Query: acacia mangium 

title: Economic Performance of Forest Plantations in Vietnam: Eucalyptus, Acacia mangium, and Manglietia conifera
abstract: Forest plantations have expanded rapidly in response to financial support from the state and local governments and have had significant positive impacts on rural livelihoods and development in Vietnam, since the late 1980s. This study used net present value (NPV) and internal rate of return (IRR) to examine the economic performance of plantations for three species, Acacia mangium Willd, Eucalyptus (Eucalyptus urophylla S.T. Blake x Eucalyptus camaldulensis Dehn) and Manglietia conifera Dandy, in Bac Kan province. On the basis of an annual discount rate of 6% the results showed that rural households earned positive financial returns from forest plantations with seven year rotations. Eucalyptus generated the highest NPV but A. mangium generated the greatest IRR. The plantations were facilitated by financial support from the state, land tenure reforms, and wood exports. The results provide valuable business information and policy implications for both local farmers and policy makers. Since the farmers consider more of the short term and economic return of the plantations, the results provide valuable information for policy makers to apply subsidies and other support to promote plantations with significant ecological and environmental benefits for sustainable development of rural economies.

title: Diversity of arthropods on Acacia mangium (Fabaceae) and production of this plant with dehydrated sewage sludge in degraded area
abstract: Sewage sludge is an organic matter rich material with abundant fractions of nitrogen and other macro and micronutrients, essential for plant growth and development such as Acacia mangium Willd.  used in recovering actions of degraded areas. The objective of this study was to evaluate over 24 months the abundance and diversity of chewing and pollinator insects and arthropod predators on A. mangium plants and the mass production and soil coverage by this plant, fertilized with dehydrated sewage sludge, in a degraded area. The experimental design was in randomized blocks with two treatments (with and without dehydrated sewage sludge) and 24 replications. The number of leaves per branch and branches per plant, defoliation percentage by chewing insects, soil cover and abundance of chewing and pollinator insects and arthropod predators were higher on A. mangium plants fertilized with dehydrated sewage sludge. Nasutitermes sp.

title: Nitrogen cycling in monospecific and mixed species plantations of Acacia mangium and Eucalyptus at 4 sites in Brazil
abstract: Mixing N fixing trees with eucalypts is an attractive option to improve the long term soil N status in fast growing plantations established in tropical soils. A randomized block design was replicated at four sites in Brazil to compare the biogeochemical cycles in mono specific stands of Eucalyptus (100E) and Acacia mangium (100A) with mixed species plantations in a proportion of 1:1 (50A50E) Our study aimed to assess the effects of introducing A. mangium trees in Eucalyptus plantations on atmospheric N2 fixation, N cycling and soil organic matter stocks. Litterfall and soil N mineralization were measured over the last two years of the rotation (4 6 years after planting) Aboveground N accumulation in the trees and C and N stocks in the forest floor and in the top soil were intensively sampled at harvesting age. N2 fixation rates were estimated using the natural abundance of 15N as well as by the difference between total N stocks in 100A and 50A50E relative to 100E (accretion method) While the 15N natural abundance method was unsuitable, the accretion method showed consistently across the four sites that atmospheric N fixation reached about 250 and 400 kg N ha 1 rotation 1 in 50A50E and 100A, respectively. Except at one site with high mortality, N contents within trees at harvesting were approximately 40% higher in 100A than in 100E. Mean N contents in litterfall and N mineralization rates were about 60% higher in 100A than in 100E, with intermediate values in 50A50E. The amounts of N in litterfall were much more dependent on soil N mineralization rates for acacia trees than for eucalypt trees. Soil C and N stocks were dependent on soil texture but not influenced by tree species. N budgets over a 6 year rotation were enhanced by about 65 kg N ha 1 yr 1 in 100A and 40 kg N ha 1 yr 1 in 50A50E relative to monospecific eucalypt plantations. Introducing N fixing trees in eucalypt plantations might therefore contribute to reducing the need for mineral N fertilization in the long term.

title: Interactions between mesofauna, microbiological and chemical soil attributes in pure and intercropped Eucalyptus grandis and Acacia mangium plantations
abstract: The introduction of nitrogen fixing trees in a mixed system with Eucalyptus can improve soil chemical and microbiological properties, especially C N contents and microbial diversity. However, the effects of this forest management on soil mesofauna remain poorly understood. Thus, we hypothesized that higher mesofauna abundance and diversity, microbial activity and soil quality are greater in the mixed plantation of Eucalyptus grandis and Acacia mangium than in pure Eucalyptus plantations. We aimed at evaluating the density and diversity of soil mesofauna, and its interaction with microbiological and chemical soil attributes in pure Acacia mangium (AC) Eucalyptus grandis (EU) and mixed E. grandis and A. mangium plantations (M) We also intended to adapt a general indicator of soil quality for such forest plantations. It is common for soil macrofauna studies to employ the general indicator of soil quality (GISQ) Since our study did not comprise soil macrofauna, but included only soil mesofauna, we adapted the GISQ to contemplate mesofaunal attributes, introducing the great interaction between them and microorganisms. Soil samples (0 5 cm) were collected at 2015, when trees were six years old. The only faunal order to show a higher density is Diplura. Our results show that the metabolic quotient (qCO2) is lower in AC, while the cation exchange capacity (CEC) H Al and soil moisture are higher in AC than in EU and M. We verified that intercropping of A. mangium in E. grandis improves soil quality and our indicator showed that soil mesofauna correlates with soil microbial attributes density. Thus, our results provide a novel evidence of ecological interactions between soil mesofauna and microorganisms under field conditions for pure and mixed plantations of Eucalyptus grandis and Acacia mangium.

title: Depolymerization and characterization of Acacia mangium tannin for the preparation of mussel inspired fast curing tannin based phenolic resins
abstract: Similar to the 3,4 dihydroxy L phenylalanine (DOPA) structures in mussel adhesive proteins (MAPs) tannin contains abundant similar catechol structures in the flavonoid units, which might be developed into high performance adhesives. In this study, Acacia mangium tannin (AMT) was depolymerized under acidic conditions with 2 methylfuran as a nucleophilic reagent. The depolymerized tannin (DAMT) was combined with polyethyleneimine (PEI) to prepare tannin based phenolic resins to mimic the MAP systems. The investigation of the chemical structures of tannin indicated the successful reaction of 2 methylfuran onto the flavonoid units to increase the chemical reactivity, as evidenced by the MALDI TOF MS, GPC, 1H NMR, and FT IR analyses. The as prepared PEI and DAMT modified phenolic (DTPF PEI) resin showed a high cross linking and three dimensional network, resulting from the high reactivity of DAMT. Complex reactions were observed during the curing of the as prepared resin, including Michael addition and/or Schiff base formation reactions between the amino groups of PEI and the ortho quinone of tannins, as well as the condensation reactions between PEI and the phenolic resins. Compared with tannin phenol formaldehyde (TPF) resin, the gel time of the DTPF PEI resin decreased from 630 s to 204 s (decreased by 67.6% the mass loss after hydrolysis decreased by 26.3% the bonding strength increased by 63.6% when cured at 135 degC, and the formaldehyde emission decreased by 64.4% Such high performance might be contributed by the formation of highly cross linked networks, as well as the hydrogen bonding and pi cation interactions between the catechol structures and the adhered surfaces. With its outstanding performance, including fast curing rate, excellent adhesion properties, low formaldehyde emission, and high thermal stability, this newly developed adhesive has the potential to be used as an alternative of conventional phenol formaldehyde resins.

title: Mechanical and physical properties of Cross Laminated Timber made from Acacia mangium wood as function of adhesive types
abstract: In this study, three layered Cross Laminated Timber (CLT) manufactured from Acacia mangium wood panels were developed by using two different types of adhesives, namely, phenol resorcinol formaldehyde (PRF) and one component polyurethane (PUR) The aim of this work is to investigate and compare the physical and mechanical properties of CLT manufactured using PRF and PUR adhesives. Water absorption (WA) thickness swelling (TS) and delamination of both types of samples were investigated as their physical properties. PRF bonded CLT showed better physical properties than PUR bonded CLT. In terms of mechanical properties, bending test, shear modulus, and compression parallel to grain were studied. The results revealed that global modulus of elasticity (Em,g) and modulus of rupture (MOR) of panels bonded with PRF adhesive were higher than three layered panels made from PUR adhesive. Meanwhile, shear modulus (G) of PRF bonded CLT was 116.50 N/mm2, 20% higher than that of the PUR bonded CLT which recorded a shear modulus value of 92.48 N/mm2. As for compressive properties, the MOE in compression (Ec,0) and compression strength (fc,0) of the PRF bonded CLT (5304 N/mm2 and 28.99 N/mm2, respectively) was slightly higher compared to that of the PUR bonded (4787 N/mm2 and 28.14 N/mm2, respectively) Three main types of bending failure modes were observed in the CLT samples, namely, rolling shear, glue line failure, and tension. The failure modes of shear were observed by two ways, which is delamination and rolling shear. Lastly, shearing, splitting, and crushing were recorded in compression failure modes.

title: Growth Responses of Eucalyptus pellita F. Muell Plantations in South Sumatra to Macronutrient Fertilisers Following Several Rotations of Acacia mangium Willd.
abstract: Eucalyptus pellita has rapidly emerged as the species that has replaced Acacia mangium in broad scale commercial plantations in Indonesia following widespread losses due to disease and in soils that have suffered a steady decline in phosphorus (P) under plantation forestry. Conversion from a nitrogen (N) fixing to a non N fixing species is expected to change the nutrient dynamics and the management required to maximise productivity. In this study in South Sumatra, responses of E. pellita to the application of N, P, potassium (K) and calcium (Ca) fertilisers were assessed at a number of trials on sites with varying site history; A. mangium was planted at one site to compare the species' responses to N and P. The growth of E. pellita responded significantly (p 0.01) to P's application but not to N, K or Ca, with the addition of P increasing the stem volume by 32.6 m3 ha 1 at 3 years of age compared with no addition of P fertiliser; the demand for P in the first two years of growth was, respectively, 4.8 and 6.8 kg ha 1. This positive and large response appears to be because E. pellita has a lower efficiency in its use of P than A. mangium and is, therefore, more responsive than A. mangium to the addition of P. The reason for the lack of response to N remains unclear, although demand for N as well as K and Ca was high. These results suggest that sites recently converted to E. pellita from A. mangium and also new ex native forest sites will be likely to only respond to P addition and that the response of E. pellita is likely to be greater than for A. mangium to maximise yield. At present, additional N, Ca or K fertilisers are not required, but this may change in the future.

title: Bond integrity of cross laminated timber from Acacia mangium wood as affected by adhesive types, pressing pressures and loading direction
abstract: Cross laminated timber (CLT) was fabricated from Acacia mangium wood by using phenol resorcinol formaldehyde (PRF) and one component polyurethane (PUR) as binders. The purpose of the study was to evaluate the bond integrity of A. mangium CLT produced using different working parameters. The assemblies were pressed at 30 degC for 30 min using three pressing pressures (0.9 N/mm2, 1.2 N/mm2, and 1.5 N/mm2) Delamination and block shear tests were conducted on the CLT according to European Standards, EN 391 and EN 392, respectively. The results revealed that PRF bonded CLT experienced lower percent delamination compared to that bonded with one component PUR. It appears that a higher clamping pressure i.e. 1.5 N/mm2, is needed to sufficiently bond A. mangium lumbers as indicated by a marked increase in bond shear strength with an increase of pressing pressure. PRF was found to be a more superior adhesive than PUR irrespective of cramping pressure and loading direction. A. mangium wood is relatively dense thus requires quite high pressure, 1.5 N/mm2, irrespective of adhesive used. PRF appears to bond A. mangium wood better compared to PUR with shear bond strength of 21% and wood failure percentage of 220% higher.

title: Effect of residue management and fertiliser application on the productivity of a Eucalyptus hybrid and Acacia mangium planted on sloping terrain in northern Vietnam
abstract: Forest plantation growers in Vietnam commonly burn residues after harvesting and often apply suboptimal amounts of nutrients during plantation establishment. We examined whether the retention of forest residue, and application of phosphorus fertiliser at higher rates, can increase rates of growth. A factorial combination of residue management (burning vs retention) and phosphorus fertiliser application at planting (15 vs 100 kg ha 1) treatments were applied at a steeply sloping site in northern Vietnam. Two adjacent experiments were established, one with Acacia mangium and the other with a Eucalyptus hybrid (Eucalyptus urophylla x Eucalyptus pellita) Standing volume and leaf area index in A. mangium were greater following burning; this was mostly attributable to the significantly higher survival rate of seedlings. Burning of residues was associated with increases in the number of large branches per tree, and a higher crown damage index (CDI) In the Eucalyptus hybrid, diameter and height responses to the higher rate of fertiliser were observed at age 6 and 12 months, but not beyond. High phosphorus application also led to higher CDI. Standard fertiliser treatment, applied in amounts equivalent to 17, 15 and 8 kg ha 1 of nitrogen, phosphorus and potassium, respectively, was adequate to meet the early growth requirement of eucalypt and acacia plantations at this site. The relatively low amounts of harvest residue and high fertility levels at the site may have masked more significant responses of trees to the silvicultural treatments applied in this study. On steep slopes, especially if soil is poorly fertile, harvest residue retention with adequate weed and termite control may be preferential to burning as it is closely correlated with reducing factors that negatively impact productivity, i.e. water run off and soil erosion.

title: Can Acacia mangium and Acacia auriculiformis hinder restoration efforts in the Brazilian Atlantic Forest under current and future climate conditions?
abstract: Climate change and biological invasions are two of the most cited factors that may affect species diversity in the coming decades. Here we used five climate scenarios to investigate the potential distribution of two invasive tree species, Acacia mangium and A. auriculiformis, in the Atlantic Forest hotspot. Additionally, we used expansion contraction maps and maps of potential areas for forest restoration to investigate whether biological invasion could affect restoration efforts. We found A. mangium has a large suitable area in all scenarios (average 268,010.1 km2 25,292.4 SD) while A auriculiformis is confined to a relatively small region (average 13,123.1 km2 361.7 SD) In the low greenhouse gas emissions scenario (RCP 2.6) the suitable area for A. mangium varied from the current scenario of 24.8% of the Atlantic Forest to 26.2% and 25.4% in the years 2050 and 2070, respectively. In the high greenhouse gas emission scenario (RCP 8.5) the suitable area contracted to 23.1% and 20.5% in 2050 and 2070, respectively. Approximately 30.8% of the potential area for restoration currently overlaps the suitable area for A. mangium, and this overlap reaches at least 23.8% of the potential areas for restoration in the future scenarios (RCP 8.5 in 2070) A. mangium has a large suitable area in the Atlantic Forest and can become a barrier to restoration efforts in the coming decades. Expansion contraction maps should be used to establish environmental policies that promote both forest restoration and prevention of biological invasion in suitable areas.