It’s an irony of faith. Usually, when you buy a little tree, the roots and the soil around it are held together by a black plastic bag. The seedlings used for reforestation also come “wrapped” in bags. Now, imagine how much plastic is thrown away after they are planted—the bags are not reused to hold new seedlings to avoid contamination.

With this in mind… Scientists from the Federal University of Sao Carlos (UFSCar) together with Corn Products Brasil and BASF have created an “ecologically correct” and rigid plastic that can be used to manufacture tubes for seedlings.

The new material is made with EcobrasTM—a BASF’s biodegradable and compostable plastic that contains a corn-based vegetal polymer—and vegetal fibers such as ground cassava bark and coconut fibers. The material decomposes when in contact with microorganisms present in the soil, generating water, CO2 and biomass.

According to Elias Hage Júnior, professor and coordinator of the project, this partnership between UFSCar and these multinational companies arises from the fact that EcobrasTM is a flexible material and can’t be used to manufacture sufficiently hard molded pieces. He says that the new compost can be used to manufacture any type of molded piece—the cassava bark provides rigidity and the fiber offers mechanical resistance, making the material less likely to rupture—meant to be disposable, such as package trays.

The first step of the project, responsible for adapting the use of the cassava bark and the coconut fiber was complete in the beginning of 2009. From now on, they need to optimize the process and improve the product. Then, it will have to be produced in large scale.

The idea is good. But there is a controversy. Some experts say that biodegradable plastic decomposes quickly because it breaks down into tiny pieces. This could pollute rivers. Others say that because the material “breaks down,” it is easily decomposed and safer for the environment. Oh my, I’m feeling so critical lately.

I wrote a post for Blog do Planeta about the invading and exotic species found in the Atlantic Forest. I talked with Helena de Godoy Bergallo, a researcher at the Rio de Janeiro State University (UERJ). She pointed out some of the things that people do in the hopes to preserve the environment but that end up harming it. Things such as feeding stray dogs and letting pet cats walk across rooftops.

This conversation reminded me of the issue of urban trees. Since the Brazilian colonization, people have been planting trees from other regions of the country and the world in front of their houses and in their backyard. For example, the mango tree mentioned in the song—”when I step on dry leaves, fallen from a mango tree”—comes from Asia. However, years ago, it was chosen by our local government to decorate public streets. Find out more about the risks it poses on the post.

So, which trees can be used in urban areas? The endemic (native) species for the area in question, of course. But there’s a detail that is worth pointing out. My beloved Araucaria tree, for example, is native to the Atlantic Forest. However, it is no longer found in the Sao Paulo coast. So, it should not be planted on the seashore. Remember that the biome also has its particularities.

Yeah… urbanization and landscaping are a little bit complex. Before planting your little seed or seedling, contact your local Secretariat of Environment. Get their help to select the right species. They can—and should—be able to give you a list of endemic species. Also, be aware of the urban technical requirements that must be observed should you decide to plant a tree on a sidewalk. In the city of Sao Paulo, it needs to be at least 1.20 meter wide. The tree should not get in the way of this measurement. I know that in practice…

Well, I’m going to leave (below) some information related to trees in urban areas. Have fun:

• Their size must be appropriate for the space available;
• Preferably, their fruit should be small to avoid accidents;
• The tree top should be compatible with the space available to avoid obstructing traffic and building facades;
• On sidewalks, choose species with deep roots to avoid damaging the public pavement;
• Choose pest and disease resistant species as the use of pesticides and fungicides is not recommended;
• Be careful with power cables; with water, sewage and gas pipes, and with directional signs. Trees must not interfere or damage these public properties;
• Make sure the trees do not interfere with the buildings’ natural and artificial lighting;
• It’s best to avoid species with thorns along their trunks and branches;
• Fallen leaves can clog gutters and sewers; therefore, prefer planting trees with small leaves.

Note: The government of the city of Sao Paulo has started a photography contest called “Árvores da Cidade de São Paulo.” See here: Anyone with a beautiful, poetic, conceptual photo or else, of a tree planted in this chaotic metropolis can participate. I’m going to enter my photos—I took the one below from my window. Kisses. Have a nice Friday.