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Since 1995, the South African government has spearheaded a national invasive species campaign known as the Working for Water Program with the dual objectives of invasive species eradication and rural development. This national narrative on invasive species reflects a politicized research agenda and a wealth of material resources directed toward eradication, yet does not accurately portray the reality of invasion at the village level. In particular, Acacia mearnsii de Wild, or the black wattle tree, is classified as one of the worst invasive species in South Africa and a primary target for Working for Water, yet represents an important livelihood resource for rural communities and impacts community members differentially. To better understand these local rural realties, I use a critical invasion science approach to interrogate the local experiences and narratives of black wattle invasion in a rural pastoral community in the Eastern Cape. Within this community, local understandings and impacts of black wattle are nuanced, spatially variable, and reflect complex knowledge politics and political economies. As invasion research moves to incorporate the human and local dimension of invasion for improved policy, it is imperative to fully consider this differentiation of perspectives and impacts within the local community.

Black wattle is planted on 110 000 ha in South Africa, and considered economically important for both private and commercial growers. Black wattle is intensively managed, with protection from abiot...

Globally, grasslands are under threat from woody encroachment by invasive alien plants and this undermines grass production. The study sought to determine the effects of Acacia mearnsii clearing on soil physico-chemical properties and grass production. Soil samples were collected from three A. mearnsii invasion statuses and analysed for representative physico-chemical variables. Using line transects and a disc pasture meter (DPM) approaches, equations were developed to predict annual grass dry matter production in areas cleared of A. mearnsii. A. mearnsii significantly (p < 0.05) altered most of the physico-chemical soil characteristics that affected grass production. Predicted grass dry matter production from sites cleared of A. mearnsii ranged from 284 to 362 g m���2 y���1. These production rates were similar to those from uninvaded landscapes, suggesting that background grass production can still be attained even if there is no active soil management. Autogenic recovery thresholds have not been surpassed despite a long history of landscape invasion in the area. Management of invaded grasslands should be informed by an appreciation of local soil background characteristics. The equations developed for grass dry matter prediction may enable farmers to non-destructively estimate forage availability and fuel loads.

Erosion and sediment control practices are implemented during construction activities to mitigate downstream effects, but limited field-performance data exists. Field assessments were conducted to evaluate ditch check installations during highway construction in Tama County, Iowa. Data collection included daily rainfall, topographical surveys of sediment deposition, pre- and post-rain event images, and visual observations. Variations to the standard Iowa Department of Transportation silt fence ditch check installation evaluated as part of this study include: (a) upgrading non-reinforced geotextile to a multi-belted, reinforced geotextile (i.e., SF-M1); (b) installing V-shape, as opposed to linear, while incorporating wire reinforcement to support hydrostatic loads placed on the geotextile, inclusion of a weir to facilitate controlled flow discharge, and offsetting the geotextile entrenchment location to improve ground securement (i.e., SF-M2); and (c) installing the dich check as described for SF-M2 substituting slicing for trenching (i.e., SF-M3). The modified wattle installation (i.e., W-M) incorporated a teepee staking configuration to facilitate ground contact, and an excelsior underlay, secured by sod staples, to minimize wattle undercutting. Results from field experiments indicated that sediment retention rates significantly improved for installations of SF-M2 and SF-M3 when compared with the standard installation and SF-M1 at the 85% confidence level, and served as viable control measures in concentrated flow applications. The W-M installation exhibited a statistically significant improvement in sediment retention over the W-S installation at the 95% confidence level. These findings suggest that ditch check performance is a function of specified practice and of installation methods described within regulatory agency specifications and design guidelines.

This study sought to evaluate the utility of remotely sensed data in estimating the impact of wattle invasion and clearance on native grass species productivity using Sentinel-2 multispectral instr...

There is great interest in how plants interactions in different spacings change along spatial gradients in resource availability, biomass and energy production. In this study, we hypothesized that a positive impact of Acacia mearnsii when grown in reduced spacing, leads to a higher biomass and energy yield. The aim of this study was to evaluate how these spacings and their corresponding effects might influence the radiation use efficiency in biomass and potential energy yield in a short-rotation cycle of black wattle (Acacia mearnsii) in southern Brazil. A field experiment was conducted from September 2008 to September 2015 in the city of Frederico Westphalen, Brazil. The forest biomass was determined by destructive method. Also, the calorific value, radiation use efficiency, light extinction coefficient, solar radiation interception, leaf area index, biomass partitioning, carbon storage and potential energy yield were evaluated. Information generated in this study is relevant and provides information for companies interested in electricity generation from wattle biomass and forest producers thereby assisting in the planning of optimal spacing to be used for biomass production for energy. The highest biomass production and radiation use efficiency were obtained in the reduced tree spacing (2.0 × 1.0 m) which results in a higher amount of biomass for energy production. Therefore, the use of reduced tree spacing should be prioritized and recommended for future exploitation of forest energy plantations.

Invasive alien plants (IAPs) pose a threat to ecosystem integrity and generally provide more disservices than services. Acacia mearnsii (black wattle) was introduced to South Africa for its...

This study assessed the strength of Sentinel-2 multispectral instrument (MSI) derived Red Edge (RE) bands in estimating Leaf Area Index (LAI) and mapping canopy storage capacity (CSC) for hydrologi...

The forest wastes removed as a strategy to control the invasive shrub Acacia dealbata Link (silver wattle) can be regarded as a low cost renewable source of biomass for the production of biofuels, bioactives and chemicals. A number of studies have reported both conventional and novel processes for the utilization of different parts of the plant. This review presents an overview of the environmental problems associated to this shrub in invaded areas and a compilation of the technologies proposed for the extraction and production of commercially interesting compounds from silver wattle. Combination of such tools for the fractionated valorization of this resource following a zero waste biorefinery approach is discussed, with emphasis on the use of greener flexible technologies.

The Zimbabwean forestry industry, which contributes significantly to the economy, was introduced in the 1940s and is dominated by Pinus spp., Eucalyptus spp. and Acacia mearnsii De Wild. This paper...

Acacia mearnsii (black wattle) plantations in South African cover approximately 110 000 ha, with Uromycladium acaciae (wattle rust) found from Limpopo to the Western Cape of South Africa. This disease of black wattle causes reductions in growth, and mortalities with severe infections. Although a limited number of fungicides have been screened for the control of wattle rust, these contain similar active ingredients and need to be applied repeatedly to be effective. Not only is this costly, but there is also the possible development of fungicide resistance. In October 2015 a trial was initiated in southern KwaZulu-Natal to determine the effectiveness of varied application schedules and adjuvants of fungicide for the management of wattle rust. The main aim was to reduce the application interval. The trial was laid out in a randomised complete block design with three replicates. The 2 × 4 factorial combination consisted of two adjuvants application schedules (42 or 56 d between application) and four adjuvants...

Castell Henllys, a partially reconstructed Iron Age settlement in south-west Wales, has been the site of long-term experiments in building reconstruction for 35 years. The first roundhouse to be excavated and then reconstructed on the site was due to be replaced in 2017, and another reconstructed 30 years ago was examined in 2018. The results indicate how timber structures with wattle walls decay over a period of decades, and the evidence can be compared to that retrieved from the original excavated late prehistoric structures on the site and those found elsewhere. The pattern of wear of floors and surfaces, and the effects of decades of fires within the roundhouses, also produced archaeological signatures that can be compared with prehistoric remains. These investigations reveal for the first time how long-term processes of experimental house use, maintenance and decay in a temperate environment create archaeological signatures very similar to those found from prehistory, indicating how ancient deposits could have been formed. It also demonstrates how even roundhouses with relatively ephemeral below-ground elements can stand for at least a human generation.

Resumen Se analizan las características térmicas y de resistencias mecánicas de materiales y elementos constructivos elaborados con suelos naturales estabilizados. La metodología parte de la recopilación bibliográfica de fuentes primarias, secundarias e información de ensayos propios, sobre la densidad, la conductividad térmica y las resistencias a la compresión, a la flexión y al corte correspondientes al adobe, los bloques de tierra comprimida (BTC), la tapia y la quincha, según diferentes autores. Además, se consideraron los valores establecidos por normas argentinas IRAM referidas al acondicionamiento térmico de edificios. Se elaboraron comparaciones entre sí y con algunos materiales industrializados, tales como los bloques de hormigón, los ladrillos cerámicos huecos y los ladrillos cocidos macizos. A partir de este análisis, se concluyó que la revisión bibliográfica no es suficiente para obtener una estandarización de los valores de conductividad y transmitancia térmica de los materiales y los elementos constructivos naturales. Así mismo, a partir de las comparaciones de valores se pudo observar cómo se relacionan la densidad de los materiales y la de los morteros, según las distintas técnicas, con el comportamiento térmico y las resistencias mecánicas. Palabras clave: Adobe; arquitectura sostenible; bahareque; bloque de tierra comprimida-BTC; materiales vernáculos de construcción; propiedades térmicas; quincha; resistencia mecánica; tapial Comparative analysis of the thermal aspects and mechanical resistances for materials and elements of earth construction Abstract The thermal characteristics and mechanical resistance of some materials and constructive elements elaborated with stabilized natural soils are analyzed. The methodology took into account the bibliographic compilation of primary and secondary sources and information from own tests, on density, thermal conductivity and resistance to compression, flexion and cutting, corresponding to adobe, BTC, tapia and wattle and daub, according to different authors. In addition, it was considered the values established by Argentine standards IRAM referring to the thermal conditioning of buildings. Comparisons were made with each other and with some industrialized materials such as concrete blocks, hollow ceramic bricks, and solid fired bricks. From this analysis, it was concluded that the literature review is not enough to obtain a standardization conductivity and thermal transmittance values of natural building materials and elements. Furthermore, from the comparisons of values it was possible to observe how the density of materials and mortars, according to the different techniques, are related to thermal behavior and mechanical resistance. Keywords: Adobe; sustainable architecture; bahareque; compressed earth block (BTC); vernacular building materials; thermal properties; quincha; mechanical strength; tapial; wattle; daub Recibido: octubre 22 / 2018 Evaluado: septiembre 10 / 2019 Aceptado: octubre 15 / 2019 Publicado en línea: noviembre de 2019 Actualizado: noviembre de 2019

Eroded bare land stabilization is important to reduce soil erosion and stimulate soil carbon (C) sequestration for improved soil biogeochemical quality in hillslope soils. This study investigated the effectiveness of wattle fencing as a bioengineering tool to improve soil stabilization, soil physico-chemical properties and soil organic C dynamics and reduce soil erodibility in the Boyabat mountain regions of Turkey with rough and over-steepened slope (50–70%). Wattle fence treatments were developed in the area of 50 ha in the spring season of 2010 and surface (0–20 cm) and subsurface soil (20–40 cm) samples were taken in Spring, 2015. Results revealed that, compared to control with bare slope, wattle fencing significantly improved some soil physico-chemical, and microbial properties and erodibility indices by increasing clay ratio, dispersion ratio and aggregate stability index in surface and subsoils. Wattle fencing enhanced plant available water contents more in surface than in subsoils. Wattle fencing also increased microbial biomass C contents by 55% and 43% in surface and subsurface soils, respectively. Soil organic C followed similar trends; however, they were indifferent between sampling depths for the control soils. Soil organic C stocks and aggregate stability index were significantly positively correlated and seemed to be better predictor of positive effects of wattle fencing on soil structural stability, erodibility and associated properties. We found positive effects of soil organic C contents on microbial biomass C and soil-water relations suggesting restoration of soil biological functions and favorable influence on soil water retention following wattle fencing. Although sparse vegetation was observed in the research area, our study emphasizes performing further research to understand the effects of wattle fencing along with afforestation with native vegetation on soil erosion rates on a long-term basis by considering the variability in edaphic and environmental factors.

Romny culture materials obtained during the excavations at Zamkova Hora hill-fort in Novhorod-Soverskyi in 2014 and 2015 are presented to the scientific circles. The research was conducted in the north-eastern part of the site. The works resulted in the discovery of a series of objects dated by various periods. Two of them (structures 1 and 4) are referred to Romny culture. Both structures’ walls are oriented by four corners of the world. The size of deepened part of the structure 1 is 4,60 × 4,50 m. Its foundation pit had a framework and pillars bordering. There was a stove of wattle and doub in the north-western corner. Structure 4 was partly covered by the excavation area, therefore its total area and constructive peculiarities were not ascertained. The goods discovered in foundation pits of the objects are quite scarce. Despite this fact, ceramic assemblage was used to specify the structures’ chronology. Typical for the ceramics is a combination of handmade and wheel-made products which are best represented by the materials from the stove in the structure 1. Analysis of the upper part of wheel-made vessels and a comparison of the obtained results with the typological developments of I.H. Sarachov allowed the author to date the objects studied by the second half of the 10th century and the beginning of the 11th century.

Insecticide decay rate on different wall surfaces is of importance to indoor residual spray (IRS) programs used as a malaria control intervention. Past IRS operations showed increasing populations of endophilic malaria vectors resting on indoor surfaces from various sites in Uganda following use of Ficam VC (bendiocarb) insecticide; variability of insecticide life was believed to be primarily due to wall surface type. Bendiocarb longevity was tested in the northern Uganda districts of Amuru, Apac, and Pader to assess its residual efficacy on three commonly encountered wall surfaces. Wall types included mud and wattle, plain brick, and painted plaster. A susceptible mosquito strain (Anopheles gambiae Kisumu) was used in all trials. Nine houses in each of the three districts were set with three test cones and one control cone per house, divided evenly among the three wall surfaces. Bioassays were run monthly through 6 mo. Painted plastered surfaces produced 100% mortality (at 24 h) through 6 mo. Plain brick surfaces killed 100% of test mosquitoes through 4 mo, while mud and wattle wall surfaces produced a 98% mortality rate at 3 mo post spray. The KD60 (knockdown at 60 min) for painted plastered surfaces was 100% for 6 mo, plain brick surface KD60 was 80% at 6 mo, and the mud and wattle surface KD60 was >80% at 3 mo. There was a significant effect on Ficam VC longevity by wall type and evidence of a relationship between test period and wall type on the KD60.

In this paper, four strategies were proposed for modeling tree crown volume using as independent variable stem variables, crown variables, combination of stem and crown variables, and stem volume. We used a dataset comprised of 170 trees from 12 temporary plots located in forest stands in southern Brazil. Models composed of stem variables presented weaker predictive ability. The best model contained crown variables, which explained 78.95% of observed variability. However, implementation of such model is bounded by its independent variables, which are not often measured in forest inventories. The model composed by diameter at breast height and crown length proved to be an adequate modeling approach. The predictive capability was kept by model which is composed by most easily measured variable in a forest - diameter at breast height, also by the most easily acquirable crown variable - crown length. In our suggested model, estimates of and are coefficients that convert volume of a regular geometric solid – RGS is dbh² times crown length) - into crown volume, whilst estimate of is an allometric constant. Key words: Crown modeling, diameter at breast height, crown length, crown volume.

Forest plantations composed of pines, eucalypts and wattle are threatened by wildfires that are responsible for an average annual loss of 700 ha. Communities neighbouring forest plantations and illegal settlers (estimated at >3000) occupying some areas within plantations are the major sources of wildfires that enter into plantations. Strategies to tackle fire problems in plantations should focus on (1) improving law enforcement to deter illegal starting of fires; (2) address illegal settlement; (3) explore possibilities of community shareholding and out-grower schemes and, (4) institute and increase fire awareness campaigns.

Complex coacervation of two naturally occurring polymers is crucial in design of wall materials, particularly in the food and related industry. This work presents an analysis of the complex coacervate yield of two oppositely charged polymers, viz., gelatin and wattle varying parameters like pH, polymeric mass ratio, and total biopolymer concentration through zeta potential and turbidity measurements. Results show that for the boundary conditions employed in the study, maximum coacervate yield (65 ± 0.9 %) was for wattle:gelatin ratio of 2:1, pH 4.2. At 2.2 ± 0.1 g of wattle/ g of gelatin, large micron-sized aggregates with polydispersity index of 1 have been obtained. Turbidity of the dispersion is inversely proportional to coacervate yield and has been optimized at a total biopolymer concentration of 3% at a wattle to gelatin mass ratio of 2 for applications.

Black wattle (Acacia mearnsii De Wild.) is a tree legume native to southeast Australia, but present in all continents. Today it covers about 142,400 ha in Brazil, with plantations concentrated in the southern region of the country. Black wattle may form nodules and establish rhizobial symbiosis capable of fixing N(2), but rhizobial inoculation is not done in commercial plantations. About 40 kg ha(−1) of urea is applied during seedling transplantation. In this review, evidences by which rhizobial inoculation affects monoculture, mixed cultivation, and agroforestry black wattle production systems were searched in literature. Previous measurements in cultivated forests have indicated that biological nitrogen fixation in black wattle may provide up to 200 kg of N ha(−1) year(−1) to the soil. Therefore, rhizobia inoculation may bring several opportunities to improve black wattle production systems. Black wattle is not a very selective partner in the rhizobial symbiosis, but the genus Bradyrhizobium dominates the rhizobial diversity of black wattle nodules. Investigation on rhizobial diversity in soils where the crop is cultivated may represent an opportunity to find more effective rhizobia strains for inoculants. The successful history of biological nitrogen fixation in grain legumes must inspire the history of tree legumes. Microbiology applied to forestry must overcome challenges on the lack of trained professionals and the development of new application technologies.

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; azoxy...

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.

This report was to re-evaluate the clay of recycle building materials. The method used to re-evaluate a numerical analysis. Constant temperature and humidity with the room with strong straw-clay wall was able to obtain even an ordinary house with a straw-clay wall that simulates wattle. Here we show the effect of clay on the house of heat insulation and indoor humidity control.

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. Key words: Global solar radiation, phosphorus, leaf biomass, black wattle, plantation cycle.

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.

Acacia mearnsii De Wild (black wattle) is an important plantation species for tannin production and woodchip exports in South Africa and Brazil. This study provides an updated overview of the black wattle industries in both countries, including planted areas and land ownership, silviculture and management, bark extract production, woodchip exports, as well as key research and development issues. The current total planted area to black wattle is 110 000 ha in South Africa and c. 170 000 ha in Brazil. In both countries black wattle is mainly cultivated by farmers (c. 76–78% of the total area). Due to the high prices fetched by the wattle woodchips in the international market, black wattle is a profitable crop. In South Africa, the timber provides 85% of the revenue and the bark the other 15%, and thus the commercial emphasis has shifted from bark to timber. At present the only significant secondary products are charcoal and firewood. Acacia mearnsii bark tannins are used in the leather industry, adhesives f...

Degradation of wattle (Acacia mearnsii) extract, a leather tanning agent which is mainly composed of polyphenolic compounds was attempted by photocatalytic degradation which is a hindrance to the conventional bio-treatment of tannery effluent. To serve the process a novel semiconductive mixed catalyst CdWO4–ZnO was prepared by a simple hydrothermal method. The degradation reaction was carried out with a visible light source in a neutral medium for three hours. The results depicted the better catalytic activity of CdWO4–ZnO (band gap 2.8 eV) in degrading the organics when compared to undoped ZnO (band gap 3.8 eV) under visible light. The results also showed that the catalyst is appropriate at 36.8 weight percentage of CdWO4 in ZnO. The catalyst morphological and optical characteristics, and degradation of wattle were carefully analyzed.

The word ‘fence’ is used here generically to denote any structure created to prevent or impede movement across the countryside. They ought to have been absent from forests, where obstructions to the free passage of deer and hunters were forbidden by forest law, which in principle, therefore, preserved open countryside. The patchwork of settlements and enclosed private fields of the characteristic English landscape could not emerge until disafforestation got rid of forest law. However, hunting required fences, and so did the preservation and management of deer so that they were available to be hunted. Growing crops abutting forests could be fenced from deer, and the statutory protection of common rights and coppices in forests required the careful regulation of areas available for fuel gathering, domestic animal grazing and wood production: whilst deer were allowed almost complete freedom of movement inside forests, commoners’ animals were not; some areas were temporarily closed even to deer; some ...

This paper reports an investigation into the use of condensed black wattle tannin as an environmental friendly sealer after zinc phosphating of carbon steel. In order to verify the sealer efficiency against corrosion, electrochemical impedance spectroscopy, potentiodynamic polarisation and salt spray tests were performed. To verify the pore modifications and phase compositions, SEM, electron dispersive spectroscopy and X-ray diffraction analysis were carried out. The influence of the sealer on the adherence of finishing coatings was analysed. The results show that the tannin/sealer did not affect the final coating adhesion and improved the corrosion resistance of sealed samples. Copyright © 2013 John Wiley & Sons, Ltd.

Wattle (Acacia mearnsii) bark extract is an important renewable industrial source of natural polymers for leather tanning and adhesive manufacturing. The wattle bark proanthocyanidin oligomers have 5-deoxy extender units that render the interflavanyl bonds resistant to acid catalysed hydrolysis and their composition cannot be determined via conventional thiolysis. We combined established phyto- and synthetic chemistry perspectives with an electrospray mass spectrometry investigation to establish that the flavan-3-ol based oligomers consist of a starter unit which is either catechin or gallocatechin, angularly bonded to fisetinidol or predominantly robinetinidol extender units.

In 2004, the courtyard of Ca’ Foscari University, Venice, was excavated in advance of building work, revealing an unbroken sequence of archaeological deposits. The earliest layers consisted of redeposited natural sediment, packed into wattle structures, a system of land reclamation first described by Cassiodorus in AD 537–8, and now known from several other sites in the city. The ground level was built up and extended several times with successive wattle structures, before the eventual construction of a stone waterfront. We have used Bayesian modeling of dendrochronological, radiocarbon, and stratigraphic dating evidence to obtain a precise chronology for the earliest phases of occupation, and to compare it to the chronology of land reclamation at similar sites elsewhere in Venice. DOI: 10.2458/azu_js_rc.v54i3–4.16149

The leather industry faces very challenging task because of the regulations enforced by the various pollution control bodies to maintain the discharged norms of the chemical in the treated water. The pollution due to the use of chromium and other chemicals in the leather industry is critically analyzed for the harmful effects. Many studies have been undertaken to optimize the amount of chemicals used in leather processing. The pollution due to chromium is one of the major constraints in the leather processing operation. Chrome recovery and reuse methods have become the compulsory recovery methods in the leather industry to recover and reuse the chromium present in the effluent. Several precipitation methods are emerging but still they are not feasible. In this paper, an attempt has been made to recover the chromium present in spent tan liquor using neutralized wattle extract. The wattle extract at different pH conditions (pH 7, 8, and 9) was used for recovery of chromium. The neutralized wattle extract was made to react with chromium in the spent liquor and allowed to settle for a period of 6 h. Major amount of chromium settles at the bottom leaving minimal amount in the supernatant. The chrome was recovered and reused for tanning the pelt. The wattle extract that was left in the tanning bath was reused for post-tanning process as a retanning agent. Therefore, complete utilization of the chromium and wattle extract has been achieved in this work. It has also been noticed that increased level of chrome exhaustion of 85% and 87% (precipitate and supernatant) in experimental leather could be obtained in comparison with the exhaustion of 74% in control sample. The physical strength and color properties of the experimental leather were comparable to the control leather. The overall results show that the recovered chromium can be well used for tanning purpose to obtain the leather of comparable properties.

Os plantios homogêneos de acácia-negra nem sempre são feitos em solos adequados às exigências da espécie, seja pelo valor da terra ou proximidade da indústria. Diferentes sistemas de preparo podem melhorar as condições do solo, evitar problemas de erosão e diminuir custos de implantação. Em áreas de propriedade da TANAGRO S.A e da SETA S.A., nos municípios de Piratini e Butiá, RS, em dois tipos de solos distintos - Neossolo Litólico e Argissolo Vermelho-Amarelo, foram testados sistemas de preparo do solo com diferentes níveis de movimentação para plantio de acácia-negra: plantio de mudas em covas e plantio após subsolagens com duas, três e cinco hastes e uso de gradagens. Foram avaliados o crescimento em DAP e altura, anualmente, e produção de biomassa aérea no corte raso. Os solos foram caracterizados química e fisicamente em seus horizontes superficiais. Nas plantas, após sete anos, foram coletadas amostras de discos em seis posições no tronco para avaliação das densidades básicas. Preparo do solo com subsolador de cinco hastes apresentou maiores perdas de solo, que foram mensuráveis apenas até 18 meses após o plantio. Essas perdas de solo são extremamente importantes na sustentabilidade da produção do Neossolo Litólico, composto em 80% de calhaus e cascalho. O preparo reduzido do solo, com a abertura de covas manual e mecanicamente para plantio da acácia negra, não diminuiu o crescimento das plantas em ambos os solos estudados. No entanto, o desenvolvimento inicial das plantas de acácia negra, plantadas em sistema de preparo reduzido, foi mais lento (altura e DAP), defasagem que permaneceu até os 24 meses após o plantio.

(2007). Jung and the Wattle-Tree: Judith Wright and the Ecology of the Collective Unconscious. Journal of the Australasian Universities Language and Literature Association: Vol. 2007, No. 107, pp. 103-124.

The relationship between construction materials used and longevity of traditional houses in three parishes adjacent to Kibale National Park in western Uganda was explored. Based on (i) resistance to termite attack, (ii) resistance to insect borers, (iii) rot resistance, (iv) wood that splits well, (v) the wood fibre not entangled, (vi) easy workability, (vii) weight, (viii) straight poles, (ix) availability within 2 km radius and (x) durability, 67 species were recorded, of which 43 are trees, nine climbers, ten shrubs and five herbs. Durable wood resistant to fungal attack, termites and woodborers is preferred in addition to being hard, straight and easy to work with a machete. Ranked high among the wild species are Harrisonia abyssinica Oliver, Millettia dura Dunn., Blighia unijugata Baker and Aegelopsis eggelingii M. R. F. Taylor. The commonly extracted pole sizes are between 5 and 12 cm dbh. Preferred wild ropes to fasten wattle, that are resistant to termites, include Cryptolepis sanguinoleta R. Br., Motandra sp., Urera trinervis (Hochst.) Friis & Imm., Paullinia pinnata L. and Cissus rotundifolia (Forssk.) Vahl. Longevity of houses greatly depended on the wall finishing by plastering with sand/wood ash and cow dung as well as the thatch material used: with the average life span of 14.7 years for grass-thatched, 20 years for papyrus and 29.9 years for iron-roofed houses.

The radiocarbon results (and Bayesian modeling) of 15 samples of carbonized food residues removed from the external surface of rim sherds of cooking pots indicate that shellyware pottery first appeared in Perth, Scotland, around cal AD 910–1020 (95% probability) and that it had disappeared by cal AD 1020–1140 (95% probability). Previously, it had been suggested that this pottery could not date to before AD 1150. These data, together with 14C analyses carried out on leather artifacts and a sample of wattle from a ditch lining, also demonstrate that there was occupation in Perth about 100 yr or more prior to the granting of royal burgh status to Perth in the 1120s.

Wattle construction is a mixed technique used on walls and that belong to the frameworks family. It is constructed with a structural frame (wood or bamboo) filled in with a mixture of clay mud in a plastic state and vegetable fiber. In this paper thermal transmittance and soft shock resistance had been studied, thermal transmittance had been measured with wattle samples of 0.10 m thickness, and result in 2.64 W/m2K and with the addition of expanded polystyrene sheet of 5 mm thicknees inside the panel, the transmittance was 2.02 W/m2K. These values are batter than a brick wall of 0.20 m thick with a finish plaster on both sides of the wall, whose value is 4.13 W/m2K. For impact resistance, panels were constructed and tested to soft shock, on 1:1 scale. The permanent deformation in all cases was less than 3.6 mm required by the current standard. This implies that there was no appreciable deformations suffered enclosures providing security to a home. It’s concludes that has a good thermal and structural behavior, plus the characteristics of being economical and appropriate for selfconstruction, make feasible to implement as a massive scale., La quincha es una técnica mixta de muros perteneciente a la familia de los entramados. Compuesta de una armazón estructural (madera o bambú) rellena con barro en estado plástico con añadido de fibras vegetales. Se determinó que la transmitancia térmica de un panel de quincha de 0,10 m de espesor, dando como resultado 2,64 W/m2K y con el agregado de una placa de poliestireno expandido de 5 mm de espesor en el interior el panel, la transmitancia es 2,02 W/m2K. Estos valores son comparables al de un muro de ladrillo de 0,20 m de espesor y revocado en ambas caras, cuyo valor es 4,13 W/ m2K. Para la resistencia al impacto, se construyeron paneles en escala 1:1 y se ensayaron al choque blando. Las deformaciones permanentes fue en todos los casos menor de 3,6 mm requerido por la Norma vigente. Esto implica que no sufrió deformaciones apreciables dando seguridad a los cerramientos de una vivienda. Se concluye que su buen comportamiento térmico y estructural, sumado a las características de ser económico y apropiado para la autoconstrucción, lo hacen viable para implementar a escala masiva.

South Africa has a proud history of forestry research and forest education spanning at least the last 100 years. Exotic tree species (pines, eucalypts and wattle) were introduced in the middle of the nineteenth century to alleviate the demands on indigenous forests for timber. This led to the development of a highly successful, plantation‐based forest industry, which is an important source of employment and foreign exchange for the country. Research institutions were established by both government and the private sector. Innovations and research outputs from these has made South Africa a leader in sustainable plantation forestry. Similarly, tertiary education institutions were established in the early 20th Century and have provided the industry with highly skilled professional foresters. Over the past two decades, both the forest industry and the country have undergone significant change that has posed new challenges, opportunities and threats on a number of fronts. Education and skills development are Go...

An investigation into the spread of two alien wattle species ( Acacia mearnsii and Acacia dealbata ) in rural parts of the Drakensberg region of South Africa and the importance of the trees to the livelihoods of the local communities was carried out. With the aid of aerial photography two plots near the village were selected. Wattle aerial cover increased from 7% and 20% in the two plots, respectively, in 1953, over 21% and 33% in 1975, to 48% and 58% in 2000. In 1995, a government-sponsored national programme, “Working for Water” was established, with the expressed purpose of employing people described as being from the poorest and disadvantaged rural communities to clear areas of invasive alien species from river catchments and water courses. Whilst the programme provides an income to thousands of families in rural areas, it may also be jeopardising the livelihoods of the same communities. The wattle is an important resource for village households; virtually all households used it as their primary heat source and for building materials. Other uses included medicine extraction and 20% of the interviewed households gained income from selling firewood. From the rural communities’ perception, the greatest concern regarding the alien species is its high water consumption (although this did not affect them directly), and the fact that it provides cover to thieves and criminals. Consequently, most villagers wanted either a reduction of the wattle stands (58% and 86% in the 2001 and 2003 study, respectively), or that they remained as at present (42% and 10%, respectively). Leaves from woody legumes have demonstrated large potential as green manures and fodder providers in many agroecosystems. The abundance of the wattle in the study area suggested an exploration of alternative beneficial uses in the low input farming systems practiced. The wattle’s potential as green manure was evaluated in a decomposition trial. In all treatments, the wattle litter immobilised nitrogen from soil, in spite of a high N content of the litter. Plant available P increased in soil after 4–5 months of incubation. We argue that the current practice of externally funded wattle control is not sustainable in the long term. We discuss alternative approaches with a higher level of community participation and ownership, and conclude that the current underutilization of land may, ironically, be one of the largest constraints for a viable solution to the spread of wattle.

Extracted from text ... *. Quoted from the Times of Natal, 6 Jan. 1922. 1. Tannin was, and continues to be, used primarily in the tanning process, in which animal hides are converted into leather. 99 South African Historical Journal, 53 (2005), 99-122 'Clothing the Once Bare Brown Hills of Natal':* The Origin and Development of Wattle Growing in Natal, 1860-1960 HARALD WITT University of KwaZulu-Natal Introduction The countryside at the time was like a prairie, one could see for miles. As there were hardly any trees ... Umvoti County: Jewel of Natal A key feature of the agricultural landscape in Natal was ..

Synopsis The black wattle breeding programme that has served the wattle bark industry ofSouth Africa for the past five decades putlittleemphasis on improvingthe yield and quality ofthe timber, as timberwas not the product ofimportance. Today the timber is as important, ifnot more so, than the bark. Adecision was taken, by the industry to re-design the breedingand production strategy for the species in SouthAfrica, to improve timber yield and quality while maintaining an acceptable bark quality. Using the available seed at the ICFR at present, a Multiple PopulationBreedingStrategyhas beenchosen. The sub-populationshavebeen established usingthe origin ofthe seed as the determiningfactor. Five sub-populationswere establishedinKwaZulu-Natal during November 2002. The sub-populations were designed as progeny tests and as seedling seed orchards planted adjacent to one another. The performance of the families in the progeny tests will determine the management ofthe seed orchards. Generation turnover will be via o...

A new kind of polyurethane (PU) foam was synthesized from wattle tannin (WT), which has good prospects of application for its biodegradation and bacteriostasis. The effects of WT content, diisocyanate dosage, and chemical modification of WT on properties of PU were investigated. It was found that WT could contribute not only to bacteriostatic activity, but also to biodegradability during soil micro-organism treatment for the polyurethane foams. Furthermore, the bacteriostasis of PU is improved by modifying the chemical structure of WT. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2756–2763, 2003

This study investigated the physical and mechanical properties of particleboards made using two types of tannin-based adhesives, wattle and pine, with three hardeners, paraformaldehyde, hexamethylenetetramine (hexamine) and TN (tris(hydroxyl)nitromethane), by measuring the physical (thickness swelling, linear expansion and water absorption) and mechanical properties (bending strength and internal bond strength). The performance of the particleboards made using tannin-based adhesives was influenced by physical conditions such as press time and temperature as well as by chemical conditions, such as the chemical structure of the tannin and the hardener. Wattle tannin-based adhesive being a thermoset, the wattle tannin-based particleboards were more influenced by physical conditions, while the pine tannin-based particleboards were influenced by the chemical structure of the pine tannin nuclei, which include phloroglucinolic A-rings. The reactivity of the hardener toward the tannin was in the order: paraformal...