Acacia Plantations Research Articles

The potential of rubber and acacia plantations for forest carbon stocks in Malaysia

In Malaysia, the primary forested land change process is due to the establishment of plantations on logged-over forests and areas used for shifting cultivation. While standing carbon stocks of natural forest have been the focus of many studies, reports on the carbon stocks in Acacia and rubber plantations in Malaysia is sparse. Therefore, this article attempts to collate and analyse Malaysian datasets on total carbon stocks for aboveground biomass in the Acacia and rubber plantations by applying the biomass expansion factor for the period from 1990 to 2013. The forest plantations have higher growth rates, and the harvesting waste and residues left behind are significantly more than the natural forests. Therefore, it leads to greater emission compared to the natural forests. Hence, Acacia and rubber plantations were not able to sequester and store carbon at the same amount as the natural forest, which resulted in carbon credit on the forest carbon stock.

Low conservation value of converted habitat for avifauna in tropical peatland on Sumatra, Indonesia

Peat swamp forest is an important refuge for biodiversity in Southeast Asia and is now becoming a target of exploitation. The scarcity of information on avifauna and ecology of birds in peat swamp forests prevents understanding of the effects of land use change on avifauna. In this study, we describe the bird assemblages in habitats with different land uses by comparing species richness, community composition, and feeding guild patterns in Bukit Batu, Indonesia. Bird assemblages in natural peat swamp forests (NPF), high-maintenance industrial acacia plantations (planted acacia forest, PAF), low-maintenance rubber plantations (jungle rubber forest, JRF), and village areas (VIL) were studied using a fixed-radius point-count method. Of the 95 species observed, 45, 20, 35, and 48 species were observed in NPF, PAF, JRF, and VIL, respectively. Estimated species richness was the highest in NPF, followed by VIL, JRF, and PAF. NPF had the highest species diversity and β-diversity, more endangered species, and a distinctive species composition characterized by fly-catching insectivores. The relative conservation value of PAF was notably low, particularly compared with JRF. The avifauna in VIL was characterized by more generalists that favor open spaces and therefore is not considered an important habitat for forest-dependent birds that are of conservation concern. Our results indicate that NPF has irreplaceable value for bird diversity conservation, but low-maintenance rubber plantations were home to several forest-dependent species and partially supported bird diversity, particularly compared with high-maintenance acacia plantations.

Selection and Screening of Superior Genotypes for Quality Planting Stock Based on Vegetative Growth Performance of Some Selected 12-Year-Old <i>Acacia</i> Species

Production of quality wood is a big problem in forestry plantation since trees grown in plantation of some high value temperate and tropical hardwood species tend to produce low value, short butt logs and bolts due to crooked stems, low fork heights and delayed shedding of lower branches. Result from existing Acacia plantation in Malaysia indicated that most existing Acacia plantation trees especially Acacia auriculiformis and Acacia mangium, fork very heavily which leads to the formation of multiple leaders more than one and some are fork so close to the ground that they will produce little to no merchantable wood. In this context, a research study was initiated to select and recommend the best performing tree species or provenance suited for timber production in Malaysia with respect to growth and other characteristics. Species/provenance/progeny test was conducted on four species of Acacia namely, A. mangium, A. auriculiformis, A. crassicarpa and A. aulococarpa, each with 4 provenances originated from Papua New Guinea (PNG) and Queensland (QL). The growth performance of the provenances was monitored in terms of some quantitative and qualitative characteristics to evaluate the genetic variation and growth performance of a base breeding population. 20 progenies for each species were selected and randomly planted with 16 trees representing each progenies in a trial plot laid out in a randomized complete block design consisting of four blocks as replication. The study showed that there were significant different (p mangium performed better compared to other Acacia species in all of the aspect tested and it was followed by A. crassicarpa, A. aulococarpa and A. auriculiformis. There were also significant differences between provenance within regions and progenies within provenances in all quantitative and qualitative traits tested in this study. Generally, provenance and progenies selected from PNG excelled those from QL both in quantitative and qualitative characteristics. The top performing progenies of Acacia species are CG 1854 of (Bensbach WP) and KN000107 (SW of Boset WP) of A. mangium, BVG2609 (Bensbach WP) of A. crassicarpa, BVG 00835 (WP Morehead) and MM1016 (Arufi E Morehead WP) of A. aulococarpa and JSL363 (Wenlock River) and BVG 2657 (Bansbach) of A. auriculiformis.

Dynamics of aboveground biomass accumulation in monospecific and mixed-species plantations of Eucalyptus and Acacia on a Brazilian sandy soil

In this study, we hypothesized that a positive impact of Acacia trees when grown in mixed stands with Eucalyptus trees in N-deficient soil, leads to a higher biomass production in mixed stands relative to the monocultures. A randomized block design experiment was set up in a Brazilian Planosol to assess the dynamics of aboveground accumulation of monospecific Eucalyptus urograndis (Eucalyptus urophylla S. T. Blake×Eucalyptus grandis W. Hill ex Maiden), with or without nitrogen fertilization (E100+N and E100, respectively), and Acacia mangium (A100) stands, and two arrangements of both species in mixed plantations (E50A50 and E100A100). The height (H), diameter at breast height (DBH), litterfall, and aboveground biomass production were measured over a full rotation. Our results partially confirm the initial hypothesis. Acacia showed limited competitive ability against Eucalyptus, which resulted in a stratified canopy in the mixed stands, with Eucalyptus dominating the top layer, especially in the E100A100 arrangement. The E100A100 stand showed greater overall productivity compared with the E100 stand and similar productivity relative to the E100+N stand. The E50A50 arrangement produced taller Eucalyptus trees with a larger diameter than the monoculture, although the smaller population of Eucalyptus trees in this mixed stand resulted in an overall biomass production that was equal to or less than that of the monocultures E100 and E100+N, respectively. However, the DBH growth rate of Eucalyptus trees in E50A50 showed no signs of stagnation up to 60months, which is different from the other treatments. Consequently, the harvesting age of such stands can be extended, which allows for the production of Eucalyptus logs with greater value for the lumber market.

The conversion of grassland to acacia forest as an effective option for net reduction in greenhouse gas emissions

This study aimed to evaluate the effect of forestation with leguminous Acacia mearnsii De Wild in native grasslands on the soil greenhouse (GHG) fluxes and their main driving factors. The experiment was conducted in the Brazilian Pampa over the period of one year in a six-year-old Acacia plantation, evaluating four treatments: Acacia (AM), Acacia with litter periodically removed (A–l), Acacia after harvest (AH) and native grassland (NG) (reference treatment). Air samples were obtained by the static chamber method, and gas concentrations were evaluated by gas chromatography. Soil and climate factors were monitored. The accumulated fluxes of methane (CH4) and nitrous oxide (N2O) were statistically similar between the soils in the AM and NG treatments, which tended to oxidize CH4 (−1445 and −1752 g C–CH4 ha−1 yr−1, respectively) and had low emission of N2O (242 and 316 g N–N2O ha−1 yr−1), most likely influenced by the low water-filled pore space and the low content of mineral N in the soil. However, the soil in the AH treatment presented higher emissions of both gases, totaling 1889 g C–CH4 ha−1 yr−1 and 1250 g N–N2O ha−1 yr−1. Afforestation neither significantly affected the total organic C stocks nor their lability, keeping the C management index for the forested area similar to that in the NG treatment. The conversion from grassland to Acacia forest represents an effective option for mitigating the net reduction in greenhouse gas emissions, which is basically determined by C accumulation in biomass and wood products.

Features of the content of carbonates in the ordinary chernozem improved by forest under plantings of false acacia (Robinia pseudoacacia L.)

Carbonate neoplasms are the characteristic feature of the black soil profile. The study of morphological and micromorphological characteristics and chemical composition gives an idea of the black soil genesis and serves as the diagnostic feature of classification units of them. The study of migration carbonate in the chernozem are of great scientific and practical interest (Afanasyeva, 1996). Nowadays the issues of migration carbonates, as well as the extent of the manifestation of this process in the soil profile need further researching, which is important as carbonates has one of the main role in basic soil processes, in particular, they affect the concentration and activity of calcium ions in the soil solution, the composition of the soil absorbing complex and pH in the soil solution. Carbonate neoplasms contribute to the formation of strong coagulation structures, which increases soil fertility and harvest agricultural crops, provides resistance against the wind, prevents reduction of the upper fertile soil layer, increases mobility of some chemical elements and improves such physical characteristics of soil as density, permeability and porosity (Goncharova, 1983). The aim of our work was to study the content of calcium carbonate in the soil profile of the test section 201–L under of the acacia plantations crops of forest ecosystems and to determine of their distribution in the soil genetic horizons. According to the aim of our work of we has the following tasks: to give a general characterization of carbonates of calcium in Chernozem usual, to perform sampling of the genetic horizons of the soil profile of test section 201–L, to determine the content of carbonates by conventional gravimetric methods; to study the features of the content of carbonates in soil profiles of test section 201–L; to conduct statistical processing of the obtained data; to formulate conclusions of the performed research. Soil samples were selected according to the standard technique in genetic horizons of the soil profile on three times (Fedorets, 2009). Determination of the percentage content of carbonates in the soil was performed by the gravimetric method, which is based on weight loss of soil due to discharge of CO2 during the destruction of carbonates with acid. It should be noted that the method can be applied in the case of the carbonates content up to 70 % (Travleev et al., 2009). The average coefficient of variation of carbonates of calcium content in genetic horizons of the soil profile is 77.5 %. This is quite a high rate, so as General it is considered that if the value of the coefficient of variation is less than 33 %, the result is considered homogeneous if more than 33 %, it is inhomogeneous. Based on this observation, we conclude that carbonate calcium has inhomogeneous redistribution of genetic horizons of test section 201–L. Regarding the reliability of the obtained data, we can see that the standard error calculations for each of the horizons does not exceed 0,34, which in turn confirms the accuracy of the our data. According to our calculations the lowest content of calcium carbonate is 1.47 % in the first horizon, and biggest – 16,07 % in the genetic horizon Ph (70–90 cm). These results are extending the current understanding of the processes of formation and distribution of calcium carbonate in the genetic horizons of the soil profile of the Chernozem ordinary. The data of percentage of calcium carbonate may be used in the solution of the question of the genesis, evolution and classification of soils, the obtained data can serve as the basis of the research the conditions of pedogenesis under the influence of natural climatic fluctuations and anthropogenic factors.

Impacts of non-oil tree plantations on biodiversity in Southeast Asia

Tree plantations are rapidly expanding throughout Southeast Asia, and likely pose threats to the conservation of native biodiversity. While the impacts of oil palm expansion on tropical biodiversity has received increasing attention, and several recent reviews, the effects of other tree crops on native flora and fauna biodiversity remain understudied. Here we assess and compare the impact of rubber, acacia, eucalyptus, teak, and cacao plantations on biodiversity throughout the region, and discuss spatial and temporal factors that influence a production landscape’s ability to support native species. Using a meta-analysis, we show that rubber and cacao plantations support lower biodiversity than intact forests, and are approximately equivalent to oil palm in their impacts on native biota. In contrast, richness of native species in acacia plantations was not statistically different from that in intact or secondary forests, though species composition could still be radically altered. Furthermore, older plantations are more similar to primary forests regarding community composition than younger plantations, likely due to increased habitat complexity and heterogeneity with plantation age. Though non-oil palm tree plantations are not ecologically equivalent to primary forests with regards to maintaining native community composition, they can support greater biodiversity than other modified landscapes such as annual crops. Increasing habitat complexity and spatial heterogeneity within plantations can improve the quality of the habitat they provide to native species. With industrial plantations projected to continue to expand, identifying ways to mitigate their impacts on biodiversity are increasingly critical.

Yearly Variation of Acacia Plantation Forests Obtained by Polarimetric Analysis of ALOS PALSAR Data

Applications of remote sensing by microwaves have become widely adopted in forest management, but microwave backscattering mechanisms in plantations remain poorly understood. This study attempts to understand backscattering characteristics under different forest structural conditions in plantation forests of fast-growing acacia trees in Sumatra, Indonesia. A general four-component scattering power decomposition method was applied to ALOS PALSAR data collected from 2007 to 2010 to see the variations of acacia plantation. The yearly variation in decomposition powers was compared to forest inventory data with visual assessments of stand conditions. The results were highly consistent with the field-measured data. Based on the variation patterns of decomposition powers, we can identify the presence of understory and distinguish between damaged and well-grown stands. The PALSAR data analysis can also reveal partial damages within a forest compartment, even minor damage in younger forests. This in-depth study indicates that changes in forest stand composition and the growth and degradation of plantation forests can be monitored by transitions in the polarimetric parameters.

FERTILIDADE DO SOLO E SUBSTÂNCIAS HÚMICAS EM ÁREA DE CAVA DE EXTRAÇÃO DE ARGILA REVEGETADA COM EUCALIPTO E LEGUMINOSAS NO NORTE FLUMINENSE

http://dx.doi.org/10.5902/1980509819606A revegetação de áreas de extração de argila com eucalipto e leguminosas pode favorecer a melhoria dos atributos químicos do solo. O objetivo do trabalho foi avaliar a influência de plantios puros e consorciados de leguminosas e eucalipto na fertilidade do solo e nos teores de carbono orgânico total e das substâncias húmicas, em uma cava de extração de argila no Norte Fluminense. O solo original da área da cava em estudo é um Cambissolo Háplico Sódico gleico, no qual a camada superficial (espessura de 20 cm, aproximadamente), com maiores teores de matéria orgânica, foi retirada e devolvida ao fundo da cava após a extração da argila. A cava foi nivelada mecanicamente e mantida sob pousio durante dois anos. A revegetação foi realizada com as espécies Eucalyptus camaldulensis (Euc), Acacia mangium (Ac) e Sesbania virgata (Sesb), em plantios puros e consorciados. O delineamento experimental utilizado foi o de blocos casualizados com sete tratamentos (plantios puros de Euc, Ac e Sesb; plantios consorciados de Euc + Ac, Euc + Sesb, Ac + Sesb; e área degradada com vegetação espontânea (ADVE)) e três repetições. Aos 48 meses após implantação dos sistemas foram coletadas amostras de solo na camada de 0,00 a 0,05 m, em que se avaliaram algumas variáveis da fertilidade do solo (pH em água, P, K+; Ca+2, Mg+2, Na+, Al+3, H+Al), carbono orgânico total (COT), nitrogênio (N) e quantificado o carbono das substâncias húmicas em carbono da humina (C-HUM), carbono da fração ácido húmico (C-FAH) e ácido fúlvico (C-FAF). Observou-se que todos os plantios promoveram aumentos nos teores Ca, Mg, P, K, N, COT, C-HUM, C-FAH e C-FAF em relação à ADVE. A revegetação de áreas de cava de extração de argila no Norte Fluminense com plantios puros ou consorciados de eucalipto e leguminosas, acarreta em melhorias da fertilidade do solo e dos teores de carbono e nitrogênio totais do solo e do carbono das substâncias húmicas. Aos quatro anos após a revegetação, os sistemas mais indicados, de uma forma geral, para acarretar em aumentos dos teores de COT, N total, Mg, soma de bases e capacidade de troca catiônica, destaca-se o plantio de acácia, dentre os plantios puros, e o plantio de eucalipto + sesbânia, dentre os plantios consorciados. Além disso, o consórcio eucalipto + sesbânia, apresentou um dos maiores teores C da fração humina.

Feasibility Study of C- and L-band SAR Time Series Data in Tracking Indonesian Plantation and Natural Forest Cover Changes

Tropical coverage by Envisat ASAR is sparse in space and time and has limited value for monitoring deforestation. The only available dual-polarized multitemporal dataset over Riau province, Indonesia (nine images in a single year), is used to distinguish and monitor tropical plantations and their dynamics and is compared with annual L-band PALSAR data and land cover maps derived from Landsat data. For the ASAR data, both VV and VH are important in discriminating different types of forest cover; whereas, at L-band, most of the relevant information is in the cross-polarized channel. The ASAR VV (but not the VH) backscatter from acacia plantations is strongly affected by whether the underlying soil is peat or nonpeat, which affects the separability of acacia from oil palm. Maximum likelihood classification of the C-band data gave overall accuracies of 86.2% and kappa coefficient of 0.78 by comparison with land cover maps derived from optical data. This was not improved by combining C- and L-band data. Classification of the C-band time series allows the rotation cycle of acacia plantations to be tracked. The available 4-year annual L-band time series shows potential for monitoring these dynamics, but the 1-year time spacing increases the risk of missing changes masked by the rapid growth of acacia.

Utilization of Pisar L-2 Data for Land Cover Classification in Forest Area Using Pixel-Based and Object-Based Methods

Abstract. Polarimetric and Interferometric Airborne SAR in L-band 2 (PiSAR-L2) program is an experimental program of PALSAR-2 sensor in ALOS-2 satellite. Japan Aerospace Exploration Agency (JAXA) and Indonesian National Institute of Aeronautics and Space (LAPAN) have a research collaboration to explore the utilization of PiSAR-L2 data for forestry, agriculture, and disaster applications in Indonesia. The research explored the utilization of PiSAR-L2 data for land cover classification in forest area using the pixel-based and object-based methods. The PiSAR-L2 data in the 2.1 level with full polarization bands were selected over part of forest area in Riau Province. Field data collected by JAXA team was used for both training samples and verification data. Preprocessing data was carried out by backscatter (Sigma naught) conversion and Lee filtering. Beside full polarization images (HH, HV, VV), texture imagess (HH deviation, HV deviation, and VV deviation) were also added as the input bands for the classification processes. These processes were conducted for 2.5 meter and 10 meter spatial resolution data applying two methods of the maximum likelihood classifier for pixel-based classification and the support vector machine classifier for the object-based classification. Moreover, the average overall accuracy was calculated for each classification result. The results show that the use of texture images could improve the accuracy of land cover classification, particularly to differentiate between forest and acacia plantation. The pixelbased method showed a more detail information of the objects, but has “salt and pepper”. In the other hand, the object-based method showed a good accuracy and clearer border line among objects, but has often some misinterpretations in object identification.

Estimation of Biomass Carbon Stocks over Peat Swamp Forests using Multi-Temporal and Multi-Polratizations SAR Data

Abstract. The capability of L-band radar backscatter to penetrate through the forest canopy is useful for mapping the forest structure, including above ground biomass (AGB) estimation. Recent studies confirmed that the empirical AGB models generated from the L-band radar backscatter can provide favourable estimation results, especially if the data has dual-polarization configuration. Using dual polarimetry SAR data the backscatter signal is more sensitive to forest biomass and forest structure because of tree trunk scattering, thus showing better discriminations of different forest successional stages. These SAR approaches, however, need to be further studied for the application in tropical peatlands ecosystem We aims at estimating forest carbon stocks and stand biophysical properties using combination of multi-temporal and multi-polarizations (quad-polarimetric) L-band SAR data and focuses on tropical peat swamp forest over Kampar Peninsula at Riau Province, Sumatra, Indonesia which is one of the most peat abundant region in the country. Applying radar backscattering (Sigma nought) to model the biomass we found that co-polarizations (HH and VV) band are more sensitive than cross-polarization channels (HV and VH). Individual HH polarization channel from April 2010 explained > 86% of AGB. Whereas VV polarization showed strong correlation coefficients with LAI, tree height, tree diameter and basal area. Surprisingly, polarimetric anisotropy feature from April 2007 SAR data show relatively high correlations with almost all forest biophysical parameters. Polarimetric anisotropy, which explains the ratio between the second and the first dominant scattering mechanism from a target has reduced at some extent the randomness of scattering mechanism, thus improve the predictability of this particular feature in estimating the forest properties. These results may be influenced by local seasonal variations of the forest as well as moisture, but available quad-pol SAR data were unable to show these patterns, since all the SAR data were acquired during the rainy season. The results of multi-regression analysis in predicting above ground biomass shows that ALOS PALSAR data acquired in 2010 has outperformed other time series data. This is probably due to the fact that land cover change in the area from 2007 – 2009 was highly dynamic, converting natural forests into rubber and Acacia plantations, thus SAR data of 2010 which was acquired in between of two field campaigns has provided significant results (F = 40.7, P < 0.005). In general, we found that polarimetric features have improved the models performance in estimating AGB. Surprising results come from single HH polarization band from April 2010 that has a strong correlation with AGB (r = 0.863). Also, HH polarization band of 2009 SAR image resulted in a moderate correlation with AGB (r = 0.440).

Forest stewardship council certificate for a group of planters in Vietnam: SWOT analysis and implications

A group of smallholders in Vietnam has obtained Forest Stewardship Council certification (FSC) for their Acacia plantation forest. Although the certification aims to improve livelihoods via economic, social, and environmental benefits, there are concerns amongst smallholders regarding the outcomes from their certification decision as well as difficulties in maintaining the certification. This article assesses the benefits and challenges of forest management certification from the perspective of small household groups who have achieved FSC certification. The FSC has brought new opportunities for farmers, such as increased selling price and extended trade networks, but is also associated with significant obstacles such as high initial and annual surveillance audit fees, difficult paper work, and complicated procedures for selling wood. Additionally, the small size of the plantations and low expertise in forest management make it more difficult and costly for farmers to achieve certification. There is a heavy dependency on donors for financial and technical support. Because subsidies from organizations like the World Wide Fund for Nature Vietnam are unlikely to continue indefinitely, the benefit of certification for smallholders is uncertain. Feasible actions to increase the sustainability of the group are suggested, including increasing the responsibility of the group members, enhancing the awareness and capacity of the local people, and searching for additional support from other organizations and wood processing companies. From the macro level, a national forest stewardship council should be established so that the audit cost for certification would be reduced.

Sustaining the future of Acacia plantation forestry – a synopsis

Australian acacias have a long history of diverse use, with Acacia mearnsii of particular significance in South Africa and Brazil. However, most of the 3 million ha now managed worldwide have been planted in South-east Asia in only the past three decades. Acacia mangium, A. auriculiformis , the hybrid between these two species, and A. crassicarpa are the most widely planted taxa. In Indonesia and Malaysia most plantations are managed by large companies but the grower base in Vietnam is very different with nearly 50% of the 1.2 million ha of acacia plantations managed by small farmers to supply an export woodchip market, local pulp mills and an expanding furniture manufacturing industry. Most of these tropical plantations are managed in rotation cycles of 7–8 years.

Soil Seed Bank of An Exotic Acacia sp. Plantation and An Adjacent Tropical Heath Forest in Brunei Darussalam

We compared seedling emergence and soil seed bank composition under an Acacia mangium plantation and an adjacent tropical heath forest in the Andulau Forest Reserve, Brunei Darussalam. Soil samples were collected from ten 20 x 20 m plots set up in three contrasting habitats: the Acacia plantation, the adjacent heath forest, and the transition zone in-between. Soil samples were subjected to smoke and heat treatments, following which seedling emergence was observed daily over a 12-week period. In a parallel investigation, variations in species richness, seed density and seed viability of the soil seed banks of the ten plots were investigated. Seedling emergence was significantly highest in the plantation and lowest in the heath forest plots respectively. However, no significant differences among treatments, and no significant treatment-habitat interactions were detected. Species richness, seed density and seed viability in the plantation plots were significantly lower than the transition zone and intact heath forest plots. A. mangium seeds were not recorded in the heath forest soil seed banks but were detected in the plantation and transition zone plots. Lower native plant species richness, seed density and viability in the A. mangium plantation could imply higher regeneration potential for the heath forest habitat if severe habitat destruction was to occur in this forest reserve. We suggest that proper plantation management practices and close monitoring of soil seed banks are the best mechanisms that could be adopted to minimize the gradual spread of invasive Acacias into natural tropical heath forests of Borneo.

The effects of tannins derived from <i>Acacia mangium</i> bark on N<sub>2</sub>O emissions from water saturated acacia plantation soil

The effects of tannins derived from <i>Acacia mangium</i> bark on N<sub>2</sub>O emissions from water saturated acacia plantation soil

Costs Comparison between FSC and Non FSC Acacia Plantations in Quang Tri Province, Vietnam

Costs Comparison between FSC and Non FSC Acacia Plantations in Quang Tri Province, Vietnam

The impact of exotic forest plantations on the chemical composition of soil organic matter in Southern Brazil as assessed by Py–GC/MS and lipid extracts study

This study evaluated the effects of Acacia and Eucalyptus plantations on the soil chemical properties and molecular composition of soil organic matter (SOM) in Cambisol profiles in Southern Brazil over 7years. Control soil profiles were collected from neighboring areas that corresponded to the initial soil conditions predating the forest plantations. Soil exchangeable cations, total N, available P and K, soil pH, and the molecular composition of SOM were determined. The molecular composition of SOM was assessed by performing pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) analysis of the soil samples and GC/MS analysis of the Soxhlet-extracted free lipid composition. The Acacia plantation was associated with reductions of available P and K+, exchangeable Ca2+ and Mg2+ as well as soil pH down to depths of 40cm, whereas only the available K+ content was reduced in the Eucalyptus plantation as compared with their respective control areas. The nitrogen (N) content was depleted in the superficial soil (5cm) in both plantations, whereas no change was found in the soil carbon (C) content for the entire soil profile (0–80cm). Alterations of the SOM composition occurred in both plantations at a molecular level. Analytical pyrolysis revealed a relative enrichment of polysaccharide-derived compounds in the soil under the Acacia plantation. Together with the increase in high molecular weight n-alkanes from lipid extracts, this result suggests the input of biomass from the new forest vegetation. Increase in the proportions of degraded compounds from lignin was observed in the SOM from Eucalyptus plantation, suggesting the degradation of the indigenous organic matter which promoted the change of the SOM composition.

Usability of noise-free daily satellite-observed green–red vegetation index values for monitoring ecosystem changes in Borneo

We examined the usability of daily green–red vegetation index (GRVI) observations from the Terra and Aqua Moderate Resolution Imaging Spectroradiometer satellite on cloud-free days for monitoring ecosystem changes in Bornean tropical forests at a 500 m spatial resolution over 11 years (2003–2013). The number of observational days of cloud-free GRVI data in the southwest monsoon period (May–October; 1–5 days/month) was greater than that in the northeast monsoon period (November–April; 0–2 days/month). Spatial variation in the observation frequency was noticed, with Terra (morning) and Aqua (afternoon) data showing different geographic distribution patterns of cloud-free data. The observation frequency in the western Kalimantan mountains (Sarawak and Sabah) was 1–2 days/month greater than that in the eastern mountains (Kalimantan). The quality of cloud-free GRVI data was validated by using sky images taken at the same time as the satellite observations and canopy surface images in a tropical rainforest. In oil palm and acacia plantations and peatlands, which were mainly distributed in coastal regions of Sarawak and West and Central Kalimantan, the cloud-free daily GRVI value fell below zero owing to deforestation and forest degradation caused by forest fire and increased with replanting and vegetation recovery. These results indicate that daily cloud-free GRVI data from multiple satellites collected at different times of the day are required for accurate monitoring of intra- and interannual phenological variation and forest degradation attributed to changes in climatic conditions and deforestation caused by human activities in tropical ecosystems.

Browsing preference and ecological carrying capacity of sambar deer (Cervus unicolor brookei) on secondary vegetation in forest plantation.

The browsing preference and ecological carrying capacity (ECC) of sambar deer (Cervus unicolor brookei) in acacia plantations for management and conservation of the ecosystem were investigated at Sabal Forest Reserve in Sarawak, Malaysia. The identification of the species browsed by the sambar deer was based on an observation of the plant parts consumed. ECC estimation was based on body weight (BW) and the physiological stages of animals browsed in six fenced 4-ha paddocks. Sambar deer were found foraging on only 29 out of 42 species of secondary vegetation in the acacia plantation. The remaining species are too high for the deer to reach. Planted species, Shorea macrophylla are not palatable to the deer. This augurs well for the integration of sambar deer into shorea plantations. The most frequently exploited plants were Ficus spp. Sambar deer preferred woody species more than non-woody species and they are browser animals. By producing metabolizable energy of 19,000 to 27,000 MJ/ha, the ECC was five head/ha to 5.25 head/ha. Given its contribution to the conservation of wildlife and its capacity to sustain the ecosystem, the sambar deer integrated farming system offers a promising strategy for the future of tropical forestry management.