Background:

Due to causes such as small-scale earthquakes or the increasing amount of heavy rainfall extreme events, many slopes are potentially unstable. Soil bioengineering is an effective tool for treatment of a variety of unstable and/or eroding sites.

Question and hypothesis:

Maximum force to breakage of the roots is influenced by diameter.

Tensile strength and modulus of elasticity of roots is different between species of the two different ecosystems: Tamaulipan thornscrub and Pine-oak forest.

Studied Species:

Site 1: Acacia berlandieri, Cordia boissieri, Acacia rigidula, Havardia pallens, and Acacia farnesiana; Site 2: Quercus rysophylla, Pinus pseudostrobus, Quercus canbyi, Quercus polymorpha, and Arbutus xalapensis.

Study area and dates:

Tamaulipan thornscrub in Northeastern Mexico (Linares, Nuevo León), from May to July 2016; and Pine-Oak forest in Sierra Madre Oriental, Iturbide, Nuevo Leon, from September to October 2016.

Methods:

The species considered were selected based on their native characteristics (natural distribution, abundance in the area and widespread existence on slopes). The tests were conducted with the Universal Testing Machine Shimadzu type SLFL-100KN.

Results:

The relationships between tensile strength (Ts) and diameters of the studied species, and root diameters and modulus of elasticity (Eroot) were negative.

The minimum and maximum values of tensile strength varied from 1.86 N/mm2 in C. boissieri to 44.65 N/mm2 in A. rigidula.

Conclusions:

Acacia berlandieri showed the highest tensile strength among all species of the two ecosystems, in the diametric group I (0.1 to 2.9 mm).