Search

The wattle tree (Acacia mearnsii) is gaining importance as an exotic species in northwestern Ethiopia, providing ecological, environmental, and economic benefits, especially for fuelwood and charcoal production. This study aimed to investigate the effect of tree spacing on the growth and biomass of wattle trees. The study employed a randomized complete block design with three replications across three spacing treatments (0.5 m × 0.5 m, 1 m × 1 m, and 1.5 m × 1.5 m) in the Fagita district. Tree height and diameter measurements were taken at 12, 18, and 30 months post-planting from stands established in 2021. The results showed significant differences in tree height among the spacing treatments at 18 and 30 months. The closest spacing (0.5 m × 0.5 m) yielded the highest average tree heights of 32.12 cm, 84.86 cm, and 302.98 cm at 12, 18, and 30 months, respectively. At 18 months, the largest average diameter (1.22 cm) was found in the narrowest spacing (0.5 m × 0.5 m), whereas at 30 months, the widest spacing (1.5 m × 1.5 m) recorded the largest diameter (1.51 cm). Throughout the study, height, diameter, and average aboveground biomass exhibited an inverse relationship with spacing, with this effect diminishing as trees aged. Tree spacing significantly impacted average aboveground biomass at 18 months, with the densest spacing (0.5 m × 0.5 m) yielding the highest average aboveground biomass (1.97 kg at 18 months and 2.41 kg at 30 months). Average aboveground biomass increased as the trees matured. These findings suggest that closer spacing of A. mearnsii can enhance biomass production, positioning it as a promising candidate for energy generation. Leveraging these insights can optimize resource utilization while supporting global energy demands and reforestation initiatives aimed at carbon sequestration. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNC) receive great attention for their physical and optical properties, high surface area, high tensile strength, rigidity (Young's modulus up to 140 GPa), and ease of surface modification. However, controlling the properties of CNC is still challenging, given the wide variety of pulp sources and the complexity of finding suitable processing conditions. In the present study, acid hydrolysis efficiently isolated CNC from wood Acacia mearnsii brown kraft pulp (AMKP). Initially, the AMKP was delignified by the treatment with acidified sodium chlorite. The Acacia mearnsii kraft pulp obtained was then subjected to acid hydrolysis with sulfuric acid at concentrations of 50 to 58% 45 °C for 60 min. The hydrolysate was sonicated in an ultrasonic processor for 30 min. The chemical composition was determined by Fourier transform infrared spectroscopy (FTIR), crystallinity by X-ray diffraction (XRD), zeta potential by Zetasizer ZS equipment, thermal stability by thermogravimetric analysis (TGA), and morphology by transmission electron microscopy (TEM) to verify the effect of acid concentration on the yield and properties of CNC. The optimization of the isolation process demonstrated that the maximum yield of 41.95% can be obtained when AMWP was hydrolyzed with sulfuric acid at a concentration of 54%. It was possible to isolate CNC with a crystallinity index between 71.66% and 81.76%, with the onset of thermal degradation at 240 °C; zeta potential of −47.87 to 57.23 mV; and rod-like morphology, with lengths and widths between 181.70 nm and 260.24 nm and 10.36 nm and 11.06 nm, respectively. Sulfuric acid concentration significantly affected the yield of acid hydrolysis, allowing the isolation of CNC with variable dimensions, high thermal stability, high crystallinity index, and great colloidal stability in aqueous medium. [ABSTRACT FROM AUTHOR]

Acacia mearnsii, among the 100 worst invasive weeds worldwide, negatively impacts native biodiversity, agriculture, and natural ecosystems. Global climate change, characterized by rising temperatures and altered precipitation patterns, enhances the risk of A. mearnsii invasion in Asia, making it crucial to identify high-risk areas for effective management. This study performed species distribution modeling using the maximum entropy (MaxEnt) algorithm to predict the potential introduction and spread of A. mearnsii under various climate scenarios based on shared socio-economic pathways (SSP2-4.5 and SSP5-8.5). Currently, only 4.35% of Asia is invaded, with a high invasion risk identified in six countries, including Bhutan, Lebanon, and Taiwan, where more than 75% of their areas are threatened. Under future climate scenarios, 21 countries face invasion risk, among which 14 countries, such as Georgia, Laos, Republic of Korea, and Turkey, are at moderate to very high risk, potentially encompassing up to 87.89% of their territories. Conversely, Northern Asian countries exhibit minimal changes in invasion risk and are considered relatively safe from invasion. These findings underscore that climate change will exacerbate invasion risks across Asia, emphasizing the urgent need for robust management strategies, including stringent quarantine measures and control efforts, to mitigate the threat of A. mearnsii expansion. [ABSTRACT FROM AUTHOR]

Plantations of Acacia mearnsii established from seeds often exhibit low levels of productivity due to significant differences in plant growth. Therefore, the aim of this study was to assess the genetic control associated with clonal propagation of A. mearnsii and use a selection index to quantify gains for traits related to vegetative propagation. Data collected from nurseries for 2 years included mini-cutting productivity per mini-stump (PD), percentage of adventitious rooting (ENR), and ramet productivity index (PI). For clone production traits, PD (r = 0.36) and PI (r = 0.24) demonstrated moderate repeatability, whereas ENR (r = 0.06) exhibited low repeatability. Tree height (H2 = 0.20), and diameter at breast height (H2 = 0.13) showed moderate and low heritability, respectively. Genotype selection for vegetative propagation supported by PI-generated selection gains of over 50%, suggesting the efficacy of using this criterion in early evaluation and selection of genotypes for nursery propagation. The additive selection index considering PI and Ht traits can be used for early selection of superior A. mearnsii genotypes, promoting estimated gains of up to 2.5%. Given the importance of these parameters, these findings provide crucial insights for A. mearnsii breeders, addressing a notable gap in the literature concerning these traits. Study Implications : The moderate heritability of traits such as mini-cutting productivity, propagule productivity index (PI), height, and diameter at breast height, except for the percentage of adventitious rooting, which showed low heritability, suggests that these traits are influenced by genetic factors to a considerable extent. The study suggests that the selection of genotypes based on PI can significantly improve vegetative propagation outcomes, with potential selection gains of more than 50%. This indicates that nurseries can achieve higher productivity and efficiency by implementing genotype selection processes based on this criterion. [ABSTRACT FROM AUTHOR]

Correct estimation of tree biomass is important when calculating uptake or emission of CO2 in relation to land-use and land-use change. The objectives of this study were (1) to estimate the root/shoot ratio for the estimation of root biomass based on the above-ground biomass (AGB) of Acacia mearnsii, and (2) to develop allometric equations for the estimation of the above-and below-ground biomass (BGB) of Acacia mearnsii. To estimate the AGB and BGB, twenty-four trees of varying ages (3, 4, 5, and 6 years) were harvested, with six trees per age group. We measured the dry biomass for different tree parts and developed allometric models using tree height (H) and diameter at breast height (DBH) as independent variables. The results showed that the biomass of the stem accounted for 69% of the total biomass, followed by branches (14%), roots (8.1%), and leaves (7.3%). The recorded mean root/shoot ratio was 0.11. The biomass of the stem and coarse roots increased with increasing tree age, while a contrary trend was observed for the other tree components. Each component has its unique allometric model.

Black wattle is a tree native to Australia and commercially planted in South Africa and Brazil. Replacement of exported nutrients by wood and bark harvesting, associated with the maintenance of harvest residues, increases productivity, thus maintaining production sustainability. Here, we review recent advances in soil nutrient dynamics, harvest residue management (HRM), and soil organic matter in black wattle plantations. Over the 7–11-year cycle of black wattle, N is the most exported macronutrient (458–1509 kg ha− 1), followed by K (200–766 kg ha− 1), Ca (270–717 kg ha− 1), Mg (62–128 kg ha− 1), S (29–57 kg ha− 1) and P (16–40 kg ha− 1). The average increase in bark yield to 20 kg P ha− 1 applications on sandy soils was 2.7–2.9 t ha− 1 and on clay soils from 2.8 to 8.7 t ha− 1. Sandy soils with low K are more responsive to fertilizer, and rates must consider the K content and cation exchange capacity. Ca and Mg addition responses are more likely when in the topsoil they are in low concentrations (< 0.75 and 0.41 cmolc dm− 3, respectively). Micronutrient fertilization reduces the occurrence of gummosis caused by Phytophthora spp, and B deficiency is the most common and can be supplied by fertilization or foliar application (1 g B L− 1). Few studies have evaluated the impact of black wattle HRM on soil organic matter (SOM) and its effects on production. However, conserving SOM should be considered an essential practice for the sustainability of black wattle production. [ABSTRACT FROM AUTHOR]

Whether environmental conditions under exotic tree plantations abandoned in the Western Ghats of India can facilitate the natural regeneration of tropical montane forest (Shola forest) tree species is being debated. In many cases, the exotic tree plantations are being cleared to allow for the restoration of native ecosystems. In this paper, we examined whether exotic tree plantations have indeed a negative effect on the regeneration of Shola forest tree species. For this, we assessed the abundance, diversity, and composition of the regeneration of Shola forest tree species in plantations, each with different dominant tree species (Acacia mearnsii , Pinus sp. and Eucalyptus sp.). We tested the abundance of regenerating native tree species against the main plantation canopy species (plantation type) as well as other environmental factors (aspect, distance to nearest Shola forest, structural diversity, slope, elevation, presence of herbivores, and canopy closure). We found that the number of native tree species regenerating in all plantation types was at an acceptable level: 1960, 1773, and 462 individuals ha−1 for Acacia , Eucalyptus , and Pinus plantations, respectively. A rare fraction analysis showed that the highest number of Shola tree species were regenerating under Acacia mearnsii (25) followed by Eucalyptus (19) and Pinus (8) plantations. The density and diversity of regenerating Shola trees was greatest under Acacia plantations and northern aspects but declined with increasing elevation. The presence of herbivores also reduced the density and diversity of Shola tree regeneration. We concluded that the restoration of Shola forest in the Western Ghats is possible in existing stands of exotic tree species and this process can be accelerated with appropriate silvicultural methods. We additionally recommend that studies involving long-term exclosures can provide valuable insights into the effects of browsing on regeneration and species composition. [ABSTRACT FROM AUTHOR]

Concerns on the expanding infestation of several Acacia species in the southern Mediterranean European countries have triggered an ever-growing requirement for costly targeted control actions. Valorizing biomass waste produced could help promote and better finance these actions. For that purpose, wood wastes from invasive control actions were tested regarding their pulp and paper potential, aiming to entice cellulose industries to partake in future conservation actions. Wood waste from the five most pervasive Acacia species was studied (Acacia dealbata Link, Acacia longifolia Willd, Acacia mearnsii De Wild, Acacia melanoxylon R.Br, and Acacia saligna Labill) regarding physical and chemical characteristics, and a central composite design was used to optimize alkali charge and reaction temperature on pulping yield and delignification. Bleached kraft pulps were produced with each species' optimized conditions and for an equitable mixture of all species. Optimized pulp yields (52.6%–53.5%) and pulp polymerization degree (2867–3690) of Acacia species were higher than those of Eucalyptus globulus Labill (used as reference). Optimized bleached pulps were refined and fiber, pulp, and handsheet properties determined. Acacia dealbata and A. longifolia presented high specific wood consumption and lower handsheet strength properties, pointing to overall lower pulping potential, while A. melanoxylon and A. mearnsii characteristics were equal to or higher than those of E. globulus. A. saligna pulp and handsheet characteristics appear more suited for tissue paper. The Acacia mixture achieved acceptable characteristics, enabling the indiscriminate use of Acacia wood regardless of the species. As a shortcoming, the Acacia pulps showed the worst optical characteristics, with brightness dropping substantially with beating (64%–76%) when compared to E. globulus (81%). [ABSTRACT FROM AUTHOR]

Australian Acacia species are among the most important trees planted for wood and pulp production in several African countries, including Ethiopia. In 2020, symptoms of a serious shoot and leaf rust disease were observed on black wattle (Acacia mearnsii De Wild.) trees across the three main wattle growing regions of Ethiopia. The aim of this study was to describe the disease and identify its causal agent based on morphological characteristics as well as DNA sequence data for the ITS and LSU regions of ribosomal DNA. Here we report for the first time, the presence of the wattle rust pathogen, Uromycladium acaciae, in Ethiopia. [ABSTRACT FROM AUTHOR]

Acacia mearnsii and Eucalyptus dunnii plantations play an important role in the South African economy as a source for a variety of wood products. However, these species are commonly associated with high evapotranspiration (ET) which may cause streamflow reduction, affecting downstream water users who are reliant on the stream for survival. The potential future increase in exotic plantations worldwide necessitates understanding the impact of these different species on the water balance, hence the streamflow. At the Two Streams research catchment in South Africa, intense hydrological observations (streamflow, ET and weather) have been conducted on A. mearnsii for almost two decades. In 2018, the catchment was clear-felled with subsequent replanting of E. dunnii and hydrological measurements continued. This provided an opportunity to present observations of the surface water balance of the catchment. However, gaps in the data at various times prevented a compilation of a continuous hydrological record. Therefore, three window periods, with complete records of streamflow, ET and precipitation, and with similar weather conditions, were compared. Only the interception loss (Il) was estimated using the Von Hoyningen-Huene method. First window, A. mearnsii trees were three years old (Amear3), second window, A. mearnsii trees were seven years old (Amear7) and the third window, E. dunnii trees were three years old (Edun3). Results indicated a negative catchment surface water balance for all window periods. During the Amear7 window period, the Il was highest compared to the young crops, which reduced effective precipitation, in turn contributing to the lowest measured streamflow. The negative surface water balance and high ET, suggests that trees were accessing water not quantified in the surface water balance. Crops of all three window periods were found to have the potential to significantly reduce the streamflow, which may in turn affect downstream water users. Further research using isotopes to trace the sources of water used by trees in the system is suggested.

Acacia mearnsii, among the 100 worst invasive weeds worldwide, negatively impacts native biodiversity, agriculture, and natural ecosystems. Global climate change, characterized by rising temperatures and altered precipitation patterns, enhances the risk of A. mearnsii invasion in Asia, making it crucial to identify high-risk areas for effective management. This study performed species distribution modeling using the maximum entropy (MaxEnt) algorithm to predict the potential introduction and spread of A. mearnsii under various climate scenarios based on shared socio-economic pathways (SSP2-4.5 and SSP5-8.5). Currently, only 4.35% of Asia is invaded, with a high invasion risk identified in six countries, including Bhutan, Lebanon, and Taiwan, where more than 75% of their areas are threatened. Under future climate scenarios, 21 countries face invasion risk, among which 14 countries, such as Georgia, Laos, Republic of Korea, and Turkey, are at moderate to very high risk, potentially encompassing up to 87.89% of their territories. Conversely, Northern Asian countries exhibit minimal changes in invasion risk and are considered relatively safe from invasion. These findings underscore that climate change will exacerbate invasion risks across Asia, emphasizing the urgent need for robust management strategies, including stringent quarantine measures and control efforts, to mitigate the threat of A. mearnsii expansion.

RESUMO O estudo objetivou quantificar a exportação de nutrientes em decorrência de diferentes modalidades de colheita em um povoamento de Acacia mearnsii, aos 2,4 anos de idade. As maiores exportações em percentagem de N, P, K, Ca e Mg, respectivamente 26; 27; 38; 32; 30 e 25 ocorreram com a colheita da madeira com casca. A exportação de N aumenta em mais de duas vezes e de Ca em mais de três vezes, quando ocorre a colheita da madeira com casca em relação à colheita da madeira sem casca.

This article describes the potential of Acacia mearnsii tannin extract for environmentally friendly vegetable tanning of leather using ultrasound. Vegetable tanning is a versatile but time-consuming process in the leather industry, particularly for heavy leather which needs more than one week for tanning using natural tanning materials. So, it is significant to develop new eco-friendly techniques employing ultrasound to speed up the vegetable tanning process without affecting the quality of the finished leather. In this study, the effect of ultrasound in vegetable tanning has been evaluated to enhance the tanning process. The effects of various parameters for example tannin dose, tanning time, temperature, and variable frequencies were studied. Tannin uptakes and other thermal properties were also investigated. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of Acacia mearnsii tannin extract on milk fatty acid profile of dairy ewes and cows. In experiment 1, twenty-four Lacaune ewes received one of the following dietary treatments: control (no tannin extract added to the diet), T30 (30 g tannin extract/kg concentrate), and T40 (40 g extract/kg concentrate). In experiment 2, thirty Jersey cows received either a control diet (no tannin extract added to the diet) or the same diet containing 40 g tannin extract/kg concentrate (T40). Dry matter intake, milk production and milk solids content of ewes and cows were unaffected by tannin supplementation. The cis-9, trans-11 conjugated linoleic acid (CLA) content increased linearly by 21% in milk fat from ewes fed tannin extract, while the C18:2 n-6 (linoleic acid) content tended (P = 0.051) to increase by 13% in cows fed TE. The supplementation with black wattle tannin extract improves the nutritional quality of milk fat of ewes and cows to a small extent, with no adverse effects on performance or gross milk composition. [ABSTRACT FROM AUTHOR]

Acacia mearnsii, an invasive alien species, is the main resource identified for the energy transition initiated on Reunion Island. It is, therefore, critical to identify the existent forest stands within the island's large tropical forest area and to determine which of these stands are accessible for logging operations. In this study, a very high-spatial-resolution image was used to map forest (Acacia mearnsii, Acacia heterophylla, Cryptomeria japonica) and non-forest land cover. To identify the accessible forest stands, we developed a geographic information system (GIS) processing chain, accounting for barriers, the distribution of slopes, and the location of forest roads. User-defined parameters, such as the slope threshold and maximal distance to forest roads, allow different scenarios to be explored. The classification yields an overall accuracy of 88% and a Kappa index of 0.86 and highlights the areas occupied by the different types of Acacia. By applying the GIS processing chain for a standard scenario, the results show that only 19% of the initial study area of 637 ha of Acacia mearnsii patches is suitable for exploitation. In conclusion, our results demonstrate how remote sensing (RS) and GIS can be combined to provide valuable tools for forest managers to design management plans for invasive alien forest species. [ABSTRACT FROM AUTHOR]

The growing worldwide demand in the pulp market has fostered research that evaluates alternative fiber sources with specific characteristics that attend the needs of the consumer market, with a view to add value to the final product and reduce production costs. Acacia mearnsii De Wild wood is a by-product of the extraction of tannin from the trunk bark, used for firewood, charcoal and pellets. However, its wood is still poorly studied, especially its anatomical characteristics, which can provide important information about its industrial potential. This study evaluated the anatomical characteristics of Acacia mearnsii wood for the production of pulp and paper. Ten trees at approximately seven years old were cut down, five from the seed production area (SPA) and five from the clonal population area (CPA). From each tree, one trunk disc was sectioned at the diameter at breast height (DBH), resulting in 10 (ten) wood samples. From each disc, a sapwood specimen was made oriented in the tangential longitudinal, radial longitudinal and transversal planes, for later obtaining the anatomical cuts and the macerates. The anatomical description of the wood followed the recommendations of the International Association of Wood Anatomists-IAWA. From the dimensions of the fibers, their quality evaluation ratios for the production of pulp and paper were calculated. Results obtained from the anatomical characterization allowed to conclude that the Acacia mearnsii woods from SPA and CPA are indicated as a source of raw material for the pulp and paper production. [ABSTRACT FROM AUTHOR]

The plastic recycling industry generates a high volume of wastewaters. In this study, an unprecedented use of Moringa oleifera and tannin (Acacia mearnsii bark) associated with magnetite was proposed for the treatment of these wastewaters. The response surface method (RSM) and central composite rotational design (CCRD) methodology was applied to optimize the influence of operational variables (pH, temperature, electrical conductivity, turbidity, apparent color, chemical oxygen demand (COD), and total solids) on the performance of the magnetic natural coagulants on coagulation, flocculation, and sedimentation process. The results indicated that temperature, pH, electrical conductivity, and total solids did not generate significant differences in treatments when magnetite was added to natural coagulants. Similarly, the parameters apparent color, turbidity, and COD also did not present significant differences in treatments with Moringa oleifera and magnetite association, although achieving high efficiencies. Finally, the addition of magnetite significantly improved tannin efficiency removal for turbidity, apparent color, and COD with the optimized treatment (21.55 mg L−1 of tannin concentration and 28 min of sedimentation). Thus, natural coagulants associated with magnetite are potential alternatives for the treatment of plastic recycling wastewater and could be used as an environmentally friendly coagulant. [ABSTRACT FROM AUTHOR]

Mechanical and textural properties of processed cheeses are affected by low-fat, and hydrocolloids are commonly used as fat mimetics due their ability to make connections with water molecules. The aim of this study was to evaluate the stabilizing effect of Acacia mearnsii gum in low-fat processed cheeses, through physicochemical, composition, rheological and texture analyses. Processed cheeses were made with a 50% fat reduction and added with 0.125, 0.250, 0.375 and 0.5% (w/v) of A. mearnsii gum (AMS), and also were prepared samples full-fat (standard sample) and low-fat without gum (control sample). The chemical composition, physicochemical, textural and viscoelastic properties of processed cheeses were analyzed. Samples with A. mearnsii gum showed a higher amount of carbohydrates and protein content similar to the standard sample. The low-fat content influenced the rheological and textural properties of the processed cheeses, and they had liquid-like behavior and were softer and more spreadable. Processed low-fat cheese with a higher AMS concentration showed viscoelastic behavior similar to the full-fat sample. With standard sample exception, all other processed cheeses when subjected to temperature variation cycles (thermoreversibility test) showed identical behavior, without changes in viscoelastic behavior, being characterized as thermostable systems. AMS addition promoted the molecular interactions (increased cohesiveness) between the formulation constituents. The results showed that A. mearnsii gum has stabilizing potential for the food processing, being able to stabilize products with low-fat content. [ABSTRACT FROM AUTHOR]

Greater importance should be attributed to finding environmentally friendly processes that are particularly suitable for the textile industry. In this work, we exploit the plant (Reseda luteola L.) for the extract of a natural yellow dye, using the tannic bark of Acacia mearnsii as a bio-mordant to ensure sustainable dyeing of wool fabrics. Four important extract parameters were optimized: hydroethanolic extract, pH = 7, 80 °C temperature, and a short duration of nearly 30 min as time of extraction. The pigment's chromatographic profile shows that 7-O-glucoside luteolin is the most dominant flavonoid in the extract. The extract shows good thermal stability up to 90 °C and pH stability under acid and neutral conditions. Then, the dyeing conditions were optimized in terms of color strength (K/S) values to produce textile shades with acceptable colorimetric characteristics of (K/S = 23.2). Pre-mordanting with alternative bio-mordant (alum stone and Acacia mearnsii tannin) improved the overall absorption of dyes into the fabric, producing a range of colors from pale yellow to dark brown, and showing strong resistance to washing and wet and dry rubbing. In addition to its good dyeing property, the fiber dyed with 100% of the extract shows antibacterial effect against Gram-positive Staphylococcus aureus bacteria, so it can be used in future applications to produce antimicrobial textiles. [ABSTRACT FROM AUTHOR]

This work aimed to obtain and investigate the properties and composition of extracts from flowers of Acacia mearnsii; this tree is widely cultivated because the bark is used as a raw material for various industry segments, but the flowers are not yet explored. The essential oil was evaluated by GC/FID, GC/MS, and GC/O. The antioxidant activity (DPPH and phosphomolybdenum methods) and chemical composition were investigated for a water-soluble extract, a by-product of the extraction process. 85.8% of the compounds present in the essential oil were identified, 8-heptadecene being the major compound. The main scents detected by the olfactory analysis were roast nutty, coffee, sweet, and floral. The water-soluble extract showed antioxidant activity that may be related to phenolic compounds. Results obtained from the LC-qTOF/MS analysis have shown that 25 likely flavonoids, such as naringenin, myricetin, quercetin, and rutin are present in the extract. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate the use of tannin extract from Acacia mearnsii as a strategy to reduce methane (CH4) in two distinct cattle genotypes and its effect on intake, digestibility, microbial efficiency and ruminal fermentation. Four Nellore (Bos indicus) and four Holstein (Bos taurus) dry cows fitted with rumen cannula were assigned to two 4 × 4 Latin square design, in a 2 × 4 factorial arrangement, where each genotype represented a square receiving four tannin levels (commercial extract of A. mearnsii) in the diet (0%, 0.5%, 1.0% and 1.5% of dry matter). Tannin levels used did not cause a reduction in feed intake or rumen passage rate for both genotypes (p > 0.05), although there was a linear reduction in the degradation rate and ruminal disappearance of diet (p < 0.05). The increase in tannin levels reduced the amount of entodiniomorph protozoa in the Nellore cattle (p < 0.05). There was no change in N retention or microbial efficiency (p > 0.05), despite the linear reduction of nutrient digestibility and the synthesis of microbial nitrogen (p < 0.05). The ruminal CH4 production was reduced (p < 0.05) without reducing the short‐chain fatty acid production. The threshold of 0.72% of tannin in the diet was estimated as the starting point for the reduction of ruminal CH4 production with long‐term efficacy. Therefore, the use of low levels of tannin extract from A. mearnsii is a potential option to manipulate rumen fermentation in Nellore and Holstein cattle and needs to be further investigated. [ABSTRACT FROM AUTHOR]

Concerns regarding water pollution and scarcity have led researchers to investigate new sustainable water treatment technologies, such as the use of natural coagulants, that can be used for water treatment in decentralized locations at small rural communities, as these materials can be used in compact water treatment plants. Thus, the present study evaluated the use of natural coagulants, drumstick tree seeds and tannins extracted from black acacia, in water treatment to remove turbidity. To determine the ideal coagulant dosage, jar tests were performed, followed by filtration to remove the formed sludge. pH and turbidity were analyzed to compare the coagulants efficiency. The natural coagulants achieved satisfactory removal of suspended solids, completely removed turbidity, and causing no significant changes in pH, unlike aluminum sulfate, hence, these natural materials can be used as an alternative to chemical coagulants. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the effect of the inclusion of Acacia mearnsii (AM) at different levels of inclusion on ruminal digestion and in vitro gas production. A. mearnsii forage was incorporated in the diet at different levels of 0 (AM0), 20 (AM20), and 40 (AM40) %. In situ degradation of dry matter (DM) and organic matter (OM) showed differences between treatments (P < 0.05), obtaining the highest value of the degradation of soluble fraction (A), insoluble but potentially degradable fraction (B), degradation rate in % per hour (c), potential degradation (A + B), and effective degradation for all passage rates in % h (0.02, 0.05, and 0.08) in AM0 with respect to AM20 and AM40. The in vitro digestibility of DM and OM was higher (P < 0.05) in AM0 with approximately 23.6% and 22.8% of DM and OM, respectively, compared to treatments AM20 and AM40. Cumulative gas production (PG) and gas production asymptote (B) were lower at AM0 and AM20 versus AM40; however, gas production rate (c) and total CH4 production were lower at AM40 with about 40.1 mL CH4/0.500 g fermented DM versus AM0 and AM20. Under the conditions of this study, it is concluded that the incorporation of A. mearnsii (20% and 40%) in the feed of ruminants negatively affected the digestion of nutrients; however, it reduced the production of CH4, which may be associated with the low activity of microorganisms toward the substrate due to the possible tannin/nutrient complex. This shows that in animals with little history of consuming plants rich in tannin, more than 3% of tannin could not be incorporated into the diet. [ABSTRACT FROM AUTHOR]

Purpose The objective was to evaluate the agronomic performance of black wattle seedlings (Acacia mearnsii) grown on substrates with increasing proportions of biochar based on anaerobic sewage sludge (ASS-biochar). In addition, the present study proposed appropriate ranges for the main physical-hydraulic and chemical attributes of these substrates. Method The evaluated substrates included ten substrates with increasing proportions of ASS-biochar, combined with a “standard” mixture (organic compost, carbonized rice husk and vermiculite), in addition to three commercial substrates (references). The experimental design was randomized blocks, with four replications and eight plants per repetition. The physical-hydraulic and chemical attributes evaluated in all substrate formulations were: wet and dry density, total porosity, aeration space, easily available water, buffering water, available water, remaining water, pH and electrical conductivity (EC). The agronomic performance of the black wattle seedlings was evaluated through plant height, length of the root system, neck diameter, dry mass of aerial parts, dry mass of roots and Dickson's quality index. Results Biochar from anaerobic sewage sludge increased the chemical and physical-hydraulic quality of the substrates, particularly within the proportion of 45-50% of the substrate formulations, and thus positively affected the growth parameters of the black wattle plants. Conclusion The biochar produced from anaerobic sewage sludge is an efficient raw material to compose substrates for the production of seedlings. Transformation of anaerobic sewage sludge into biochar and its combination with other locally available raw materials can be considered a safe way of reusing this residue in agriculture.

Simple Summary: The anthropogenic generation of greenhouse gases (GHG) from the production of ruminants has contributed to environmental deterioration throughout the world; therefore, reducing their production becomes one of the main objectives today. The manipulation of the ruminant diet with forage sources rich in bioactive compounds (tannins) is considered an alternative to mitigate the production of CH4 and improve the productive performance of the animals. Based on this, this research aimed to evaluate the effect of the incorporation of different amounts of Acacia mearnssi, rich in tannins, on the parameters of ruminal degradation, digestibility of DM and OM, and the generation of gas, CH4, and CO2. The incorporation of A. mearnssi forage in the ration had a reducing effect on GHG production and possibly improved utilization of dietary protein in response to the presence of tannins. However, even with the lowest level of acacia in the diet, the effective digestion of DM and OM was affected. Under the conditions of this study, it was concluded that it is possible to replace traditional forages with up to 20% of A. mearnsii, without observing changes in the production of greenhouse gases with respect to the control treatment (0% of A. mearnsii); however, A. mearnsii is not usable because it significantly decreases rumen degradability of DM and OM, which would considerably affect the production in animals. In recent years, the worrying generation of GHG from ruminant production has generated widespread interest in exploring nutritional strategies focused on reducing these gases, presenting the use of bioactive compounds (tannins) as an alternative in the diet. The aim of this research was to determine the effect of the addition of different levels of Acacia mearnsii on ruminal degradation, nutrient digestibility, and mitigation of greenhouse gas production. A completely randomized design with four treatments and six repetitions was used. The treatments were: T1, T2, T3, and T4 diets with, respectively, 0%, 20%, 40%, and 60% A. mearnsii. The rumen degradation kinetic and in vitro digestibility, and the production of gas, CH4, and CO2 were evaluated. In situ rumen degradation and in vitro digestibility of DM and OM showed differences between treatments, with T1 being higher (p < 0.05) in the degradation of the soluble fraction (A), potential degradation (A + B), and effective degradation for the different passage rates in percent hour (0.02, 0.05, and 0.08), compared to the other treatments. Rumen pH did not show differences (p > 0.05) between treatments. The lowest (p < 0.05) gas, CH4, and CO2 production was observed in treatments T1 and T2 with an approximate mean of 354.5 mL gas/0.500 g fermented DM, 36.5 mL CH4/0.500 g fermented DM, and 151.5 mL CO2/0.500 g fermented DM, respectively, compared to treatments T3 and T4. Under the conditions of this study, it was concluded that it is possible to replace traditional forages with up to 20% of A. mearnsii, without observing changes in the production of greenhouse gases with respect to the control treatment (0% of A. mearnsii); however, A. mearnsii is not usable because it significantly decreases rumen degradability of DM and OM, which would considerably affect the production in animals. [ABSTRACT FROM AUTHOR]

Acacia is the largest genus of flowering plants in Australia, occurring in all terrestrial habitats. Black acacia (Acacia mearnsii De Wild) is adapted to different geographical areas of the world. Its forage can be used in the feeding of ruminants using different alternatives (hay, silage, silvopasture, protein bank, meal or fresh forage) to reduce costs of low and mediumscale livestock farming. The present work is a descriptive-analytical review of the available scientific literature with the purpose of contributing to the update on the potential of Acacia negra as feed for ruminants. The methodology consisted in the compilation of scientific articles and publications of scientific, academic and technological institutions on the object of study. The results focused on: Origin and distribution, Taxonomy and plant characteristics, Crop characteristics, Forage production, Nutritive value and Effects of forage consumption in ruminants. The review concluded that A. mearnsii adapts to diverse ecosystems and under low-input conditions shows rapid growth and acceptable forage production, which, together with its protein content, make it an option for small and medium producers. This allows lowering production costs by reducing the consumption of concentrates or alfalfa (Medicago sativa L.), without affecting production yields, mainly due to its high tannin content (main secondary metabolite), which favors the flow of amino acids from the diet from the rumen to the duodenum, among other beneficial effects on animal health and reproduction. [ABSTRACT FROM AUTHOR]

Stator limbatus is a phytophagous beetle native to warm regions of North and Central America, feeding on Fabaceae seeds and one of the most polyphagous species within the subfamily Bruchinae, here reported for the first time in Europe and on new hosts. Adult beetles emerged from Acacia spp. seeds collected in the islands of Corsica (France), and Sardinia (Italy). The wide presence in Sardinia and Corsica supports the hypothesis that this alien species was introduced several years ago. In both islands, S. limbatus emerged from Acacia mearnsii seeds, with infestation rates of up to 74.2 and 90.8% in 2019 and 2020, respectively. This seed beetle also emerged from two previously unreported host species, Acacia saligna and A. pycnantha, showing highest infestation rates of 4.0 and 95.1%, respectively. Both Acacia species are reported as new host associations with S. limbatus. Overall, seed infestation rates recorded in 2019 and 2020 indicate that S. limbatus is well established and that Mediterranean bioclimatic conditions are suitable for its population increase in size. This study lays the foundations for further research on known and potential host species and the spread and distribution of S. limbatus in Europe. [ABSTRACT FROM AUTHOR]

Black wattle (Acacia mearnsii) has great economic value as a commercial source of tannins, timber and a source of firewood for local and international markets. It has been suggested that to maximize the genetic gain of A. mearnsii plantations in South Africa, the gene pool that exist within ICFR needs to be broadened via introduction of new genotypes with diverse traits. In this work, 282 A. mearnsii samples sourced from the ICFR breeding program were genotyped using 11 cross-species SSR markers. Our results showed low to moderate genetic differentiation (FST) among the six breeding subpopulations, with positive inbreeding (FIS) values that could be attributed to an historical inbreeding event. Low levels of relatedness could however indicate some mechanism of inbreeding avoidance. The effects from a recent supplementation of genetic material from two native Australian populations were observed through genetic structuring analyses. Analysis of molecular variance (AMOVA) revealed that significant genetic variation was mainly distributed within populations (75%) and among individuals (23%). The results provide significant information on A. mearnsii population genetic diversity and structure, which can be used for conservation of the current subpopulations and future tree improvement programs. [ABSTRACT FROM AUTHOR]

Proanthocyanin (PA) dimers isolated from Acacia mearnsii bark were enzymatically acylated with palmitic acid as the acyl donor by immobilized Candida antarctica lipase on acrylic resin (Novozym 435). The acylation reaction conditions were optimized by comparing the amount of enzyme, the temperature, the reaction solvents, initial water content, substrate molar ratios and reaction time. The highest acylation conversion of 96.53% was achieved under the follow conditions: PA dimers/palmitic acid at a molar ratio of 1 >10 in tert-amyl alcohol; initial water content of 5% at 60 °C for 12 h with 30 g/L enzyme dosage. Introducing palmitic acid into PA dimers significantly improved both the lipophilicity and antioxidant properties. The 1-octanol/water partition coefficient of the PA dimers and their derivatives showed that the lipophilicity of the derivatives were 2.4 times higher than that of the PA dimers. The derivatives exhibited strong antioxidant scavenging capacities, approximately 1.6 times greater than the original dimers. This work is of great significance to expand the application of natural PA dimers in cosmetic and food industries and also lay a foundation for the high value-added utilization of A. mearnsii . [ABSTRACT FROM AUTHOR]

Black wattle is a forest species of great economic importance in the southern of Brazil. Researches for vegetative propagation methods to constitute clonal forests are effective to increase forest productivity. The goal of this work was to evaluate the action of compounds of root promotion in minicuttings of Acacia mearnsii as an alternative to vegetative propagation to the species. The experiment was conducted in July/2018 (winter season), with one negative control, two concentrations of indole butyric acid – IBA (2000 and 4000 mg L-1) and two concentrations of AzoTotal™ (100% e 50%), an inoculant containing Azospirillum brasilense bacterium. In the IBA treatments, the base of minicuttings remained immersed in hydroalcoholic solution 50% for 10 seconds and for the inoculant treatments during 15 minutes. The experiment took place in a greenhouse and after 45 days they were evaluated: the percentage of rooted minicutting; number of roots per minicutting; length of the three largest roots per minicutting; percentage of minicuttings with calluses; percentage of minicuttings survival; percentage of minicutting with budding and percentage of minicutting that kept the leaflets. There was significant difference between treatments considering rooted minicuttings, number of roots by minicutting, length of the three largest roots by minicutting, and there were not observed differences to the other variables analyzed. The use of IBA was more effective for the vegetative propagation process in this species.

Abstract Background Recent studies demonstrated that warming and elevated carbon dioxide (CO2) indirectly affect the soil microbial community structure via plant root exudates. However, there is no direct evidence for how the root exudates affect soil microbes and how the compositions of root exudates respond to climate change. Results The results showed that warming directly decreased biomass of soil-borne bacteria and fungi for Acacia mearnsii De Willd but it did not impact soil microbial community for Eucalyptus urophylla S.T. Blake. In contrast, elevated CO2 had strong direct effect on increasing soil microbial biomass for both plant species. However, plant roots could significantly increase the secretion of antibacterial chemicals (most probable organic acids), which inhibited the growth of bacteria and fungi in elevated CO2 environment. This inhibitory effect neutralized the facilitation from increasing CO2 concentration on microbial growth. Conclusions We concluded that climate change can directly affect microorganisms, and indirectly affect the soil microbial community structure by changes in composition and content of plant root exudates.

The aim of this research was to evaluate the effect of the inclusion of Acacia mearnsii (AM) at different levels of inclusion on ruminal digestion and in vitro gas production. A. mearnsii forage was incorporated in the diet at different levels of 0 (AM0), 20 (AM20), and 40 (AM40) %. In situ degradation of dry matter (DM) and organic matter (OM) showed differences between treatments (P < 0.05), obtaining the highest value of the degradation of soluble fraction (A), insoluble but potentially degradable fraction (B), degradation rate in % per hour (c), potential degradation (A + B), and effective degradation for all passage rates in % h (0.02, 0.05, and 0.08) in AM0 with respect to AM20 and AM40. The in vitro digestibility of DM and OM was higher (P < 0.05) in AM0 with approximately 23.6% and 22.8% of DM and OM, respectively, compared to treatments AM20 and AM40. Cumulative gas production (PG) and gas production asymptote (B) were lower at AM0 and AM20 versus AM40; however, gas production rate (c) and total CH4 production were lower at AM40 with about 40.1 mL CH4/0.500 g fermented DM versus AM0 and AM20. Under the conditions of this study, it is concluded that the incorporation of A. mearnsii (20% and 40%) in the feed of ruminants negatively affected the digestion of nutrients; however, it reduced the production of CH4, which may be associated with the low activity of microorganisms toward the substrate due to the possible tannin/nutrient complex. This shows that in animals with little history of consuming plants rich in tannin, more than 3% of tannin could not be incorporated into the diet.

• In vitro antidiabetic screening of the three most prolific invasive plants are explored. • This is the first study to investigate cytotoxicity of Acacia cyclops extracts on a human cell-line (Caco-2). • Study validates therapeutic possibilities of Acacia spp. for diabetes treatment. • Presents a future alternative management solution to invasive plants in South Africa. Acacia cyclops, Acacia saligna and Acacia mearnsii are characterized as prolific invasive alien plants (IAPs) presenting a substantial ecological and economic burden on South Africa. While conventionally these species are perceived as weeds having little value, this study attempts to demonstrate their respective potential as a phytomedicinal resource in the treatment of type 2 diabetes – thereby incentivizing their eradication. Moreover, this study aimed to assess the antidiabetic and cytotoxic effects of extracts from these three invasive Australian acacias in vitro. The α-glucosidase and ɑ-amylase activities of ethanolic and aqueous extracts derived from aerial tissues of A. cyclops, A. saligna , and A. mearnsii were investigated, followed by a cytotoxicity assessment using Hoechst 33342-Propidium Iodide (PI) dual staining and quantitative fluorescence microscopy on the human colon (Caco-2) cell line. Of the extracts screened, A. saligna ethanolic bark demonstrated the highest inhibitory activity against α-amylase and α-glucosidase with an IC 50 of 10.45 ± 3.79 μg/ml and 2.35 ± 0.61 μg/ml followed by leaf extract depicting strong α-glucosidase (IC 50 of 3.64 ± 1.59 μg/ml) and moderate α-amylase (IC 50 of 17.67 ± 3.84 μg/ml) inhibition. The IC 50 values of all extracts were significantly (p < 0.05) lower than Acarbose (IC 50 of 330.71 ± 28.36 μg/ml) and Epigallocatechin gallate (IC 50 of 68.2 ± 8.34 μg/ml). All extracts were found to be nontoxic at test concentrations on Caco-2 cells as confirmed by Hoescht 33342-PI dual staining. Overall, the findings presented in this study provide the first concurrent account of three invasive Acacias in South Africa reporting on their potential as an alternative therapeutic option for the treatment of type 2 diabetes. [ABSTRACT FROM AUTHOR]

Problems associated with the invasiveness of exotic tree species such as Acacia mearnsii have increased recently causing vast damage in environment and economy worldwide. Sao Hill Forest Plantation (SHFP) in southern Tanzania which is the potential plantation in East Africa is under Acacia mearnsii invasion which threatens the productivity of the planted species, Pinus patula. This study aimed to gather information on the performance of Pinus patula by comparing areas invaded by Acacia mearnsii with the non-invaded areas in SHFP. The study used a combination of stratified and random sampling techniques to select sample plantation blocks and plots allocation, respectively. Data collected included survival, height, and diameter of Pinus patula in both invaded and non-invaded areas as well as Acacia mearnsii stem counts in invaded areas. The mean basal area, density, and volume of Pinus patula were subjected to paired sample T-test and relationship between the density of Acacia mearnsii and survival of Pinus patula were established by Pearson's correlation analysis in R software version 3.5.2. Results showed that survival of Pinus patula was decreasing as the density of Acacia mearnsii increased. Also, there was a significant difference in density, basal area and volume of Pinus patula between invaded and non-invaded areas with higher performance being in non-invaded areas. Results suggest that Acacia mearnsii has a negative effect on the performance of Pinus patula in both its growth and survival. This study has generated the information for which among others will help to formulate policies and strategies that will contribute to the effective and sustainable management of forest plantations that should incorporate invasive control measures to avoid the negative performance of desirable tree species. [ABSTRACT FROM AUTHOR]

Purpose The objective was to evaluate the agronomic performance of black wattle seedlings (Acacia mearnsii) grown on substrates with increasing proportions of biochar based on anaerobic sewage sludge (ASS-biochar). In addition, the present study proposed appropriate ranges for the main physical-hydraulic and chemical attributes of these substrates. Method The evaluated substrates included ten formulations with increasing proportions of ASS-biochar, combined with a "standard" mixture (organic compost, carbonized rice husk and vermiculite), in addition to three commercial substrates (references). The experimental design was randomized blocks, with four replications and eight plants per repetition. The physical-hydraulic and chemical attributes evaluated in all substrate formulations were: wet and dry density, total porosity, aeration space, easily available water, buffering water, available water, remaining water, pH and electrical conductivity (EC). The agronomic performance of the black wattle seedlings was evaluated through plant height, length of the root system, neck diameter, dry mass of aerial parts, dry mass of roots and Dickson's quality index. Results Biochar from anaerobic sewage sludge increased the chemical and physical-hydraulic quality of the substrates, particularly within the proportion of 45-50% of the substrate formulations, and thus positively affected the growth parameters of the black wattle plants. Conclusion The biochar produced from anaerobic sewage sludge is an efficient raw material to compose substrates for the production of seedlings. Transformation of anaerobic sewage sludge into biochar and its combination with other locally available raw materials can be considered a safe way of reusing this residue in agriculture. [ABSTRACT FROM AUTHOR]

Quantity of water is a major concern, but the quality is of more urgent concern due to heavy metal pollution. In this study, the focus was to develop adsorbents (tannin resin (TR) and iron-doped tannin resin (Fe-TR)) from invasive Acacia mearnsii for Pb2+ and Ni2+ in solution. The developed TR and Fe-TR were prepared directly by crosslinking and iron-grafting; respectively with thermal stable at ≤ 350 °C. Surface functionality analysis revealed the presence of chelating groups at ≈ 1688 and 3661 cm−1. The crystallite sizes of the adsorbents were smaller compared to tannin; however, the % carbon and nitrogen were significantly higher. Also, the Brunauer–Emmet–Teller study revealed that iron-grafting of tannin after crosslinking increases the surface area, pore volume and pore size. Furthermore, the surface morphology of adsorbents indicated a well-defined structure with the formation of a whitish deposit and rough lump-like after ion uptake. Both adsorbents showed a type II isotherm with adsorption capacities of 40.650 mg/g and 13.763 mg/g for Pb2+and 120.63 mg/g and 110.74 for Ni2+ ion by TR and Fe-TR; respectively. The absorbate-adsorbent interactions were observed to be endothermic with negative and positive Gibb's free energy values for the adsorption of Pb2+ and Ni2+; respectively. The adsorption kinetics of Ni2+ is governed by several models; however, Pb2+ interaction is regulated by Pseudo-second-order model. Furthermore, the data generated offered the possibility of both chemisorption and physisorption processes; highlighting the flexibility and multifunctionality of tannin traps for the erasure of ion impurities in wastewater.

Tannins and their toxic effects against various decay organisms have been interrelated for centuries. As natural products have gained more interest, waste from several production fields abundant in tannins has yielded promising components for wood preservation. In this work, the main approach was to split condensed tannins into smaller fractions by chemical hydrolysis and evaluate their suitability for beech wood impregnation. Commercial extract from black wattle was treated with mineral acid of low concentration. The volatile hydrochloric acid was completely removed after reaction by evaporation in the course of freeze-drying. The modified extract was then applied as aqueous solution into beech wood. The water resistance of the modified beech wood was not increased significantly, and scanning electron microscopy (SEM) showed no evidence of tannin successful bonding within wood cells. Nevertheless, after strong leaching cycles, part of the extract accumulated in fibers. Moreover, lyophilization was found to be a suitable technique to eliminate volatile acids from temperature-sensitive extracts, such as tannins. These findings could help in the development of water-borne tannin formulations for wood protection, while using phlobaphene formation as a potential natural pathway of tannin autocondensation. [ABSTRACT FROM AUTHOR]

The analysis of variance is the statistical test most used for comparison of three or more means simultaneously. Its application requires, however, the compliance to some assumptions, with main emphasis on normality of the data and homoscedasticity of variances. When such requirements are not met, one of the alternatives is the data transformation to enable the continuity of the experimental evaluation. With the proposition of the Tukey’s data transformation system, understood as a power transformation system, i.e. the application of nth root on a data set (X⅟n) this statistical procedure has methodologically evolved to ensure such solutions. In the present research we proposed a complement to this system, denominated here as transformation in four steps, with inclusion of two hypothesis tests to evaluate normality and homoscedasticity. This was applied on experimental data to evaluate the amount of radiation available at soil level within stands of Acacia mearnsii De Wild. We have proposed a model for data transformation to simultaneously obtain homoscedasticity and normality. The methodology was appropriate to ensure these two statistical aspects on the experimental data, allowing comparison of eight treatments by conventional analysis of variance. Index terms: Analysis of variance, homoscedasticity, normality.

Despite using antimycotic drugs in the treatment of dermatomycoses as an age long practice, the fungicidal activities of indigenous plants on spores of dermatophytes from germinating in vitro need to be investigated further. In this study, methanol extract of Acacia mearnsii was assessed for its antifungal activity against dermatophytic pathogenic fungi by agar diffusion and broth dilution methods. The cytotoxicity activity of the extract was determined by the brine shrimp lethality assay. The study showed that the mean ± standard deviation of the inhibition zones ranged between 13 and 24 ± 0.58 mg/ml and the activity of the extract was concentration dependent. While the minimum inhibitory concentration (MIC) was 0.3125 - 2.5 mg/ml, the minimum fungicidal concentration (MFC) values ranged between 0.3125 mg/ml and 5 mg/ml. The susceptibility of the yeast to the extract was more than those of the molds. The MIC of the yeasts ranged between 0.3125 and 1.25 mg/ml while those of the molds ranged between 0.625 and 2.5 mg/ml. The mechanism of antibiosis showed that the extract was 7.69% fungistatic and 92.31% fungicidal wielding more killing effects on the fungi than potentiating their growth. The cytotoxicity assay showed that the crude methanolic extract with the LC50 being 101.59 µg/ml was pharmacologically active and nontoxic (LC50 > 100 μg/ml). The antifungal activity of this plant can be exploited as an alternative or complementary means of treating fungal infections to eliminate fungal spread. The study further justified the folkloric use of A. mearnsii in the treatment of a variety of microbial infections.

Copyright of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira is the property of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context: Tannin extracts have been investigated as natural feed additives with the potential to decrease the enteric emission of methane and urinary N and to improve the productive performance of ruminants. However, the impact of this additive in dairy cattle grazing tropical grass pastures has not been extensively evaluated. Aims: To evaluate the impact of the Acacia mearnsii bark extract (TA) on productive and nutritional variables in dairy cows grazing a Cynodon dactylon pasture and receiving supplementary corn silage and concentrate. Methods: Fourteen multiparous Holstein dairy cows were assigned in a randomised block design to either of the following two treatments: concentrate without TA (control) or with 10 g of TA/kg dry matter (DM). The concentrate and corn silage accounted for ~0.30 and 0.30 of total DM intake respectively. Key results: The dietary concentration of TA was 2.9 g/kg DM and it did not affect nutrients intake, milk production and composition, rumen microbial protein synthesis, plasma urea concentration or faecal N excretion. Total N and urea N excreted in urine were higher, whereas total N excreted in manure tended to be higher in TA treatment. Conclusions: No productive advantage was obtained by including TA in the diet of dairy cows grazing Cynodon dactylon pasture. Instead, it increased the excretion of labile urinary N. Implications: The effect of the use of TA as a feed additive for cows fed tropical grass-based diets is negative from the environmental point of view. Some natural feed additives such as tannins are promising for decreasing the environmental pollution of dairies. A tannin extract from mimosa tree was evaluated as a feed additive for dairy cows grazing a tropical grass pasture. The additive did not improve the productive performance and, instead, it increased the excretion of labile urinary N by dairy cows which had a negative effect from the environmental point of view. [ABSTRACT FROM AUTHOR]

Invasion by exotic woody species is a major concern in grasslands worldwide. Woody invasions pose a particularly serious threat to forest–grassland mosaics globally, but the factors influencing the success of woody species in these systems, including the role of disturbances such as fire, are not well understood. In this study, we evaluated the role of fire in influencing mortality and regeneration success of three globally widespread woody invasives, Acacia mearnsii (black wattle), Cytisus scoparius (scotch broom) and Ulex europaeus (gorse) in the montane forest–grassland mosaics of the Nilgiri Biosphere Reserve in the Western Ghats biodiversity hotspot, India. Our results indicate that mortality and regeneration responses to fire are species-specific. Fire-induced adult mortality was highest in scotch broom and lowest in gorse, and high, but variable in wattle. Burning greatly increased the abundance of gorse and wattle seedlings, but only marginally increased scotch broom seedling abundance. Fire effects on invasive seedling densities were most pronounced at the edges of invasive patches. Overall, our results indicate that fires are likely to differentially affect invasion patterns of these three species, with fire potentially encouraging invasion by gorse and wattle and discouraging invasion by scotch broom. [ABSTRACT FROM AUTHOR]

A widely disseminated native species from Australia, Acacia mearnsii, which is mainly cultivated in Brazil and South Africa, represents a rich source of natural tannins used in the tanning process. Many flowers of the Acacia species are used as sources of compounds of interest for the cosmetic industry, such as phenolic compounds. In this study, supercritical fluid extraction was used to obtain non-volatile compounds from A. mearnsii flowers for the first time. The extract showed antimicrobial activity and the presence of p-anisic acid, a substance with industrial and pharmaceutical applications. The fractionation of the extract was performed using a chromatographic column and the fraction containing p-anisic acid presented better minimum inhibitory concentration (MIC) results than the crude extract. Thus, the extraction process was optimized to maximize the p-anisic acid extraction. The response surface methodology and the Box–Behnken design was used to evaluate the pressure, temperature, the cosolvent, and the influence of the particle size on the extraction process. After the optimization process, the p-anisic acid yield was 2.51% w/w and the extraction curve was plotted as a function of time. The simulation of the extraction process was performed using the three models available in the literature.

Abstract: The objective of this work was to evaluate the soil mesofauna composition in non-mining and in mining areas under environmental recovery with native vegetation and forest planting, in a coalmine in Southern Brazil. Five treatments were evaluated: native vegetation in non-mining area; plantation of Acacia mearnsii in non-mining area; plantation of A. mearnsii in mining area; plantation of Eucalyptus dunnii in non-mining area; and plantation of E. dunnii in mining area. Four soil samples per treatment were collected monthly, during one year. The organisms were extracted using a Berlese funnel with 50-W incandescent light. A total of 23,911 organisms were collected from the soil mesofauna, which were identified and distributed into 13 taxonomic groups. The abundance of specimens was similar between treatments. The greatest diversity of taxonomic groups was found under A. mearnsii plantation, in the mining area, and under E. dunnii plantations in non-mining and mining areas, all with 13 groups. Eucalyptus dunnii and A. mearnsii help to mitigate the impact of coal mining on the diversity of the soil mesofauna taxonomic groups, since the composition of mesoarthropods is similar to that of areas that have not been directly affected by mining.