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1
Bodnár, István. "Simulation of acacia gasification process." Analecta Technica Szegedinensia 14, no. 1 (2020): 24–33. http://dx.doi.org/10.14232/analecta.2020.1.24-33.
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This electronic document presents the thermokinetical modelling of the gasification process done on acacia-tree with variable operating conditions and different humidity levels. Gasification does not produce flue gas, but due to imperfect burning, synthesis gas appears which is rich in flammable components (CO2 and H2). The chemical structure of this gas depends on the components of the fuel and the humidity level, but greatly affected by the technological parameters too, such as pressure and temperature, as well as the air-ratio. The study shows the change in the amount of the fuel and the reaction efficiency, caused by varying gasification temperature and pressure. Rising temperature results in improved efficiency, while higher pressure worsens reaction efficiency. However, at higher temperature intervals, the effect of the pressure is neglectable.
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Herrero, Celia, Amelework Kassa, Valentín Pando, Felipe Bravo, and Ricardo Alía. "Effect of heat shock on the germination of seeds of the species Acacia senegal L. and Acacia seyal Del. from sub-Saharan Africa (Ethiopia)." Forest Systems 28, no. 2 (2019): e006. http://dx.doi.org/10.5424/fs/2019282-14227.
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Aim of the study: Understanding post-fire germination of tree species in arid and semi-arid zones of sub-Saharan Africa.Area of study: Ethiopian Acacia senegal L. and Acacia seyal Del. forests.Material and methods: Seeds were subjected to heat shocks at combinations of four temperatures (60º, 90º, 120º and 150ºC) and three exposure times (1, 5 and 10 minutes). A control was also included, resulting in a total of thirteen treatments. After the application of the heat shocks, the viability of no germinated seeds was assessed after immersion in a Tetrazolium solution. A mixed and a logistic model were used to analyse the influence of heat shock on germination.Main results: Results showed that germination depended on the species, the heat shock treatment and their interaction. Both species showed similar germination results at temperatures below 90ºC in all exposure times, however, germination in Acacia senegal was statistically higher in most of the heat shocks. On the other hand, germination probability decreased in both species, when the exposure time increased, although with a different behaviour. In 1 minute of time of exposure, the germination probability was higher than 60% in the two species throughout the temperature range. However, at 5 minutes of time and temperature smaller than 90°C, the probability of germination was higher than 70% in A. senegal and 50% in A. seyal. Although germination in both species was impacted by the different heat shocks, non-germinated seeds were viable.Research highlights: This paper showed, according to these results, that heat shock would negatively influence the regeneration of both species, and especially for A. seyal.Key words: germination, Acacia, heat shock, logistic model.
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Bellairs, SM, and DT Bell. "Temperature Effects on the Seed-Germination of 10 Kwongan Species From Eneabba, Western-Australia." Australian Journal of Botany 38, no. 5 (1990): 451. http://dx.doi.org/10.1071/bt9900451.
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The germination responses of 10 species (Acacia blakelyi, A. pulchella, Allocasuarina humilis, Beaufortia elegans, Conostylis neocymosa, Eucalyptus tetragona, Kennedia prostrata, Leptospermum spinescens, Melaleuca acerosa and Xanthorrhoea drummondii) to constant temperatures ranging from 5 to 35� C were studied. These Western Australian perennial species had optimum germination percentages between 15 and 20�C, except Eucalyptus tetragona which had an optimum at 25�C and Leptospermum spinescens which had an optimum at 10�C. Seeds were transferred from high and low temperatures to 15�C to determine whether high or low temperatures induced dormancy. Low temperatures tended not to affect subsequent germination but high temperature decreased subsequent germination for some species. Wetting and drying stimulated the germination of Acacia blakelyi, A. pulchella and Kennedia prostrata seeds.
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Wright, Boyd R., and Peter J. Clarke. "Germination biologies and seedbank dynamics of Acacia shrubs in the Western Desert: implications for fire season impacts on recruitment." Australian Journal of Botany 66, no. 3 (2018): 278. http://dx.doi.org/10.1071/bt18003.
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In arid Australia, fires in different seasons often result in markedly different recruitment rates of woody plants, and this can have important and long-lasting impacts on post-fire community structure and composition. The current study investigated ecological mechanisms behind this effect in four widespread arid Acacia species: Acacia aptaneura, Maslin & J.E.Reid Acacia kempeana F.Muell., Acacia maitlandii F.Muell. and Acacia melleodora Pedley. Specifically, the study examined whether increased recruitment after summer compared with winter burning relates to (1) higher soil temperatures during summer fires having increased capacity to overcome dormancy of seeds with heat-stimulated germination; (2) warmer soil temperature conditions after summer fires providing more favourable incubation temperatures for germination; and/or (3) summer fires coinciding with seasonal fluxes in seedbank densities, which may occur in response to granivory and/or rapid rates of seed deterioration after dispersal. Results supported hypotheses (1) and (2), as germination of all species responded positively to heat shock and warmer incubation temperatures. Some support was also demonstrated for hypothesis (3), as seedbank densities were shown to fluctuate seasonally, most likely in response to strong granivory. This multi-species study provides insights into mechanisms behind enhanced shrub recruitment after arid zone summer fires; and reinforces the notion that season of burn can be a strong determinant of regeneration trajectories of woody plants after fire.
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Arsad, Effendi. "SIFAT FISIK DAN KIMIA WOOD PELLET DARI LIMBAH INDUSTRI PERKAYUAN SEBAGAI SUMBER ENERGI ALTERNATIF." Jurnal Riset Industri Hasil Hutan 6, no. 1 (2014): 1. http://dx.doi.org/10.24111/jrihh.v6i1.1219.
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Carakteristic physical and chemistry of Wood pellet from Industrial Disposal of Wood as Sources Energy Alternatif The research to gaved for physical and chemistry of Wood pellet from Industrial. Processing approximately 12%, sawdust dried to moisture content of sieved that is size of 15 mesh, 25 mesh and 35 mesh. Heating temperature were 60 0C and 110 0C. Moisture content of flawer wood pellet 4,46% - 9,95%, acacia wood pellet were 4.38% - 7.52% and tarap wood pellet were 4.60% - 9.98%. Density of flawer wood pellet were 0.51 - 0.78, acacia wood pellet were 0.61 - 0.78 and tarap wood pellet were 0.56 - 0.71, ash content of wood flawer from 0.87 - 2.04%, acacia 0.54 - 0.94% and ash content of tarap wood 1.71 - 2.05%. Calorific value of wood pellets flawers wood 3921,12 - 4150,19 cal/g, acacia wood 4022,29 - 4254,91 cal/g and tarap wood 3920,13 - 4125,28 cal/g. The higher temperature of the heating effect on reality the reduction of water and the weight of ash wood pellets while it was increasing calorific value.Keywords: waste wood, flawers wood, acacia wood, tarap wood, wood pellet
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Martin, Chris A., L. Brooke McDowell, and Shiela Bhattacharya. "Below Ground Pot-in-Pot Effects on Growth of Two Southwest Landscape Trees was Related to Root Membrane Thermostability." Journal of Environmental Horticulture 17, no. 2 (1999): 63–68. http://dx.doi.org/10.24266/0738-2898-17.2.63.
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Abstract Two southwestern desert landscape trees, Acacia smallii L. (sweet acacia) and Cercidium floridum Benth. ex A. Gray (blue palo verde), were grown outdoors in full sun during Summer 1997 in 19-liter (#5) containers placed either pot-in-pot (PIP) below ground or unshielded in above-ground containers (AGC). Soil moisture sensors wired to electronic solenoid valves regulated occurrence of six cyclic micro-irrigation pulses per day (0600, 0900, 1200, 1500, 1800, and 2100 HR) such that container substrate moisture tensions were continuously maintained between −0.005 to −0.01 MPa (90% of water holding capacity) in both PIP and AGC. Mean maximum recorded root-zone temperatures in PIP containers were 19C (34F) lower than for AGC. Micro-irrigation volumes were 40% less for trees grown PIP compared with those in AGC. Growth of sweet acacia was enhanced by PIP placement while in containers and one year after transplanting trees into field plots in 1998. Only caliper growth of blue palo verde was increased by PIP placement while in containers, but had no effect on blue palo verde growth one year after transplanting into field plots. The critical killing temperature (TM) for root tissues of sweet acacia and blue palo verde were 45.3 ± 1.8C (113.5 ± 3.2F) and 49.4 ± 0.8C (120.9 ± 1.4F), respectively, indicating differences in root membrane thermostability. Based on our data, we suggest that sweet acacia trees benefitted from PIP placement more than blue palo verde trees because root-zone temperatures in PIP containers were lower than for AGC in central Arizona, and sweet acacia roots were more susceptible to injury by supraoptimal root zone temperatures.
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Quyen, Trinh Van, and Nagy Sándor. "AGGLOMERATION OF ACACIA MANGIUM BIOMASS." Vietnam Journal of Science and Technology 56, no. 2 (2018): 198. http://dx.doi.org/10.15625/2525-2518/56/2/9293.
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The aim of this study is to analyze the effects of temperature (T), moisture content (MC) and particle size (x) on Acacia mangium biomass and also to find the optimal conditions of the densification process for producing tablet with high density. The result shows that at constant pressure, increasing temperature (T) resulted in higher density of tablets and also increasing moisture content resulted in higher density of tables. Tablets made from raw material with smaller particle size have lower strength than those made from material with larger particle size.
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Maccioni, Alfredo, Andrea Santo, Danilo Falconieri, et al. "Inhibitory effect of rosemary essential oil, loaded in liposomes, on seed germination of Acacia saligna, an invasive species in Mediterranean ecosystems." Botany 97, no. 5 (2019): 283–91. http://dx.doi.org/10.1139/cjb-2018-0212.
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Acacia saligna (Labill.) Wendl. is native of southwestern Australia, but has been planted extensively in many areas of the world, including the Mediterranean region, becoming highly invasive especially in coastal habitats. The aim of this study was to test whether the indigenous Rosmarinus officinalis L. essential oil (EO), loaded in liposomes, can inhibit the seed germination of the invasive alien Acacia saligna. Variability in seed germination requirements and responses among populations were evaluated. Germination tests under light, at constant temperatures and three concentrations of rosemary EO were carried out. Among the examined factors, only the EO amount and temperature had a highly significant effect on seed germination. The lowest EO quantity did not show differences compared with the control, while the highest amount inhibited significantly seed germination of all populations at all the tested temperatures. No seed recovered the ability to germinate after the EO treatment with either of the two washing methods. Our results allowed us to identify the minimum amount of rosemary EO capable of inhibiting the seed germination of the invasive Acacia saligna. These results could be useful for the control of this invasive alien species, thus allowing the conservation of indigenous Mediterranean plant species and habitats.
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Rodrigues, Lucas Oliveira, Rachel Andrade de Faria, Marcos Martins Gouvêa, Carlos Augusto de Freitas Peregrino, Elizabeth Valverde Macedo, and Samanta Cardozo Mourão. "Effect of spray drying process parameters on Uncaria tomentosa (Willd. ex Schult.) DC. dried extracts." Revista Fitos 14, no. 4 (2020): 469–75. http://dx.doi.org/10.32712/2446-4775.2020.969.
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Uncaria tomentosa (Willd. ex Schult.) DC. (Cat's claw) is a plant member of the Rubiaceae family, from the Amazon region, and used in traditional medicine as raw material for phytomedicines indicated for arthritis and osteoarthritis. This study aimed to evaluate the spray drying process parameters on the properties of different extracts obtained from Uncaria tomentosa. A reduced 24-1 multifactorial design was applied to evaluate the importance of the equipment variables (pump speed, spray nozzle diameter, air inlet temperature, and atomization airflow rate) in the process. Maltodextrin and acacia gum were used as carriers in a 1:1 (m/m) ratio, considering the solid residue content of the liquid plant extract. Process yield, moisture, and hygroscopicity were evaluated as dependent variables. Higher atomization airflow rate led to higher process yield for powdered dried extracts with maltodextrin. Higher temperature led to lower moisture contents regarding powdered dried extracts with acacia gum. No variable, for any carrier, was considered significant for hygroscopicity. The best spray drying configuration for the desired characteristics (i.e. lower hygroscopicity and moisture) used the larger spray nozzle with a diameter of 1.2 mm and the higher temperature of 150 °C, with both carriers.
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Rodrigues, Lucas Oliveira, Rachel Andrade de Faria, Marcos Martins Gouvêa, Carlos Augusto de Freitas Peregrino, Elizabeth Valverde Macedo, and Samanta Cardozo Mourão. "Effect of spray drying process parameters on Uncaria tomentosa (Willd. ex Schult.) DC. dried extracts." Revista Fitos 14, no. 4 (2020): 469–75. http://dx.doi.org/10.32712/2446-4775.2020.969.
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Uncaria tomentosa (Willd. ex Schult.) DC. (Cat's claw) is a plant member of the Rubiaceae family, from the Amazon region, and used in traditional medicine as raw material for phytomedicines indicated for arthritis and osteoarthritis. This study aimed to evaluate the spray drying process parameters on the properties of different extracts obtained from Uncaria tomentosa. A reduced 24-1 multifactorial design was applied to evaluate the importance of the equipment variables (pump speed, spray nozzle diameter, air inlet temperature, and atomization airflow rate) in the process. Maltodextrin and acacia gum were used as carriers in a 1:1 (m/m) ratio, considering the solid residue content of the liquid plant extract. Process yield, moisture, and hygroscopicity were evaluated as dependent variables. Higher atomization airflow rate led to higher process yield for powdered dried extracts with maltodextrin. Higher temperature led to lower moisture contents regarding powdered dried extracts with acacia gum. No variable, for any carrier, was considered significant for hygroscopicity. The best spray drying configuration for the desired characteristics (i.e. lower hygroscopicity and moisture) used the larger spray nozzle with a diameter of 1.2 mm and the higher temperature of 150 °C, with both carriers.
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Bodnár, István, Patrik Iski, and Ádám Skribanek. "Examination of Acacia-Tree Gasification Process Under Varying Operating Parameters." Műszaki Tudományos Közlemények 8, no. 1 (2018): 21–30. http://dx.doi.org/10.33894/mtk-2018.08.02.
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Abstract This paper presents the thermokinetic modeling of the gasification process performed on the acacia-tree under varying operating circumstances and different humidity levels. Gasification does not produce flue gas, but due to imperfect burning, synthesis gas appears which is rich in flammable components (CO2 and H2). The chemical structure of this gas depends on the components of the fuel and the humidity level, but is also greatly affected by the technological parameters, such as pressure and temperature, as well as the air-ratio. The study shows the change of chemical composition, fuel value and the reaction efficiency as a function of varying gasification temperature and pressure. Rising temperature results in improved efficiency, while higher pressure worsens reaction efficiency. However, at higher temperature intervals, the effect of the pressure is neglectable.
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YADAV, SWATI, and ALKA SHARMA. "EFFECT OF TEMPERATURE ON PROTECTIVE PROPENSITY OF ACACIA NILOTICA ON ACID CORROSION OF COPPER." Review Of Research II, no. VII (2013): 1–12. http://dx.doi.org/10.9780/2249-894x/272013/284.
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Yu, Hua, and Bee-Lian Ong. "The Effect of Phyllode Temperature on Gas Exchange and Chlorophyll Fluorescence of Acacia mangium." Photosynthetica 40, no. 4 (2002): 635–39. http://dx.doi.org/10.1023/a:1024328808629.
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Fraser, S., A. R. McTaggart, M. J. Wingfield, and J. Roux. "Effect of temperature, leaf wetness and the developmental stage of host tissue on infection of Acacia mearnsii by Uromycladium acaciae (Pucciniales)." Australasian Plant Pathology 46, no. 5 (2017): 407–19. http://dx.doi.org/10.1007/s13313-017-0503-2.
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Sedgley, M. "Some Effects of Temperature and Light on Floral Initiation and Development in Acacia pycnantha." Functional Plant Biology 12, no. 2 (1985): 109. http://dx.doi.org/10.1071/pp9850109.
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Floral initiation and development in Acacia pycnantha were studied under three environments. Two had ambient southern Australian temperatures of warm summer (mean max. 32°C, mean min. 16°C) and cool winter (mean max. 19°C, mean min. 8°C), one with full sunlight (outside) and the other with 30% light intensity (shadehouse). The other environment (glasshouse) had slightly lower than normal light intensity and a relatively constant year round temperature of mean 28°C maximum and 16°C minimum. Plants were scored for microscopic and macroscopic evidence of floral initiation and development. Floral primordia were initiated all year round under all environments. Floral development proceeded normally under ambient conditions of temperature and light, and anthesis occurred between August and October. Under low light intensity, floral development did not progress beyond a very early stage and macroscopically visible racemes were rare. Under the constant temperatures, floral development proceeded normally up to the stage of microsporogenesis and megasporogenesis. Meiosis did not occur and inflorescence buds ceased growth and were shed from the plant. Plants were transferred between the outside and glasshouse conditions in June, at around the stage of meiosis. Those transferred from outside to the glasshouse did not flower whereas some of those transferred from the glasshouse to outside flowered, but later and for a shorter period than plants maintained outside throughout. It appears that a 70% reduction in sunlight inhibits floral development at an early stage and that temperatures of approximately mean maximum 19°C and minimum 8°C are required for meiosis in Acacia pycnantha.
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Getahun, Alemayehu, Diriba Muleta, Fassil Assefa, and Solomon Kiros. "Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings." International Journal of Microbiology 2020 (October 29, 2020): 1–13. http://dx.doi.org/10.1155/2020/8897998.
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Drought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the effect of inoculating Acacia abyssinica seedlings with PGPR isolated from rhizosphere soil of Ethiopia to enhance DS tolerance. The strains were selected based on in vitro assays associated with tolerance to drought and other beneficial traits such as salinity, acidity, temperature, heavy metal tolerances, biofilm formation, and exopolysaccharide (EPS) production. The strains with the best DS tolerance ability were selected for the greenhouse trials with acacia plants. The results indicate that out of 73 strains, 10 (14%) were completely tolerant to 40% polyethylene glycol. Moreover, 37% of the strains were strong biofilm producers, while 66 (90.41%) were EPS producers with a better production in the medium containing sucrose at 28 ± 2°C and pH 7 ± 0.2. Strains PS-16 and RS-79 showed tolerance to 11% NaCl. All the strains were able to grow in wider ranges of pH (4–10) and temperature (15–45°C) and had high tolerance to heavy metals. The inoculated bacterial strains significantly ( p ≤ 0.05 ) increased root and shoot length and dry biomass of acacia plants. One of the strains identified as P. fluorescens strain FB-49 was outstanding in enhancing DS tolerance compared to the single inoculants and comparable to consortia. Stress-tolerant PGPR could be used to enhance acacia DS tolerance after testing other phytobeneficial traits.
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Semple, K. E., R. B. Cunningham, and P. D. Evans. "Cement Hydration Tests Using Wood Flour may not Predict the Suitability of Acacia mangium and Eucalyptus pellita for the Manufacture of Wood-Wool Cement Boards." Holzforschung 53, no. 3 (1999): 327–32. http://dx.doi.org/10.1515/hf.1999.053.
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Summary Wood-wool cement boards (WWCBs) are manufactured in many tropical countries which have extensive eucalypt and acacia plantations. Wood from such plantations could act as a potential raw material for WWCBs, but the suitability of most tropical eucalypts and acacias for the manufacture of such products is unknown. This study was undertaken to assess whether the standard laboratory test for wood-cement compatibility, which measures heat of hydration in wood flour-cement mixtures, is an appropriate method for screening tropical eucalypts and acacias for their compatibility with cement and suitability for the manufacture of WWCBs. Wood samples from a tropical eucalypt (E. pellita) and a tropical acacia (A. mangium) were tested in two forms, i. e. flour and wool, for their compatibility (expressed by maximum hydration temperature and CA-factor) with Portland cement. Form significantly influenced the effect of the wood on cement hydration, resulting in a different species compatibility ranking for flour and wool. As the heartwood content of wood-wool-cement hydration test samples increased, Tmax. and CA factor increased whereas the opposite occured for those containing wood flour. Tests using wood flour ranked E. pellita as being more compatible with cement than A. mangium whereas the ranking was reversed when wood-wool was used. Furthermore at low wood levels the compatibility of samples containing wood-wool or wood flour with cement was similar whereas at high wood levels, samples containing wood-wool were much more compatible with cement than those containing wood flour. Laboratory tests designed to screen eucalypts and acacias for their compatibility with cement should use wood in a coarser form with a lower surface-to-volume ratio than flour. Caution should be exercised if using results from wood flour-cement hydration tests to estimate the suitability of wood species for the manufacture of WWCBs and possibly other wood-cement composites.
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Reichman, S. M., S. M. Bellairs, and D. R. Mulligan. "The effects of temperature and salinity on Acacia harpophylla (brigalow) (Mimosaceae) germination." Rangeland Journal 28, no. 2 (2006): 175. http://dx.doi.org/10.1071/rj06027.
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Acacia harpophylla F. Muell. (brigalow) used to naturally occur over a range of about 50 000 km2 in Queensland and New South Wales, Australia. Large scale clearing for agriculture has reduced the area to less than 20 000 km2 and it is estimated that 20–25% of vertebrate fauna living in brigalow communities will become locally extinct as a result of the current clearing induced loss of habitat. Some coal mining companies in central Queensland have become interested in providing habitat for the endangered bridle nail-tailed wallaby that lives in brigalow vegetation. However, there is little known about establishment techniques for brigalow on mine sites and other disturbed ground; an understanding of brigalow biology and ecology is required to assist in the conservation of this threatened vegetation community and for re-creation of bridled nail-tail wallaby habitat in the post mining landscape. Brigalow is an unusual species of Acacia because it is not hard-seeded and germinates readily without the need to break seed-coat imposed dormancy. Germination trials were undertaken to test the ability of brigalow seed to germinate with a range of temperatures and salinity levels similar to those experienced in coal mine spoil. Optimum germination was found to occur at temperatures from 15 to 38°C and no germination was recorded at 45°C. Brigalow was very tolerant of high salt levels and germinated at percentages greater than 50% up to the highest salinity tested, 30 dS/m. Germination of greater than 90% occurred up to an electrical conductivity of 20 dS/m. The results indicate brigalow seed can be sown in summer when rains are most likely to occur, however, shading of the seed with extra soil or mulch may ensure the ground surface does not become too hot for germination. Because of its ability to germinate at high salinity levels, brigalow may be suitable for use in saline mine wastes which are common on sites to be rehabilitated after mining.
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Tuong, Vu Manh, and Jian Li. "Changes caused by heat treatment in chemical composition and some physical properties of acacia hybrid sapwood." Holzforschung 65, no. 1 (2011): 67–72. http://dx.doi.org/10.1515/hf.2010.118.
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Abstract Acacia hybrid (Acacia mangium×auriculiformis) sapwood was heat-treated in nitrogen under laboratory conditions for 2–6 h at 210°C–230°C. Chemical composition and physical properties including water absorption and swelling were examined. The results showed that these properties were reduced significantly by heat treatment, and there is an interactive effect of temperature and time on them. Chemical changes of the wood surface were determined by X-ray photo-electron spectroscopy analysis. Results indicate that the O/C ratio decreases as a function of treatment intensity due to the migration of extractives and degradation products to the surface during heat treatment. The C1s peaks showed an elevated content of lignin and extractives, whereas the hydroxyl group content was diminished with elevated treatment temperature. The O1s peaks revealed an increase in the O1 peak and confirmed the course of C1s peaks. These results coincide with the decrease in water absorption and swelling of wood after heat treatment.
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Beck-Pay, S. L. "The effect of temperature and relative humidity on Acacia mearnsii polyad viability and pollen tube development." South African Journal of Botany 83 (November 2012): 165–71. http://dx.doi.org/10.1016/j.sajb.2012.08.011.
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Emam, Hossam E., M. H. El-Rafie, Hanan B. Ahmed, and M. K. Zahran. "Room temperature synthesis of metallic nanosilver using acacia to impart durable biocidal effect on cotton fabrics." Fibers and Polymers 16, no. 8 (2015): 1676–87. http://dx.doi.org/10.1007/s12221-015-5197-x.
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Sivasubramanian, Palanisamy, Mayandi Kalimuthu, Murugesan Palaniappan, Azeez Alavudeen, Nagarajan Rajini, and Carlo Santulli. "Effect of Alkali Treatment on the Properties of Acacia Caesia Bark Fibres." Fibers 9, no. 8 (2021): 49. http://dx.doi.org/10.3390/fib9080049.
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As possible substitutes for non-biodegradable synthetic fibre, ligno-cellulosic fibres have attracted much interest for their eco-friendliness; a large number of them are already used for the production of green polymer composites. The search for further green candidates brings into focus other fibres not previously considered, yet part of other production systems, therefore available as by-products or refuse. The purpose of this study is to explore the potential of alkali treatment with 5% sodium hydroxide (NaOH) to enhance the properties of bark-extracted Acacia Caesia Bark (ACB) fibres. The microscopic structure of the treated fibres was elucidated using scanning electron microscopy (SEM). Moreover, the fibres were characterised in terms of chemical composition and density and subjected to single-fibre tensile tests (SFTT). Following their physico-chemical characterisation, fibre samples underwent thermal characterisation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and their crystallinity was assessed using X-ray diffraction (XRD). This level of alkali treatment only marginally modified the structure of the fibres and offered some improvement in their tensile strength. This suggested that they compare well with other bark fibres and that their thermal profile showed some increase of degradation onset temperature with respect to untreated ACB fibres. Their crystallinity would allow their application in the form of fibres with an average length of approximately 150 mm, even in thermoplastic biocomposites.
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Moreno-Casasola, Patricia, John Philip Grime, and M. Luisa Martínez. "A comparative study of the effects of fluctuations in temperature and moisture supply on hard coat dormancy in seeds of coastal tropical legumes in Mexico." Journal of Tropical Ecology 10, no. 1 (1994): 67–86. http://dx.doi.org/10.1017/s0266467400007720.
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ABSTRACTThe effect of fluctuations in temperature and moisture supply on hard seeds of nine tropical coastal sand dune legumes, including herbs (Schrankia atiadrivalvis, Macropiilium atropurpureum and Canavalia rosea), and shrubs (Acacia farncsiana, A. macracantha, Mimosa chaetocarpa, Indigoftra sujjruticosa, Crolalaria incana and Chamaecrista chamaecrutoides), has been studied under laboratory and field conditions. Using a fluctuating temperature gradient bar seeds buried in sand were exposed to various amplitudes of diurnal temperature fluctuation over an extended period of time and seed germinability was examined at intervals. Germination percentage increased considerably in most species as a consequence of treatment with marked effects occurring at temperature fluctuations greater than 20°C and becoming detectable after 45 days. In several species the effect of applying wetting and drying cycles was to lower the amplitude of temperature fluctuation necessary to soften the seeds. Species can be grouped into physiological groups on the basis of differences in seed response to temperature fluctuations. It is suggested that these differences may help to explain the mechanisms distinguishing the different colonization patterns observed in tropical sand dune systems.
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Mazlan, Mohammad Amir Firdaus, Yoshimitsu Uemura, Norridah Osman, and Suzana Yusup. "Review on Pyrolysis of Hardwood Residue to Biofuel." Applied Mechanics and Materials 625 (September 2014): 714–17. http://dx.doi.org/10.4028/www.scientific.net/amm.625.714.
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In Malaysia, approximately 7 million tonne/year of rubber wood waste and 5 million tonne/year of acacia wood waste were generated in 2011. These hardwood residues could be utilized to produce biofuel through pyrolysis process. The aims of the paper are to study the fluidized bed pyrolysis system, determine the properties of pyrolytic bio-oil, and highlight the effect of biomass type, size and pyrolysis temperature on pyrolytic products distribution.
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Fathanah, Umi, and Sofyana Sofyana. "Pembuatan Papan Partikel (Particle Board) dari Tandan Kosong Sawit dengan Perekat Kulit Akasia dan Gambir." Jurnal Rekayasa Kimia & Lingkungan 9, no. 3 (2013): 138. http://dx.doi.org/10.23955/rkl.v9i3.783.
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The need of wood as one of raw materials in furniture industry keeps increasing. One of efforts to reduce wood consumption is to develop research by creating composite design from material that contains sellulose to be particle board. Particle board is one of material alternatives that can be wood substitute. The objective of this research is to investigate the effect of natural-adhesive-mixture composition (acacia bark and gambier) with oil-palm-empty bunch toward mechanical property of particle board. Characterization of particle board was carried out by undertaking mechanical property testing (tensile strength and compressive strength) under wet and dry conditions. Composition variations of adhesive and oil-palm-empty bunch were 30:70; 40:60; 50:50; 60:40; 70:30. Making process of particle board is carried out by mixing oil-palm-empty bunch and adhesive with addition of 2% para-formaldehyde and water as much of 10%. Furthermore, the mixture is compressed by using Hot Press at temperature of 150oC and pressure of 10 kg/cm2 for 15 minutes. The research result indicates that the higher the adhesive composition (either adhesives of acacia bark or gambier), particle board resulted is better. In dry condition, values of the tensile strength of particle boards that have acacia bark adhesive and gambier adhesive have range of 84.2 - 104 Kgf/cm2 and 83.4 - 81.5 kg/cm2, respectively. Whereas, values of compressive strength of particle boards that have adhesives of acacia bark and gambier are in the range of 6.8 - 10.5 kg/cm2 and 6.3 - 9.3 kg/cm2, respectively. The values of tensile strength and compressive strength are obtained on compositions of adhesive: oil-palm-empty bunch ≥ 40:60, and they have fulfilled satandard of SNI 03-2105-1996. The values of tensile strength and compressive strength of particle board in wet condition, either adhesives of acacia bark or gambier, have not fulfilled standard of SNI 03-2105-1996.Keywords: empty-bunch-oil palm, acacia bark, gambier, particle board, tensile strength
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Al-Mefarrej, Hamad A. "Cambial Activity in Acacia Tortilis Subsp. Tortilis is Highest During the Hottest and Driest Month." IAWA Journal 35, no. 2 (2014): 138–54. http://dx.doi.org/10.1163/22941932-00000055.
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This study, aimed at elucidating cambial activity and wood formation in Acacia tortilis subsp. tortilis growing in the dry region of Al Baha in Saudi Arabia, reveals that the vascular cambium was active for almost the whole year, producing phloem in two flushes (February to March and then June to August), and xylem for about 11 months. The maximum number of cell layers in the cambial zone (10–13) was observed during June at high temperature, high leaf water deficit and lowest relative humidity (52%) and rainfall. A close relationship existed between the emergence of new leaves and the initiation/acceleration of cambial activity and tissue differentiation. The mean and maximum monthly temperature of the site showed positive and highly significant correlations (p < 0.01) with the width of the cambial zone. The mean monthly relative humidity and mean monthly rainfall were negatively but significantly correlated with cambial activity (p < 0.05). Leaf water deficit had a favorable effect on the cambial activity (r = 0.894, p < 0.01). Acacia tortilis subsp. tortilis has thick-walled vessels of medium diameter and frequency, thick-walled fibers occupying a high tissue proportion, high wood density (0.905 g cm-3) and tannin-like deposits in the vestured vessel pits. The apparent drought tolerance of this species is hypothesized to be due to its deep root system, allowing optimal cambial activity during extreme drought and extremely high day temperatures.
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Paz-Kagan, Tarin, Micha Silver, Natalya Panov, and Arnon Karnieli. "Multispectral Approach for Identifying Invasive Plant Species Based on Flowering Phenology Characteristics." Remote Sensing 11, no. 8 (2019): 953. http://dx.doi.org/10.3390/rs11080953.
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Invasive plant species (IPS) are the second biggest threat to biodiversity after habitat loss. Since the spatial extent of IPS is essential for managing the invaded ecosystem, the current study aims at identifying and mapping the aggressive IPS of Acacia salicina and Acacia saligna, to understand better the key factors influencing their distribution in the coastal plain of Israel. This goal was achieved by integrating airborne-derived hyperspectral imaging and multispectral earth observation for creating species distribution maps. Hyperspectral data, in conjunction with high spatial resolution species distribution maps, were used to train the multispectral images at the species level. We incorporated a series of statistical models to classify the IPS location and to recognize their distribution and density. We took advantage of the phenological flowering stages of Acacia trees, as obtained by the multispectral images, for the support vector machine classification procedure. The classification yielded an overall Kappa coefficient accuracy of 0.89. We studied the effect of various environmental and human factors on IPS density by using a random forest machine learning model, to understand the mechanisms underlying successful invasions, and to assess where IPS have a higher likelihood of occurring. This algorithm revealed that the high density of Acacia most closely related to elevation, temperature pattern, and distances from rivers, settlements, and roads. Our results demonstrate how the integration of remote-sensing data with different data sources can assist in determining IPS proliferation and provide detailed geographic information for conservation and management efforts to prevent their future spread.
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Mohamad Samsani, Aidi-Naim, Kiew Ooi Foong, Chee Keong Chen, and Mohamed Saat Ismail. "Effects of Acacia Honey Drink after Exercise-Induced Dehydration on Selected Physiological Parameters and Subsequent Running Performance." Sains Malaysiana 50, no. 8 (2021): 2293–308. http://dx.doi.org/10.17576/jsm-2021-5008-13.
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This study examined the effect of honey supplementation on exercise performance and biochemical markers in comparison to plain water and sports drink in the heat. Ten recreational athletes (Age: 22.2 ± 2.0 years, weight: 65.7 ± 5.3 kg; height: 170.4 ± 3.5 cm; VO2max: 51.5 ± 3.7 mL.kg−1.min−1) participated in this study. Participants ran at 70% of their VO2max for 1 h in a pre-load phase (Run-1), followed by a rehydration phase for 2 h and then a 20 min self-paced time trial (Run-2). After Run-1, participants drank either Acacia honey, sports drink or plain water with an amount equivalent to 150% of body weight loss. Subsequently, the participants performed the 20 min self-paced time trial. Acacia honey elicited an improved running time trial performance with a significantly (p<0.05) longer distance ran compared to plain water trial, but it was not different from the sports drink trial. In addition, there was no significant difference in running performance between sports drink and plain water trials. Plasma glucose, insulin and free fatty acids were significantly (p<0.05) higher in H and sports drink compared to the W trial during the rehydration phase. There were no significant differences in body weight changes, oxygen uptake, heart rate, rate of perceived exertion, tympanic temperature, plasma volume changes, plasma cortisol, urine osmolality, volume, and specific gravity among the three trials. Thus, Acacia honey can be recommended to be used as a rehydration drink for individuals who train and compete in the heat.
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Welgama, Amali, Singarayer Florentine, Hélia Marchante, Muhammad Mansoor Javaid, and Christopher Turville. "The germination success of Acacia longifolia subsp. longifolia (Fabaceae): a comparison between its native and exotic ranges." Australian Journal of Botany 67, no. 5 (2019): 414. http://dx.doi.org/10.1071/bt19018.
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Acacia longifolia subsp. longifolia is native to South-eastern Australia and has naturalised in many regions across the globe, including in Portugal, Spain, and South Africa invading extensive areas. Prolific seed production and a long-lived seedbank are considered key factors that enhance its invasiveness. Yet, the effects of different factors on germination are still underexplored. Seeds were collected from Portuguese and Australian populations, and germination was evaluated under different temperature regimes, photoperiods, pH levels, salt stress, osmotic potential and burial depths. Findings show both populations share some similar patterns but also reveal important differences related to their germination. Higher temperatures induce increased germination rates while the photoperiod has no effect on germination. Both populations had quicker seed emergence under dark conditions. Seeds from both populations decrease germination rate under increasing salt-stress and show a wide range of pH tolerance, but Australians seeds are more tolerant to increase of both parameters. Seeds from the Portuguese population are bigger and germinated from deeper depths than the Australian. Our results may provide information to improve management of this species seedbank. Germination can prevent by, tillage or other interventions that help to increase burial depths; adding lime (to increase the soil alkalinity) can reduce its germination rate in both geographical ranges.
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Sabajo, Clifton R., Guerric le Maire, Tania June, Ana Meijide, Olivier Roupsard, and Alexander Knohl. "Expansion of oil palm and other cash crops causes an increase of the land surface temperature in the Jambi province in Indonesia." Biogeosciences 14, no. 20 (2017): 4619–35. http://dx.doi.org/10.5194/bg-14-4619-2017.
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Abstract. Indonesia is currently one of the regions with the highest transformation rate of land surface worldwide related to the expansion of oil palm plantations and other cash crops replacing forests on large scales. Land cover changes, which modify land surface properties, have a direct effect on the land surface temperature (LST), a key driver for many ecological functions. Despite the large historic land transformation in Indonesia toward oil palm and other cash crops and governmental plans for future expansion, this is the first study so far to quantify the impacts of land transformation on the LST in Indonesia. We analyze LST from the thermal band of a Landsat image and produce a high-resolution surface temperature map (30 m) for the lowlands of the Jambi province in Sumatra (Indonesia), a region which suffered large land transformation towards oil palm and other cash crops over the past decades. The comparison of LST, albedo, normalized differenced vegetation index (NDVI) and evapotranspiration (ET) between seven different land cover types (forest, urban areas, clear-cut land, young and mature oil palm plantations, acacia and rubber plantations) shows that forests have lower surface temperatures than the other land cover types, indicating a local warming effect after forest conversion. LST differences were up to 10.1 ± 2.6 °C (mean ± SD) between forest and clear-cut land. The differences in surface temperatures are explained by an evaporative cooling effect, which offsets the albedo warming effect. Our analysis of the LST trend of the past 16 years based on MODIS data shows that the average daytime surface temperature in the Jambi province increased by 1.05 °C, which followed the trend of observed land cover changes and exceeded the effects of climate warming. This study provides evidence that the expansion of oil palm plantations and other cash crops leads to changes in biophysical variables, warming the land surface and thus enhancing the increase of the air temperature because of climate change.
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Noumi, Eric S., Joel Blin, Jeremy Valette, and Patrick Rousset. "Combined Effect of Pyrolysis Pressure and Temperature on the Yield and CO2 Gasification Reactivity of Acacia Wood in macro-TG." Energy & Fuels 29, no. 11 (2015): 7301–8. http://dx.doi.org/10.1021/acs.energyfuels.5b01454.
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Radovanovic, Mirjana, Branimir Racic, Snezana Tanaskovic, Goran Markovic, Dalibor Tomic, and Jelena Pantovic. "The catalytic effect of honey on formation of reducing sugars during sucrose hydrolysis." Chemical Industry 71, no. 2 (2017): 105–10. http://dx.doi.org/10.2298/hemind140313068r.
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In commercial apiculture, beekepers usually remove honey from hives and replenish food reserves with sugar syrup. When honeybees use sugar syrup (sucrose solution), they break down sucrose into glucose and fructose. These processes exhaust and weaken bees. In order to prevent bee exhaustion resulting from this processing, bees should preferably be supplied with ready made food before winter, i.e., with syrup in which sucrose has already been inverted. Feeding with inverted syrups is the most popular way of honeybee feeding. Beekeepers usually prepare inverted syrups by adding a weak organic acid (citric, oxalic, acetic or lactic acid) to sucrose solution at elevated temperatures. Inverted syrup production under uncontrolled pH, temperature and time conditions can cause the formation of 5-hydroxymethyl-2-furaldehyde (HMF), a compound harmful to bees. High quality inverted syrup can be obtained through the hydrolytic decomposition of sucrose by the enzyme invertase. Due to its invertase content, honey can be used as a biocatalyst for sucrose inversion. Invertase activity depends on the type, method and time of honey storage. This study evaluates the catalytic effect of acacia honey on formation of reducing sugars during hydrolysis of 50 wt.% sucrose solution. The ratio of reducing sugars and sucrose at 40?C, after 5 days of hydrolysis at a concentration of honey and 10 wt.% was 0.30 g reducing sugars/g of sucrose. The highest content of reducing sugars was achieved at a temperature of 35?C, after 48 h of invertion. In all samples of hydrolysates obtained at different temperatures (35?65?C), HMF was detected at concentrations of less than 4.32 mg kg?1. A high degree of negative correlation (coefficient of linearity ?0.94) was established between parameters of volumetric and polarimetric measurements during the hydrolysis of sucrose.
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Chang, Chia-Wei, Wei-Ling Kuo, and Kun-Tsung Lu. "On the Effect of Heat Treatments on the Adhesion, Finishing and Decay Resistance of Japanese cedar (Cryptomeria japonica D. Don) and Formosa acacia (Acacia confuse Merr.(Leguminosae))." Forests 10, no. 7 (2019): 586. http://dx.doi.org/10.3390/f10070586.
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In Taiwan, it is important to maintain sustainable development of the forestry industry in order to raise the self-sufficiency of domestic timber. Japanese cedar (Cryptomeria D. Don and Formosa acacia (Acacia confusa Merr.(Leguminosae)) have abundant storage options and are the potential candidates for this purpose. Heat treatment is a new environment-friendly method used to enhance the dimensional stability and durability of wood. On treatment, a surface with new characteristics is produced because of wood component changes. Consequently, an inactivated surface and a weak boundary layer are generated, and the wettability for adhesives and coatings is reduced. Furthermore, it decreases the pH value of the wood surface, and results in delay or acceleration during the curing of adhesives. This phenomenon must be paid attention to for practical applications of heat-treated wood. Ideal heat-treated conditions of C. japonica and A. confusa woods with productive parameters such as temperature, holding time, heating rate, and thicknesses of wood were identified in our previous study. In this research work, we focus on the normal shear strength of heat-treated wood with adhesives such as urea-formaldehyde resin (UF) and polyvinyl acetate (PVAc), and the finishing performances of heat-treated wood with polyurethane (PU) and nitrocellulose lacquer (NC) coatings as well as assessing the decay-resistance of heat-treated wood. The results show that heat-treated wood had a better decay resistance than untreated wood. The mass decrease of heat-treated wood was only 1/3 or even less than the untreated wood. The normal shear strength of heat-treated wood with UF and PVAc decreased from 99% to 72% compared to the untreated wood, but the wood failure of heat-treated wood was higher than that of the untreated one. Furthermore, the adhesion and impact resistance of wood finished by PU and NC coatings showed no difference between the heat-treated wood and untreated wood. The finished heat-treated wood had a superior durability and better gloss retention and lightfastness than that of the untreated wood.
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Sabaruddin, Siti Nurul Aidil Fitri, and Lesi Lestari. "Hubungan antara Kandungan Bahan Organik Tanah dengan Periode Pasca Tebang Tanaman HTI Acacia Mangium Willd." Journal of Tropical Soils 14, no. 2 (2013): 106–10. http://dx.doi.org/10.5400/jts.2009.v14i2.106-110.
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Timber harvesting may have significant effects on soil organic matter content through mechanical disturbance, inputs of logging slash, alterations in litter production, and leaching of dissolved organic matter, as well as the alteration of temperature and moisture regimes. To investigate the effect of post-harvest period of tree harvesting on the dynamics of soil organic matter content, surface soils (0 to 10 cm and 10 to 20 cm) were collected from intact Acacia mangium Willd. plantation (control) and from A. mangiumWilld. harvested in 2001, 2002, 2004, and 2006 in four replicates. Each replicate consisted of composited 4 subsamples. Timber harvesting reduced litter accumulation on soil surface. However, the amount of litter accumulated on soil surface increased as post-harvest period increased. Timber harvesting significantly (p<0.001) affected soil organic matter content both in 0 to 10 cm and 10 to 20 cm. The increases in soil organic matter content were significantly correlated (r=0.85; p<0.001 in 0 to10 cm and r=0.62; p<0.01 in 10 to 20 cm) with post harvest period.
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Nahdi, Maizer Said, and Darsikin Darsikin. "Distribusi dan Kemelimpahan Spesies Tumbuhan Bawah pada Naungan Pinus mercusii,Acacia auriculiformis danEucalyptus alba di Hutan Gama Giri Mandiri, Yogyakarta." Jurnal Natur Indonesia 16, no. 1 (2015): 33. http://dx.doi.org/10.31258/jnat.16.1.33-41.
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The purpose of this research was to study distribution and abundance of (shrubs, herbs, and rumput) under the three stands,i.e. Pinus mercusii, Acacia auriculiformis and Eucalyptus alba and environmental factors influencing them in Gama Girimandiri Forest. Data were collected in April-May 2011, using square plots. Plots were located in three locations by followinga stratified random sampling method. We administered 10 repetitions, and plot size 5x5 m for shrubs and herbs, and 1X1 m forgrass. The species found in each stand were identified and calculated for their density, frequency, domination, importantvalue, diversity index, and those parameters’ correlation with the measured environmental factors. The study shows that 59species of herbs and shrubs, and 12 species of grass. In the three stands, it could be shown various domination of grass,meanwhile there is no dominant species at the level of herbs and shrubs. The highest density, measured by diversity index,was observed at the stand of Pinus (3,13), followed by Acacia (3,12) and Eucalyptus (2,8). The distribution and density ofMemecylon sp and Oplismenus burmanni were observed at their highest value under the stand of Pinus, Lantana camaraLinn (37.2). At the same fashion, Paspalum conjugatum (58.3) does under the stand of Acacia, and Desmodium triflorum(64,2) and Ischaemum magnum (122) under Eucalyptus. Lantana camara could always be found under the three stands, ithad high important value, categorized as strategy species and invasive. Light density and pH significantly influenced thediversity index of shrubs and herbs. In addition, only soil temperature gave an effect to grass.
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Wright, B. R., and P. J. Clarke. "Relationships between soil temperatures and properties of fire in feathertop spinifex (Triodia schinzii (Henrard) Lazarides) sandridge desert in central Australia." Rangeland Journal 30, no. 3 (2008): 317. http://dx.doi.org/10.1071/rj07049.
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Soil temperatures during wildfires are known to influence seed bank and plant resprouting dynamics in arid Australian grasslands. Nevertheless, relationships between soil temperatures and factors such as fuel load, fuel type, season of burn, time-of-day and soil moisture are poorly understood. This study used small-scale experimental burns to determine the effects of these five variables on soil temperature profiles (0–4 cm) during fire in spinifex sandridge country in the Haasts Bluff Aboriginal Reserve, west of Alice Springs. Fuel load and type were found to strongly influence soil temperatures, with soils directly beneath Triodia hummocks experiencing more heating than hummock edges or between-hummock gaps, and soils beneath Triodia hummocks experiencing more heating than either mulga (Acacia aneura F.Muell. ex. Benth.) litter or Aristida holathera Domin. tussocks. Season and time-of-day also had strong effects on below-ground heating, with soil temperatures remaining elevated for longer periods during summer compared to winter burns, and day-time burns producing higher temperature maxima and longer durations of elevated soil temperatures than night burns. Soil moisture also had a strong impact on temperature profiles during fire, with high levels of soil moisture strongly reducing the soil heating during fire. These results indicate that the examined factors will strongly influence soil temperature regimes during spinifex wildfires. Hence, they are likely to affect the composition of plant assemblages in post-fire environments through their impacts on vegetative regeneration and on seed bank processes.
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Jauhiainen, J., A. Hooijer, and S. E. Page. "Carbon dioxide emissions from an <i>Acacia</i> plantation on peatland in Sumatra, Indonesia." Biogeosciences Discussions 8, no. 4 (2011): 8269–302. http://dx.doi.org/10.5194/bgd-8-8269-2011.
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Abstract. Peat surface CO2 emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m) in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations. The autotrophic root respiration component of the CO2 emission was separated from heterotrophic emissions caused by peat oxidation in three ways: (i) by comparing CO2 emissions within and beyond the tree rooting zone, (ii) by comparing CO2 emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone), and (iii) by comparing CO2 emissions before and after Acacia tree harvesting. On average, the contribution of root respiration to daytime CO2 emission is 21 % along transects in mature tree stands. At locations 0.5 m from trees this is up to 80 % of the total emissions, but it is negligible at locations more than 1.3 m away. This means that CO2 emission measurements well away from trees are free of any root respiration contribution and thus represent only peat oxidation emission. We find daytime mean annual CO2 emission from peat oxidation alone of 94 t ha−1 yr−1 at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha−1 yr−1 after correction for the effect of diurnal temperature fluctuations, which resulted in a 14.5 % reduction of the daytime emission. There is a positive correlation between mean long-term water table depths and peat oxidation CO2 emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO2 emissions. The increase in the temperature of the surface peat due to plantation development may explain over 50 % of peat oxidation emissions.
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Wang, Xiao Mei, and Cheng Rong Zhang. "Preparation of Chitosan/Acacia Microcapsule Facilitating Photo-Catalytic Degradation of Polypropylene Nonwovens." Advanced Materials Research 331 (September 2011): 160–64. http://dx.doi.org/10.4028/www.scientific.net/amr.331.160.
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Since the “plastic limit order” was released, shopping bags made of polypropylene spun-bonded nonwovens have been wildly used in daily life for their portability and recyclability. However, polypropylene materials are difficult to be degraded in natural conditions, thus they are not the “real” environmental protection bags. Many studies demonstrate that TiO2 has obvious effects on raising nonwovens’ photo-catalytic degradation rate. In this study, the microcapsules were prepared with complex coacervation method using chitosan and acacia as wall and TiO2 as core material. In addition, the main process parameters including the concentration of chitosan, PH of the coacervation solution and stirring speed, which have effects on the microcapsule formation behavior were discussed specially. The results show that the good microcapsules were produced at the condition of the chitosan concentration of 0.4%, the PH valued about 3.18, stirring speed of 300r/min, temperature of the coacervation 60°Cand the condensation reaction time for 15 minutes.
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Gambo, Anthony Victor. "CORROSION INHIBITION PERFORMANCE OF ACACIA NOLITICA POD EXTRACT ON ALUMINIUM ALLOY IN 1M ALKALINE SOLUTION." FUDMA JOURNAL OF SCIENCES 4, no. 3 (2020): 154–61. http://dx.doi.org/10.33003/fjs-2020-0403-284.
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The effect of extract of Acacia Nolitica pod on the corrosion inhibition of LM 6 aluminium alloy in 1M NaOH was studied using weight loss, gasometric, and open circuit potential techniques. Corrosion rates were found to reduce in the presence of the inhibitor. The inhibition efficiency was found to increase with increase in the concentration of the inhibitor and decreased with increase in the temperature. Thermodynamic parameters showed that the adsorption of the inhibitor on the metal surface is a spontaneous process and that the adsorption was via a physisorption mechanism. The adsorption process fitted perfectly with the Langmuir adsorption isotherm indicating that the extract was strongly adsorbed on the aluminium alloy surface. Morphology of the surface was examined by scanning electron microscopy (SEM) in the absence and presence of 0.5%v/v of the used inhibitor which confirmed the existence of a protective film of inhibitor molecule on the metal surface.
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D'Souza, Nola K., Ian J. Colquhoun, Bryan L. Shearer, and Giles E. St J. Hardy. "The potential of five Western Australian native Acacia species for biological control of Phytophthora cinnamomi." Australian Journal of Botany 52, no. 2 (2004): 267. http://dx.doi.org/10.1071/bt03089.
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Five Acacia species native to Western Australia were assessed for their potential to protect the highly susceptible species Banksia grandis Wield from infection by the plant pathogen Phytophthora cinnamomi Rands. In a rehabilitated bauxite pit at Jarrahdale 55 km south-east of Perth and in a glasshouse trial, B. grandis planted either alone or with A. pulchella R.Br., A. urophylla Benth., A. extensa Lindl., A. lateriticola Maslin or A. drummondii Lindl., was soil inoculated with P. cinnamomi. It could only be shown that A. pulchella significantly protected B. grandis from P. cinnamomi infection in the rehabilitated bauxite pit trial up to 1 year after inoculation. This confirms the potential of this species for biological control of the pathogen in infested plant communities. The observed protection was not the result of a decrease in soil temperature or moisture. Protection was not emulated in a glasshouse trial where optimum environmental conditions favoured P. cinnamomi. Despite a delay in infection of B. grandis planted with Acacia spp., none of the five species definitively protected B. grandis from P. cinnamomi. However, in the glasshouse trial, A. pulchella, A. extensa, A. lateriticola and A. drummondii did significantly reduce the soil inoculum of P. cinnamomi, indicating a possible biological control effect on the pathogen. The mechanisms of biological control are discussed and the implications for management of rehabilitated bauxite mined areas and forests severely affected by P. cinnamomi are considered.
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Huang, Zhenxiong, Lang Liu, Guojian Li, Hong Li, Dapeng Ye, and Xiaoli Li. "Nondestructive Determination of Diastase Activity of Honey Based on Visible and Near-Infrared Spectroscopy." Molecules 24, no. 7 (2019): 1244. http://dx.doi.org/10.3390/molecules24071244.
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The activities of enzymes are the basis of evaluating the quality of honey. Beekeepers usually use concentrators to process natural honey into concentrated honey by concentrating it under high temperatures. Active enzymes are very sensitive to high temperatures and will lose their activity when they exceed a certain temperature. The objective of this work is to study the kinetic mechanism of the temperature effect on diastase activity and to develop a nondestructive approach for quick determination of the diastase activity of honey through a heating process based on visible and near-infrared (Vis/NIR) spectroscopy. A total of 110 samples, including three species of botanical origin, were used for this study. To explore the kinetic mechanism of diastase activity under high temperatures, the honey of three kinds of botanical origins were processed with thermal treatment to obtain a variety of diastase activity. Diastase activity represented with diastase number (DN) was measured according to the national standard method. The results showed that the diastase activity decreased with the increase of temperature and heating time, and the sensitivity of acacia and longan to temperature was higher than linen. The optimum temperature for production and processing is 60 °C. Unsupervised clustering analysis was adopted to detect spectral characteristics of these honeys, indicating that different botanical origins of honeys can be distinguished in principal component spaces. Partial least squares (PLS) and least squares-support vector machine (LS-SVM) algorithms were applied to develop quantitative relationships between Vis/NIR spectroscopy and diastase activity. The best result was obtained through Gaussian filter smoothing-standard normal variate (GF-SNV) pretreatment and the LS-SVM model, known as GF-SNV-LS-SVM, with a determination coefficient (R2) of prediction of 0.8872, and root mean square error (RMSE) of prediction of 0.2129. The overall results of this paper showed that the diastase activity of honey can be determined quickly and non-destructively with Vis/NIR spectral methods, which can be used to detect DN in the process of honey production and processing, and to maximize the nutrient content of honey.
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Morales-Antonio, Miguel A., Gisela M. Santiago-Martínez, Alfonso Vásquez-López, et al. "Uredospore germination of Hemileia vastatrix and its inhibition by the effect of plant extracts in vitro." International Journal of Agriculture and Natural Resources 48, no. 2 (2021): 108–17. http://dx.doi.org/10.7764/ijanr.v48i2.2272.
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Coffee leaf rust, caused by Hemileia vastatrix, is the most important disease of coffee (Coffea arabica L.) in Mexico. It causes production losses of up to 40% and leads to the use of considerable volumes of synthetic fungicides. The main goals of this research were to identify the temperature, pH, incubation time, and luminosity required for in vitro germination of H. vastatrix uredospores and to evaluate the effect of plant extracts on their germination. Uredospores from coffee plants (var. Caturra) grown in the state of Oaxaca, Mexico, were collected and subjected to treatments consisting of combined levels of T°, pH, and incubation time. The treatments were evaluated in darkness and under low-intensity white light (15 W). Uredospore germination occurred in the absence and presence of light. The highest percentage of uredospore germination was 44.95%, which occurred at pH 5.7, between 18 and 24 °C, and with an incubation time of 24 h. The effect of 30 plant extracts was evaluated in terms of inhibition of uredospore germination. The acetone and ethanol extracts of Tribulus terrestris, Datura ferox, Mansoa alliacea, Ricinus communis, and Acacia farnesiana inhibited 100% of uredospore germination. Thus, plant extracts may contribute to the integrated disease management of coffee leaf rust.
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El - Kheir, Murwan K. Sabah, Abu El Gasim A. Yagoub, and Asma A. Abu Baker. "Emulsion-Stabilizing Effect of Gum from Acacia senegal (L) Willd. The Role of Quality and Grade of Gum, Oil Type, Temperature,Stirring Time and Concentration." Pakistan Journal of Nutrition 7, no. 3 (2008): 395–99. http://dx.doi.org/10.3923/pjn.2008.395.399.
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Nuhu, B., Z. Yusuf, S. Hapsatu, and IA Ishiyaka. "Effects of Hot Water Treatment and Temperature on Seedling Emergence and Morphological Attributes of Acacia senegal L. Seeds." Journal of Agricultural Research and Development 12, no. 1 (2014): 53. http://dx.doi.org/10.4314/jard.v12i1.6.
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Jauhiainen, J., A. Hooijer, and S. E. Page. "Carbon dioxide emissions from an <i>Acacia</i> plantation on peatland in Sumatra, Indonesia." Biogeosciences 9, no. 2 (2012): 617–30. http://dx.doi.org/10.5194/bg-9-617-2012.
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Abstract. Peat surface CO2 emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m) in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations, over a 2 year period. The autotrophic root respiration component of CO2 emission was separated from heterotrophic emission caused by peat oxidation in three ways: (i) by comparing CO2 emissions within and beyond the tree rooting zone, (ii) by comparing CO2 emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone), and (iii) by comparing CO2 emissions before and after Acacia tree harvesting. On average, the contribution of autotrophic respiration to daytime CO2 emission was 21% along transects in mature tree stands. At locations 0.5 m from trees this was up to 80% of the total emissions, but it was negligible at locations more than 1.3 m away. This means that CO2 emission measurements well away from trees were free of any autotrophic respiration contribution and thus represent only heterotrophic emissions. We found daytime mean annual CO2 emission from peat oxidation alone of 94 t ha−1 y−1 at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha−1 y−1 after correction for the effect of diurnal temperature fluctuations, which may result in a 14.5% reduction of the daytime emission. There is a positive correlation between mean long-term water table depth and peat oxidation CO2 emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO2 emissions. The increase in the temperature of the surface peat due to plantation establishment may explain over 50% of peat oxidation emissions. Our study sets a standard for greenhouse gas flux studies from tropical peatlands under different forms of agricultural land management. It is the first to purposefully quantify heterotrophic CO2 emissions resulting from tropical peat decomposition by separating these from autotrophic emissions. It also provides the most scientifically- and statistically-rigorous study to date of CO2 emissions resulting from anthropogenic modification of this globally significant carbon rich ecosystem. Our findings indicate that past studies have underestimated emissions from peatland plantations, with important implications for the scale of greenhouse gas emissions arising from land use change, particularly in the light of current, rapid agricultural conversion of peatlands in the Southeast Asian region.
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Triboli, Edison Paulo De Ros, and Jorge Andrey Wilhelms Gut. "Study of Spray-dried Yoghurt Production in a Pilot-scale Equipment Using Drying Agents to Reduce Wall Deposition." International Journal of Food Engineering 12, no. 8 (2016): 793–803. http://dx.doi.org/10.1515/ijfe-2015-0355.
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Abstract The objective of this study was to determine suitable conditions for yoghurt spray drying in a pilot-scale equipment with a rotary atomizer using drying auxiliary agents to reduce wall deposition in the drying chamber. First, the effects of the main process variables (disk rotation speed: 25,000–30,000 rpm; inlet air temperature: 160–180 °C; feed flow rate: 5.2–8.7 kg/h) were studied with a 23 central composite experimental design. Following, six different drying agents (maltodextrins 5 dextrose equivalent [DE] and 10 DE, EmCap®, acacia gum, skimmed milk and fumed silica) were tested to identify the most promising additive to improve process yield. Excellent results on wall deposition, product recovery, product color and particle size distribution span were achieved with fumed silica Aerosil® at 3 %, 26,000-rpm atomizer speed, 160 °C inlet air temperature and 8.7 kg/h yoghurt feed flow rate. The action of the fumed silica on particle agglomerates produced a free-flowing powder with good homogeneity.
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Al-Badawy, Ahmed A., M. I. El-Amry, and M. A. Salem. "Growth and Performance of Some Woody Plants Grown under Salinity Stress." HortScience 35, no. 4 (2000): 554D—554c. http://dx.doi.org/10.21273/hortsci.35.4.554d.
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Six woody plant species, (Atriplex lentiformis, Acacia ampliceps, Conocarpus erectus, Conocarpus erectus var. sericeus, Laguncularia racemosa, and Thespesia populnea) different in age, were grown in the field and irrigated with saline water (25 ppt). The physiological performance of these species was measured. Some macro- and micro-elements, carbohydrates, protein, proline, and photosynthetic pigments were estimated in the plants. The obtained results indicated in most cases, that age of plants has no effect on nutrients, protein, or carbohydrate concentrations. For each plant species, there were some differences in the chemical composition of the leaves and stems. No significant differences were detected in Mg and Mn concentrations in leaves and stems of all studied species. Photosynthetic pigments and proline concentrations were different depending on the plant species and age. The air and leaf temperature differentials, leaf conductance, and transpiration rate were also discussed. The overall growth and physiological performance of these plants was good.
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Idol, Travis, Patrick J. Baker, and Dean Meason. "Indicators of forest ecosystem productivity and nutrient status across precipitation and temperature gradients in Hawaii." Journal of Tropical Ecology 23, no. 6 (2007): 693–704. http://dx.doi.org/10.1017/s0266467407004439.
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Precipitation and temperature are known to have important effects on forest productivity, but these effects may be strongly mediated through their influence on soil and leaf nutrients. We measured indicators of forest productivity and soil and leaf nutrients across independent gradients of precipitation and elevation/temperature in lower montane Hawaiian forests dominated by a single overstorey species, Acacia koa, situated on 1500–3000-y-old soils that were mixtures of volcanic ash and basalt. Stand basal area was highest at the wettest site, 2000 mm mean annual precipitation (MAP), and leaf N and P were lowest at the driest site, 1000 mm MAP. Soil N availability and leaf N concentration declined across an 850-m elevation gradient, but this was not correlated with stand basal area or soil organic matter content. Across all stands, basal area was negatively correlated with the exchangeable soil P fraction. As well, the soil C:N ratio was negatively correlated with both soil P availability and the size of the primary mineral P fraction. Soil P availability and weathering appear to be important determinants of soil organic matter quantity and quality. Overall, precipitation is the major driving force for forest productivity, but P weathering and availability play important roles in limiting productivity in wetter sites and in controlling soil organic matter dynamics in these N-fixing forests.
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Piotraszewska-Pająk, Allna, and Anna Gliszczyńska-Świgło. "Directions of Colour Changes of Nectar Honeys Depending on Honey Type and Storage Conditions." Journal of Apicultural Science 59, no. 2 (2015): 51–61. http://dx.doi.org/10.1515/jas-2015-0019.
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AbstractThe colour of honey is one of the most important quality criteria for consumers. The colour depends mainly on the content of plant pigments but the honey consistency, shape, and size of the crystals may also influence the honey colour parameters. It is related to the crystallisation and decrystallisation processes of honey during storage. In the present study, directions of colour changes of honey during storage were evaluated using a tristimulus colorimeter and the CIE 1976 L*a*b* and CIE L*C*hosystems. The effect of time (3 and 9 months) and storage conditions (cold storage, room temperature storage with access to light, and room temperature storage without access to light) on the colour of nectar honeys was investigated. The results obtained showed that both the type of honey and the storage conditions influenced the honey colour parameters. Significant differences in direction and intensity of the colour changes of honey during storage were observed. These differences make it difficult to indicate which storage conditions are optimal to preserve the colour of the honey. It was found that acacia and heather honeys were the most susceptible to colour changes during long-term storage in all of the study’s applied conditions, whereas rape and buckwheat honeys were the most stable in colour parameters.
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Khurana, Ekta, and J. S. Singh. "Ecology of seed and seedling growth for conservation and restoration of tropical dry forest : a review." Environmental Conservation 28, no. 1 (2001): 39–52. http://dx.doi.org/10.1017/s0376892901000042.
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Dry forests are among the most threatened ecosystems and have been extensively converted into grasslands, secondary forest, savanna or agricultural land. Knowledge of seed germination and seedling establishment is required for the success of efforts on restoration of these forests. This review focuses on the ecological requirements at seed and seedling stages, and collates the current knowledge of seed viability, dormancy, germination pattern and seedling behaviour of dry tropical tree species. The spatio-temporal variations within the tropical dry forest biome in soil moisture, light, temperature, nutrients and intensity of predation, significantly affect the seed and seedling traits of component species. The majority of dry tropical species possess orthodox seeds which are characterized by dormancy, while a few have recalcitrant seeds which possess little or no dormancy. Seed coat dormancy, which can be overcome by mechanical or acid scarification or sometimes by transit through animal guts, is most prevalent in the dry tropical forest species. Persistent species dominating the undisturbed portions of the forest have bigger seeds compared to those that mostly occur in disturbed regions and require shade for the survival of their seedlings. Shade demand is associated with drought endurance, and may be absolute in species such as Guettarda parviflora and Coccoloba microstachya, or facultative as in Plumeria alba and Bursera simaruba. The fluctuation in temperature significantly affects seed germination in several species of dry Afromontane forest trees of Ethiopia. Seedling mortality is primarily a function of moisture stress during the dry period. Adaptive responses of seedlings to drought stress include increased chlorophyll content, for example in Acacia catechu, and root biomass, as in several dry forest species (for example Drypetes parvifolia, Teclia verdoornia) of Ghana. Mulching, application of fertilizers, interplanting of leguminous species and mycorrhizal inoculation are useful tools for promoting seedling establishment in nutrient-poor dry tropical soils. Periodic forest fires, and predation affect recruitment and seedling development according to their intensity. Many species experiencing frequent fires have evolved thick seed coats, produce fire-hardy seedlings, or escape the effect by temporal separation of seed dispersal and fire events. Predation may result in abortion of fruits or may enhance germination and recruitment by scarification and dispersal, as in most species of the Guanacaste dry forest. Exposure to elevated CO2 has increased relative growth rate, total leaf area and water use efficiency in most of the dry tropical seedlings tested, but the magnitude of the effect has varied markedly among species. Due to the availability of a large source of energy, large seeds show higher germination percentage, greater seedling survival and increased growth. Seeds originating from different provenances exhibit differences in germination and seedling growth (for example Prosopis cineraria, Albizia lebbeck, Eucalyptus camaldulensis and Acacia mangium), efficiency of nodulation (for example Acacia nilotica, A. auriculiformis), and stress resistance (for example Populus deltoides, Dalbergia sissoo). The review points out the need for coordinated, long-term, field-based studies for identification of multiple cues and niches for germination, on seed and seedling dynamics in response to fire, and on within-species genetic variability for selection of suitable provenances. Field-based studies at species and community levels are also needed to permit manipulations of biotic components to augment the recruitment of desired species and to suppress that of undesirable species.