Welcome to part one out of four in the series FIRE: Mediterranean Climate Permaculture Design. This first episode is a simple Top 10 of Mediterranean Fire Resistant Trees. I hope it will spark your interest, and make you do your own research. Remember, your context/site is unique, and you have to find out what works best. Now, before we start on our exciting journey of cool trees, please allow me to take you on a short rant about the recent fires in Portugal. (Nah, Bring me Straight to the Top 10 Please)
Recently we have again seen the devastating effect of forest fires in Portugal. It is an outrage and abomination how this disastrous mode of land use is stimulated and continued. All at the cost of the ecosystem and her services; her natural resources, her biological diversity and the cultural heritage that she sustains. Many innocent people have died again. This forest fire was ascribed to lightning, however it is a known fact that most forest fires are man-made. If it does not happen out of negligence, it is done on purpose; what is called ‘salvage logging‘, is one of the reasons to start a fire.
Much about the Eucalyptus mono-culture industry is paradoxical and regrettable (read: insane). There is an economic incentive in cultivating a tree that is destroying the landscape, ruining the soil, lowering the water table, and waiting to go up in flames; and there is an economic reason to set the tree on fire as well. Portugal clearly has a problem; the people need to act on this huge issue, especially the Portuguese establishment, who is ultimately responsible for this atrocity. In any case, the purpose of this rant is not to leave the reader just upset. Rather, a bit of anger can be a good thing, when it makes you get up and act! (Don’t go punching anyone now!) Ahem… so, continuing on a much brighter note:
This dilemma also offers opportunities. There is now increased attention through (social) media, and we can make use of that momentum to create change. Local permaculture action groups are for instance getting together around the Pedrógão Grande Disaster; these people are heroes and we should all support their efforts! We have many forums and websites to come together and share infomation; to help each other and support these initiatives. Doug Crouch from Treeyo wrote a great article on the Fires in Portugal recently, I suggest you check it out; and I know the folks at Gravito meditation retreat also need help. Who else needs help? Who wants to help?
Bill Mollison, the grandfather of Permaculture once said something in the vein of: although the problems of the world are exceedingly complex, the solutions remain embarrassingly simple. We are smart enough to come up with alternatives, but more than that we must be bold enough to put them into action. For your property there are small scale solutions using many of the useful species mentioned below. The large scale solutions are more difficult to tackle however, and cannot just be ecological solutions; they must also present economic incentives if things are really to change. These are themes that we can hopefully explore together in the course of this series, I’d love to hear your ideas about this in the comments.
Without further ado, in the vein of positive and simple solutions, enjoy this series on fire. Starting off, finally, with the long-awaited and at last available exclusively to your eyes, Top 10 Essential Fire Resistant Trees. I hope you find this list useful; let me know what you think, add, comment, and share!!
Top 10 Essential Mediterranean Fire Resistant Trees
- Plants with high salt content
- Plants with fleshy or watery leaves
- Plants with thick insulating bark
- Plants which have their lowest branches clear of the ground
- Plants with dense crowns
Plants which are more likely to burn include:
- Those with fibrous, loose bark
- Those with volatile oils in their leaves
- Those with volatile, resinous foliage
- Those with dry foliage.
- Those which retain or accumulate dead leaves and twigs.
I keep saying it, if there is one tree that the Mediterranean needs more of it’s Oak trees. But, a very necessary second one is the Mulberry! If it weren’t for the fact that evergreen Oaks are the keystone and largely missing species of the Mediterranean region, I’d put Mulberry first. Apparently it’s the sap of the Mulberry tree, a white latex like fluid that makes it resist fire better than many other trees. That, plus its many many productive uses (food/fodder/timber/bark/medicinal), and the fact it’s so easily adapted to extreme conditions, is what puts it way up in the list of fire resistant trees.
Figs are a good candidate for almost the exact same reasons as the Mulberry, and that means also the non-fruit bearing varieties in the whole Ficus spp. genus. It also has the white latex-like fluid that protects it from heat, and it also yields delicious food and is well adapted to dry conditions. However, the fig does like some care, some water, and doesn’t thrive in conditions as adverse as non fruit yielding trees. It’s most appropriate application makes most sense if we look at our landscape from an energy efficient planning perspective; when we apply zoning we’ll see that figs will form a barrier closer to our habitation, whilst non fruit yielding, less demanding plants and trees provide barriers of fire control further out.
Following the recent forest fires the Chestnut (Castanea sativa) has been mentioned numerous times as one of the trees that survived. The Chestnut is a broad-leaf deciduous tree and therefore holds relatively high amounts of moisture, and has no volatile substances. This tree once was and hopefully will again be one of the main staples to people in Europe; it’s nuts are delicious and nutritious. Moreover, as demonstrated the tree resists fire well; it must be said though that you will mostly see this tree planted by streams and waterlines because most broad-leaf deciduous trees in the Mediterranean climate need good access to water. If you have these conditions, go out and make it happen!
Plane (and other broad-leaf deciduous trees)
Also known as old world Sycamore, or Platanus orientalis, this very adaptable tree originates in an area spanning from Turkey to Iran to the Himalayas. It has naturally spread all the way to the Iberian peninsula, and is mostly found close to riperian systems, i.e. streams or rivers. It can however survive well in drought once it has properly established. As mentioned broadleaf decidious trees have a naturally high moisture content, and therefore withstand fire fairly well.
In this category we also find Beech (Fagus sylvatica), Alder (Alnus spp.), Ash (Fraxinus spp), and Oaks like (Quercus robur), Walnut (Juglans), Poplar (Populus) etc. These deciduous trees are more commonly found in the Köppen Csa warm Mediterranean climate type; and less in the Csb hot Mediterranean climate type. Plane however, once established seems well equipped even in hot dryland ecosystems, which warrants its own position in the list of fire resistant trees.
This list is not in a descending order of awesomeness, otherwise the Oak would have been number one. Oaks deserve an honorable mention in this list because they are, as mentioned before, the number one keystone species of many Mediterranean region biomes; and have in many cases been replaced by agriculture, or Pines and Eucalyptus. The most famous Oak of the Mediterranean region must be the Cork Oak (Quercus suber), which produces thick layers of cork bark to protect itself from the hazard of fire. In other words it should be the number one species to replace the Pines and Eucalyptus. Well, well, does anyone else see an economic incentive and booming cork industry all along the Mediterranean!?? Avoid the Shrub Oak, it’s one of the few Oak species not so well adapted to resist fire.
Another familiar face in the Mediterranean climates is the Mediterranean native Strawberry tree (Arbutus unedo). Many people will be happy to hear that this wild ally is also very fire resistant. The Strawberry tree is most known for its delicious strange fruit, from which also special liquor is distilled, called Medronho in Portugal. This tree occurs frequently in the natural forest systems of the Mediterranean region, and is well adapted to its fire ecology. Arbutus species like Arbutus menziesii that occurs in California and the Sierra Nevada grow a big ball-shaped root at the base of the tree called a ligno-tuber, which is fire resistant and from which new shoots grow if the tree has been damaged too much in a fire.
The almighty Carob tree (Ceratonia siliqua) is yet another giant of the Mediterranean region, especially found along the coastal regions, as it thrives the most on calcareous soils. Yet another tree that has great qualities, needs no maintenance, is drought resistant, is beautiful to behold and is slowly disappearing from the landscape. Where the Carob is native, it must be replanted in large numbers, it has such great economic value, to humans and to animals. To know that it deals well with fire and has fire resistant qualities is truly empowering. Now remember, no tree is fire proof, all trees will combust/burn given the severity of the circumstances. However, some trees are just more adjusted to fire ecologies and are able to withstand fire well. The Carob is one of them and deserves a central place in a list of fire resistant trees.
Also known as Bay Laurel, the Laurel (Laurus nobilis) is a remnant from the days that the whole Mediterranean region was much more humid and covered in all different kinds of Laurel-like vegetation. These broadleaf evergreen forests still exist as Laurosilvic ecosystems found on the Azores, as well as places like Taiwan. The tree is currently most known for its aromatic leaves, which are used in cooking. Laurels are low maintenance trees, are somewhat drought tolerant, and also resist fire well. Their thick rubbery leaves don’t combust readily, and its wood does not ignite easily.
Many trees fall into this category, these trees are mostly broad leafed, some are deciduous others evergreen, they all like water and hold water well. This last quality makes them fire resistant. Not so needy of water are Pomegranates, Loquats, and Quinces. More water needy in this category are almost all stone fruit, so Peaches, Nectarines, Cherries, etc., also Apples and Pears, and Citrus’ of course. From a zoning and defensible space perspective these trees would stand close to your house, and receive water regularly.
Strangely enough this coniferous tree (Cupressus sempervirens) has featured on many article covers as the sole survivor of massive forest fires in the Mediterranean region. Strangely, because as a general rule of thumb, we can say that from more fire resistant to most fire sensitive, it’s generally deciduous broad-leafed trees that are fire resistant; coniferous trees are drier, and have volatile oils and resins that easily catch fire. That having been said, the Cypress has been studied and they found that it is very difficult to ignite, and therefore withstands moderate forest fires. However it does have high combustibility, which means that ONCE it starts to burn, well then it REALLY starts to burn. Still. it ignites so difficultly that many studies are done on it, and really a picture says more than a thousand words.
PS. Other trees well adapted to the Mediterranean climate that resist fire well are: Peruvian/Californian Pepper tree (Schinus molle), Cape lilac (Melia azedarach), Love tree (Cercis siliquastrum), and Mirror tree (Coprosma repens)
PPS. I forgot to mention the Olive tree! Oops!
Which Trees do You Recommend? Inspired? Curious? Questions? Leave your comments below!
Next week: Principles and Strategies in Mediterranean Climate Fire Management
Greetings from Dennis Posthumus