Acacia Mangium

Agroforestry, the purposeful growing of trees and crops in interacting combinations, began to attain prominence in the late 1970s, when the international scientific community embraced its potentials in the tropics and recognized it as a practice in search of science. During the 1990s, the relevance of agroforestry for solving problems related to deterioration of family farms, increased soil erosion, surface and ground water pollution, and decreased biodiversity was recognized in the industrialized nations too. Thus, agroforestry is now receiving increasing attention as a sustainable land-management option the world over because of its ecological, economic, and social attributes. Consequently, the knowledge-base of agroforestry is being expanded at a rapid rate as illustrated by the increasing number and quality of scientific publications of various forms on different aspects of agroforestry.

spatial analysis of root rot of Acacia mangium in Indonesia. Root rot caused by Ganoderma spp. is a serious concern in commercial plantations of Acacia mangium in Indonesia. This study surveyed root rot incidence and spatial arrangement in commercial plantations and trials. In second rotation commercial plantations in Sumatra and Kalimantan, root rot incidence was recorded between 3 and 28% in trees aged from three to five years old. The compartments surveyed in Riau province and East Kalimantan had significantly higher root rot than South Sumatra. In a progeny trial of A. mangium in Java, root rot incidence was surveyed twice, when trees were eight and again at nine years old. Root rot incidence was about 7 and 13% respectively. Spatial analysis by distance indices (SADIE) revealed that infected trees were randomly distributed at the first time point but tended to become aggregated by the time of the second survey. This highlights the probability of vegetative spread of the fungus after initial introduction to the site. Assessment of root rot incidence on the basis of A. mangium provenance did not reveal any statistically significant differences. . Insidens dan analisis ruangan bagi reput akar Acacia mangium di Indonesia. Reput akar yang diakibatkan oleh Ganoderma spp. merupakan masalah serius di ladang komersial Acacia mangium di Indonesia. Kajian ini meninjau insidens serta susunan ruangan reput akar di ladang komersial serta tapak ujian. Di ladang komersial pusingan kedua di Sumatra dan Kalimantan, insidens reput akar pada pokok berusia tiga tahun hingga lima tahun adalah sebanyak 3% hingga 28%. Kompartmen yang ditinjau di daerah Riau dan Kalimantan Timur menunjukkan kejadian reput akar yang lebih tinggi daripada Sumatra Selatan. Dalam ujian progeni A. mangium di Jawa, tinjauan untuk insidens reput akar dilakukan sebanyak dua kali iaitu ketika pokok berusia lapan tahun dan sembilan tahun. Insidens reput akar yang dicerap dalam tinjauan tersebut masing-masing adalah sebanyak 7% dan 13%. Analisis ruangan melalui indeks jarak (SADIE) menunjukkan bahawa pokok yang dijangkiti bertabur secara rawak pada tinjauan pertama namun menjadi teragregat pada tinjauan kedua. Ini menunjukkan kulat mungkin tersebar secara vegetatif selepas muncul pertama kali di tapak. Penilaian insidens reput akar atas dasar provenans A. mangium tidak menunjukkan sebarang perubahan signifikan.

Acacia mangium is a fast-growing tree species. It is mainly planted in large monocultures for pulpwood in South-East Asia. Root rot has become the most economically damaging disease of this species with high tree mortality rates observed during second and third rotations. Two main types of root rots have been found in A. mangium, viz. brown root-rot and red-root disease caused by Phellinus spp. and Ganoderma spp., respectively. To assess the future management options for root rot of A. mangium, we review past and current disease-management strategies for root rot in different temperate and tropical industrial tree crops. The efficacies of a wide range of silvicultural, chemical and biological options are detailed, and their potential utilization in managing root rot of A. mangium is discussed. We conclude that the current gaps in knowledge regarding identification, biology and disease epidemiology of the root-rot pathogens will need to be addressed so that effective management options can be developed.

The differences in socio-economic and perceptional characteristics between tree planting and non- tree planting farmers were analysed in four case studies from three provinces in Indonesia. For each case study, the paper describes: a) the reasons for planting or not planting trees, b) how the income received from wood was used, c) the main disadvantages related to tree planting, and d) farmers willingness to continue tree planting under the current arrangements. The tree planters were mainly the farmers with more land; higher value of total assets; and with more active participation in farmer's groups or other social organizations. Long rotation length, lack of capital, low wood prices, and poor access to production inputs or markets affected farmers' willingness to plant trees in the future. Policies are needed that are conducive to the establishment of markets for fiber and timber with fair and reasonable pricing structures.

Fungal sporocarps and cultures associated with signs and symptoms of root-rot disease were collected from Acacia mangium and other tropical hardwood species. The collections were identified by either morphological characters and/or by phylogenetic analysis based on DNA sequences as Ganoderma philippii, G. mastoporum, G. aff. steyaertanum, G. australe and Amauroderma rugosum. Phylogenetic analysis unequivocally placed in the G. philippii clade four sequences amplified from A. mangium root and butt tissue showing clear signs of red root-rot disease (roots are covered by a red rhizomorphic skin). Whereas G. philippii was the most frequently encountered fungal species in A. mangium with red root-rot disease, this study indicates that other fungal species related to G. mastoporum may cause root-rot disease with very similar symptoms. An isolate (FRIM 138) that had caused red root-rot disease in artificial inoculations carried out before this study and was presumed to be G. philippii, is here determined to be closely related to G. mastoporum, G. cupreum and G. sinense. A Ganoderma species associated with a yellow-brown root-rot disease killing trees in an A. mangium plantation in Central Java, previously identified as G. lucidum, is shown by phylogenetic analysis to be closely related to G. steyaertanum, though some morphological characters vary from the original description of that species.

Plantations of exotic trees for industrial and agricultural purposes are burgeoning in the tropics, and some of them offer the opportunity to study community ecology of animals in a simplified forest setting. We examined bird community assembly in different aged groves of the industrial tree mangium (Acacia mangium) at two plantations in Malaysian Borneo: Sabah Softwoods near Tawau, Sabah, and the Planted Forest Project, near Bintulu, Sarawak. Bird communities were compared among three agegroups of mangium (2-, 5-, and 7-years old) and logged native forest. Mangium rapidly developed into a secondary forest consisting of a wide diversity of understory trees and shrubs. The bird community correspondingly increased in species richness and diversity, and we were able to relate these increases specifically to canopy height, secondary canopy development, and shrub cover. Species of common, small bodied frugivores, nectarivores, and insectivores were diverse in older plantation groves, as were common mid-sized insectivores. However, large, specialized, and normally uncommon taxa (e.g., galliforms, pigeons, hornbills, barbets, midsized woodpeckers, muscicapine flycatchers, and wren babblers) were rare or nonexistent in the plantations. Because we lacked species-specific data on foraging, nesting, and other behaviors of most groups of birds, it was difficult to explain the precise causes of seral diversification in any group except woodpeckers, which have been well studied in Southeast Asia. Thus, in future, particular emphasis needs to be placed on obtaining such data. Industrial plantations, by virtue of their simple structure, variably aged groves, and bird community richness, are good places to gather such data.

Two consecutive years of investigation on soil surface features, surface runoff and soil detachment within 1-m 2 microplots on 40% slope highlighted the effects of land-use change, vegetation cover and biological activity on the water pathways in Northern Vietnam. Three replicate plots were set up on each of five land-uses: cassava (CAS), grass fodder of Bracharia ruziziensis (BRA), a 3-year old fallow (FAL), tree stands of Acacia mangium and Venicia montana (FOR), and a fallow with regrowth of Eucalyptus regularly cut (EUC).

Water use of Acacia mangium trees grown in plantations was measured by a heat balance method in two stands that largely differed in tree density. Tree sap flow was closely coupled to climatic drivers and responded with minimal time delay. Using no time shift, sap flow rate could be tightly fitted to a simple equation that combined a parabolic response to radiation and an inverse linear response to air humidity. On the contrary, the analysis of canopy conductance showed no meaningful response to either individual or combined microclimatic variables. No indication of water deficit was observed, though the measurement period was during the dry period of the year. The measurements indicate a minimal diurnal use of water stored in plant tissues. The difference in tree water use from the two studied stands was effectively scaled by tree sapwood area. Canopy transpiration of the densest stand reached in average 3.9 mm d Ϫ1 compared with 2.7 mm d Ϫ1 for the stand representing the average conditions in the catchment. ᭧

Small volumes of timber are now being produced from Acacia mangium plantations in Indonesia. These trees require pruning and thinning to increase the strength and appearance of the wood. However, cut surfaces from pruning are potential infection courts for the entry of decay-causing fungi like heart rot. This study investigated the effects of pruning on stem form and the incidence of heart rot in an 18-month-old plantation of Acacia mangium in South Sumatra. The objectives were to assess whether pruning is associated with an increase in the incidence of heart rot and whether form pruning compared to lift pruning reduced the incidence of heart rot and improved stem form. Form pruning removed 25% of leaf area by removing large branches and those subtending a narrow angle with the stem up to 3 m height, and lift pruning removed 25% of crown length from below. Trees in these treatments were singled before pruning. The third treatment, a control, was not singled and was used to assess base levels of heart rot.

Fungal sporocarps and cultures associated with signs and symptoms of root-rot disease were collected from Acacia mangium and other tropical hardwood species. The collections were identified by either morphological characters and/or by phylogenetic analysis based on DNA sequences as Ganoderma philippii, G. mastoporum, G. aff. steyaertanum, G. australe and Amauroderma rugosum. Phylogenetic analysis unequivocally placed in the G. philippii clade four sequences amplified from A. mangium root and butt tissue showing clear signs of red root-rot disease (roots are covered by a red rhizomorphic skin). Whereas G. philippii was the most frequently encountered fungal species in A. mangium with red root-rot disease, this study indicates that other fungal species related to G. mastoporum may cause root-rot disease with very similar symptoms. An isolate (FRIM 138) that had caused red root-rot disease in artificial inoculations carried out before this study and was presumed to be G. philippii, is here determined to be closely related to G. mastoporum, G. cupreum and G. sinense. A Ganoderma species associated with a yellow-brown root-rot disease killing trees in an A. mangium plantation in Central Java, previously identified as G. lucidum, is shown by phylogenetic analysis to be closely related to G. steyaertanum, though some morphological characters vary from the original description of that species.

An introduced plantation tree species, Acacia mangium Willd., is becoming invasive in the Brunei region of Borneo. To examine its invasive potential, a greenhouse, additive series experiment (target-neighbour) involving seedlings of A. mangium and those of a common native heath-forest (kerangas), Melastoma beccarianum Cogn. was carried out under low and high light regimes in intra-and interspecific combinations over a 6-month period. Significant variations in growth parameters (other than biomass allocation patterns) existed amongst seedlings from different treatments. A major part of this variation in growth could be attributed to the main factors of target species, neighbour species, and competition (seedling density). For the growth variables examined, the target-species response was not consistent across light regimes. Under high light conditions, Acacia was the better competitor; the Lotka-Volterra competition coefficient effect of Melastoma on Acacia was lower (a=0.30) than the effect of Acacia on Melastoma (b=0.54). However, the reverse occurred under low light conditions with Melastoma gaining the upper hand (a=1.45 and b=0.44). These results show that light (and hence disturbance) can strongly influence the pattern and intensity of both intra-and interspecific competition between invasive and local flora species. Relatively intact forest is unlikely to be invaded by Acacia trees (as they are poor competitors under this scenario). On the other hand, the Acacia trees can easily invade disturbed forests, especially those prone to recurring drought and fire, and over time convert the habitats to nearly monospecific stands, as is presently being observed in Brunei.

Some tropical N2-fixing trees exhibit specific characteristics for phosphorus (P) acquisition and utilisation that contrast with the large nitrogen (N) fluxes in their litterfall. To investigate differences in N and P cycling in N2-fixing plantations, litterfall and fresh leaf quality of a N2-fixing Acacia mangium plantation were compared with that of a non-N2-fixing Swietenia macrophylla plantation and a coniferous Araucaria cunninghamii plantation. The N concentration in the A. mangium litterfall was higher than that in the litterfall of the two other species, whereas the P concentration in the A. mangium leaf litterfall was 0.16 mg g–1, which was only 12–22% of that of the other species. The P concentration in the reproductive parts of A. mangium was markedly higher (16.1 mg g–1) than those in the other fractions. The N:P ratio was higher in the leaf fall (81) compared to the fresh leaves (29) of A. mangium, in contrast to the N:P ratios in the leaf samples of the other two species. An analysis of a global litterfall dataset of tropical plantations indicated that N:P ratios in litterfall were significantly higher in N2-fixers than in non-N2-fixers, and those of A. mangium were high among species in the N2-fixer group. These results indicated that A. mangium efficiently retranslocated P in contrast to very large N cycling, under field conditions. These differences may be related to other physiological characteristics of A. mangium.

Pycnoporus coccineus and Coriolus versicolor are among the tropical white rot basidiomycetes that degrade lignin selectively. In this research work, crude enzyme produced during biopulping using both fungi were extracted, filtered and assayed using specific substrates. Both the peroxidases enzyme activities and residual lignin content were measured for the incubation period of 20, 40 and 60 days of biopulping. For both fungi, manganese peroxidase is predominant and highly expressed thus shows the highest rate compared to other ligninolytic enzymes activities in all of extract preparations. After 60 days of inoculation, manganese peroxidase activities are recorded as 270.51 U/mL and 274.36 U/mL for C. versicolor and P. coccineus, respectively. On the evaluation of the lignin content after biopulping, the lignin content showed significant decreased. Wood chip biotreated with C. versicolor showed higher percentage in lignin loss (9.42%) compared to with P. coccineus (8.10%).

The development of plantation forests in Indonesia is an ongoing activity, with planting of fast-growing species, such as Paraserianthes falcataria and Acacia mangium. The establishment of exotic fast-growing trees is one way of rehabilitating unproductive forest lands, which are usually covered by bushes, weeds or alang-alang grass (Imperata cylindrica). This paper explores the carbon-sequestration potential of two tree species. This is achieved by estimating their growth rates and performing economic analysis when carbon-credit payments are available. The effect of different carbon-accounting methods on the economic performance of plantation forests is analysed. The paper shows that carbon-credit payments may increase the net present value of a plantation by 11% to 20 % above the timber value alone. Discount rates are shown to have an important effect on economic performance of plantation forests, the effects of carbon prices and baseline settings are not as important.

spatial analysis of root rot of Acacia mangium in Indonesia. Root rot caused by Ganoderma spp. is a serious concern in commercial plantations of Acacia mangium in Indonesia. This study surveyed root rot incidence and spatial arrangement in commercial plantations and trials. In second rotation commercial plantations in Sumatra and Kalimantan, root rot incidence was recorded between 3 and 28% in trees aged from three to five years old. The compartments surveyed in Riau province and East Kalimantan had significantly higher root rot than South Sumatra. In a progeny trial of A. mangium in Java, root rot incidence was surveyed twice, when trees were eight and again at nine years old. Root rot incidence was about 7 and 13% respectively. Spatial analysis by distance indices (SADIE) revealed that infected trees were randomly distributed at the first time point but tended to become aggregated by the time of the second survey. This highlights the probability of vegetative spread of the fungus after initial introduction to the site. Assessment of root rot incidence on the basis of A. mangium provenance did not reveal any statistically significant differences. . Insidens dan analisis ruangan bagi reput akar Acacia mangium di Indonesia. Reput akar yang diakibatkan oleh Ganoderma spp. merupakan masalah serius di ladang komersial Acacia mangium di Indonesia. Kajian ini meninjau insidens serta susunan ruangan reput akar di ladang komersial serta tapak ujian. Di ladang komersial pusingan kedua di Sumatra dan Kalimantan, insidens reput akar pada pokok berusia tiga tahun hingga lima tahun adalah sebanyak 3% hingga 28%. Kompartmen yang ditinjau di daerah Riau dan Kalimantan Timur menunjukkan kejadian reput akar yang lebih tinggi daripada Sumatra Selatan. Dalam ujian progeni A. mangium di Jawa, tinjauan untuk insidens reput akar dilakukan sebanyak dua kali iaitu ketika pokok berusia lapan tahun dan sembilan tahun. Insidens reput akar yang dicerap dalam tinjauan tersebut masing-masing adalah sebanyak 7% dan 13%. Analisis ruangan melalui indeks jarak (SADIE) menunjukkan bahawa pokok yang dijangkiti bertabur secara rawak pada tinjauan pertama namun menjadi teragregat pada tinjauan kedua. Ini menunjukkan kulat mungkin tersebar secara vegetatif selepas muncul pertama kali di tapak. Penilaian insidens reput akar atas dasar provenans A. mangium tidak menunjukkan sebarang perubahan signifikan.

Plantations of exotic trees for industrial and agricultural purposes are burgeoning in the tropics, and some of them offer the opportunity to study community ecology of animals in a simplified forest setting. We examined bird community assembly in different aged groves of the industrial tree mangium (Acacia mangium) at two plantations in Malaysian Borneo: Sabah Softwoods near Tawau, Sabah, and the Planted Forest Project, near Bintulu, Sarawak. Bird communities were compared among three agegroups of mangium (2-, 5-, and 7-years old) and logged native forest. Mangium rapidly developed into a secondary forest consisting of a wide diversity of understory trees and shrubs. The bird community correspondingly increased in species richness and diversity, and we were able to relate these increases specifically to canopy height, secondary canopy development, and shrub cover. Species of common, small bodied frugivores, nectarivores, and insectivores were diverse in older plantation groves, as were common mid-sized insectivores. However, large, specialized, and normally uncommon taxa (e.g., galliforms, pigeons, hornbills, barbets, midsized woodpeckers, muscicapine flycatchers, and wren babblers) were rare or nonexistent in the plantations. Because we lacked species-specific data on foraging, nesting, and other behaviors of most groups of birds, it was difficult to explain the precise causes of seral diversification in any group except woodpeckers, which have been well studied in Southeast Asia. Thus, in future, particular emphasis needs to be placed on obtaining such data. Industrial plantations, by virtue of their simple structure, variably aged groves, and bird community richness, are good places to gather such data.

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P P . At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m−3 at Yen Thanh at age 8 years, and 473 kg m−3 at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m−3. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.

Estimation of the magnitude of sinks and sources of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations (mostly less than 10 years of age) in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea Roxb., Paraserianthes falcataria (L.) Nielsen Swietenia macrophylla King and Dipterocarp species in Mindanao, and Leucaena leucocephala de Wit from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur. Non-linear regression was used to derive speciesspecific, site-specific and generic equations between yield and diameter of the form y
= αDβ . Equations were evaluated based on the correlation coefficient, standard error of estimate and residual plots. Regressions resulted in high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies.

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m−3 at Yen Thanh at age 8 years, and 473 kg m−3 at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m−3. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.

Decades of deforestation and unsustainable land use have created large expanses of degraded lands across Central America. Reforestation may offer one means of mitigating these processes of degradation while sustaining resident human communities. However, a lack of information regarding tree species performance has been identified as an important limitation on the success and adoption of diversified reforestation strategies. We analyzed the initial growth of 22 native and 2 exotic tree species planted at three sites across a precipitation gradient in the Republic of Panama (1100-2200 mm year À1 ), and identify promising species for use in forest restoration, timber production and on-farm systems.

Timber extraction with crawler tractors in humid tropical forests causes degradation of soil physical properties and decreases plant growth. We tested rehabilitation of tracks in a second rotation Acacia mangium plantation in Sabah, Malaysia, by tilling with additions of NPK-fertilizer, ash and organic material to a depth of 15-20 cm. Two years after planting total basal area of A. mangium seedlings was 62% higher outside tracks compared to unimproved tracks, while on NPK-fertilized tracks performance was 700% higher compared to unimproved tracks. Corresponding figures for average height were 40 and 80%. After 8 days with little rain track topsoil experienced water shortage with all studied soil improvements. For 'non-tracked' areas wilting-point (À1500 kPa) was not reached during 17 days of dry weather, and more meso-pores were present. Consequently, depending on rainfall after planting the effect of soil rehabilitation on tree performance may be less positive than shown here, because dry periods of 2 weeks length are common in the humid tropics. Bulk density on plots outside tracks in this second-generation plantation was 60% higher than have been reported in similar first-generation plantations. It is discussed that this might be a warning that repeated logging and fire may have a detrimental effect on soil physical properties.

Some Acacia mangium Willd. plantations in Asia grow poorly due to low soil fertility and the absence of compatible mycorrhizal fungi. This legume tree can be colonized by arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi but inoculation is not routinely practiced. This study aimed to compare the effectiveness of AM fungi and four isolates of the ECM fungus Pisolithus tinctorius (Pers.) Coker and Couch (Pt) in promoting growth of A. mangium seedlings under glasshouse conditions. AM inoculants were: Glomus etunicatum, G. fasciculatum, G. macrocarpum and Gigaspora margarita and mixed species extracted from rhizosphere soil of a Populus stand in Suwon (AMKFRI), and Carex (AMM6) and Populus (AMM7) growing in mine tailings in Korea. Pisolithus isolates were from Philippines (PtPhil) and Korea (PtKFRI, PtMKACC, PtKACC). Generally, ECM fungi promoted height and diameter growth of A. mangium more than the AM inoculants. The Korean Pisolithus increased plant dry weight by 122-145%, mixed AM inoculants by 61-97%, and Glomus and Gigaspora by 45-72% over the control. PtKACC gave the highest root colonization and promoted the highest growth and concentration of most nutrients. Mycorrhizal root colonization was positively correlated with plant dry weight, Na, Fe and Cu concentrations and N, P, K, Ca, Na, Fe and Cu contents. In conclusion, the results provide strong evidence for benefits of mycorrhizal inoculation on A. mangium seedlings under glasshouse conditions. The Korean Pisolithus isolates (particularly PtKACC), and two AM fungi (AMKFRI and AMM6) are potential mycorrhizal inoculants but their effectiveness and persistence should be determined on degraded lands in tropical countries where A. mangium is being planted for rehabilitation.

We measured fine-root production at Acacia mangium (AM), Swietenia macrophylla (SM), and Araucaria cunninghamii (AC) sites in response to nitrogen (N) and phosphorus (P) application using the rootingrowth core method for a period of 5 months in Sabah, Malaysia. Root growth increased significantly using a combined N and P application at the AM site, whereas it did not increase at the SM and AC sites. The number of nodules at the AM site increased significantly following N application and the combined application of N and P.

The aim of our work was to assess the growth and mineral nutrition of salt stressed Acacia auriculiformis A. Cunn. ex Benth. and Acacia mangium Willd. seedlings inoculated with a combination of selected microsymbionts (bradyrhizobia and mycorrhizal fungi). Plants were grown in greenhouse conditions in non-sterile soil, irrigated with a saline nutrient solution (0, 50 and 100 mM NaCl). The inoculation combinations consisted of the Bradyrhizobium strain Aust 13c for A. mangium and Aust 11c for A. auriculiformis, an arbuscular mycorrhizal fungus (Glomus intraradices, DAOM 181602) and an ectomycorrhizal fungus (Pisolithus albus, strain COI 007). The inoculation treatments were designed to identify the symbionts that might improve the salt tolerance of both Acacia species. The main effect of salinity was reduced tree growth in both acacias. However, it appeared that, compared with controls, both rhizobial and mycorrhizal inoculation improved the growth of the salt-stressed plants, while inoculation with the ectomycorrhizal fungus strain appeared to have a small effect on their growth and mineral nutrition levels. Endomycorrhizal inoculation combined with rhizobial inoculation usually gave good results. Analysis of foliar proline accumulation confirmed that dual inoculation gave the trees better tolerance to salt stress and suggested that the use of this dual inoculum might be beneficial for inoculation of both Acacia species in soils with moderate salt constraints.

Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Fomitopsis palustris. However the filtrates from sugi wood processed at 270°C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot.

Introduction: Invasive plants can impact biodiversity as well as the lives of native human populations. Natural ecosystems represent sources of natural resources essential for the subsistence and socio-cultural continuity of these social groups. Approximately 30,000 ha of Acacia mangium were planted for commercial purposes in savanna areas surrounding indigenous lands in Roraima State, Brazil, at the end of the 1990s. We examined the local ecological knowledge of indigenous Wapichana and Macuxi Amerindians, members of the Arawak and Carib linguistic families, respectively, concerning A. mangium Willdenow (Fabaceae) in a savanna ecosystem (" Lavrado ") to attempt to understand its propagation beyond the limits of the commercial plantations and contribute to mitigating its impacts on socio-ecological systems.

Plants are frequently moved around the world, creating new regional landscapes and environmental imaginaries. Building on previous work in environmental history and geography, we develop a three-part approach to analyzing plant movements and apply it to trees from the Acacia genus (sens. lat.) exchanged between Australia and the rest of the world. First, we investigate the agents, circuits, and frequencies of acacia movements, including transoceanic transfers, regional diffusion, and ecological dispersal. Second, we trace bundles of knowledge or technology that accompany the acacias, highlighting how they help shape regional biogeographies. Finally, we analyze how different societies, with distinct economies, politics, and environmental sensibilities, receive introduced plants. This approach allows us to see transferred plants as active agents in region-forming processes, and to avoid normative tropes like 'miracle plants' or 'alien invasives'. The highlighted species include Acacia colei, Acacia melanoxylon, Acacia mearnsii, Acacia farnesiana, Acacia nilotica, Acacia mangium, and their close relatives.

RESUMO -(Respostas de Acacia mangium Willd e Sclerolobium paniculatum Vogel a fungos micorrízicos arbusculares nativos provenientes de áreas degradadas pela mineração de bauxita na Amazônia). A resposta de Acacia mangium Willd (mangium) e Sclerolobium paniculatum Vogel (tachi) à inoculação de fungos micorrízicos arbusculares (FMA), oriundos de áreas em recuperação após a extração de bauxita, foi avaliada em experimento com delineamento inteiramente casualizado, com 14 tratamentos (duas espécies leguminosas e sete tipos de solo) e três repetições. Avaliou-se o número de esporos no solo, a colonização micorrízica, a matéria seca total, o P acumulado, a dependência micorrízica das mudas, e a abundância e a freqüência de espécies. O número de propágulos infectivos (NPI) foi estudado em delineamento em blocos casualizados, com oito diluições de solo inóculo, cinco repetições e uma planta isca (Brachiaria decumbens Stapf). Utilizou-se substrato da mistura de um Planossolo mais areia lavada e fosfato de rocha araxá (0,60 g/kg). O número de esporos aumentou em função do tempo de cobertura das leguminosas. A colonização micorrízica foi mais intensa no tachi. Os valores de matéria seca dessa espécie foram inferiores aos de mangium, que por sua vez extraiu em torno de seis vezes mais P do substrato. Em geral, mangium, ao contrário do tachi, foi facultativa à presença dos FMA, sugerindo sua utilização na recuperação de áreas degradadas sem inoculação prévia. Dentre as 39 espécies de FMA identificadas, Glomus macrocarpum Tul. & Tul. apresentou maior índice de abundância e freqüência (IAF) e maior NPI, destacando-se entre as espécies pioneiras, ao passo que outras apareceram apenas em estádios sucessionais mais avançados das áreas em recuperação.

Understanding the light absorption and light use efficiency of each species at the tree scale is essential to disentangle the effects of intra-and inter-species interactions on productivity in mixed-species forest plantations. A complete randomized block design was set up using Eucalyptus grandis (E) and Acacia mangium (A), which is a N 2 -fixing species, planted in monospecific stands (100A, 100E) and in additive (25A:100E, 50A:100E, 100A:100E) and replacement (50A:50E) mixtures. Tree size and biomass were monitored over the complete rotation (6 years). The absorbed photosynthetically active radiation (APAR) for each tree in the experiment was simulated over the full rotation with the MAESTRA model. Measurements of tree leaf area, leaf angle distributions, leaf area density, and leaf and soil optical properties were performed to parameterize this model. The APAR and the ratio of stem biomass increment divided by the APAR (which is a measure of the Light Use Efficiency [LUE] for stem production) were calculated at tree and plot scales for each year of the rotation. The LUE of the 100E stand increased with age until stabilizing at 4 years of age, while the LUE of the 100A stand decreased between 2 and 4 years of age and increased between the two last years of the rotation. Eucalyptus trees dominated Acacia trees in mixed plantations. The stratification of the canopy led to an increase of stand Leaf Area Index (LAI) and APAR compared to monospecific plantations. However, both Eucalyptus and Acacia LUE decreased at the end of the rotation in the mixed-species stands, with the decrease occurring more markedly in Acacia, and the final stem biomass of the stand was not enhanced in mixed-species plantations compared with the average of the pure stands. Our results indicate that a stratified canopy may offer the potential benefit of capturing more light in mixed-species forests, but this may be negated if another resource deficiency prevents trees from converting intercepted radiation into dry matter. Mixed-species plantations should be established at sufficiently rainfed sites to maximize LUE, and appropriate fertilizer regimes should be applied.

Basado en la tesis: Bolívar V, Diana. 1998. Contribución de Acacia mangium al mejoramiento de la calidad forrajera de Brachiaria humidicola y la fertilidad de un suelo ácido en el trópico húmedo. Tesis Magister Scientae. CATIE, Turrialba, Costa Rica. 105 p. 2 Mg. MSc. Sistemas Agroforestales. Investigadora proyecto CONISILVO. 3 Profesor Investigador, CATIE, Costa Rica. Palabras claves: digestibilidad, lignina, pared celular, suelo ácido, valor nutritivo.

Estimation of the magnitude of sinks and sources of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea, Paraserianthes falcataria, Swietenia macrophylla and Dipterocarp species in Mindanao; Leucaena leucocephala from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur, and Acacia mangium, Acacia auriculiformis and G. arborea in Leyte. Non-linear regression was used to derive species-specific, site-specific and generic equations between yield and diameter of the form y = aD b . Equations were evaluated based on the correlation coefficient, standard error of the estimate and residual plots. Regressions resulted to high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies.

This manuscript focuses on the effects of above-ground earthworm casts on water runoff and soil erosion in steep-slope ecosystems in Northern Vietnam. We investigated the effects of Amynthas khami, an anecic species producing above-ground casts of prominent size, on water infiltration and soil detachment along a land-use intensification gradient: a cultivation of cassava (Mahinot esculenta; CAS), a plantation of Bracharia (Bracharia ruzziziensis; BRA), a fallow (FAL), a fallow after a forest of Eucalyptus sp. (EUC) and a plantation of trees (Acacia mangium and Venicia Montana; FOR). Two scales of studies were considered: (i) at the structure scale (cm 2 ), a water runoff simulation was used to differentiate the effects of casts, free biogenic aggregates that previously belong to casts, and free physicogenic aggregates; (ii) at the station levels, 1-m 2 plots were used to determine runoff and soil detachment rates during the rainy season in 2005.

An in vitro propagation of a tropical leguminous tree, Acacia mangium, has been established. Induction of bud sprout was obtained from mature nodal explants of 10-years-old tree of Acacia mangium on Murashige and Skoog (MS) [10] basal medium supplemented with 6-benzylaminopurine (BAP) (1.0 mg/L), gibberellic acid (GA 3 ) 1.0 mg/L and indole-3-acetic acid (IAA) 0.05 mg/L. The rate of multiplication was obtained on MS medium supplemented with 1.5 mg/L BAP, 0.05 mg/L IAA and 100 mg/L adenine sulfate (Ads). The multiplication rate varied from 1 to 8 depending on the growth regulators used. Excised shoots were rooted on half-strength MS basal salts supplemented with 0.5 mg/L indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) and 20 g/L (w/v) sucrose after 13-14 days of culture. The micropropagated plantlets have been acclimatized and successfully transferred to soil. The micropropagated plantlets appeared morphologically similar to the mother plant. No variation was detected among the micropropagated plants by the use of Randomly Amplified Polymorphic DNA (RAPD) markers.

A growth model consisting of a polymorphic site index equation, a reciprocal equation for the diameter-density effect, and a self-thinning equation was presented to predict the course of stand development of Acacia mangium. This model firstly predicts height growth with the polymorphic site index equation, and then density-related growth and mortality, that is, diameter and stand density, are calculated to satisfy the mathematical relationship for the reciprocal and self-thinning equations. The latter equation relates the rate of reduction in stand density to the diameter increment derived from a fitted trend of the distance from the maximum size-density line. The cumulative predictions, starting with stands 3 years after planting and continuing until they were 9 years old, agreed well with observations of group-age means of measurements calculated for the three levels of initial density. Contrasting height diameter relationships among the three levels of initial density were described reasonably well with this model, and the predicted basal area growth was found to agree well with observations. This indicated a good potential for its use in yield prediction. Simulations for stand growth under different spacing and thinning options were demonstrated in a stand density control diagram, which suggested a reasonable flexibility for practical application. #

Acacia mangium grown in aeroponic culture was co-inoculated with selected strains of Bradyrhizobium sp. and Glomus intraradices. A single-step technique using alginate as an embedding and sticking agent for an inoculum composed of arbuscular mycorrhiza (AM)-infected sheared roots was used to infect plants. This method resulted in the successful establishment of AM in 100% of the inoculated plants after 7 weeks. The results indicated that dual microbial inoculation with Glomus intraradices strain S-043 and Bradyrhizobium strain AUST 13C stimulated the growth of A. mangium in aeroponic culture. The effects of single and dual microbial inoculations were also evaluated at two levels of P in the nutrient medium. A concentration of 5 mg P kg −1 stimulated the development of AM without affecting plant development or establishment of Bradyrhizobium symbiosis. In contrast, saplings supplemented with a higher concentration of P (25 mg kg −1 ) alone or co-inoculated with Bradyrhizobium had lower AM frequencies.

Aeroponics, a soilless plant culture method, was used to produce Acacia mangium saplings associated with arbuscular mycorrhiza (AM) fungi. A. mangium seedlings were ®rst grown in multipots and inoculated with Endorize, a commercial AM fungal inoculum. They were then, either transferred to aeroponic systems or to soil. Aeroponics was found to be a better system than soil, allowing the production of tree saplings twice as high as those grown in soil. Moreover, compared to plants grown in soil, aeroponically grown saplings inoculated with AM fungal inoculum exhibited signi®cantly different rates of mycorrhization, resulting in an increase in phosphorus and chlorophyll in plant tissues. Our results suggest that the aeroponic system is an innovative and appropriate technology which has the potential to produce in large quantities, tree saplings associated with soil micro-organisms, such as AM fungi, for reforestation of degraded land in the humid tropics. # 1999 Elsevier Science B.V. All rights reserved.

In agroforestry systems, the distribution of light transmitted under tree canopies can be a limiting factor for the development of intercrops. The light available for intercrops depends on the quantity of light intercepted by tree canopies and, consequently, on the architecture of the tree species present. The influence of tree architecture on light transmission was analysed using dynamic 3D architectural models. The architectural analysis of Acacia mangium and Tectona grandis was performed in Indonesian agroforestry systems with trees aged from 1 to 3 years. 3D virtual trees were then generated with the AmapSim simulation software and 3D virtual experiments in which tree age, planting density, planting pattern and pruning intensity varied were reconstructed in order to simulate light available for the crop. Canopy closure of trees was more rapid in A. mangium than in T. grandis agroforestry systems; after 3 years the quantity of light available for A. mangium intercrops was three times lower than under T. grandis. Simulations with A. mangium showed that practices such as pruning and widening tree spacing enable to increase the total transmitted light within the stand. On T. grandis, modification of the tree row azimuth resulted in changes in the spatial and seasonal distribution of light available for the intercrops. These results are discussed in terms of agroforestry system management.

Aeroponics, a soilless plant culture method, was used to produce Acacia mangium saplings associated with arbuscular mycorrhiza (AM) fungi. A. mangium seedlings were ®rst grown in multipots and inoculated with Endorize, a commercial AM fungal inoculum. They were then, either transferred to aeroponic systems or to soil. Aeroponics was found to be a better system than soil, allowing the production of tree saplings twice as high as those grown in soil. Moreover, compared to plants grown in soil, aeroponically grown saplings inoculated with AM fungal inoculum exhibited signi®cantly different rates of mycorrhization, resulting in an increase in phosphorus and chlorophyll in plant tissues. Our results suggest that the aeroponic system is an innovative and appropriate technology which has the potential to produce in large quantities, tree saplings associated with soil micro-organisms, such as AM fungi, for reforestation of degraded land in the humid tropics. # 1999 Elsevier Science B.V. All rights reserved.

To investigate soil amelioration effects by older tropical fast-wood plantations, we examined the fine litterfall and accompanying nutrient flux of a 20-year-old Acacia mangium site over 3 years under a wet tropical climate in Sabah, Malaysia. The litterfall of a Swietenia macrophylla site and an Araucaria cunninghamii site was also examined for comparison. Annual nitrogen (N) flux through litterfall (kg N ha−1) was larger in A. mangium (207–223) than in S. macrophylla (126–153) or A. cunninghamii (72–94), whereas annual phosphorus (P) flux through litterfall (kg P ha−1) was considerably smaller in A. mangium (2.7–3.4) than in S. macrophylla (7.5–15.6) or A. cunninghamii (7.8–9.2). N flux through litterfall, forest floor N, and N concentration in topsoil (0–5 cm) were in the order of A. mangium > S. macrophylla > A. cunninghamii, but other element fluxes were not related to concentrations in soils. Our findings suggest that topsoil N increased because of a large N flux from litterfall. We conclude that these plantation trees, including A. mangium have the potential to produce a N flux in litterfall for the rapid return of organic N to soils larger than or equivalent to that in adjacent primary forests. However, the litterfall of a single species may lead to deficits of a particular element and cause nutrient imbalances. Using a mixture of fertilizer tree species or applying mixed litter might be a better solution.

— Thirteen years old provenance trials of Acacia mangium from five provenances were established at five sites in the state of Sarawak, Malaysia, were sampled for this study. Fifty trees were sampled at random and cut to study radial variation in microfibril angle in the SS2 of secondary wall of the fibre using polarised microscope. Microfibril angle decreased from pith to bark with the greatest decrease occurred within the first two radial sampling near to the pith. It ranged from 5.9 ° to 28.8 ° with an overall mean and coefficient of variation of 12.6 ° and 45.8% respectively. It had a mean value of 21.4  at pith and 6.9  near the bark, which is a decrease of 67.8%. Highly significant different in mircrofibril angle were detected between radials of individual trees at α≥0.001. It was the major contributors to the total variance in which contributed for about 64.8%. Variations between trees were highly significant at α≥0.001 and accounted for 25.5% of the variation in microfibril angle while differences between the two orientations were not significant at α≤0.05. Keywords— Acacia mangium, microfibril angle, radial variation, pith to bark, interaction.