Secondary metabolites, antibacterial and antioxidant properties of the leaf extracts of Acacia rigidula benth. and Acacia berlandieri benth.

The use of plants as sources for novel antimicrobial as well as antioxidant agents offers advantages. Plants are readily accessible and inexpensive, extracts or compounds from plant sources often demonstrate high level of biological activities. Previous studies have reported antibacterial and antifungal activities within the Fabaceae family that included Acacia species. This study aims to determine presence of antibacterial activity, antioxidant activity, and the secondary metabolites of sequential solvent extracts (acetone, methanol, and acetic acid) of Acacia berlandieri and Acacia rigidula leaves. The antibacterial activity was investigated using a disc diffusion assay. The ferric thiocyanate method was used to assess the ability of all extracts to prevent oxidation. Qualitative phytochemical tests, NMR, IR, and UV–Vis spectroscopy were done to identify potential secondary metabolites. P. alcalifaciens (p < 0.001), E. faecalis (p < 0.01), S. aureus (p < 0.001), and Y. enterocolitica (p < 0.001) were significantly inhibited by A. rigidula extracts when compared to A. berlandieri extracts. A. rigidula’s acetone extract exhibited the significantly (p < 0.001) highest inhibition of peroxidation, 42%. Qualitative phytochemical tests showed positive results for presence of phenols, flavonoids, saponins, terpenes and tannins. NMR, IR, and UV–Vis spectroscopy revealed chemical structures found in flavonoids, saponins, terpenes and tannins, supporting the results of qualitative phytochemical tests. A. berlandieri and A. rigidula leaf extracts have revealed presence of medicinally valued bioactive components. The results of this study provide a basis for further investigations of the A. rigidula leaf extracts. A. rigidula leaf extracts have the potential to serve as a source of novel antimicrobial and antioxidant agents. Graphic abstract

Importancia del matorral desértico micrófilo para el venado cola blanca (Odocoileus virginianus Mearns, 1898) en Coahuila

Resumen El venado cola blanca es la especie cinegética más importante en México. El conocimiento sobre los componentes de la vegetación es importante en los planes de manejo e influyen en la presencia y mantenimiento de ese taxón. Se caracterizó la diversidad taxonómica y productividad de un matorral desértico en Coahuila y se enfatizó el valor de dicho ecosistema en la conservación de las poblaciones del venado; para ello, se utilizaron la línea Canfield y el método Adelaide en las cuatro estaciones del año, de octubre 2018 a agosto 2019, en la Unidad de Manejo para la Conservación de la Vida Silvestre Rancho San Juan, Monclova, Coahuila. Se estimó el Índice de Valor de Importancia (IVI) de cada especie vegetal por estación y el índice de Diversidad de Shannon. La producción de biomasa se expresó en kg ha-1 por estación y estrato. Se identificaron 46 taxa de plantas, algunas forrajeras: Acacia berlandieri y Acacia rigidula, además de otras que ofrecen protección térmica: Cenchrus ciliaris y Yucca filifera. De acuerdo al IVI, Agave lechuguilla (59.78 %) en primavera, Hilaria mutica en verano (62.02 %) y otoño (86.59 %), así como Cenchrus ciliaris en invierno (107.00 %) registraron las cifras más altas. El estrato medio aportó mayor cantidad de biomasa (> 1 000 kg ha-1), a diferencia del estrato superior que produjo menos (≤ 250 kg ha-1). Los taxones del matorral desértico que conforman pastos y arbustos brindan los recursos fundamentales para el desarrollo de las poblaciones de Odocoileus virginianus en el lugar.

Ten Native Tree Species for potential use in Soil Bioengineering in northeastern Mexico

<p><strong>Background:</strong> 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.</p><p><strong>Question and hypothesis: </strong>Maximum force to breakage of the roots is influenced by diameter.</p><p>Tensile strength and modulus of elasticity of roots is different between species of the two different ecosystems: Tamaulipan thornscrub and Pine-oak forest.</p><p><strong>Studied Species:</strong> Site 1: <em>Acacia berlandieri, Cordia boissieri, Acacia rigidula, Havardia pallens,</em> and<em> Acacia farnesiana</em>;<em> </em>Site 2:<em> Quercus rysophylla, Pinus pseudostrobus, Quercus canbyi, Quercus polymorpha, </em>and<em> Arbutus xalapensis</em>.</p><p class="Sous-auteur1"><strong>Study area and dates: </strong>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.</p><p><strong>Methods:</strong> 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.</p><p><strong>Results:</strong> The relationships between tensile strength (T_s) and diameters of the studied species, and root diameters and modulus of elasticity (E_root) were negative.</p><p>The minimum and maximum values of tensile strength varied from 1.86 N / mm² in <em>C. boissieri</em> to 44.65 N/mm² in <em>A. rigidula</em>.</p><p><strong>Conclusions: </strong><em>Acacia berlandieri</em> showed the highest tensile strength among all species of the two ecosystems, in the diametric group I (0.1 to 2.9 mm).</p>

Elemental Composition and Flue Gas Emissions of Different Components from Five Semi-Arid Woody Species in Pyrolysed and Non-Pyrolysed Material

Biofuels are sustainable alternatives to fossil fuels. However, they must comply with energy efficiency requirements and contribute to environmental protection. This study was focused on elemental composition (carbon, hydrogen, nitrogen, sulphur and chlorine) of different plants’ components (stems, branches, twigs and leaves) from pyrolysed (charcoal) and non-pyrolysed samples of five semi-arid trees: Acacia berlandieri, A. wrightii, Ebenopsis ebano, Havardia pallens and Helietta parvifolia. Carbon fluctuated from 80.77% to 89.30% in charcoal and 44.99% to 49.70% in non-pyrolysed biomass, and hydrogen ranged from 2.38% to 2.69% in charcoal and 5.89% to 6.62% in non-pyrolysed biomass. Nitrogen accounted for 0.39%–0.65% (branches) and 0.32%–0.64% (stems) in charcoal, and the ranges for non-pyrolyzed material were 2.33–4.00% (leaves), 1.06%–1.76% (twigs), 0.21%–0.52% (branches) and 0.15%–0.28% (stems). Considerably higher concentrations of sulphur compared to chlorine were found, with increasing values for both elements from the base of trees to the leaves. Non-pyrolysed samples were characterized by 68.05 mg/kg–769.16 mg/kg (stems), 118.02 mg/kg–791.68 mg/kg (branches), 225.11 mg/kg–1742.25 mg/kg (twigs) and 374.73 mg/kg–6811.52 mg/kg (leaves) for sulphur, and 117.86 mg/kg–528.08 mg/kg (stems), 109.18 mg/kg–464.15 mg/kg (branches), 905.47 mg/kg–4205.19 mg/kg (twigs) and 2799.68 mg/kg–5072.76 mg/kg (leaves) for chlorine. In charcoal, the concentration ranges for sulphur were 47.54 mg/kg–376.95 mg/kg (branches) and 42.73–292.20 mg/kg (stems) and 139.34 mg/kg–419.68 mg/kg (branches) and 177.39 mg/kg–479.16 (stems) for chlorine. The study has shown that pyrolysis increased the amount of carbon and decreased the amount of hydrogen. Coincidentally, the amount of nitrogen, chlorine and sulphur could be decreased significantly by pyrolysis which means an improvement of the fuel considering the flue gas emissions. Besides the influence of the type of combustion plant and the influence of the source of biofuel, the treatment has a significant influence on the amount and composition of flue gases emitted in the combustion.

GERMINACIÓN DE ESPECIES DEL MATORRAL ESPINOSO TAMAULIPECO EN UN GRADIENTE DE ALTITUD

El cambio climático se considera una amenaza para la biodiversidad, en especial, para aquellas especies que se localizan en ecosistemas frágiles. La presente investigación tuvo como objetivo estudiar el efecto de la altitud en la germinación y el crecimiento de 10 especies de diferentes poblaciones (localidades) que ocurren en el Matorral Espinoso Tamaulipeco. La información generada permitirá pronosticar los efectos potenciales del cambio climático en la regeneración natural, así como sus posibles desplazamientos a mayores altitudes y definir cuáles son adecuadas para futuras plantaciones. Se escarificaron y sembraron las semillas en tres altitudes: 350, 550 y 1 600 m. La germinación y crecimiento de las plántulas se monitorearon por 30 días. Se observó que Caesalpinia mexicana, Ehretia anacua y Parkinsonia aculeata registraron el porcentaje de germinación mayor en las tres condiciones altitudinales. Las semillas de algunas procedencias de Prosopis glandulosa, Caesalpinia mexicana, Ehretia anacua, Acacia berlandieri y Parkinsonia aculeata presentaron mayor germinación. Lepidium virginicum y Acacia berlandieri registraron, en promedio, los valores más altos a 1 600 msnm. Los resultados sugieren que algunos taxa pueden germinar por encima de su intervalo de distribución actual y quizá tengan la capacidad de desplazarse hacia altitudes superiores por efecto del cambio climático.

Comparisons of the Root Mechanical Properties of three Native Mexican Tree Species for Soil Bioengineering Practices

<p class="Sous-auteur1"><strong>Background:</strong> Urbanized slope areas in Sierra Madre Oriental are prone to sediment related disasters mainly caused by heavy rainfall episodes during hurricane season, knowledge on the factors on soil-roots dynamics are required to mitigate or lessen those disasters.</p><p class="Sous-auteur1"><strong>Questions and hypothesis: </strong>The mechanical properties of roots of native species vary according species. The mechanical properties of the roots are influenced by the morphology of root: diameter.</p><p class="Sous-auteur1"><strong>Species studied: </strong><em>Quercus rysophylla</em>, <em>Pinus pseudostrobus</em> and <em>Acacia berlandieri</em>.</p><p class="Sous-auteur1"><strong>Study site and dates:</strong> Sierra Madre Oriental, Chipinque National Park in Monterrey, Nuevo Leon. From middle of December 2014.</p><p class="Sous-auteur1"><strong>Methods:</strong> Selection of species was made base on widespread distribution and predominance in degraded areas. Samples were taken at field and tensile tests to calculate maximum force to root breakage were conducted using a laboratory dispositive, calculations of tensile strength and modulus of elasticity were calculated using formulas. The corresponding relations between root diameter and mechanical properties were established.</p><p class="Sous-auteur1"><strong>Results:</strong> Results confirmed that bigger diameters require bigger forces to break. In other hand, results confirmed the negative relationship between diameter and tensile strength and diameter and modulus of elasticity. Pointing out that roots of bigger diameter have less tensile strength and elasticity. The order of importance of the species studied according its mechanical properties was found like: <em>Acacia berlandieri</em> &gt; <em>Quercus rysophylla</em> &gt; <em>Pinus pseudostrobus</em>.</p><p class="Sous-auteur1"> <strong>Conclusions<em>:</em></strong> The results of this study begin the data contribution of the mechanical properties of native species of Sierra Madre Oriental in order to use it in the application of soil bioengineering practices on urbanized slopes prone to disasters.</p>

Foliar biomass production and litterfall pattern of five timber species in forest plantations of semi-arid lands of the northeastern Mexico

<p>Fodder shrubs and trees have both economic as well as ecological values in most extensive systems of arid and semiarid regions.</p><p> As hypothesis, there is a relationship between the litterfall pattern and the foliar biomass production in forest plantations of semiarid areas, depending on the different seasons and species.</p><p> The studied species were: <em>Acacia berlandieri </em>(Benth.), <em>Acacia wrightii </em>(Benth.), <em>Ebenopsis ebano </em>(Berl.)<em> </em>Barneby,<em> Havardia pallens </em>(Benth.) Britton &amp; Rose and <em>Helietta parvifolia </em>(Gray) Benth.</p><p> The foliar biomass was evaluated seasonally, from the dry weight of a representative branch of each species. The litterfall was collected every 15 days through litter traps installed under tree canopies, in experimental plantations of 30 years old, in the semi-arid zone of northeastern Mexico.</p><p> There were highly significant differences (p&lt;0.01) both among<strong> </strong>species as seasons in the foliar biomass values, whereas there were no significant differences (P&gt;0.05) among species in litterfall, but highly significant differences (P&lt;0.01) among seasons. The foliar biomass reached the maximum production in summer (9029 kg ha^-1) with <em>E. ebano</em>, while the lowest value (103 kg ha^-1) was recorded with <em>A. wrightii</em> in winter. The litterfall greatest accumulation occurred in winter (296 kg ha^-1) with <em>A. wrightii</em>. A significant linear correlation (R²=63%) was determined between accumulation of litterfall and foliar biomass production.</p> As conclusion, the litterfall pattern is related to the foliar biomass production, depending on the seasons and species. That constitutes a practical tool for the management of the forest ecosystems in semiarid areas.