your property and plant only fire-retarding trees and shrubs. There is a lot of information on this on Australian websites, this one below is an example, and has photographs of houses protected from catastrophic fire loss by strategic planting of deciduous (wet) trees. Search for this and some of the Aussie photographs on google images are very dramatic, whole landscapes blackened by fire with one little oasis of green left by utilising fire-retardant trees. Eucs or pines on their own are very dangerous trees, some Aussies call eucs "fire-sticks"!

https://www.recreatingthecountry.com.au/blog/deciduous-trees-can-provide-crucial-bushfire-protection

Ben Waimata wrote:Hi again Teaoh Be,

Dustin said Eucs are always monoculture and I post pictures of my eucs starting a rainforest succession, so our advice seems contradictory but in fact we are both correct, given the context. Dustin in San Diego sees only 20-25% of the rainfall I get here (and I am in a dry part of New Zealand!), so we are looking at this from very different perspectives. If you are in a rainfall zone less than 800-1000mm I would agree, remove the eucs,

You are right Ben, I was basing my information on the Mediterranean climate, and not on Beautiful NZ - in your situation, Eucalyptus makes perfect sense!  Another consideration when outside of their natural habitat is there are no local understory species acclimated to living beneath eucalyptus (Eucalyptus oils leaching from leaf litter and bark into soil, inhibiting growth, which contributes to the monoculture affect. )

Dustin Rhodes wrote:Another consideration when outside of their natural habitat is there are no local understory species acclimated to living beneath eucalyptus (Eucalyptus oils leaching from leaf litter and bark into soil, inhibiting growth, which contributes to the monoculture affect. )

Which also goes to prove the point that everything is relative! You are of course correct, given the species you are familiar with in SoCal.  The trees around there are going to be the ones suited to a drier climate, and inland and dryland eucalyptus trees are highly alleopathic as well as highly competitive for nutrients and moisture. However, having said that, there are eucs that grow very well in rainforest margin situations and allow dense ground cover to grow around them. These trees are part of the succession to full rainforest in the wetter parts of Australia, and given no disturbance for long enough they are outcompeted and disappear. This ground cover is not an Australian-specific thing, it happens here too, and in South America, and anywhere the rainforest margin Eucs are grown in a moist climate that would naturally hold rainforest.  I can see the difference here inside the same microclimate, I've got a stand of E. microcorys (rainforest margin tree) with dense native seedlings under them, with E. globoidea (moister dryland tree) alongside, with no native seedlings. The only difference is the Euc species, the site is otherwise identical.

These kind of discussions are always difficult, we are saying different things but both 100% correct. Not to mention the possibility of cultural or language misunderstandings!

Hey everyone,

so I havent been able to distinguish the variety of eucalyptus - asking the previous (portuguese) landowner and doing research (other blogs about the most common types say its most likely e.globulus - blue gum). It is definitely unbeatable, as 2 weeks after pruning/cutting new sprouts are already knee high.

To an earlier question, two properties surrounding ours are respectvely eucalyptus forest and pine forest. Thus, ill be thinning this forest down to the bare minimum (only the most beautiful and straight of pines will stay) and Im wondering, do you have any recommendations as to what trees do well in regenerating the soil after decades of eucalyptus?

Ive heard black locusts (robinalia pseudoacacia) does well here in portugal and is a soil fixer, and personally I'm going for all sort of variety and diversity over mass planting. The closest rows to the neighbour are going to be cypress (cypressus sempervirens) as research in spain is showing (insane!) fire retardant properties.

Any others I should be aware of?

Thanks a ton guys, this has been so utterly helpful!

I would recommend against Black locust, it will do exactly the same as the eucalyptus is doing there. Once it gets established, it will be very difficult to eradicate.

Instead of going for n fixing trees you might want to look into other plant types for n fixing simply so you have the base for what ever type of food plants you decide to install.

For the soil, may I humbly recommend reading my soil threads, they should be of help. The soil threads

Since others have given really good advice, I'll hold my own to this for now.

Redhawk

I don't have ironclad advice on what to replant (as my local fire-surviving vegetation in Southern California isn't really of economic or permaculture value)

but I did find this link:

http://www.readyforwildfire.org/Fire-Safe-Landscaping/

Granted, it is coming from an aesthetics-only slant, but there are some economically viable plants listed here that are fire and drought resistant, (Lavender, Sage, and Garlic) as well as a passing mention that hardwoods and low sap/resin species are generally less flammable.

One of my dream trees is Mulberry - I don't know if it's fire resistant, but it does well enough in hot/dry climates, and can withstand HEAVY Coppicing/Pollarding almost yearly - so maybe that "will to live" is strong enough to survive peripheral fire damage? (also, the berries are delicious, and the leaves are good fodder for livestock) - I don't know how valuable it is from an agro-forestry perspective though...

Sadly it is the bark of the Mulberry that is not fire resistant, it simply isn't thick enough to protect the cambium layer from cooking. (that is what normally kills trees in fires that don't go to crown fires)

That said, you can grow mulberry in southern California, just make sure there is adequate space all the way around the tree that is short vegetation. and that is not anywhere near the inside border of the space that is fire break.

Thank you Redhawk; even though that's bad news for my dreams, it's good to know for the future - I will keep my future Mulberries far away from my house then.

If you've got E.globulus the coppice growth will have foliage distinctly different from the adult leaves, with very glaucous leaf and high oil levels. If you break a coppice/juvenile leaf there will be a very strong smell. If this is the tree, it is in the better half of the genus for alleopathy, but will not be a good choice to grow anything else under unless you have  a lot of rain.  Heartwood durability is reasonable, but sapwood is low durability. A widely planted tree, but not a great choice unfortunately. Reasonably good firewood!

I didn't know C.sempervirens had fire-retardant characteristics,  but from what I've seen it might be as hard to garden around as any Eucalyptus, most of them around here have a distinct dead patch in their dripzone.

Regarding fixing the soil under the eucs, The Redhawk Soil Threads are obviously the first start, but I would suggest that you might be surprised how little regeneration is required. You've got forest soil there, as long as it has not been burned regularly you might find the soil mineral levels, organic matter levels and microbiology are much better than you expect. Once the competitive trees are removed this asset may well begin to reveal itself.

Good call Ben, I would check the soil for worm activity and probably look for hyphae in the soil.
Those are pretty good indicators of soil health.
If the hyphae are there, then odds are the fungi will handle the allopathic compounds.

Redhawk

Going on an intuition I googled the fire resistance of grape vines, and yes they are credited with saving lives and property in the Sonoma Valley.

Hi, I see this was posted 3 years ago & I wondered if you have any updates to post?
We have a lot of blue gum monoculture plantations in our area (Cantabria, Spain, with rainfall of approx. 1200mm/year) -- so far fire hasn't been a big problem but I suspect it's only a matter of time. So we are interested in ways of recovering these plantations, which are typically clear-felled on an 8-12 year rotations. One interesting possibility I'd like to try is planting _Paulownia_, a fast-growing, N-fixing genus of trees.
I also remember reading somewhere of the use of _Cannabis sativa_ to regenerate soils after Eucalyptus...