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Net primary production (NPP) is one of the approaches used to estimate the amount of carbon sequestration by plants. This research aims to estimate the total carbon flux exchanged from different ages of oil palm using remote sensing. The study site was at the PTPN VI Batang Hari, Jambi, Sumatra, Indonesia. The amount of carbon sequestration by oil palm plantations at PTPN VI Batang Hari, Jambi can be estimated using remote sensing based on the light use efficiency (LUE) model. The results showed that the oil palm age affects the amount of carbon sequestrated. The lowest Net primary production value was found at one year of planting 4.28 gCm-2day-1, and the highest was 9.38 gCm-2day-1 at 20 years of planting. The model LUE output was validated using Eddy covariance data and the results showed a low error and a high accuracy rate with RMSE = 0.05 gCMJ-1, R2 = 92%, and p-value = 0.04. We concluded that the LUE model can be used with high accuracy to estimate the amount of carbon absorption of oil palm when direct measurement is unavailable.

Vegetation canopy height is a relevant proxy for aboveground biomass, carbon stock, and biodiversity. Wall-to-wall information of canopy height with high spatial resolution and accuracy is not yet available on large scales. For the globally consistent TanDEM-X data, simplifications are necessary to estimate canopy height with semi-empirical models based on polarimetric synthetic aperture radar interferometry (PolInSAR). We trained the semi-empirical models with sampled GEDI data, because the assumptions behind the application of such simplifications are not always valid for TanDEM-X. General linear as well as sinc models and empirical parameterizations of these models were applied to estimate the canopy height in tropical landscapes of Sumatra, Indonesia. Airborne laser scanning (ALS) data were consistently used as an independent reference. The general simplified models were compared with the trained empirical versions to assess the potential improvement of the empirical parameterization of the models. The residuals of the different canopy height models were further evaluated in relation to land use and structural information of the vegetation. Our results indicated that the empirical parameters substantially improved the estimation from a root-mean-square-error (RMSE) of 10.3 m (55.8%) to 8.8 m (47.7%), when using the linear model. In contrast, the improvement of the sinc model with empirical parameters was not substantial compared to the general sinc model (7.4 m [40.4%] vs. 6.9 m [37.5%]). A consistent improvement was observed in the linear model, whereas the improvement of the sinc model was dependent on the land-use type. Structural attributes like the canopy height itself and vegetation cover had a significant effect on the accuracies, with higher and denser vegetation generally resulting in higher residuals. We demonstrate the potential of the combined exploitation of the TanDEM-X and GEDI missions for a wall-to-wall canopy height estimation in a tropical region. This study provides relevant findings for a consistent mapping of vegetation canopy height in tropical landscapes and on large scales with spaceborne laser and SAR data.

Effects of oil-palm (Elaeis guineensis Jacq.) management on silicon (Si) cycling under smallholder oil-palm plantations have hardly been investigated. As oil palms are Si accumulators, we hypothesized that management practices and topsoil erosion may cause Si losses and changes in spatial Si concentration patterns in topsoils under oil-palm cultivation. To test this hypothesis, we took topsoil samples under mature oil-palm plantations in well-drained and riparian areas of Jambi Province, Indonesia. The samples were taken from four different management zones within each oil-palm plot: palm circles, oil-palm rows, interrows, and below frond piles. We quantified mobile Si (SiM) and Si in amorphous silica (SiAm) by the extraction of CaCl2 and NaCO3, respectively. Both fractions are important Si pools in soils and are essential for plant–soil Si cycling. We further installed sediment traps on sloping, well-drained oil-palm plantations to estimate the annual loss of soil and SiAm caused by erosion. In well-drained areas, mean topsoil SiAm concentrations were significantly higher below frond piles (3.97 ± 1.54 mg g−1) compared to palm circles (1.71 ± 0.35 mg g−1), oil-palm rows (1.87 ± 0.51 mg g−1), and interrows (1.88 ± 0.39 mg g−1). In riparian areas, the highest mean topsoil SiAm concentrations were also found below frond piles (2.96 ± 0.36 mg g−1) and in grass-covered interrows (2.71 ± 0.13 mg g−1), whereas topsoil SiAm concentrations of palm circles were much lower (1.44 ± 0.55 mg g−1). We attributed the high SiAm concentrations in topsoils under frond piles and in grass-covered interrows to phytolith release from decaying oil-palm fronds, grasses, and sedges. The significantly lower SiAm concentrations in palm circles (in both well-drained and riparian areas), oil-palm rows, and unvegetated interrows (only in well-drained areas) were explained by a lack of litter return to these management zones. Mean topsoil SiM concentrations were in the range of ∼ 10–20 µg g−1. They tended to be higher in riparian areas, but the differences between well-drained and riparian sites were not statistically significant. Soil-loss calculations based on erosion traps confirmed that topsoil erosion was considerable in oil-palm interrows on slopes. Erosion estimates were in the range of 4–6 Mg ha−1 yr−1, involving SiAm losses in a range of 5–9 kg−1 ha−1 yr−1. Based on the observed spatial Si patterns, we concluded that smallholders could efficiently reduce erosion and support Si cycling within the system by (1) maintaining a grass cover in oil-palm rows and interrows, (2) incorporating oil-palm litter into plantation management, and (3) preventing soil compaction and surface-crust formation.

Indonesia is one of the hotspots of land transformation from forest ecosystems toward oil palm and other cash-crop monocultures. Land-cover changes directly impact below-canopy microclimate, which are critical drivers for many ecological functions, such as greenhouse gas exchange and soil microbial activity. However, microclimatic variability below canopies, even within the same land-use type can be quite large due to structural heterogeneity, vegetation age or vitality, and differences in management practices.In this study, we focused on the assessment of microclimatic differences within the most common land-use types in tropical lowland Jambi province (Sumatra, Indonesia), using mini-meteorological stations. We used a rapid assessment approach in which we monitored below-canopy key meteorological parameters at a total of 120 different locations from June to November 2021, covering lowland tropical rainforest, oil palm monoculture, rubber monoculture and agroforestry systems, and fallow shrublands. We clustered the study region into 16 micro-regions, each with a radius of four kilometres. In each micro-region, an open-land area served as a reference meteorological location. Based on the gradients of meteorological parameters between below-canopy and open-land conditions we derived the site-specific impact of the respective land-use type on below-canopy microclimate. To further explore microclimatic characteristics of the different land-use types, we used airborne laserscanning (ALS) data available at a subset of 90 plots as well as information on age, management intensities and ownerships of plantations, distance between plantations and forests, and overall land cover distribution.Preliminary results show that forests and fallow shrublands are generally cooler, wetter and receive lower below-canopy radiation compared to agricultural systems and open land. Forests show a strong capacity to buffer high levels of open-land air temperature and atmospheric vapour pressure deficit (VPD) variability by, on average, 1.7°C and 6.4 hPa, respectively, while oil palm showed very little buffering capacities (0.2°C and 2.2 hPa). At a regional scale, mixed land-use systems tend to be slightly warmer (+0.36±0.18°C) and drier (+1.47±0.52 hPa VPD) compared to forest-dominated land-use systems. Within the mixed land-use systems, forests tend to be drier (+1.05±0.41 hPa VPD) while below-canopy temperature remains similar (+0.38±0.34°C) compared to forests in the forest-dominated land-use systems. Interception is an important component in the hydrology of the studied forest locations, with approx. 66% of precipitation being intercepted, while at fallow shrubland, rubber and oil palm locations, only 24, 25 and 17%, respectively, of precipitation was intercepted. Overall, our preliminary results show that there is high variability in meteorological conditions, even within the same micro-region or land-use type.

Over the last decade, monoculture plantations have rapidly developed in Jambi Province on Sumatra, Indonesia. Meanwhile, there has been intensification of discharge fluctuation in the study area. ...

Special thanks to our field assistants in Indonesia (Basri, Bayu and Darwis) and to Frank Tiedemann, Edgar Tunsch, Dietmar Fellert and Malte Puhan for technical assistance. We thank PTPN VI and the owner of the plantation at Pompa Air for allowing us to conduct our research at their plantation. We would also like to thank the Spanish national project GEISpain (CGL2014-52838-C2-1-R) and the DAAD (scholarship from the programme ‘Research Stays for University Academics and Scientist 2018, ref. no. 91687130)' for partly financing A. Meijide during the preparation of this paper., The potential of palm-oil biofuels to reduce greenhouse gas (GHG) emissions compared with fossil fuels is increasingly questioned. So far, no measurement-based GHG budgets were available, and plantation age was ignored in Life Cycle Analyses (LCA). Here, we conduct LCA based on measured CO2, CH4 and N2O fluxes in young and mature Indonesian oil palm plantations. CO2 dominates the on-site GHG budgets. The young plantation is a carbon source (1012 ± 51 gC m−2 yr−1), the mature plantation a sink (−754 ± 38 gC m−2 yr−1). LCA considering the measured fluxes shows higher GHG emissions for palm-oil biodiesel than traditional LCA assuming carbon neutrality. Plantation rotation-cycle extension and earlier-yielding varieties potentially decrease GHG emissions. Due to the high emissions associated with forest conversion to oil palm, our results indicate that only biodiesel from second rotation-cycle plantations or plantations established on degraded land has the potential for pronounced GHG emission savings., This study was financed by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)— Project-ID 192626868—in the framework of the collaborative German-Indonesian research project CRC990 (subprojects A03, A04 and A05)., Spanish national project GEISpain (CGL2014-52838-C2-1-R) and the DAAD (scholarship from the programme ‘Research Stays for University Academics and Scientist 2018, ref. no. 91687130)

We measured CO2 and CH4 fluxes using chambers and eddy covariance (only CO2) from a moist moss tundra in Svalbard. The average net ecosystem exchange (NEE) during the summer (June–August) was −0.40 g C m−2 day−1 or −37 g C m−2 for the whole summer. Including spring and autumn periods the NEE was reduced to −6.8 g C m−2 and the annual NEE became positive, 24.7 gC m−2 due to the losses during the winter. The CH4 flux during the summer period showed a large spatial and temporal variability. The mean value of all 214 samples was 0.000511 ± 0.000315 µmol m−2s−1 which corresponds to a growing season estimate of 0.04 to 0.16 g CH4 m−2. We find that this moss tundra emits about 94–100 g CO2-equivalents m−2 yr−1 of which CH4 is responsible for 3.5–9.3 % using GWP100 of 27.9 respectively GWP20. Air temperature, soil moisture and greenness index contributed significantly to explain the variation in ecosystem respiration (Reco) while active layer depth, soil moisture and greenness index were the variables that best explained CH4 emissions. Estimate of temperature sensitivity of Reco and gross primary productivity showed that a modest increase in air temperature of 1 degree did not significantly change the NEE during the growing season but that the annual NEE would be even more positive adding another 8.5 g C m−2 to the atmosphere. We tentatively suggest that the warming of the Arctic that has already taken place is partly responsible for the fact that the moist moss tundra now is a source of CO2 to the atmosphere.

Microclimate and Land Surface Temperature (LST) are important analytical variables used to understand complex oil palm agroforestry systems and their effects on biodiversity and ecosystem functions. In order to examine experimental effects of tree species richness (0, 1, 2, 3 or 6), plot size (25 m2, 100 m2, 400 m2, 1600 m2) and stand structural complexity on microclimate and Land Surface Temperature, related data were collected following a strict design. The experiment was carried out in the Jambi province, in Sumatra (Indonesia), as part of the collaborative project EFForTS [Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems]. Microclimate data collected using miniaturized data loggers combined with drone-based thermal data were considered within an oil palm plantation enriched with six target tree species. The timeframe considered for data analysis was 20th September 2017 to 26th September 2017. The experiment data can be used for comparison with data from conventional oil palm agroforestry systems in the tropics. They can more specifically be used as reference to assess microclimate and Land Surface Temperature patterns within similar agroforestry systems.

A comprehensive study of the pervasive role of immersion and immersive media in postmodern culture, from a humanities and social sciences perspective. Virtual reality, augmented reality, mixed reality, and other modes of digitally induced immersion herald a major cultural and economic shift in society. Most academic discussions of immersion and immersive media have focused on the technological aspects. In The 360° Gaze, Christian Stiegler takes a humanities and social science approach, emphasizing the human implications of immersive media in postmodern culture. Examining characteristics common to all immersive experiences, he uncovers dominant metaphors, such as the rabbit hole, and prevailing ideologies. He raises fundamental questions about opportunities and risks associated with immersion, as well as the potential effects on individuals, communities, and societies. Stiegler expands the range of media practices we should consider immersive. Introducing his theoretical framework of “the 360° gaze,” he navigates immersive experiences in literature, film, television, the performing arts, digital games, and immersive technologies. He considers their implications for psychology and reception, as well as their role in cultural industries and digital ecosystems. As he examines the intersections among immersive settings in media and in everyday immersive acts, he reframes such topics as mediation of the self, binge-watching, fandom, extended reality, and artificial intelligence. Immersion, he argues, is key to understanding the role of mass media in postmodern society. Stiegler perceives immersion to be an even more powerful and enduring form of engagement than mediation. Writing as a researcher and storyteller, he provides a guide to rethinking immersion in mediated experiences from the past, to enable us to prepare ourselves for the future.

The global population growth and changes in human lifestyle and consumption patterns put immense pressure on the limited freshwater resources in the world. Aiming at sustainable use and equitable allocation of the water resources, it becomes crucial to know the water appropriation for the production of different commodities and consumer goods. These days, oil palm (Elaeis guineensis) is one of the highest-demanded crops around the globe since the oil of its fruits and kernel is widely used as biofuel and major ingredients in food and cosmetic industries. Given this massive demand, the areas under oil palm cultivation in the tropics have continuously been expanding in the last decades, particularly in Indonesia. With the oil palm boom, not only biodiversity loss, and carbon dioxide emissions from deforestation have been increasing, but also the consumptions of blue and green water resources are of concern. In this ongoing research, the concept of water footprint (WF) is employed to quantify the green and blue water use of oil palm production in the Bajubang district, Batanghari regency, Jambi province, Sumatra, Indonesia. This is one of the first studies that uses field-measured data of evapotranspiration (ET) from oil palm plantations in different growth stages over seven years for the purpose of WF assessment, compared to the available literature where ET was estimated using modelling approaches. The multi-year measurements were conducted using the eddy covariance technique, which continuously measures water vapor (H2O) fluxes at the ecosystem level over the plantation. Based on these measurements, specifically, the WF assessment is performed on a product basis during the plantation life cycle, per area and time unit, for the oil palm fruit yield and oil palm derived products (palm oil, palm-oil biodiesel). Besides the crop water consumption at the plantation (i.e. ET) as the core element, other water consumptions in the products’ processing chain are included in the WF assessment. Preliminary results indicate a WF of 2440 m3 t-1 for palm oil and 65 m3 GJ-1 for palm-oil biodiesel. This is about 50% lower than the global average estimates. Local WF account of oil palm products has a critical contribution to product transparency while being useful for comparative purposes. Contrasting the WFs of products serving the same function (e.g., palm oil biodiesel, soybean biodiesel) is of essential importance, aiming at conscious product choices in a world of freshwater scarcity.Keywords: water footprint, oil palm, palm oil, Indonesia, eddy covariance, evapotranspiration

Rainforest conversion to woody croplands impacts the carbon cycle via ecophysiological processes such as photosynthesis and autotrophic respiration. Changes in the carbon cycle associated with land-use change can be estimated through Land Surface Models (LSMs). The accuracy of carbon flux estimation in carbon fluxes associated with land-use change has been attributed to uncertainties in the model parameters affecting photosynthetic activity, which is a function of both carboxylation capacity (Vcmax) and electron transport capacity (Jmax). In order to reduce such uncertainties for common tropical woody crops and trees, in this study we measured Vcmax25 (Vcmax standardized to 25 °C), Jmax25 (Jmax standardized to 25 °C) and light-saturated photosynthetic capacity (Amax) of Elaeis guineensis Jacq. (oil palm), Hevea brasiliensis (rubber tree), and two native tree species, Eusideroxylon zwageri and Alstonia scholaris, in a converted landscape in Jambi province (Sumatra, Indonesia) at smallholder plantations. We considered three plantations, a monoculture rubber, a monoculture oil palm, and an agroforestry system (jungle rubber plantation), where rubber trees coexist with some native trees. We performed measurements on leaves at the lower part of the canopy, and used a scaling method based on exponential function to scale up photosynthetic capacity related traits to the top of the canopy. At the lower part of the canopy, we found (i) high Vcmax25 values for H. brasiliensis from monoculture rubber plantation and jungle rubber plantation that was linked to a high area-based leaf nitrogen content, and (ii) low value of Amax for E. guineensis from oil palm plantation that was due to a low value of Vcmax25 and a high value of dark respiration. At the top of the canopy, Amax varied much more than Vcmax25 among different land-use types. We found that photosynthetic capacity declined fastest from the top to the lower part of the canopy in oil palm plantations. We demonstrate that photosynthetic capacity related traits measured at the lower part of the canopy can be successfully scaled up to the top of the canopy. We thus provide helpful new data that can be used to constrain LSMs that simulate land-use change related to rubber and oil palm expansion.

In tall vegetation canopies, such as forest or oil palm monoculture plantations, the below-canopy airflow can be influenced by the local topography and thereby cause horizontal exchange of the below-canopy air. Especially during night time, calm weather conditions may result in the formation of an isolated layer near the surface, which is decoupled from the above-canopy air layer. When decoupling and below-canopy horizontal air flow occurs, there is a high potential that above-canopy measured carbon dioxide (CO2) fluxes based on eddy covariance measurements might not represent the true ecosystem CO2 flux as below-canopy respiration might be undetected by the eddy covariance system. Nevertheless, eddy covariance data are frequently used as the reference for fluxes of tall vegetation ecosystems or for validation of modelling approaches estimating gross primary production (GPP) and net ecosystem exchange (NEE). It is therefore important to have accurate information on air mixing, decoupling and sub-canopy drainage flow to understand the complex CO2 exchange behaviour in tall vegetation ecosystems.In this context, we investigate wind and micrometeorological dynamics of a mature oil palm monoculture plantation (tropical lowland, Jambi Province, Sumatra, Indonesia). We use data from above- and below-canopy eddy covariance and micrometeorological measurements within the oil palm plantation to assess the wind dynamics and the strength of the turbulent mixing as an estimator for the degree of coupling. Further, we explore the potential implications of decoupling and horizontal below-canopy flow on the above-canopy derived NEE.Preliminary results show that wind is generally weak in the oil palm plantation. Using a breakpoint analysis, the correlation of below- and above-canopy standard deviation of vertical wind speed (σw) derived from sonic eddy covariance measurements below (2.4 m height) and above the canopy (22 m height), we identified a site-specific σw threshold of 0.11 m s-1 (below-canopy) and 0.26 m s-1 (above-canopy) above which the atmospheric conditions are in fully coupled state. During the day, unstable conditions dominate over stable conditions while in the twilight hours and during the night, the reverse is the case. Below-canopy wind comes mostly from south-eastern directions during both day and night, and tends to blow independently from wind above the canopy for conditions with above-canopy u* < 0.3 m s-1. Based on the above-canopy eddy covariance NEE measurements and on the direction difference (ΔWD) between above- and below-canopy wind, we observe a threshold of ~70° ΔWD above which the two layers might be decoupled. Below-canopy air flow might therefore influence the above-canopy NEE detections, biasing carbon balance estimates.

Evapotranspiration (ET) is a key flux in hydrological cycles; it is affected by both climate and land-use change. A recent study across 42 study sites in four land-use types in lowland Sumatra (Indonesia) reported that local and regional transpiration are on the rebound due to the high water use and continuing expansion of oil palm plantations. Conventional ET assessment methods such as satellite-based thermography or the eddy covariance (EC) technique lack the high spatial resolution and spatial replicability, respectively, that are required for ET assessments in dynamic and heterogeneous, mosaic-like landscapes. For such assessments of ET, near-surface airborne thermography offers new opportunities for studies with high numbers of spatial replicates and in a fine spatial resolution. In our study, we tested drone-based thermography and the subsequent application of three energy balance models (DATTUTDUT, TSEB-PT, DTD) using the widely accepted EC technique as a reference method. The study site was a mature oil palm plantation in lowland Sumatra. For 61 flight missions, latent heat flux estimates of the DATTUTDUT model with measured net radiation agreed well with eddy covariance measurements (r²=0.85; MAE=47; RMSE=60) across variable weather conditions and daytimes. Confidence intervals for slope and intercept of a Deming regression suggest no difference between drone-based and eddy covariance method, thus indicating interchangeability. TSEB-PT and DTD yielded agreeable results, but all three models are highly sensitive to the configuration in which net radiation is assessed. Overall, we conclude that drone-based thermography with energy-balance modeling is a reliable method complementing available methods for ET studies. It offers promising, additional opportunities for fine grain and spatially explicit studies. Further steps in the near future will include the testing and if necessary calibrating of the method across different biomes as well as ecological applications.

This article applies and extends the concept of social media logic to assess the politics of immersive storytelling on digital platforms. These politics are considered in the light of what has been identified as mass media logic, which argues that mass media in the 20th century gained power by developing a commanding discourse that guides the organization of the public sphere. The shift to social media logic in the 21st century, with its grounding principles of programmability, popularity, connectivity, and datafication, influenced a new discourse on the logics of digital ecosystems. Digital platforms such as Facebook are offering all-surrounding mediated environments to communicate in Virtual Reality (‘Facebook Spaces') as well as immersive narratives such as Mr. Robot VR. This article provides an understanding of the politics of immersive storytelling and of its underlying principles of programmability, user experience, popularity, and platform sociality, which define immersive technologies in the 21st century.

This chapter applies and extends the concept of social media logic to assess the politics of immersive storytelling on digital platforms. These politics are considered in the light of what has been identified as mass media logic, which argues that mass media in the 20th century gained power by developing a commanding discourse that guides the organization of the public sphere. The shift to social media logic in the 21st century, with its grounding principles of programmability, popularity, connectivity, and datafication, influenced a new discourse on the logics of digital ecosystems. Digital platforms such as Facebook are offering all-surrounding mediated environments to communicate in virtual reality (‘Horizon') as well as immersive narratives such as Mr. Robot VR. This chapter provides an overview of the changing dynamics within Facebook's VR strategy as well as an understanding of the politics of immersive storytelling and its underlying principles of programmability, user experience, popularity, and platform sociality, which define immersive technologies in the 21st century.

The rapid expansion of rubber and oil palm plantations in Jambi Province, Sumatra, Indonesia, is associated with large-scale deforestation and the impairment of many ecosystem services. According to villagers' observations, this land use change has, together with climate change, led to an increase in the magnitude and frequency of river flood events, which constrain village and plantation development. Based on this empirical societal problem, we investigate whether we can find measurable indications for the presumed linkages between land use change, climate change, and changing flooding regimes. We follow an explorative, bottom-up research approach that builds on a review of multidisciplinary datasets, integrating local ecological knowledge with scientific measurements from soil science, climatology, hydrology, and remote sensing. We found that water levels of one of the largest rivers in Jambi Province, the Tembesi, have increased significantly during the last two decades. Data of local and regional meteorological stations show that alterations in rainfall patterns may only partly explain these changes. Rather, increased soil densities and decreased water infiltration rates in monoculture plantations suggest an increase in surface runoff following forest conversion. Moreover, additional interview data reveal that an increasing encroachment of wetlands in Jambi Province may contribute to changes in local flooding regimes, as the construction of drainage and flood control infrastructure redistributes floodwater at the local scale. We conclude that changing flooding regimes are the result of multiple interacting social-ecological processes associated with the expansion of rubber and oil palm plantations in Jambi Province. Although ecohydrological changes are likely to contribute to an increase of flood occurrence, their social impacts are increasingly mediated through flood control infrastructure on industrial oil palm plantations.

Evapotranspiration (ET) is one of the climate elements which plays an important role in ecosystem water balance, including in oil palm plantations. Therefore, many mathematical equations and algorithms have been developed and designed to estimate and determine the spatial distribution of evapotranspiration. Remote sensing data are one of the important sources and techniques to estimate spatial variation of various climate elements, including ET. The main objective of this research is to estimate the spatial variation of ET using the SEBAL algorithm and Landsat-8 imagery of a large-scale commercial oil palm plantation, i.e. PT Perkebunan Nusantara VI Batanghari, Jambi Province, Indonesia. The analysis is carried out using Landsat-8 (OLI/TIRS) data and reference meteorological data from a micrometeorology flux tower. We calculated surface radiance, reflectance, albedo, Normalized Difference Vegetation Index (NDVI), emissivity, surface temperature, net radiation, soil heat flux, sensible heat flux, and latent heat flux to derive the hourly and daily evapotranspiration from the study area. Validation of ET from the SEBAL model were performed against ET from aerodynamic measurements from a micrometeorological tower at the same site. Differences in ET within “only oil palm cover” are relatively low and that difference in ET over the entire area of the oil palm plantation is mainly between oil palm vs. open lands, roads, and buildings. The evapotranspiration values of oil palm cover (NDVI 0.45-0.54) were between 2.42 ± 0.36 – 3.36 ± 0.17 mm d-1 . There was no significant difference between ET derived from SEBAL compared to aerodynamic methods (p-value = 0.598; r = 0.75).

The 2015–16 El Niño event ranks as one of the most severe on record in terms of the magnitude and extent of sea surface temperature (SST) anomalies generated in the tropical Pacific Ocean. Corresponding global impacts on the climate were expected to rival, or even surpass, those of the 1997–98 severe El Niño event, which had SST anomalies that were similar in size. However, the 2015–16 event failed to meet expectations for hydrologic change in many areas, including those expected to receive well above normal precipitation. To better understand how climate anomalies during an El Niño event impact soil moisture, we investigate changes in soil moisture in the humid tropics (between ±25°) during the three most recent super El Niño events of 1982–83, 1997–98, and 2015–16, using data from the Global Land Data Assimilation System (GLDAS). First, we validate the soil moisture estimates from GLDAS through comparison with in-situ observations obtained from 16 sites across five continents, showing an r2 of 0.54. Next, we apply a k-means cluster analysis to the soil moisture estimates during the El Niño mature phase, resulting in four groups of clustered data. The strongest and most consistent decreases in soil moisture occur in the Amazon basin and maritime southeast Asia, while the most consistent increases occur over east Africa. In addition, we compare changes in soil moisture to both precipitation and evapotranspiration, which showed a lack of agreement in the direction of change between these variables and soil moisture most prominently in the southern Amazon basin, Sahel and mainland southeast Asia. Our results can be used to improve estimates of spatiotemporal differences in El Niño impacts on soil moisture in tropical hydrology and ecosystem models at multiple scales.

Agroforestry options such as mixed-species tree planting and natural regeneration in oil palm plantations may alleviate negative effects of forest loss on biodiversity and ecosystem functioning. The effects of agroforestry on microclimate and land surface temperatures (LST) remain largely unknown despite their central role in controlling abiotic and biotic factors and in buffering climate at a larger scale. We assessed spatial and temporal microclimate and LST variability in a biodiversity enrichment experiment, in which tree islands have been planted in an oil palm plantation in Sumatra (Indonesia). Four years after establishment of the experiment, we measured microclimate and LST using mini microclimate sensors and drone-recorded thermal images. We examined experimental effects of tree species richness (0, 1, 2, 3 or 6), plot size (25 m2, 100 m2, 400 m2, 1600 m2) and stand structural complexity on microclimate and LST. Diurnal patterns showed ambient air temperature peaks and relative humidity (RH) minima at 3 pm, whereas diurnal soil temperatures peaked around 6 pm. The lowest LST were observed from oil palm canopy leaves and the highest from bare soils and understorey vegetation (including trees). Spatial and temporal ranges of ambient air temperature were smaller than LST ranges, and average ambient air temperature and LST were positively correlated. Tree species diversity had no overall significant effect neither on microclimate nor LST, but humidity was higher in planted tree islands compared to natural regeneration only. Smaller plots were characterized by higher mean air, soil and LST, compared to larger plots. Structurally complex plots were associated with low mean and maximum values of ambient air temperature, soil temperature and LST and high mean and minimum RH. Still, conditions were hotter and drier in several experimental plots compared to conventional oil palm plantations, considering a higher transpiration in the latest. We conclude that stand structural complexity and tree island size control microclimate and LST in the experimental oil palm agroforests, but alleviating the harsh microclimate conditions in oil palm plantations might take longer to occur.

CONTEXT The increasing world demand for palm oil led to the expansion of oil palm plantations, especially in the new lands in Southeast Asia, the main producing region in the world. The expansion of oil palm plantations has also occurred in Latin American countries, such as Brazil. Roughly 400 million hectares in Brazil are suitable for the planting of oil palm, but most of this area is currently covered by forest, mainly by the Amazon Rainforest. Climate change has reduced the extent of land suitable for oil palm cultivation in Brazil since under unfavorable climatic conditions, crop yields are reduced. To reconcile the increase in oil palm production in Brazil with the preservation of forests, modeling has been used as a tool to define the best suitable areas for planting expansion, as well as for the assessment of management techniques that aim to increase the yield. OBJECTIVE Thus, the object of this study was to implement the oil palm crop sub-model in the ECOSMOS integrated simulator and to evaluate its performance to simulate oil palm energy and carbon balance and the crop yield. METHODS The carbon allocation scheme for oil palm is quite different from the other crops of ECOSMOS. So, we use the sub-PFT (plant functional type) approach, where each phytomer in the plant evolves simultaneously, but individually. RESULTS AND Conclusions The results showed that the model was able to simulate net radiation (Rn), latent heat flux (LE), and net ecosystem CO2 exchange (NEE) with good accuracy. In contrast, the sensible heat flux (H) was not well simulated due to the lack of information on the soil's physical-hydric properties. The model simulated accurately the annual yield for plants aged between 12 and 25 years, whereas the yield was overestimated for plants aged outside this range. Also, the model better simulated the yield of genetic varieties with seasonal yield, compared to varieties with more uniform yield over the months. SIGNIFICANCE The robust and consistent results presented for most of the evaluated processes, especially for energy and carbon fluxes, make the oil palm sub-model described here suitable for improve the oil palm production in Brazil. For future studies, efforts should be directed to consider key factors for oil palm, such as the ratio between male and female inflorescences and the abortion rate of inflorescences, which affect crop yield, for a better understanding of the oil palm growth and production.

The El Niño–Southern Oscillation (ENSO) in 2015 was one of the strongest observed in almost 20 years and set the stage for a severe drought and the emergence of widespread fires and related smoke emission over large parts of Southeast Asia. In the tropical lowlands of Sumatra, which were heavily affected by the drought and haze, large areas of tropical rainforest have been converted into oil palm (Elaeis guineensis Jacq.) plantations during the past decades. In this study, we investigate the impact of drought and smoke haze on the CO2 exchange, evapotranspiration and surface energy budget in a commercial oil palm plantation in Jambi province (Sumatra, Indonesia) by using micrometeorological measurements, the eddy covariance method and a multi linear regression model (MLRM). With the MLRM we identify the contribution of meteorological and environmental parameters to net ecosystem CO2 exchange. During the initial part of the drought, when incoming shortwave radiation was elevated, CO2 uptake increased by 50 % despite a decrease in upper-layer soil moisture by 35 %, an increase in air temperature by 10 % and a tripling of atmospheric vapor pressure deficit. Emerging smoke haze decreased incoming solar radiation by 35 % compared to non-drought conditions and diffuse radiation became almost the sole shortwave radiation flux for two months resulting in a strong decrease in CO2 uptake by 86 %. Haze conditions resulted in a complete pause of oil palm carbon uptake for about 1.5 months and contributed to a decline in oil palm yield by 35 %. With respect to climate change and a pronounced drying trend over the western Pacific during El Niño, our model showed that an increase in drought may stimulate CO2 uptake while more severe smoke haze, in combination with drought, can lead to pronounced losses in productivity and CO2 uptake highlighting the importance of fire prevention.

Land-use change has a strong impact on carbon, energy and water fluxes and its effect is particularly pronounced in tropical regions. Uncertainties exist in the prediction of future land-use change impacts on these fluxes by land surface models due to scarcity of suitable measured data for parametrization and poor representation of key biogeochemical processes associated with tropical vegetation types. Rubber plantations (Havea brasilliensis) are a crucial land-use type across tropical landscapes that has greatly expanded in recent decades. Here, we first synthesize the relevant data for describing the biogeochemical processes of rubber from our past measurement campaigns in Jambi province, Indonesia. We then use these data-sets to develop a rubber plant functional type (PFT) for the Community Land Model (CLM4.5). Field measured data from small-holder plantations on leaf litterfall, soil respiration, latex harvest, leaf area index, transpiration, net primary productivity, and above-ground and fine root biomass were used to develop and calibrate a new PFT-based model (CLM4.5-rubber). CLM-rubber predictions adequately captured the annual net primary productivity and above-ground biomass as well as the seasonal dynamics of leaf litterfall, soil respiration, soil moisture and leaf area index. All of the predicted water fluxes of CLM-rubber were very similar to a site-specific calibrated soil water model. Including temporal variations in leaf life span enabled CLM-rubber to better capture the seasonality of leaf litterfall. Increased sensitivity of stomata to soil water stress and the enhancement of growth and maintenance respiration of fine roots in response to soil nutrient limitation enabled CLM-rubber to capture the magnitude of transpiration and leaf area index. Since CLM-rubber predicted reasonably well the carbon and water use, we think that the current model can be used for larger-scale simulations within Jambi province because more than 99 % of the rubber plantations are smallholder owned in Jambi province and have low soil fertility.

The 2014 Sony hack has revealed an unsettling amount of questionable behaviour and practices, yet representative for one of the most powerful creative industries. The chapter examines the Sony case by analyzing performative, interpretative and cultural approaches within media industries, referring to Cultural turns in management by focusing on leaked emails and data in relation to the case. By reflecting the in-visibilities of power within media corporations, issues such as transparency and sustainabilty will be raised and discussed.