Robinia = Acacia?

Robinia pseudoacacia L. is the botanical name of the Robinia tree that grows in our latitudes - translated as “false acacia.” People want it short and simple, which is why the term “acacia” has become established in common language. “Acacia” is widely used as a term for Robinia. If someone talks about acacia posts, they are most likely referring to Robinia posts. Thus, it holds true: Robinia wood equals acacia wood.

However, Robinia wood is different from acacia wood when it comes to the wood of the tropical Acacia mangium L. which is also sold as “acacia.” This tropical wood is produced in large quantities in tropical plantations, particularly in Southeast Asia - especially in Vietnam -, in Africa, and also in Latin America. Garden furniture, glued wood panels, and glued wood boards, as well as, for example, wood tiles for the garden are made from tropical acacia and offered in European trade.

So when “acacia” is labeled, you should take a closer look. The tropical acacia is also quite hard and durable (though not as hard and durable as our European Robinia), but the concerning aspect is its origin from tropical plantation agriculture – see below.

Robinia and tropical acacia are easy to distinguish. Robinia is a light and strongly grained wood. The tropical acacia, on the other hand, is reddish-brown and has little grain.

 

Robinia: Premium hardwood, premium outdoor wood

Wood properties of Robinia – the best in comparison

 

Hard to believe, but European Robinia outperforms - overall - even the best tropical hardwood. It is therefore the wood for outdoor use par excellence. While Bongossi is slightly harder, it is not as durable, which is what matters most for outdoor use. Even the famous teak wood is not more durable than Robinia - and it has significantly poorer strength values. Robinia is the unrecognized queen of outdoor woods that deserves the appreciation it should receive - also as your garden wood.

“Natural durability” refers to the durability of the wood itself - without the use of protective measures, particularly without chemical wood protection.

What the natural durability of Robinia means in practice is shown by the following experiences (MOLNAR 1988).

With our Robinia fence posts, you can expect a lifespan of at least 20 years. This also depends on which Robinia variety is used and whether the tree has grown under good conditions. We manufacture our products exclusively from the variety Robinia pseudoacacia rectissima L. (the so-called “ship mast Robinia”), which is even more durable than the common Robinia referenced in the preceding tables (GÖHRE 1952). Additionally, the climatic and soil conditions in Bulgaria, the country of origin of our Robinia wood, prove to be optimal for the growth of Robinia – unlike, for example, in Germany – which is why the Robinia wood grown in Bulgaria shows greater durability than that grown in Germany.

The soil type also plays a role in the lifespan of Robinia wood when in contact with the ground. If the soil contains a lot of moisture, as is the case with very clayey soil, the lifespan is lower. The more water-permeable the soil, the higher the lifespan of the wood. In sandy soil, it can significantly exceed the above-mentioned period of 30 years.

Robinia without ground contact – e.g., for terrace boards, but also for fences when they are insulated from the ground – means "lifetime." One can rightly call Robinia the most sustainable wood.

 

Pressure-treated wood (KDI wood) and thermally modified wood – no alternatives

There is hardly any information on the durability of pressure-treated wood (KDI wood). Everything depends on the impregnation agent used and its concentration. When in contact with the ground, commercially available KDI wood often rots after just 1 to 2 years. Without ground contact (outdoors), pressure-treated wood lasts about 10 years – this depends on the type and concentration of the impregnation agent. It lasts longer if coatings additionally protect the wood.

The rule is simple: The more toxic the impregnation agent used, the more effective the pressure treatment is. Wood preservatives that are lethal to wood pests (fungi, insects) are usually also highly toxic to humans. The list of active substances reads like the Who's Who of poisons: arsenic compounds (extremely toxic), chromium compounds (carcinogenic), fluorine compounds (highly toxic), copper compounds (hazardous to humans and animals).

Although the use of the worst toxins is now prohibited in Germany, this does not guarantee that they are not actually used. Much KDI wood, for example, comes from Poland, where the bans do not apply or are not sufficiently monitored. In practice, there is no control over what is offered to you in the market.

The toxic substances introduced during pressure treatment do not break down after the KDI wood decays but remain in the environment for a very long time.

Even when burning the wood, most toxins are not destroyed. Therefore, KDI wood may only be burned in special facilities that capture the toxins. Pressure-treated wood is hazardous waste (pollutant class IV) and must be disposed of at authorized facilities for a fee.

Thermally treated wood, on the other hand, is harmless from a health perspective and for the environment, at least as long as no chemical substances are introduced. Thermally treated wood means that by heating the wood, the natural components of the wood are partially broken down (breaking of molecular chains, chemical reactions). The altered components are no longer "edible" for many wood pests (especially for certain fungi), meaning that thermally treated wood is more durable than the original wood. The most commonly thermally treated woods are pine and ash (thermally treated pine, thermally treated ash).

The downside of the reactions in wood due to thermal treatment is that the cracking of the original wood components results in a reduction of hardness and strength. This is partially compensated for by the introduction of synthetic resin. Thus, thermally treated wood effectively becomes a composite material, meaning it is a plastic that must now be specially disposed of.

 

WPC, BPC – losers in terms of durability and ecology

WPC stands for "Wood-Plastic Composites." If you replace "Wood" with "Bamboo," you get BPC. WPC and BPC consist of about 75% wood or bamboo flour and about 25% plastic, which binds the two materials together. Thus, WPC and BPC are plastics with a filler that supports shape retention and stiffness (this is common with many plastics). Additionally, WPC and BPC contain chemicals that provide coloring, are intended to increase durability, or have manufacturing functions.

WPC and BPC are wood imitations, not wood. However, providers of WPC and BPC decking often communicate this misleadingly by presenting the boards as „wooden boards“ bring to market. WPC and BPC boards actually look very similar to wooden boards in new condition. Moreover, the products are often misleadingly labeled, for example, only with „Mahogany“ or „Teak“ labeled - however, these designations only refer to the appearance, and only to the appearance in new condition.

However, the appearance of WPC/BPC changes quickly. While black locust wood and other durable woods develop a silver-gray patina over time outdoors, under which the vibrant wood structure stands out even more, the surface of WPC/BPC products fades quite quickly to a monotonous, dull gray-brown. The providers then turn this into a positive claim of "no graying like with wood."

What is the lifespan of WPC/BPC products? The providers incorrectly apply the classes of natural durability defined only for wood in DIN EN 350 ("natural" means "without chemicals") and refer to class 2 (durable) to class 3 (moderately durable). However, WPC/BPC is about the durability of plastic, not that of wood. Wikipedia states: "Previous long-term studies and damage cases from practice have shown that WPC can be damaged by UV radiation, moisture and temperature effects, as well as fungal infestation."

The WPC/BPC products, which have only been around for about 20 years, have not yet proven their durability. General experience with plastics leads to skepticism. In contrast, with black locust, one knows: black locust lasts for decades. And one also knows how black locust will look after decades – like beautifully weathered wood.

We predict that you will want (and need) to dispose of your WPC/BPC products at the latest after 20 years. But where to take them? They are considered special waste. The material must be taken to special disposal facilities. No word about this from the WPC/BPC providers; they misleadingly label their products as "recyclable."

In this regard, you cannot compare the products with those made from natural wood like black locust wood. And if the question of disposal for black locust ever arises (which you will have to wait a long time for) - no problem. Black locust wood is a natural material. It returns to nature. It is best to compost the wood.

                                                            

Black locust versus Bangkirai & Co.

Tropical hardwood – from the plundering of nature

It is an unspeakable tragedy that even more tropical hardwood continues to flood the market. For this, centuries-old giant trees are being cut down in the last remaining original tropical rainforests, which will never grow back. Yes, these giants provide excellent wood with their long, knot-free trunks, which cannot be found anywhere else. But it is a plunder of nature. What right do we have to decide the fate of these trees, planted by nature and nurtured over centuries? Are they being cut down for the profit of corrupt politicians in the countries of origin as well as international timber companies? Or to save a few euros?

The plundered tropical timber, which is sold cheaply on the market as stolen goods, also undermines the production of quality wood from sustainable forestry. When humans plant and care for the trees, it costs money, which must be recouped through the sale of the wood. Therefore, quality wood produced through forestry cannot compete in price with the plundered tropical wood, for which not a cent is paid to nature. In the foreseeable future, when the last primeval forest giant has been felled, the beautiful, cheap tropical wood will be a thing of the past. For nature, it will then be too late. And also for the timely transition to sustainable forestry production of quality wood, which should take place in the temperate zones – see a bit further down.

A large part of the timber industry is preparing for the time after the depletion of the original tropical rainforests by establishing huge tropical plantations. These are even more harmful to the environment than the plundering of the giant trees from the primeval forests. The tropical plantations represent total environmental destruction. First, the original forest is completely cleared, and all the original vegetation is eradicated with the most toxic herbicides. Then, fast-growing tree species are planted in monocultures, which are usually sourced from other parts of the world, particularly eucalyptus (native to Australia) and the previously mentioned species of acacia, Acacia mangium L. (native to Australia and Papua New Guinea). But that’s not all. For rapid growth, newly settling other plants – considered weeds by the plantation owners – are suppressed with herbicides, and the naturally nutrient-poor tropical soil is supplemented with artificial fertilizers.

All of this not only comes at the expense of biodiversity and pollutes the waters, as we also know in Germany, but the rain that falls largely unhindered on the ground in the plantations gradually washes away the fertile topsoil for good. The result is the formation of steppes and deserts on a gigantic scale. And all this for the profit and cheap consumption of the wealthy countries of the North.

 

Robinia – from sustainable forestry in Europe

Germany was in a similar situation several hundred years ago, as is observed today in many tropical countries - albeit on a much smaller, pre-industrial scale. (A similar situation also developed in other European countries and in Japan.) The forests were ruthlessly cleared to meet the growing demand for wood, and the forests could no longer regenerate.

The answer that developed over a longer period was the introduction of "sustainable forestry." This simply meant: no more wood may be taken from the forest than can grow back in it. In the modern, expanded understanding of sustainable forestry, this means that the forest must be managed in such a way that its foundations for life and its long-term flourishing are preserved and strengthened.

This understanding has now become established in all EU and other developed countries. It has been promoted by the growing environmental awareness. Its implementation is regulated in these countries by legal provisions. Specifically in the EU countries, environmental and forestry laws are largely standardized. Therefore, you can generally assume that wood from EU countries is sourced with respect for the environment.

In temperate regions, sustainable forestry is favored by several natural factors. One of these factors is that there are natural monocultures in our latitudes. Monocultures are generally the most economically effective (whether one likes it or not).

According to the laws of biology, a species always occupies the ecological niche for which it is best adapted. This leads to the formation of natural monocultures. For the sandy soils around Berlin, particularly south of Berlin, the pine tree, with its very deep taproot and low water requirements, is best adapted. Other tree species cannot naturally compete with the pine in these locations. In many other locations in Germany, the beech is so well adapted that pure beech forests arise naturally, where there are no other trees at all. In many higher elevations, the spruce forms a natural monopoly. However, there are also locations without clear advantages for a single species, where mixed forests occur naturally. To act in accordance with nature, humans should base their planting on the natural forest suitable for the respective locations.

Another very important factor is that in our latitudes, no forest type leads to soil erosion. Either plant remains form a protective layer (e.g., leaves in beech forests, needles in spruce forests, generally also fallen dead branches) or the ground vegetation reliably protects the soil (in forests where enough light penetrates through the crowns).

The Robinia wood for the products we offer comes from Bulgarian forests, for which all of the above applies. The natural conditions for Robinia are optimal in many places in Bulgaria, making it widely distributed there. The Bulgarian forest law is closely aligned with the German one and is implemented with great consistency.

 

Tropical wood from sustainable forestry?

In the tropical rainforests, which consist of several “layers” – which fundamentally distinguishes them from the simply structured forests of temperate regions – there are many different ecological niches and therefore a huge biodiversity as well as many tree species. This makes sustainable forestry very complex. Tropical wood from sustainable management would therefore be very expensive, and demand would correspondingly decrease. Everything would balance out.

The dense plant canopy of the tropical rainforest, consisting of multiple layers, is essential to prevent the intense impact of tropical downpours on the largely bare ground and subsequent soil erosion. Although plant debris constantly rains down on the ground, no protective layer forms on the soil because a community of life on the ground quickly breaks down everything that falls. Additionally, no dense, protective ground vegetation forms in the twilight at the ground level. The consequence of this is that sustainable forestry in the tropics can only occur in the form of preserving the natural rainforest.

Plantation farming (whether in monocultures or mixed cultures) cannot be sustainably managed in the tropics, but rather means - as already stated - blatant destruction of nature.

 

European Robinia – the ecological trend wood

European Robinia is the ecological trend wood. Robinia wood is the only European wood that can fully replace tropical wood for gardens, playgrounds, and parks. It is on par with the most resilient tropical woods and even surpasses them overall with its properties. The sustainably managed European Robinia forests regenerate nature. The extraction of tropical wood – whether from original rainforests or plantations – destroys nature.

Robinia wood – perfected by Mother Nature over millions of years – also represents an alternative to chemical applications for gardens, playgrounds, and parks. It comes completely without impregnation agents and is not a wood imitation based on plastic.