Black Wattle Research Articles

Deterioração da Madeira de Acácia-Negra em Dois Ambientes de Exposição

Advanced stages of deterioration have a critical effect on the mechanical properties of wood. This study aimed to use the mechanical bending test as a parameter for assessing the deterioration of the wood of Acacia mearnsii in different environments. The experiment consisted in two fields of rot in the northern region of the State of Rio Grande do Sul: environment 1 (open field) and environment 2 (seasonal deciduous forest), with seven samples in each, where they stayed for 12 months. After the period were made the specimens to the bending test in order to compare with those of unexposed samples. Was also performed a survey of the soil and climate characteristics of the areas for better understanding of the results. Both fields have indicated a significant reduction in the studied variables (MOE, MOR, σLP) in relation to the control. When evaluated the two environments, the contrast was significant only for the modulus of elasticity, at the other properties there was no significant influence of environments, the forest produced the greatest reductions in mechanical bending the wood of black wattle, related to the environment characteristics.

ANTIMICROBIAL ACTIVITY OF AQUEOUS, ETHANOLIC AND METHANOLIC LEAF EXTRACTS FROM ACACIA SPP. AND Eucalyptus nicholii.

Background:In Europe, Acacia and Eucalyptus, originate large amounts of biomass, due to their need by industries and other biological control, that can be used to extract antimicrobial substances.Materials and Methods:Foliar aqueous, ethanolic and methanolic extracts of Acacia baileyana (Cootamundra wattle), Acacia dealbata (silver wattle), Acacia melanoxylon (black wattle) and Eucalyptus nicholii (narrow-leaved black peppermint) were assessed for antimicrobial activity against Escherichia coli, Bacillus cereus, Candida albicans and Candida parapsilosis, using the disc diffusion method.Results:Ethanolic extracts from A. baileyana and A. dealbata showed significant (P< 0.05) antimicrobial activity. Concerning the microbial species tested, differences were found in A. baileyana (P< 0.01) and E. nicholii (P< 0.0001) extracts. These two extracts were effective mostly against B. cereus, followed by C. parapsilosis. According to the antimicrobial activity classification, eucalypt and Cootamundra and silver wattles extracts (both water and ethanol) presented good efficacy against B. cereus, a food poisoning agent, and moderate efficacy against the remaining microorganisms. E. coli, a Gram negative, exhibited low sensibility to all foliar extracts.Conclusion:A. baileyana, E. nicholii and A. dealbata foliar biomass could be used to develop alternative substances in microbial control.

Pest Status of Whitegrub Species (Coleoptera: Scarabaeidae) Attacking Commercially GrownAcacia mearnsiiSeedlings and Its Management Implications in KwaZulu-Natal Plantations, South Africa

The abundance and distribution of whitegrub species that attacked black wattle seedlings during their establishment were assessed to determine their pest status and their contribution to the whitegrub species community structure patterns. Ten trials were planted on previous wattle sites. Monthly collections of whitegrubs that attacked seedlings were conducted during the first year of seedling growth. Very stressed or dying wattle seedlings and their surrounding roots were dug out and the soil was assessed to collect any whitegrub pests that caused seedling mortality. A multivariate analysis was used to rank the average abundance of the various whitegrub species that attacked wattle. The individual contribution of whitegrub species to the average similarity within a community and the dissimilarity between communities were tested with similarity percentages comparisons. The best two-dimensional (2-D) model obtained for each species pattern of distribution and relative abundance had a good ordination (stress value: 0.07). From a complex of 13 whitegrub pests found, six whitegrub species (Pegylis sommeri, Schizonycha affinis, Adoretus ictericus, Schizonycha fimbriata, an undescribed Maladera sp. 2 and an unknown species M8), with an average cumulative abundance of 96.4 %, were confirmed to have a high pest status. They accounted for the community structure pattern in the black wattle growing areas of KwaZulu-Natal. The remaining seven species, Heteronychus licas, undescribed Maladera sp. 1, and M5, M10, M11, M12 and M13 (all unknown species), contributed only 3.6 % to the average cumulative abundance and were considered to be minor pests within the whitegrub community structure.

Tracking leaf area index and coefficient of light extinction over the harvesting cycle of black wattle

The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (LAI), and the light extinction coefficient (k). We quantified LAI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. LAI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. LAI depends on the planting site and stand age. Between the two sites, the LAI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to LAI and was correlated with LAI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter.

Screening of fungicides for the management of wattle rust (Uromycladium acaciae) in Acacia mearnsii plantations, South Africa

South Africa has c. 110 000 ha planted to Acacia mearnsii (black wattle) with 85% of the revenue from the species obtained from the timber and 15% from the bark. From 2012/13 a wattle rust disease has spread throughout the black wattle plantation area in KwaZulu-Natal and from 2015 it was recorded in southern Mpumalanga. The pathogen affects trees of all age classes, causing a reduction in growth, as well as mortality with severe infection. No fungicides are currently registered in South Africa for the control of wattle rust. In October/November 2014, three black wattle trials were initiated in the KwaZulu-Natal Midlands and south-eastern Mpumulanga where fungicides were tested at varying rates for the control of wattle rust. The same trial design was used for all three trials and consisted of a 3 × 3 factorial with one additional control, replicated three times and laid out as a randomised complete block design. The factorial combination consisted of three fungicides (azoxystrobin + difenoconazole; azoxystrobin + cyproconazole; azoxystrobin) applied at three rates (×, 2× and ½ ×). The additional control was not treated with fungicides. Wattle rust had a significant and negative impact on tree growth, irrespective of site and/or previous infection. All fungicides tested, and at all rates applied, proved effective for the control of wattle rust. The optimum rate selected, timing and frequency of application will be based on a combination of prevention of resistance as well as optimisation of growth. For the most effective control of wattle rust, fungicides should be applied as a preventative, rather than corrective, measure. However, in cases of severe infestation, a corrective application could also be used to aid the management of wattle rust.

Community Structure and Morphospecies Composition of Whitegrubs (Coleoptera: Scarabaeidae) Attacking PlantationAcacia mearnsiiSeedlings in KwaZulu-Natal, South Africa

There is a paucity of knowledge of whitegrub pest species in black wattle (Acacia mearnsii) plantations, which hampers the development of integrated pest management programmes. This study determined the composition and community structure of the various whitegrub morphospecies that attacked seedlings during their re-establishment on 10 previous wattle sites in KwaZulu-Natal, South Africa. Whitegrub specimens collected from these trials were examined in the laboratory to determine which morphospecies were present and their abundance. Morphospecies were separated on the basis of their species-specific raster patterns. Multivariate analyses were done using PRIMER (Plymouth Routines in Multivariate Ecological Research) as statistical package. The proportions of morphospecies at the different sites were evaluated by using the non-metric multi-dimensional scaling (MDS). Thirteen whitegrub pest morphospecies were found attacking A. mearnsii seedlings. About 98%of the total whitegrub abundance was represented by ...

Principal Component Analysis of Commercial Tannin Extracts Using Digital Images on Mobile Devices

Tannins from trees are an abundant renewable resource. The use of tannins is safe for the environment and human health, making it possible to develop environmentally friendly products, such as adhesives, flocculant agents for water treatment, flame retardant foams and anticorrosives. In this study, a methodology was developed for the identification of six commercial tannin extracts (chestnut, valonea, tara, myrobalan, quebracho and black wattle) using digital images on mobile devices. The identification of the extracts was based on principal component analysis using the PhotoMetrix® mobile application. In the evaluation of the principal components, it was possible to define the separation between the six classes of extracts by color evaluation, according to the extract origin. In the analysis of PC1 × PC2, black wattle was very close to quebracho and chestnut was close to valonea; these extracts are chemically similar. The methodology developed for the analysis of tannin extracts obeys the principles of green chemistry requiring no reagents, and is fast, non-destructive and inexpensive.

Evaluation of the Coagulating Potential of the Crude Extract from the Barbatim&amp;#227;o Bark for the Treatment of Dairy Effluents

The coagulating potential of the crude extract from the barbatimao bark for the treatment of dairy effluent was assessed and compared with industrial coagulants such as aluminum sulfate (inorganic coagulant), the crude extract of black wattle bark (used in the manufacture of natural organic coagulants), and gallic acid (the main constituent of condensed tannins). The aqueous extract of barbatimao was obtained by refluxing for 12 h, and the black wattle was provided by a producer of natural coagulants. The determinations of total phenolic compounds and tannins in the extracts were performed by the Folin-Ciocalteu method and precipitation with casein, respectively. The treatment of the effluent with coagulant was performed by the Jar-Test. After testing, the effluent was evaluated for turbidity, total solids, and biochemical oxygen demand (BOD). A higher content of phenolic compounds (19.81% mg of gallic acid/g extract) was observed in the barbatimao extract than in the black wattle extract (14.24% mg of gallic acid/g extract). However, the extracts contained the same amount of tannins, 13.95% for the barbatimao extract and 12.89% for the black wattle extract. A 63%, reduction in BOD was observed for the effluent treated with barbatimao extract, 35% for the black wattle extract, 58% for gallic acid and 60.59% for the treatment with aluminum sulfate. Treatment with gallic acid caused a 98% reduction in the turbidity of the effluent; with aluminum sulfate, a 97% reduction was obtained; with barbatimao extract, 96%, and with black wattle extract, 93%. The barbatimao extract was shown to be a potential coagulant for dairy effluents.

The impact of black wattle encroachment of indigenous grasslands on soil carbon, Eastern Cape, South Africa

Black wattle (Acacia mearnsii, De Wild.) is a fast growing tree species introduced into South Africa in the nineteenth century for commercial purposes. While being an important source of timber and firewood for local communities, black wattle is an aggressive invasive species and has pervasive adverse environmental impacts in South Africa. Little is known about the effects of black wattle encroachment on soil carbon, therefore the aim of this study was to investigate the impact of black wattle encroachment of natural grassland on soil carbon stocks and dynamics. Focussing on two sites in the Eastern Cape, South Africa, the study analysed carbon stocks in soil and litter on a chronosequence of black wattle stands of varying ages (up to >50 years) and compared these with adjacent native grassland. The study found that woody encroachment of grassland at one site had an insignificant effect on soil and litter carbon stocks. The second site showed a clear decline in combined soil and litter carbon stocks following wattle encroachment. The lowest stock was in the oldest wattle stand, meaning that carbon stocks are still declining after 50 years of encroachment. The results from the two sites demonstrate the importance of considering changes in soil carbon when evaluating ecosystem effects of invasive species.

Self-Established Black Wattle Populations in Rwanda: Implications for Nature Conservation

Based on empirical evidence from a vegetation survey, this paper investigates the occurrence of self-established populations of black wattle (Acacia mearnsii De Wild.) in various environmental contexts and identifies areas where this species could be allowed to grow as a useful plant. The frequency of occurrence of self-established black wattle was found to be comparatively high above 1600 m of altitude. Three agro-ecological zones of Rwanda (Congo Nile Crest, Non-volcanic Highlands and Central Plateau) account for 70 % of the occurrence, most of which are inside tree plantations and woodlots and natural forests. In areas of most concern to black wattle invasion (especially in proximity of natural ecosystems), the following policy approach should be considered: eradication of current occurrences and a ban on the cultivation of this species. Elsewhere, control through utilization by local communities and adaptive management in areas least vulnerable to its invasion could suffice to keep this species under check.

Ground level photosynthetically active radiation dynamics in stands of Acacia mearnsii De Wild.

The objective is to study the dynamics of photosynthetic radiation reaching the soil surface in stands of Acacia mearnsii De Wild and its influence on height growth in stands. This fact gives rise to the formulation of the following hypothesis for this study: "The reduction of the incidence of light inside the stand of black wattle will cause the inflection point in its height growth when this reaches 4 to 5 m in height, i.e. when the stand is between 2 and 3 years of age". The study was conducted in stands in the state of Rio Grande do Sul, Brazil, where diameters at breast height, total height and photosynthetically active radiation available at ground level were measured. The frequency tended to be more intense when the age of the stands increases. It was evident that a reduction of light incidence inside the forest occurred, caused by canopy closure. Consequently, closed canopy propitiated the competition of plants. This has affected the conditions for growth in diameter and height of this species, reason why it becomes possible to conceive the occurrence of an inflection point in the growth of these two variables, confirming the formulated hypothesis.

English

Leaf area is one of the most important biophysical characteristics of a plant, as it determines how much photosynthetic radiation is intercepted so that the photosynthesis can occur. The presented research aim was to generate numerical indicators of leaf area and to study the behavior of black wattle (Acacia mearnsii De Wild.) throughout a plantation cycle (7 years), relating them with environmental variables. The study was conducted in commercial stands located in agroecological regions with high densities of black wattle plantations in the state of Rio Grande do Sul, Brazil. The leaf area was obtained by measuring leaf biomass and leaf area with an integrator (3000 Canopy Analyser, Li-Cor). Leaf area was found to be strongly related to leaf biomass, and is not influenced by planting site, but rather by stand age. Values ​​of individual leaf area vary depending on stand age and plantation area. The leaf area is related to soil properties and particularly with the phosphorus content. It is also related to meteorological conditions, most notably accumulated solar radiation. The obtained model, which involves global accumulated solar radiation, phosphorus and clay content, adequately explain variations in leaf area. &nbsp; Key words: Global solar radiation, phosphorus, leaf biomass, black wattle, plantation cycle.

Development of methodology for identification the nature of the polyphenolic extracts by FTIR associated with multivariate analysis

Tannins are polyphenolic compounds of complex structures formed by secondary metabolism in several plants. These polyphenolic compounds have different applications, such as drugs, anti-corrosion agents, flocculants, and tanning agents. This study analyses six different type of polyphenolic extracts by Fourier transform infrared spectroscopy (FTIR) combined with multivariate analysis. Through both principal component analysis (PCA) and hierarchical cluster analysis (HCA), we observed well-defined separation between condensed (quebracho and black wattle) and hydrolysable (valonea, chestnut, myrobalan, and tara) tannins. For hydrolysable tannins, it was also possible to observe the formation of two different subgroups between samples of chestnut and valonea and between samples of tara and myrobalan. Among all samples analysed, the chestnut and valonea showed the greatest similarity, indicating that these extracts contain equivalent chemical compositions and structure and, therefore, similar properties.

Fast Pyrolysis of Residues from Paper Mill Industry to Bio-oil and Value Chemicals: Optimization Studies

Biomass is a renewable energy and had been recognized as a promising feedstock for producing bio-fuels. In this work, pyrolysis of black wattle residues was investigated with the aim to study the product distribution and their chemical composition and predicting the optimal condition for maximized bio-oil especially aromatics content by using a two level factorial design of experiment. The pyrolysis were performed at temperature of 380 – 580 oC, Under screw feeder carried the biomass residues and weight of dolomite as catalyst of 1-5 wt% inside pyrolyzer with nitrogen gases flow rate of 20 to 80 cm3/min The detention time was controlled by reactor screw feeder at feeding rate of 120 to 240rpm. Based on the analysis from a design-expert program to determine the appropriated condition of experiment was 515.18 oC, 120.01rpm of feed rate and 20.00 cm3/min of nitrogen flow rate using 5.00wt% of dolomite catalyst. The elemental and physicochemistry analysis of bio-oil were determined, the chemical composition also investigated using gas chromatography-mass spectrometry and 1H NMR. The composition of bio-oil mainly oxygenated compound with high molecular weight and phenol. The results show that the biomass residual can be considered as a potential alternative fuels and relevant to valuable chemical feedstock.

English

The aim of the present study was to model the crown volume in black wattle stands (Acacia mearnsii De Wild.) in Rio Grande do Sul, Brazil. The study was carried out in plots installed in black wattle stands in area where the plantations of the species are common. Two trees in each plot of average diameter were felled to determination total height, crown length (crown height) and crown width taken twice, each measurement oriented perpendicular to the other across the bole axis and parallel to the base of the crown. To calculate crown volume (cv) widths were taken every meter starting at the base of the tree bole. Stepwise, backward, and forward variable selection methods were used to formulate the volume equations. The combined variable squared diameter and crown height (d²ch) was the most highly correlated with crown volume (r=0.84). This in turn was the variable that was integrated into the selected model, both in the stepwise and forward selection methods. The equation cv = b1 d²ch + ei was the model that provided the best fit for predicting crown volume in black wattle stands, both in age rotation and in young stands. Key words: Acacia mearnsii; morphometry; stepwise; models.

MIXED AND MONOSPECIFIC STANDS OF EUCALYPTUS AND BLACK-WATTLE. II - FINE ROOT BIOMASS DENSITY

The aim of this study was to evaluate fine root biomass density (FRBD) in mixed and monospecific stands of Eucalyptus grandis x E. urophylla and Acacia mearnsii(black wattle) in Bagé-RS (Southern Brazil). An experimental trial was installed with three treatments: 100% Eucalyptus (100E); 100% Acacia mearnsii (100A); 50% Eucalyptus + 50% Acacia mearnsii (50E:50A). The trial was carried using a randomized block design with three replicates. The fine root (&amp;le; 2.0mm) biomass density was determined 8 and 18 months after planting the trees. Soil samples were collected, with a cylindrical extractor auger (d = 7.0 cm), from four depths (0 - 5, 5 - 10, 10 - 20 and 20 - 30 cm) at each sampling point. After 8 months, the FRBD distribution was the same in both species and in all soil layers, reaching the maximum projection at 125 cm from the tree trunk. After 18 months, the root biomass density was higher in the monospecific black wattle stand than in the monospecific eucalyptus stand and the mixed stand. The fine root biomass density was highest in the 5 - 10 cm layer close to the trunk, for the planting row spacing, the planting line and the diagonals between two planting lines. Knowledge about fine root growth and distribution in soil at initial stages of stand development may help in decision-making for intensive forestry, thus ensuring more efficient use of soil resources.

Análise econômica da produção de Acacia mearnsii De Wild e carvão vegetal no Vale do Caí e Taquari, Rio Grande do Sul

O estudo objetivou analisar a viabilidade econômica da produção de acácia-negra e carvão vegetal em Brochier, Maratá, Paverama e Poço das Antas. Os subsídios foram obtidos com aplicação de questionários in loco. Os critérios econômicos utilizados foram: Valor Presente Líquido (VPL), Valor Presente Líquido Infinito (VPL inf.). Valor Anual Equivalente (VAE), Valor Esperado da Terra (VET), Relação Benefício Custo (B/C), Taxa Interna de Retorno (TIR) e Custo Médio de Produção (CMPr). A taxa média de atratividade utilizada foi de 6,8% a.a. Os dados de produção de madeira foram oriundos de SCHNEIDER et al. (2000). Assim, o plantio de acácia-negra consorciada com milho mostrou-se viável, apresentando maior atratividade no Índice de Sítio 18: VPL de R$ 2529,22 ha-1, VET de R$ 384,91 ha-1, VPL infinito de R$ 506,37 ha-1, TIR de 18,91% e CMPr de R$ 36,44 m-3. A produção de carvão vegetal mostrou-se mais viável nos fornos Brochier (CMPr de R$ 0,32 m-3 e B/C de 1,94).

Utilization of Flavonoid Compounds from Bark and Wood: A Review

Flavonoid compounds, which are extracted from bark and wood and used commercially, are flavan 3-ols as monomers and their polymers, which are called "condensed tannins". Reactions of the condensed tannins with formaldehyde are the basis for wood adhesives. In the late 1940s, tannin research for wood adhesives was begun and the world-first commercial use of wattle tannin from black wattle (Acacia mearnsii) bark as wood adhesives occurred in Australia in the 1960s. In addition, wattle tannin-based adhesives were further developed in South Africa and the uses of these adhesives have been continuing to date. The success of wattle tannin in wood adhesives is demonstrated by the collaboration of the ACIAR with the CAF in the early 1990s. Although radiata pine bark (Pinus radiata) could be a useful resource for the production of wood adhesives, three problems prevented its use in this application: low extractive yields from the bark, variable quality of the tannin extracts and excessive viscosity of the formulated tannin adhesives. In order to overcome these problems, various extraction methods have been proposed. Studies on tannin adhesives from bark of other pine species are also described. Furthermore, the use of the tannin in the bark without extraction is described as "bark adhesives" from radiata pine and black wattle. The use of radiata tannin without formaldehyde for moulded wood products is also described. Owing to the strong antioxidant activity of flavonoid compounds, bark extracts from French maritime pine (Pinus pinaster, synonym P. maritima) and radiata pine have been commercialized as nutritional supplements: Pycnogenol and Enzogenol, respectively. The background and the development of Pycnogenol and the basic difference in the preparation processes between Pycnogenol and Enzogenol are described. On the basis of the discovery that the SOSA value for wattle tannin is approximately 10 times that of extracts from pine bark supplements (Pycnogenol and Enzogenol), chemical, biochemical and clinical studies on wattle tannin were conducted. Results from these studies are outlined. Wattle tannin has been developed as a nutritional supplement and marketed as Acapolia in Japan.

Pengaruh Zat Alelopati Dari Pohon Akasia, Mangium, Dan Jati Terhadap Pertumbuhan Semai Akasia, Mangium, Dan Jati

ABSTRACT Allelopathy is the compound released by the plants to the environtment where actualy another plants is living in. The purpose of this research were to find out the effect of allelopathy which came from earpod wattle (Acacia auriculiformis), black wattle (Acacia mangium), and teak (Tectona grandis) to the seedlings plants of earpod wattle, black wattle, and teak, and also to find out the effect of allelopathy above mentioned that had the weakest effect. This research was designed based on factorial in a complete random design. Factor I was the seedlings which consist of earpod wattle, black wattle, and teak, while factor II was the allelopathy which consists of non allelopathy was used, the use of allelopathy from the extraction of earpod wattle leaves, the extraction of black wattle leaves, and the extraction of teak leaves. The variable that was observed were seedlings height increasing, seedlings stem diameter increasing, number of leaves increasing, and living percentage of the seedlings. This observation data was tested by Bartlett test to know the homogenity of variance. Then it was analyzed by analysis of variance, then it is continually tested by least significant difference test. All the counting were done at 5% significant level. The result of this research showed that allelopathy which one came from earpod wattle, black wattle, and teak were not different effect for seedlings from allelopathy source in the same species. The giving of black wattle allelopathy had significant different effect in height earpod wattle seedlings. That also the giving of teak allelopathy had significant different effect in height black wattle seedlings. The earpod wattle allelopathy had significant different effect in diameter of stem earpod wattle, black wattle, and teak seedlings. Key words : allelopathy, extraction of earpod wattle, black wattle, and teak, seedlings growth

Black Wattle (Acacia mearnsii De Wild.) in Rwanda’s Forestry: Implications for Nature Conservation

Invasive species pose a serious threat to the conservation of biodiversity. Forestry is the most important driver of the introduction and spread of invasive woody plant species after horticulture. Nearly 450 invasive tree species have been recorded worldwide, amounting to more than half the world’s total invasive woody flora. Australian-native Acacia mearnsii De Wild. is one of world’s top invasive alien tree species related to forestry. The negative impacts of alien species spilling over into conservation areas because of forestry are increasingly being recognized, and we examined the context and timing of this Australian species’ arrival in Rwanda. The role of A. mearnsii in Rwanda’s colonial and postcolonial forestry and the species’ threat to biodiversity conservation are also investigated. The results suggest that A. mearnsii (a) was introduced into Rwanda between 1903 and 1918, with the earliest formal record dating back to 1941; (b) was a major forestry tree species until the late 1960s when its use in forestry declined significantly; and (c) demonstrates a comparatively higher occurrence and potential of regeneration within the understory of Eucalyptus plantations within the Congo-Nile ridge buttress; Bufundu and Bushiru; and Budaha, Ndiza, and Buberuka agro-bioclimatic zones. More recently, A. mearnsii has invaded national parks and forest reserves above 1,600 m of altitude. The most significant case was recorded at Nyungwe National Park (NNP), East Africa’s largest montane rainforest. A study of biomass and spatial patterns of this species in specific ecosystems, such as NNP, is strongly recommended in order to uphold effective conservation practices.