Land-use change from market responses to oil palm intensification in Indonesia.

Oil palm is a major driver of tropical deforestation. A key intervention proposed to reduce the footprint of oil palm is intensifying production to free up spare land for nature, yet the indirect land-use implications of intensification through market forces are poorly understood. We used a spatially explicit land-rent modeling framework to characterize the supply and demand of oil palm in Indonesia under multiple yield improvement and demand elasticity scenarios and explored how shifts in market equilibria alter projections of crop expansion. Oil palm supply was sensitive to crop prices and yield improvements. Across all our scenarios, intensification raised agricultural rents and lowered the effectiveness of reductions in crop expansion. Increased yields lowered oil palm prices, but these price-drops were not sufficient to prevent further cropland expansion from increased agricultural rents under a range of price elasticities of demand. Crucially, we found that agricultural intensification might only result in land being spared when the demand relationship was highly inelastic and crop prices were very low (i.e., a 70% price reduction). Under this scenario, the extent of land spared (∼0.32 million ha) was countered by the continued establishment of new plantations (∼1.04 million ha). Oil palm intensification in Indonesia could exacerbate current pressures on its imperiled biodiversity and should be deployed with stronger spatial planning and enforcement to prevent further cropland expansion.

Cambios en el uso de suelo causados por la reacción del mercado a la intensificación de la palma aceitera en Indonesia Resumen La palma aceitera es una de las principales causas de la deforestación. Una intervención importante propuesta para reducir la huella de esta palma es la intensificación de la producción para que el suelo sobrante sea usado por la naturaleza, pero se sabe muy poco sobre las implicaciones del uso indirecto de suelo de la intensificación a través de las fuerzas del mercado. Usamos un marco de modelos de renta de suelo espacialmente explícito para caracterizar la oferta y demanda de la palma aceitera en Indonesia bajo varios escenarios de mejoras en la producción y elasticidad de demandas y exploramos cómo los cambios en el equilibrio del mercado alteran las proyecciones de la expansión agrícola. La oferta de palma aceitera fue susceptible a los precios de los cultivos y a las mejoras en la producción. La intensificación elevó la renta agrícola y redujo la efectividad de la reducción de la expansión agrícola en todos nuestros escenarios. El aumento en la producción bajó los precios de la palma, pero estas caídas no fueron suficientes para evitar la expansión agrícola a partir de las rentas agrícolas elevadas bajo un rango de elasticidad de precios de demanda. Más importante, descubrimos que la intensificación agrícola puede sólo resultar en que sobre el suelo cuando la relación de demanda casi no sea elástica y los precios de las cosechas sean muy bajos (una reducción del 70% en los precios). Bajo este escenario, la extensión de suelo sobrante (∼0.32 millones de ha) fue contrarrestado por el establecimiento continuo de nuevos sembradíos (∼1.04 millones de ha). La intensificación de la palma aceitera en Indonesia podría agravar las presiones existentes sobre su biodiversidad en peligro y debería implementarse con una mayor planeación espacial y aplicación para prevenir una expansión agrícola superior.

Metabolic effect of drought stress on the leaves of young oil palm (Elaeis guineensis) plants using UHPLC-MS and multivariate analysis.

The expansion of the oil palm in marginal areas can face challenges, such as water deficit, leading to an impact on palm oil production. A better understanding of the biological consequences of abiotic stresses on this crop can result from joint metabolic profiling and multivariate analysis. Metabolic profiling of leaves was performed from control and stressed plants (7 and 14 days of stress). Samples were extracted and analyzed on a UHPLC-ESI-Q-TOF-HRMS system. Acquired data were processed using XCMS Online and MetaboAnalyst for multivariate and pathway activity analysis. Metabolism was affected by drought stress through clear segregation between control and stressed groups. More importantly, metabolism changed through time, gradually from 7 to 14 days. The pathways most affected by drought stress were: starch and sucrose metabolism, glyoxylate and dicarboxylate metabolism, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, and glycine, serine and threonine metabolism. The analysis of the metabolic profile were efficient to correlate and differentiate groups of oil palm plants submitted to different levels of drought stress. Putative compounds and their affected pathways can be used in future multiomics analysis.

An integrated linkage map of interspecific backcross 2 (BC2) populations reveals QTLs associated with fatty acid composition and vegetative parameters influencing compactness in oil palm.

BACKGROUND: Molecular breeding has opened new avenues for crop improvement with the potential for faster progress. As oil palm is the major producer of vegetable oil in the world, its improvement, such as developing compact planting materials and altering its oils' fatty acid composition for wider application, is important. RESULTS: This study sought to identify the QTLs associated with fatty acid composition and vegetative traits for compactness in the crop. It integrated two interspecific backcross two (BC2) mapping populations to improve the genetic resolution and evaluate the consistency of the QTLs identified. A total 1963 markers (1814 SNPs and 149 SSRs) spanning a total map length of 1793 cM were integrated into a consensus map. For the first time, some QTLs associated with vegetative parameters and carotene content were identified in interspecific hybrids, apart from those associated with fatty acid composition. The analysis identified 8, 3 and 8 genomic loci significantly associated with fatty acids, carotene content and compactness, respectively. CONCLUSIONS: Major genomic region influencing the traits for compactness and fatty acid composition was identified in the same chromosomal region in the two populations using two methods for QTL detection. Several significant loci influencing compactness, carotene content and FAC were common to both populations, while others were specific to particular genetic backgrounds. It is hoped that the QTLs identified will be useful tools for marker-assisted selection and accelerate the identification of desirable genotypes for breeding.

Microbial Diversity and Metabolite Profiles of Palm Wine Produced From Three Different Palm Tree Species in Côte d'Ivoire.

Palm wine, the most commonly consumed traditional alcoholic beverage in Western Africa, harbours a complex microbiota and metabolites, which plays a crucial role in the overall quality and value of the product. In the present study, a combined metagenomic and metabolomic approach was applied to describe the microbial community structure and metabolites profile of fermented saps from three palm species (Elaeis guineensis, Raphia hookeri, Borassus aethiopum) in Côte d'Ivoire. Lactobacillaceae (47%), Leuconostocaceae (16%) and Acetobacteriaceae (28%) were the most abundant bacteria and Saccharomyces cerevisiae (87%) the predominant yeasts in these beverages. The microbial community structure of Raphia wine was distinctly different from the others. Multivariate analysis based on the metabolites profile clearly separated the three palm wine types. The main differentiating metabolites were putatively identified as gevotroline hydrochloride, sesartemin and methylisocitrate in Elaeis wine; derivative of homoserine, mitoxantrone in Raphia wine; pyrimidine nucleotide sugars (UDP-D-galacturonate) and myo-Inositol derivatives in Borassus wine. The enriched presence of gevotroline (an antipsychotic agent) and mitoxantrone (an anticancer drug) in palm wine supports its therapeutic potential. This work provides a valuable insight into the microbiology and biochemistry of palm wines and a rationale for selecting functional microorganisms for potential biotechnology applications.

Genome-wide association study (GWAS) for morphological and yield-related traits in an oil palm hybrid (Elaeis oleifera x Elaeis guineensis) population.

BACKGROUND: The genus Elaeis has two species of economic importance for the oil palm agroindustry: Elaeis oleifera (O), native to the Americas, and Elaeis guineensis (G), native to Africa. This work provides to our knowledge, the first association mapping study in an interspecific OxG oil palm population, which shows tolerance to pests and diseases, high oil quality, and acceptable fruit bunch production. RESULTS: Using genotyping-by-sequencing (GBS), we identified a total of 3776 single nucleotide polymorphisms (SNPs) that were used to perform a genome-wide association analysis (GWAS) in 378 OxG hybrid population for 10 agronomic traits. Twelve genomic regions (SNPs) were located near candidate genes implicated in multiple functional categories, such as tissue growth, cellular trafficking, and physiological processes. CONCLUSIONS: We provide new insights on genomic regions that mapped on candidate genes involved in plant architecture and yield. These potential candidate genes need to be confirmed for future targeted functional analyses. Associated markers to the traits of interest may be valuable resources for the development of marker-assisted selection in oil palm breeding.

Density-dependent seed predation in Attalea geraensis Barb. Rodr. (Arecaceae) caused by bruchid beetles in the Brazilian Cerrado / Predação dependente da densidade em sementes de Attalea geraensis Barb. Rodr. (Arecaceae), causada por besouros no Cerrado brasileiro

Abstract Palms are an important component of Neotropical communities as they are often diverse and abundant. In some areas, palms occur in high density and act as limiting factor in tree recruitment by limiting tree seedling and sapling abundance. In this study, I evaluated the intensity of seed mortality caused by insects in Attalea geraensis, in a large area of preserved Cerrado (Serra do Cabral, MG, Brazil) during wet season when both A. geraensis fruits and bruchid beetles were abundant. I collected a total of 63 infructescences which had from 3 fruits and 7 seeds to 82 fruits and 251 seeds. Endocarps had from 1 to 6 seeds. Seed mortality per infructescence due to beetles (Pachymerus cardo) was intense, and increases positively and disproportionally according to seed number per infructescence. Besides that, average proportions of seeds preyed upon by insects were consistently high (> 0.83), irrespective of seed number per endocarp. Positive density-dependent seed mortality caused by specialized natural enemies has been assumed to promote species rarity, an important feature of species coexistence in Neotropical forests. Then, the intense seed mortality documented in this study suggests that seed predators may contribute to the richness and diversity of plant species in the Cerrado, the richest and most endangered savanna in the world.

Resumo Devido à abundância e diversidade, as palmeiras são um componente importante das comunidades neotropicais. Em algumas áreas as palmeiras ocorrem em elevada densidade, tornando-se um fator limitante ao recrutamento de árvores, por restringir a abundância de plântulas e árvores jovens. Neste estudo, avaliei a intensidade de mortalidade das sementes de Attalea geraensis , causada por insetos, em uma grande área preservada de Cerrado (Serra do Cabral, MG, Brasil), durante a estação chuvosa, quando frutos de A. geraensis e besouros predadores de sementes eram abundantes. Coletei um total de 63 infrutescências que tinham de 3 frutos e 7 sementes a 82 frutos e 251 sementes. Os endocarpos tinham de 1 a 6 sementes. Nas infrutescências a mortalidade das sementes causada por besouros (Pachymerus cardo) foi intensa e aumentou positiva e desproporcionalmente conforme o número de sementes por infrutescência. Além disso, independentemente do número de sementes por endocarpo, as proporções médias de sementes predadas por endocarpo foram consistentemente altas (> 0,83). A mortalidade densidade dependente positiva de sementes causada por inimigos naturais especializados é assumida como uma das principais causas da raridade das espécies vegetais, um fator importante para coexistência de espécies nas florestas neotropicais. Portanto, a intensa mortalidade de sementes documentada neste estudo sugere que predadores de sementes podem contribuir para a riqueza e diversidade de espécies de plantas no Cerrado, a savana mais rica e ameaçada do mundo.

Oil palm concessions in southern Myanmar consist mostly of unconverted forest.

The increased demand for palm oil has led to an expansion of oil palm concessions in the tropics, and the clearing of abundant forest as a result. However, concessions are typically incompletely planted to varying degrees, leaving much land unused. The remaining forests within such concessions are at high risk of deforestation, as there are normally no legal hurdles to their clearance, therefore making them excellent targets for conservation. We investigated the location of oil palm plantations and the other major crop - rubber plantations in southern Myanmar, and compared them to concession boundaries. Our results show that rubber plantations cover much larger areas than oil palm in the region, indicating that rubber is the region's preferred crop. Furthermore, only 15% of the total concession area is currently planted with oil palm (49,000 ha), while 25,000 ha is planted outside concession boundaries. While this may in part be due to uncertain and/or changing boundaries, this leaves most of the concession area available for other land uses, including forest conservation and communities' livelihood needs. Reconsidering the remaining concession areas can also significantly reduce future emission risks from the region.

Designing oil palm architectural ideotypes for optimal light interception and carbon assimilation through a sensitivity analysis of leaf traits.

Background and Aims: Enhancement of light harvesting in annual crops has successfully led to yield increases since the green revolution. Such an improvement has mainly been achieved by selecting plants with optimal canopy architecture for specific agronomic practices. For perennials such as oil palm, breeding programmes were focused more on fruit yield, but now aim at exploring more complex traits. The aim of the present study is to investigate potential improvements in light interception and carbon assimilation in the study case of oil palm, by manipulating leaf traits and proposing architectural ideotypes. Methods: Sensitivity analyses (Morris method and metamodel) were performed on a functional-structural plant model recently developed for oil palm which takes into account genetic variability, in order to virtually assess the impact of plant architecture on light interception efficiency and potential carbon acquisition. Key Results: The most sensitive parameters found over plant development were those related to leaf area (rachis length, number of leaflets, leaflet morphology), although fine attributes related to leaf geometry showed increasing influence when the canopy became closed. In adult stands, optimized carbon assimilation was estimated on plants with a leaf area index between 3.2 and 5.5 m2 m-2 (corresponding to usual agronomic conditions), with erect leaves, short rachis and petiole, and high number of leaflets on the rachis. Four architectural ideotypes for carbon assimilation are proposed based on specific combinations of organ dimensions and arrangement that limit mutual shading and optimize light distribution within the plant crown. Conclusions: A rapid set-up of leaf area is critical at young age to optimize light interception and subsequently carbon acquisition. At the adult stage, optimization of carbon assimilation could be achieved through specific combinations of architectural traits. The proposition of multiple morphotypes with comparable level of carbon assimilation opens the way to further investigate ideotypes carrying an optimal trade-off between carbon assimilation, plant transpiration and biomass partitioning.

Comparative transcriptome analysis of oil palm flowers reveals an EAR-motif-containing R2R3-MYB that modulates phenylpropene biosynthesis.

BACKGROUND: Oil palm is the most productive oil crop and the efficiency of pollination has a direct impact on the yield of oil. Pollination by wind can occur but maximal pollination is mediated by the weevil E. kamerunicus. These weevils complete their life cycle by feeding on male flowers. Attraction of weevils to oil palm flowers is due to the emission of methylchavicol by both male and female flowers. In search for male flowers, the weevils visit female flowers by accident due to methylchavicol fragrance and deposit pollen. Given the importance of methylchavicol emission on pollination, we performed comparative transcriptome analysis of oil palm flowers and leaves to identify candidate genes involved in methylchavicol production in flowers. RESULTS: RNA sequencing (RNA-Seq) of male open flowers, female open flowers and leaves was performed using Illumina HiSeq 2000 platform. Analysis of the transcriptome data revealed that the transcripts of methylchavicol biosynthesis genes were strongly up-regulated whereas transcripts encoding genes involved in lignin production such as, caffeic acid O-methyltransferase (COMT) and Ferulate-5-hydroxylase (F5H) were found to be suppressed in oil palm flowers. Among the transcripts encoding transcription factors, an EAR-motif-containing R2R3-MYB transcription factor (EgMYB4) was found to be enriched in oil palm flowers. We determined that EgMYB4 can suppress the expression of a monolignol pathway gene, EgCOMT, in vivo by binding to the AC elements present in the promoter region. EgMYB4 was further functionally characterized in sweet basil which also produces phenylpropenes like oil palm. Transgenic sweet basil plants showed significant reduction in lignin content but produced more phenylpropenes. CONCLUSIONS: Our results suggest that EgMYB4 possibly restrains lignin biosynthesis in oil palm flowers thus allowing enhanced carbon flux into the phenylpropene pathway. This study augments our understanding of the diverse roles that EAR-motif-containing MYBs play to fine tune the metabolic flux along the various branches of core phenylpropanoid pathway. This will aid in metabolic engineering of plant aromatic compounds.

Reproductive phenology of Mauritia flexuosa L. (Arecaceae) in a coastal restinga environment in northeastern Brazil / Fenologia reprodutiva de Mauritia flexuosa L. (Arecaceae) em ambiente de Restinga no Nordeste do Brasil

Abstract The buriti, Mauritia flexuosa, is the most common palm in Brazil, where it has considerable ecological and economic importance. However, few data are available on the phenology of the species, mainly in coastal restinga ecosystems. The present study monitored the reproductive phenology of M. flexuosa in the restinga of Barreirinhas, in the Brazilian Northeast, and investigated the relationship between phenophases and climatic variables. The presence/absence of flowers and fruits was recorded monthly in 25 individuals of each sex between August, 2009, and October, 2012. There was no difference in the phenology of male and female specimens, with flowering and fruiting occurring exclusively in the dry season. We believe that the specific abiotic characteristics of the study environment, such as the intense sunlight and availability of water in the soil, contribute to the reproductive success of M. flexuosa in the dry season, with consequent germination and establishment of seedlings occurring during the subsequent rainy season.

Resumo Popularmente conhecido como buriti, Mauritia flexuosa é a palmeira mais abundante no Brasil, com grande importância ecológica e econômica, porém ainda são poucos os estudos sobre a sua fenologia, não existindo nenhum em ambiente de Restinga. O presente trabalho teve como objetivo estudar a fenologia reprodutiva de M. flexuosa na Restinga de Barreirinhas, no Nordeste do Brasil, verificando como as fenofases se correlacionam com os fatores climáticos. Foram acompanhados mensalmente 25 indivíduos de cada sexo, de agosto/2009 a outubro/2012, verificando a presença/ausência de floração e frutificação. Não houve diferença no padrão fenológico entre indivíduos femininos e masculinos de M. flexuosa, com floração e queda dos frutos exclusivamente na estação seca. Acreditamos que as características abióticas específicas do ambiente estudado, como a forte incidência solar e a disponibilidade de água no solo, contribuíram para o sucesso reprodutivo de M. flexuosa na estação seca, com consequente germinação e estabelecimento de plântulas no período chuvoso.

Relative Estimation of Water Content for Flat-Type Inductive-Based Oil Palm Fruit Maturity Sensor.

The paper aims to study the sensor that identifies the maturity of oil palm fruit bunches by using a flat-type inductive concept based on a resonant frequency technique. Conventionally, a human grader is used to inspect the ripeness of the oil palm fresh fruit bunch (FFB) which can be inconsistent and inaccurate. There are various new methods that are proposed with the intention to grade the ripeness of the oil palm FFB, but none has taken the inductive concept. In this study, the resonance frequency of the air coil is investigated. Samples of oil palm FFB are tested with frequencies ranging from 20 Hz to 10 MHz and the results obtained show a linear relationship between the graph of the resonance frequency (MHz) against time (Weeks). It is observed that the resonance frequencies obtained for Week 10 (pre-mature) and Week 18 (mature) are around 8.5 MHz and 9.8 MHz, respectively. These results are compared with the percentage of the moisture content. Hence, the inductive method of the oil palm fruit maturity sensor can be used to detect the change in water content for ripeness detection of the oil palm FFB.

Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil / Efeitos do clima e da estrutura da vegetação em palmeiras, bromélias e bambus em fragmentos de Mata Atlântica no nordeste brasileiro

Abstract Palms, bromeliads and bamboos are key elements of tropical forests and understanding the effects of climate, anthropogenic pressure and forest structure on these groups is crucial to forecast structural changes in tropical forests. Therefore, we investigated the effects of these factors on the abundance of these groups in 22 Atlantic forest fragments of Northeastern Brazil. Abundance of bromeliads and bamboos were assessed through indexes. Palms were counted within a radius of 20 m. We also obtained measures of vegetation structure, fragment size, annual precipitation, precipitation seasonality and human population density. We tested the effects of these predictors on plant groups using path analysis. Palm abundance was higher in taller forests with larger trees, closed canopy and sparse understory, which may be a result of the presence of seed dispersers and specific attributes of local palm species. Bromeliads were negatively affected by both annual precipitation and precipitation seasonality, what may reflect adaptations of these plants to use water efficiently, but also the need to capture water in a regular basis. Bamboos were not related to any predictor variable. As climate and forest structure affected the abundance of bromeliads and palms, human-induced climatic changes and disturbances in forest structure may modify the abundance of these groups. In addition, soil properties and direct measurements of human disturbance should be used in future studies in order to improve the predictability of models about plant groups in Northeastern Atlantic Forest.

Resumo Palmeiras, bromélias e bambus são importantes elementos das florestas tropicais e, entender os efeitos do clima, pressão antrópica e estrutura da floresta nesses grupos é crucial para prever alterações estruturais em florestas tropicais. Portanto, nós investigamos os efeitos desses fatores na abundância desses grupos vegetais em 22 fragmentos de Mata Atlântica no nordeste brasileiro. Abundâncias de bromélias e bambus foram registradas através de índices. Palmeiras foram contadas em um raio de 20 m. Nós também obtemos medidas da estrutura da vegetação, tamanho de fragmento, precipitação anual, sazonalidade na precipitação e densidade populacional humana. Nós testamos os efeitos desses preditores nos grupos vegetais através de análises de caminhos. A abundância de palmeiras foi maior em florestas mais altas, com árvores mais grossas, dossel fechado e sub-bosque aberto, o que deve refletir a presença de dispersores de sementes e atributos específicos das espécies de palmeiras locais. Bromélias foram negativamente afetadas pela precipitação anual e pela sazonalidade na precipitação, o que deve refletir adaptações dessas plantas para o uso eficiente da água, mas também a necessidade de captar água regularmente. Bambus não estiveram relacionados com nenhum dos preditores avaliados. Dado que clima e estrutura florestal afetaram a abundância de bromélias e palmeiras, as mudanças climáticas e distúrbios na estrutura das matas causados por ações antrópicas podem alterar a abundância desses grupos. Adicionalmente, propriedades do solo e medidas diretas de distúrbios antrópicos devem ser usadas em estudos futuros para melhorar o poder preditivo dos modelos sobre a abundância de plantas na Mata Atlântica do nordeste brasileiro.

Soil Nitrogen-Cycling Responses to Conversion of Lowland Forests to Oil Palm and Rubber Plantations in Sumatra, Indonesia.

Rapid deforestation in Sumatra, Indonesia is presently occurring due to the expansion of palm oil and rubber production, fueled by an increasing global demand. Our study aimed to assess changes in soil-N cycling rates with conversion of forest to oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations. In Jambi Province, Sumatra, Indonesia, we selected two soil landscapes - loam and clay Acrisol soils - each with four land-use types: lowland forest and forest with regenerating rubber (hereafter, "jungle rubber") as reference land uses, and rubber and oil palm as converted land uses. Gross soil-N cycling rates were measured using the 15N pool dilution technique with in-situ incubation of soil cores. In the loam Acrisol soil, where fertility was low, microbial biomass, gross N mineralization and NH4+ immobilization were also low and no significant changes were detected with land-use conversion. The clay Acrisol soil which had higher initial fertility based on the reference land uses (i.e. higher pH, organic C, total N, effective cation exchange capacity (ECEC) and base saturation) (P≤0.05-0.09) had larger microbial biomass and NH4+ transformation rates (P≤0.05) compared to the loam Acrisol soil. Conversion of forest and jungle rubber to rubber and oil palm in the clay Acrisol soil decreased soil fertility which, in turn, reduced microbial biomass and consequently decreased NH4+ transformation rates (P≤0.05-0.09). This was further attested by the correlation of gross N mineralization and microbial biomass N with ECEC, organic C, total N (R=0.51-0. 76; P≤0.05) and C:N ratio (R=-0.71 - -0.75, P≤0.05). Our findings suggest that the larger the initial soil fertility and N availability, the larger the reductions upon land-use conversion. Because soil N availability was dependent on microbial biomass, management practices in converted oil palm and rubber plantations should focus on enriching microbial biomass.

Comparative proteomic analysis of oil palm leaves infected with Ganoderma boninense revealed changes in proteins involved in photosynthesis, carbohydrate metabolism, and immunity and defense.

The basidiomycete fungal pathogen Ganoderma boninense is the causative agent for the incurable basal stem rot (BSR) disease in oil palm. This disease causes significant annual crop losses in the oil palm industry. Currently, there is no effective method for disease control and elimination, nor is any molecular marker for early detection of the disease available. An understanding of how BSR affects protein expression in plants may help identify and/or assist in the development of an early detection protocol. Although the mode of infection of BSR disease is primarily via the root system, defense-related genes have been shown to be expressed in both the root and leafs. Thus, to provide an insight into the changes in the global protein expression profile in infected plants, comparative 2DE was performed on leaf tissues sampled from palms with and without artificial inoculation of the Ganoderma fungus. Comparative 2DE revealed that 54 protein spots changed in abundance. A total of 51 protein spots were successfully identified by LC-QTOF MS/MS. The majority of these proteins were those involved in photosynthesis, carbohydrate metabolism as well as immunity and defense.

Oil palm water use: calibration of a sap flux method and a field measurement scheme.

Oil palm (Elaeis guineensis Jacq.) water use was assessed by sap flux density measurements with the aim to establish the method and derive water-use characteristics. Thermal dissipation probes were inserted into leaf petioles of mature oil palms. In the laboratory, we tested our set-up against gravimetric measurements and derived new parameters for the original calibration equation that are specific to oil palm petioles. In the lowlands of Jambi, Indonesia, in a 12-year-old monoculture plantation, 56 leaves on 10 palms were equipped with one sensor per leaf. A 10-fold variation in individual leaf water use among leaves was observed, but we did not find significant correlations to the variables trunk height and diameter, leaf azimuthal orientation, leaf inclination or estimated horizontal leaf shading. We thus took an un-stratified approach to determine an appropriate sampling design to estimate stand transpiration (Es, mm day(-1)) rates of oil palm. We used the relative standard error of the mean (SEn, %) as a measure for the potential estimation error of Es associated with sample size. It was 14% for a sample size of 13 leaves to determine the average leaf water use and four palms to determine the average number of leaves per palm. Increasing these sample sizes only led to minor further decreases of the SEn of Es. The observed 90-day average of Es was 1.1 mm day(-1) (error margin ± 0.2 mm day(-1)), which seems relatively low, but does not contradict Penman-Monteith-derived estimates of evapotranspiration. Examining the environmental drivers of Es on an intra-daily scale indicates an early, pre-noon maximum of Es rates (11 am) due to a very sensitive reaction of Es to increasing vapor pressure deficit in the morning. This early peak is followed by a steady decline of Es rates for the rest of the day, despite further rising levels of vapor pressure deficit and radiation; this results in pronounced hysteresis, particularly between Es and vapor pressure deficit.

Vegetative and reproductive phenology of Butia purpurascens Glassman (Arecaceae) under the effects of leaf harvesting / Fenologia vegetativa e reprodutiva de Butia purpurascens Glassman (Arecaceae) sob efeitos da extração de folhas

Butia purpurascens is an endemic and threatened palm tree species that occurs in open areas of the Brazilian Cerrado, predominantly in southwestern Goiás. The leaves of this palm tree are harvested by local people to fabricate brooms. This study evaluated changes in vegetative and reproductive phenology in two different natural populations of this palm tree: one population with leaf harvesting and another non-harvested population. Twenty plants were monitored in each area for 23 months. The phenophases were related to the temperature and precipitation averages for a 30-year period. Leaf sprouting occurred throughout the year, with a slight reduction in periods of low temperatures and low rainfall. The first spathes emerged in March and flowering began during the dry season (June), continuing until January of the following year, concurrent with the period of most intense fruiting. Flowering and fruiting appear to be triggered by periods of drought, which are commonly observed in the Cerrado. The harvested sites produced significantly fewer leaves, spathes, inflorescences and infructescences than the non-harvested sites. Thus, the supply of resources to the local fauna is possibly reduced in sites under leaf exploitation, which in the long term can represent damage to the palm tree population’s structure and dynamics. Other socioeconomic and ecological studies about the effects of leaf harvesting in B. purpurascens are necessary to enable strategies for sustainable use, devise management alternatives and conserve this threatened palm species.

Butia purpurascens é uma palmeira endêmica e ameaçada que ocorre em áreas de cerrado sentido restrito do sudoeste goiano e tem suas folhas extraídas pela população local para a confecção de vassouras. O estudo avaliou variações na fenologia vegetativa e reprodutiva em duas populações naturais da palmeira em Jataí, GO: uma área sem extração e outra com extrativismo foliar. Vinte indivíduos foram monitorados em cada área durante 23 meses. As fenofases foram relacionadas às medias de temperatura e precipitação por um período de 30 anos. O brotamento foliar ocorreu ao longo de todo o ano, embora tenha reduzido nos períodos de menor temperatura e pluviosidade. A emissão das primeiras espatas se iniciou em março e a floração teve início durante a estação seca (junho), perdurando até janeiro do ano seguinte, concomitante ao período de intensa frutificação. Floração e frutificação parecem ser desencadeadas por períodos de estiagem, comum no Cerrado brasileiro. Áreas com extração produziram número significativamente menor de folhas, espatas, inflorescências e infrutescências do que áreas sem extração. Assim, a oferta de recursos para a fauna local é reduzida em áreas sob extrativismo, o que pode prejudicar a estrutura e a dinâmica populacional da palmeira, em longo prazo. Outros estudos sócio-econômicas e ecológicos sobre os efeitos da extração foliar em B. purpurascens são necessários para permitir estratégias de exploração sustentável, alternativas de manejo e a conservação dessa espécie atualmente ameaçada.

Oil palm plantations fail to support mammal diversity.

Agricultural expansion is the largest threat to global biodiversity. In particular, the rapid spread of tree plantations is a primary driver of deforestation in hyperdiverse tropical regions. Plantations tend to support considerably lower biodiversity than native forest, but it remains unclear whether plantation traits affect their ability to sustain native wildlife populations, particularly for threatened taxa. If animal diversity varies across plantations with different characteristics, these traits could be manipulated to make plantations more "wildlife friendly." The degree to which plantations create edge effects that degrade habitat quality in adjacent forest also remains unclear, limiting our ability to predict wildlife persistence in mixed-use landscapes. We used systematic camera trapping to investigate mammal occurrence and diversity in oil palm plantations and adjacent forest in Sabah, Malaysian Borneo. Mammals within plantations were largely constrained to locations near native forest; the occurrence of most species and overall species richness declined abruptly with decreasing forest proximity from an estimated 14 species at the forest ecotone to -1 species 2 km into the plantation. Neither tree height nor canopy cover within plantations strongly affected mammal diversity or occurrence, suggesting that manipulating tree spacing or planting cycles might not make plantations more wildlife friendly. Plantations did not appear to generate strong edge effects; mammal richness within forest remained high and consistent up to the plantation ecotone. Our results suggest that land-sparing strategies, as opposed to efforts to make plantations more wildlife-friendly, are required for regional wildlife conservation in biodiverse tropical ecosystems.

The impact of selective-logging and forest clearance for oil palm on fungal communities in Borneo.

Tropical forests are being rapidly altered by logging, and cleared for agriculture. Understanding the effects of these land use changes on soil fungi, which play vital roles in the soil ecosystem functioning and services, is a major conservation frontier. Using 454-pyrosequencing of the ITS1 region of extracted soil DNA, we compared communities of soil fungi between unlogged, once-logged, and twice-logged rainforest, and areas cleared for oil palm, in Sabah, Malaysia. Overall fungal community composition differed significantly between forest and oil palm plantation. The OTU richness and Chao 1 were higher in forest, compared to oil palm plantation. As a proportion of total reads, Basidiomycota were more abundant in forest soil, compared to oil palm plantation soil. The turnover of fungal OTUs across space, true ß-diversity, was also higher in forest than oil palm plantation. Ectomycorrhizal (EcM) fungal abundance was significantly different between land uses, with highest relative abundance (out of total fungal reads) observed in unlogged forest soil, lower abundance in logged forest, and lowest in oil palm. In their entirety, these results indicate a pervasive effect of conversion to oil palm on fungal community structure. Such wholesale changes in fungal communities might impact the long-term sustainability of oil palm agriculture. Logging also has more subtle long term effects, on relative abundance of EcM fungi, which might affect tree recruitment and nutrient cycling. However, in general the logged forest retains most of the diversity and community composition of unlogged forest.

Evaluation of reference genes for quantitative real-time PCR in oil palm elite planting materials propagated by tissue culture.

BACKGROUND: The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR). With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels. RESULTS: In this study, eight candidate reference genes selected from cDNA microarray study and literature review were evaluated comprehensively across 26 tissue culture samples using RT-qPCR. These samples were collected from two tissue culture lines and media treatments, which consisted of leaf explants cultures, callus and embryoids from consecutive developmental stages. Three statistical algorithms (geNorm, NormFinder and BestKeeper) confirmed that the expression stability of novel reference genes (pOP-EA01332, PD00380 and PD00569) outperformed classical housekeeping genes (GAPDH, NAD5, TUBULIN, UBIQUITIN and ACTIN). PD00380 and PD00569 were identified as the most stably expressed genes in total samples, MA2 and MA8 tissue culture lines. Their applicability to validate the expression profiles of a putative ethylene-responsive transcription factor 3-like gene demonstrated the importance of using the geometric mean of two genes for normalization. CONCLUSIONS: Systematic selection of the most stably expressed reference genes for RT-qPCR was established in oil palm tissue culture samples. PD00380 and PD00569 were selected for accurate and reliable normalization of gene expression data from RT-qPCR. These data will be valuable to the research associated with the tissue culture process. Also, the method described here will facilitate the selection of appropriate reference genes in other oil palm tissues and in the expression profiling of genes relating to yield, biotic and abiotic stresses.

Selective­logging and oil palm: multitaxon impacts, biodiversity indicators, and trade­offs for conservation planning.

Strong global demand for tropical timber and agricultural products has driven large-scale logging and subsequent conversion of tropical forests. Given that the majority of tropical landscapes have been or will likely be logged, the protection of biodiversity within tropical forests thus depends on whether species can persist in these economically exploited lands, and if species cannot persist, whether we can protect enough primary forest from logging and conversion. However, our knowledge of the impact of logging and conversion on biodiversity is limited to a few taxa, often sampled in different locations with complex land-use histories, hampering attempts to plan cost-effective conservation strategies and to draw conclusions across taxa. Spanning a land-use gradient of primary forest, once- and twice-logged forests, and oil palm plantations, we used traditional sampling and DNA metabarcoding to compile an extensive data set in Sabah, Malaysian Borneo for nine vertebrate and invertebrate taxa to quantify the biological impacts of logging and oil palm, develop cost-effective methods of protecting biodiversity, and examine whether there is congruence in response among taxa. Logged forests retained high species richness, including, on average, 70% of species found in primary forest. In contrast, conversion to oil palm dramatically reduces species richness, with significantly fewer primary-forest species than found on logged forest transects for seven taxa. Using a systematic conservation planning analysis, we show that efficient protection of primary-forest species is achieved with land portfolios that include a large proportion of logged-forest plots. Protecting logged forests is thus a cost-effective method of protecting an ecologically and taxonomically diverse range of species, particularly when conservation budgets are limited. Six indicator groups (birds, leaf-litter ants, beetles, aerial hymenopterans, flies, and true bugs) proved to be consistently good predictors of the response of the other taxa to logging and oil palm. Our results confidently establish the high conservation value of logged forests and the low value of oil palm. Cross-taxon congruence in responses to disturbance also suggests that the practice of focusing on key indicator taxa yields important information of general biodiversity in studies of logging and oil palm.