Suchergebnisse

Three fundamental processes running in plant organisms under influence of environment (light, gravity) and key importance were considered. In the light case these are phytоchrome regulation and phototropism considering process is gravitropism. Phytochrome is responsible for regulatory reaction at the inhibition of which the plants cannot be normally developed. The plants do not need phototropism and gravitropism. They were elaborated by evolution as protective reactions to optimize the plant vitality. All these processes are realized according to one and the same logical scheme: stimulus reception, signaling processes in plant cell (transduction) and proper biological effect. According to this scheme the three reactions were considered. As the result the data adout the reception stages are principally different because receptor nature. Signaling processes proceed with participation of many low molecular and high molecular mediators to participate and biophysical, biochemical and genetic reactions. One fact attracts attention that the same mediators are involved to signaling ending by principally different final biological effect.This allows to suggest the existance in plant cell no separate chains for each stimulus but regulatory network formed by lateral and horizontal transduction chains.

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record. ; Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface-volume ratios and greater convective coefficients than larger eggs, so that small eggs can dissipate heat quickly. We tested whether the reflectance of eggshells, egg spottiness and egg size of the ground-nesting Kentish plover Charadrius alexandrinus are affected by maximum ambient temperature and solar radiation at breeding sites. We measured reflectance, both in the UV and human visible spectrum, spottiness and egg size in photographs from a museum collection of plover eggshells. Eggshells of lower reflectance (darker) were found at higher latitudes. However, in southern localities where solar radiation is very high, eggshells are also of dark coloration. Eggshell coloration had no significant relationship with ambient temperature. Spotiness was site-specific. Small eggs tended to be light-coloured. Thermal constraints may drive the observed spatial variation in eggshell coloration, which may be lighter in lower latitudes to diminish the risk of overheating as a result of higher levels of solar radiation. However, in southern localities with very high levels of UV radiation, eggshells are of dark coloration likely to protect embryos from more intense UV radiation. Egg size exhibited variation in relation to coloration, likely through the effect of surface area-to-volume ratios on overheating and cooling rates of eggs. Therefore, differential effects of solar radiation on functions of coloration and size of eggshells may shape latitudinal variations in egg appearance in the Kentish plover. ; Financial support was received from Estación Biológica de Doñana (EBD-CSIC) through Severo Ochoa Programme for Centres of Excellence (grant SEV-2012-0262, Ministerio de Economía y Competitividad of Spain), and partly by grants CGL2011-24230 and CGL2017-83518-P from the Spanish Government, with EU-ERDF financial support. JG was supported by an FPU predoctoral fellowship (FPU12-01616) from Ministerio de Educación, Cultura y Deporte, Spain. MS and JT were funded by a Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/J018309/1 to MS.

Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface‐volume ratios and greater convective coefficients than larger eggs, so that small eggs can dissipate heat quickly. We tested whether the reflectance of eggshells, egg spottiness, and egg size of the ground‐nesting Kentish plover Charadrius alexandrinus is affected by maximum ambient temperature and solar radiation at breeding sites. We measured reflectance, both in the UV and human visible spectrum, spottiness, and egg size in photographs from a museum collection of plover eggshells. Eggshells of lower reflectance (darker) were found at higher latitudes. However, in southern localities where solar radiation is very high, eggshells are also of dark coloration. Eggshell coloration had no significant relationship with ambient temperature. Spotiness was site‐specific. Small eggs tended to be light‐colored. Thermal constraints may drive the observed spatial variation in eggshell coloration, which may be lighter in lower latitudes to diminish the risk of overheating as a result of higher levels of solar radiation. However, in southern localities with very high levels of UV radiation, eggshells are of dark coloration likely to protect embryos from more intense UV radiation. Egg size exhibited variation in relation to coloration, likely through the effect of surface area‐to‐volume ratios on overheating and cooling rates of eggs. Therefore, differential effects of solar radiation on functions of coloration and size of eggshells may shape latitudinal variations in egg appearance in the Kentish plover. ; Ministerio de Economía y Competitividad of Spain SEV‐2012‐0262 ; Spanish Government CGL2011‐24230 CGL2017‐83518‐P ; Ministerio de Educación, Cultura y Deporte, Spain FPU12‐01616 ; Biotechnology and Biological Sciences Research Council (BBSRC) BB/J018309/1

"The past five decades have witnessed a rapid growth of computer models for simulating ecosystem functions and dynamics. This has been fueled by the availability of remote sensing data, computation capability, and cross-disciplinary sciences. These models contain many sub-modules for simulating different processes and forcing mechanisms, albeit it has become challenging to truly understand the details due to their complexity. Most ecosystem models, fortunately, are rooted in a few core biophysical foundations, such as widely recognized Farquhar's model, Ball-Berry-Leuning-Medlyn family models, Penman-Monteith model, Priestley-Taylor Model, Machaelis-Menten kinetics, and others. After an introduction of biophysical essentials, four chapters present the core algorithms and their behaviors in modeling ecosystem production, respiration, evapotranspiration, and global warming potentials"--

Abstract
We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recover their summer elevation after thawing and becoming unloaded. This is counterintuitive, because biological materials (including branches that show cryocampsis) generally become stiffer when frozen, so should flex less, rather than more, under a given bending load. Cryocampsis involves straining of the cell walls of a branch's xylem (wood), and depends upon the branch being hydrated. Among woody species tested, cryocampsis occurs in almost all Arctic, some boreal, only a few temperate and Mediterranean, and no tropical woody species that we have tested. It helps cold-winter climate shrubs reversibly get, and stay, below the snow surface, sheltering them from winter weather and predation hazards. This should be advantageous, because Arctic shrub bud winter mortality significantly increases if their shoots are forcibly kept above the snow surface. Our observations reveal a physically surprising behavior of biological materials at subfreezing temperatures, and a previously unrecognized mechanism of woody plant adaptation to cold-winter climates. We suggest that cryocampsis' mechanism involves the movement of water between cell wall matrix polymers and cell lumens during freezing, analogous to that of frost-heave in soils or rocks.

The topic of the reduction of mental processes to biophysical mechanisms touches at the core of the mind-body problem, a puzzle in the philosophy of mind since the days of Descartes. This book is about philosophical aspects of neuroscience, centred on perspective dualism. The topic unfolds in the discussion of mechanisms in world and mind. Neuronal mechanisms of differing complexity are described in a general way. It is shown how models of such mechanisms may be classified and assigned to levels of systems theory. Reduction strategies are applied to processes of life, mind, and consciousness

Abstract
A number of intrinsically disordered proteins (IDPs) encoded in stress-tolerant organisms, such as tardigrade, can confer fitness advantage and abiotic stress tolerance when heterologously expressed. Tardigrade-specific disordered proteins including the cytosolic-abundant heat-soluble proteins are proposed to confer stress tolerance through vitrification or gelation, whereas evolutionarily conserved IDPs in tardigrades may contribute to stress tolerance through other biophysical mechanisms. In this study, we characterized the mechanism of action of an evolutionarily conserved, tardigrade IDP, HeLEA1, which belongs to the group-3 late embryogenesis abundant (LEA) protein family. HeLEA1 homologs are found across different kingdoms of life. HeLEA1 is intrinsically disordered in solution but shows a propensity for helical structure across its entire sequence. HeLEA1 interacts with negatively charged membranes via dynamic disorder-to-helical transition, mainly driven by electrostatic interactions. Membrane interaction of HeLEA1 is shown to ameliorate excess surface tension and lipid packing defects. HeLEA1 localizes to the mitochondrial matrix when expressed in yeast and interacts with model membranes mimicking inner mitochondrial membrane. Yeast expressing HeLEA1 shows enhanced tolerance to hyperosmotic stress under nonfermentative growth and increased mitochondrial membrane potential. Evolutionary analysis suggests that although HeLEA1 homologs have diverged their sequences to localize to different subcellular organelles, all homologs maintain a weak hydrophobic moment that is characteristic of weak and reversible membrane interaction. We suggest that such dynamic and weak protein–membrane interaction buffering alterations in lipid packing could be a conserved strategy for regulating membrane properties and represent a general biophysical solution for stress tolerance across the domains of life.

Rapid hydropower development is occurring in China's Yunnan province in response to increasing clean energy demands, exposing potential vulnerabilities of the area's ecosystems, communities, and geopolitical systems. Here, we present original data on the cultures, economics, hydro-politics, and environments of the Nu River basin, based on household surveys, analysis of geopolitical events, and hydrological, hydraulic, and landscape modeling. We identify sources of vulnerability and investigate relationships among biophysical, socioeconomic, and geopolitical elements that contribute to vulnerability. Our results illustrate the role of geographic isolation in intensifying vulnerability to hydropower development and how access to information, data uncertainty, and geopolitics influence the vulnerability of people and the environment. We emphasize specific needs for developing support mechanisms for social, ecological, and political groups that are vulnerable to hydropower development.

Short-term synaptic depression (STD) is a form of synaptic plasticity that has a large impact on network computations. Experimental results suggest that STD is modulated by cortical activity, decreasing with activity in the network and increasing during silent states. Here, we explored different activity-modulation protocols in a biophysical network model for which the model displayed less STD when the network was active than when it was silent, in agreement with experimental results. Furthermore, we studied how trains of synaptic potentials had lesser decay during periods of activity (UP states) than during silent periods (DOWN states), providing new experimental predictions. We next tackled the inverse question of what is the impact of modifying STD parameters on the emergent activity of the network, a question difficult to answer experimentally. We found that synaptic depression of cortical connections had a critical role to determine the regime of rhythmic cortical activity. While low STD resulted in an emergent rhythmic activity with short UP states and long DOWN states, increasing STD resulted in longer and more frequent UP states interleaved with short silent periods. A still higher synaptic depression set the network into a non-oscillatory firing regime where DOWN states no longer occurred. The speed of propagation of UP states along the network was not found to be modulated by STD during the oscillatory regime; it remained relatively stable over a range of values of STD. Overall, we found that the mutual interactions between synaptic depression and ongoing network activity are critical to determine the mechanisms that modulate cortical emergent patterns. ; Jose M. Benita and Antoni Guillamon are supported by the MICINN/FEDER grant MTM2009-06973 (DACOBIAN) and the Generalitat de Catalunya CUR-DIUE grant number 2009SGR-859. GD is supported by the European Union, grant EC005-024 ("STREP Decisions in Motion"), by the Spanish Research Project BFU2007-61710, and CONSOLIDER CSD2007-00012. Maria V. Sanchez-Vives is supported by the MICINN (BFU2008-01371/BFI) and MINECO (BFU2011-27094).

Hippocampal pyramidal neurons sustain propagation of fast electrical signals and are electrotonically non-compact structures exhibiting cell-to-cell variability in their complex dendritic arborization. In this study, we demonstrate that sharp place-field tuning and several somatodendritic functional maps concomitantly emerge despite the presence of geometrical heterogeneities in these neurons. We establish this employing an unbiased stochastic search strategy involving thousands of models that spanned several morphologies and distinct proflies of dispersed synaptic localization and channel expression. Mechanistically, employing virtual knockout models (VKMs), we explored the impact of bidirectional modulation in dendritic spike prevalence on place-field tuning sharpness. Consistent with the prior literature, we found that across all morphologies, virtual knockout of either dendritic fast sodium channels or N-methyl-d-aspartate receptors led to a reduction in dendritic spike prevalence, whereas A-type potassium channel knockouts resulted in a non-specifc increase in dendritic spike prevalence. However, place-field tuning sharpness was critically impaired in all three sets of VKMs, demonstrating that sharpness in feature tuning is maintained by an intricate balance between mechanisms that promote and those that prevent dendritic spike initiation. From the functional standpoint of the emergence of sharp feature tuning and intrinsic functional maps, within this framework, geometric variability was compensated by a combination of synaptic democracy, the ability of randomly dispersed synapses to yield sharp tuning through dendritic spike initiation, and ion-channel degeneracy. Our results suggest electrotonically non-compact neurons to be endowed with several degrees of freedom, encompassing channel expression, synaptic localization and morphological microstructure, in achieving sharp feature encoding and excitability homeostasis.

We present a robust protocol based on iterations of free energy perturbation (FEP) calculations, chemical synthesis, biophysical mapping and X‐ray crystallography to reveal the binding mode of an antagonist series to the A2A adenosine receptor (AR). Eight A2AAR binding site mutations from biophysical mapping experiments were initially analyzed with sidechain FEP simulations, performed on alternate binding modes. The results distinctively supported one binding mode, which was subsequently used to design new chromone derivatives. Their affinities for the A2AAR were experimentally determined and investigated through a cycle of ligand‐FEP calculations, validating the binding orientation of the different chemical substituents proposed. Subsequent X‐ray crystallography of the A2AAR with a low and a high affinity chromone derivative confirmed the predicted binding orientation. The new molecules and structures here reported were driven by free energy calculations, and provide new insights on antagonist binding to the A2AAR, an emerging target in immuno‐oncology ; This work was financially supported by the Swedish Research Council (Grant 521‐2014‐2118); Consellería de Cultura, Educación e Ordenación Universitaria of the Galician Government (Grant ED431B2017/70); Centro Singular de Investigación de Galicia accreditation 2016–2019 (Grant ED431G/09), and the European Regional Development Fund (ERDF). Additional support from the Swedish strategic research program eSSENCE is acknowledged. The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC). This research program has been developed in the frame of the European COST action ERNEST (Grant CA 18133) and GLISTEN (Grant CA 1207) ; SI

Au cours des dernières décennies, l'Indonésie a connu des transformations spectaculaires des terres avec une expansion des plantations de palmiers à huile au détriment des forêts tropicales. L'Indonésie est actuellement l'une des régions ayant le plus haut taux de transformation de la surface terrestre dans le monde à cause de l'expansion des plantations de palmiers à huile et d'autres agricultures qui remplacent les forêts à grande échelle. Comme la végétation est un modificateur du climat près du sol, ces transformations à grande échelle ont des impacts majeurs sur les variables biophysiques de surface telles que la température de surface, l'albédo, les indices de végétation (NDVI), sur le bilan énergétique de surface et le partitionnement énergétique. Ce travail de thèse vise à quantifier les impacts des changements d'usage des terres en Indonésie sur les variables biophysiques de surface. Pour évaluer ces changements à l'échelle régionale, des données de télédétection sont nécessaires. Étant une variable clé de nombreuses fonctions écologiques, la température de surface (LST) est directement affectée par les changements de la couverture terrestre. Nous avons analysé la LST à partir de la bande thermique d'une image Landsat et produit une carte de température de surface avec une haute résolution (30m) pour les basses terres de la province de Jambi à Sumatra (Indonésie), une région qui a subi de grandes transformations au cours des dernières décennies. La comparaison des LST, albédo, NDVI et évapotranspiration (ET) entre sept différents types de couverture terrestre (forêts, zones urbaines, terres incultes, plantations de palmiers à huile jeunes et matures, plantations d'acacias et de caoutchouc) montre que les forêts ont des températures de surface inférieures à celles des autres types de couvert végétal, ce qui indique un effet de réchauffement local après la conversion des forêts vers des plantations. Les différences de LST atteignaient 10,1 ± 2,6 ºC (moyenne ± écart-type) entre les forêts et les terres déforestées. Les différences de températures de surface s'expliquent par un effet de refroidissement évaporatif des forêts, qui compense l'effet de réchauffement de l'albédo. Basé sur des différences observées dans les variables biophysiques entre les plantations de palmiers à huile jeunes et matures, nous avons analysé trois images Landsat couvrant une chronoséquence de plantations de palmiers à huile pour étudier la dynamique des variables biophysiques de surface pendant le cycle de rotation de 20-25 ans des plantations de palmiers à huile. Nos résultats montrent que les différences entre les plantations de palmiers à huile à différents stades du cycle de rotation du palmier à huile se reflètent dans les différences du bilan énergétique de surface, du partitionnement énergétique et des variables biophysiques. Au cours du cycle de rotation des plantations de palmiers à huile, les différences de température à la surface diminuent graduellement et se rapprochent de zéro autour du stade mature de la plantation de palmiers à huile de 10 ans. Parallèlement, le NDVI augmente et l'albédo diminue à proximité des valeurs typiques des forêts. Le bilan énergétique de surface et le partitionnement énergétique montrent des tendances de développement liés aux variables biophysiques et à l'âge des plantations de palmiers à huile. Les nouvelles plantations et les jeunes plantations (<5 ans) ont un rayonnement net plus faible que les plantations de palmiers à huile matures, mais ont des températures de surface plus élevées que les plantations de palmiers à huile matures. Les changements dans les variables biophysiques, le bilan énergétique et la répartition de l'énergie au cours du cycle d'une rotation du palmier à huile peuvent s'expliquer par l'effet de refroidissement évaporatif précédemment identifié dans les forêts, qui compense l'effet de réchauffement de l'albédo. L'un des principaux déterminants de ce mécanisme est la couverture végétale au cours des différentes phases du cycle de rotation du palmier à huile. Le NDVI en tant qu'indicateur du couvert végétal a montré une relation inverse cohérente avec LST de différentes plantations de palmiers à huile âgés, une tendance qui est également observée pour différents types d'utilisation des terres dans cette étude. Une analyse régionale et à plus long terme de la tendance LST entre 2000 et 2015 basée sur les données MODIS montre que dans la journée la température moyenne de Jambi a augmenté de 1,05 ºC, suivant la tendance des changements observés et dépassant les effets du réchauffement climatique. Afin d'évaluer les effets de l'expansion du palmier à huile sur le climat, le bilan énergétique de surface, le partitionnement énergétique et les processus biophysiques jouent un rôle important et le cycle complet de rotation des plantations de palmiers à huile doit être envisagé. Basé sur nos résultats, nous construisons le cycle de rotation des plantations de palmiers à huile et les changements qui se produisent au cours du développement de la végétation de palmiers à huile. Cette étude fournit des preuves que l'expansion des plantations de palmiers à huile et d'autres cultures commerciales entraîne des changements dans les variables biophysiques, réchauffant la surface du sol et augmentant ainsi l'augmentation de la température de l'air à cause du changement climatique. En utilisant des données Landsat à haute résolution, nous avons pu inclure les effets du changement d'utilisation des terres sur les variables biophysiques. Comprendre les effets du changement de la couverture terrestre sur les variables biophysiques peut soutenir des politiques concernant la conservation des forêts existantes, la planification et l'expansion des plantations de palmiers à huile et les mesures de boisement possibles. La connaissance des variables biophysiques, du bilan radiatif et de la répartition énergétique au cours du cycle de rotation du palmier à huile peut inclure de nouvelles pratiques de gestion susceptibles de réduire les conditions environnementales et microclimatiques extrêmes dans la phase initiale des plantations de palmiers à huile. ; In den letzten Jahrzehnten hat Indonesien umfassende Veränderungen der Landnutzung mit einer Ausweitung von Ölpalmplantagen auf Kosten tropischer Wälder erlebt. Derzeit ist Indonesien weltweit eine der Regionen mit der höchsten Umwandlungsrate der Landnutzung, die mit der Ersetzung von Wäldern durch Ölpalmplantagen und andere Nutzpflanzen verbunden ist. Da die Vegetation ein Einflussfaktor für das Bodenklima ist, haben diese großflächigen Landtransformationen große Auswirkungen auf die biophysikalischen Variablen wie Landoberflächentemperatur (LST), Albedo, Vegetationsindizes (z.B. der normalisierte Differenzvegetationsindex, NDVI) und auf die Energiebilanz und die verschiedenen Komponenten der ausgetauschten Energie. Trotz des großen Umfangs der bereits vollzogenen und von der Regierung geplanten Landtransformationen in Indonesien hin zu Ölpalmplantagen und anderen Nutzpflanzen, ist dies die bisher erste Studie, welche die Auswirkungen dieser Landtransformation auf die biophysikalischen Variablen in Indonesien quantifiziert. Um solche Veränderungen auf regionaler Ebene zu bewerten, werden Fernerkundungsdaten benötigt. Als einer der Hauptantriebsfaktoren für viele ökologische Prozesse ist die LST direkt von Veränderungen der Landnutzung betroffen. Wir analysieren die LST aus dem thermischen Band eines Landsat-Bildes und erstellen eine hochauflösende Oberflächentemperaturkarte (30 m) für das Tiefland der Provinz Jambi auf Sumatra (Indonesien), eine Region die in den letzten Jahrzehnten eine große Landumwandlung hin zu Ölpalmen und anderen Nutzpflanzen erfahren hat. Der Vergleich von LST, Albedo, NDVI und Evapotranspiration (ET) zwischen sieben verschiedenen Landbedeckungstypen (Wald, städtische Gebiete, Brachland, junge und reife Ölpalmplantagen, Akazien- und Kautschukplantagen) zeigt, dass Wälder niedrigere Oberflächentemperaturen haben als die anderen Landbedeckungstypen, was auf einen lokalen Erwärmungseffekt nach der Umwandlung des Waldes in einen anderen Landbedeckungstyp hindeutet. Die LST-Unterschiede betrugen bis zu 10,1 ± 2,6 ºC (Mittelwert ± Standardabweichung) zwischen Wald und Brachland. Die Unterschiede in den Oberflächentemperaturen lassen sich durch einen Verdunstungskälteeffekt, der den Albedo-Erwärmungseffekt kompensiert erklären. Auf Grundlage der beobachteten Unterschieden in den biophysikalischen Variablen zwischen reifen und jungen Ölpalmplantagen, analysieren wir drei Landsat-Bilder, die eine Chronosequenz von Ölpalmplantagen enthalten um die Entwicklung von biophysikalischen Oberflächenvariablen während des 20-25 jährigen Rotationszyklus der Ölpalmplantagen zu untersuchen. Unsere Ergebnisse zeigen, dass sich die Unterschiede zwischen Ölpalmplantagen in verschiedenen Phasen des Ölpalmen-Rotationszyklus in Unterschieden in der Energiebilanz, Energiepartitionierung und biophysikalischen Variablen widerspiegeln. Während des Lebenszyklus der Ölpalmplantage nehmen die Oberflächentemperaturunterschiede allmählich ab und nähern sich grob den Werten der reifen Ölpalmphase mit einem Alter von 10 Jahren. Gleichzeitig nimmt der NDVI zu und der Albedo ab und beide Größen nähern sich den typischen Werten von Wäldern. Die Energiebilanz und die Energiepartitionierung zeigen einen Entwicklungstrend, der mit den biophysikalischen Variablen und mit dem Alter der Ölpalmplantagen zusammenhängt. Neu etablierte und junge Plantagen (<5 Jahre) haben eine geringere Nettostrahlung als reife Ölpalmplantagen, aber eine höhere Oberflächentemperaturen als reife Ölpalmplantagen. Die Veränderungen der biophysikalischen Variablen, der Energiebilanz und der Energieaufteilung während des Ölpalmen-Rotationszyklus können durch den zuvor identifizierten Verdunstungskälteeffekt erklärt werden, durch den der Albedo-Erwärmungseffekt kompensiert wird. Eine Hauptdeterminante in diesem Mechanismus ist die Vegetationsbedeckung während der verschiedenen Phasen im Rotationszyklus der Ölpalme. Der NDVI als Proxy für die Vegetationsbedeckung zeigt einen inversen Zusammenhang zur LST der Ölpalmplantagen unterschiedlichen Alters; ein Trend, der auch für andere Landnutzungstypen in dieser Studie beobachtet wurde. In einer auf MODIS Daten basierenden regionalen und langfristigeren Analyse des LST-Trends zwischen den Jahren 2000 und 2015 zeigt sich, dass die durchschnittliche Tagesoberflächentemperatur in der Provinz Jambi um 1,05 °C gestiegen ist, was dem Trend der beobachteten Landbedeckungsänderungen folgt und die Auswirkungen der Klimaerwärmung übersteigt. Um die volle Auswirkungen der Ölpalmenexpansion auf das Klima abzuschätzen, spielen die Energiebilanz, die Energiepartitionierung und biophysikalische Prozesse eine wichtige Rolle, wobei der gesamte Rotationszyklus von Ölpalmplantagen berücksichtigt werden muss. Basierend auf unseren Ergebnissen entwickeln wir eine Struktur des Rotationszyklus von Ölpalmplantagen der die während der Entwicklung der Ölpalmenvegetation auftretenden Veränderungen darstellt. Diese Studie belegt, dass die Ausweitung von Ölpalmplantagen und anderen Nutzpflanzen zu Veränderungen der biophysikalischen Variablen führt, die die Landoberfläche erwärmen und somit den Anstieg der Lufttemperatur aufgrund des Klimawandels verstärken. Durch den Einsatz von hochauflösenden Landsat-Daten konnten wir die Auswirkungen von Landnutzungsänderungen auf biophysikalische Variablen in unserer Analyse einbeziehen. Ein besseres Verständnis der Auswirkungen von Landbedeckungsänderungen auf die biophysikalischen Variablen kann Maßnahmen zur Erhaltung der bestehenden Wälder, zur Planung und zum Ausbau von Ölpalmplantagen und zu möglichen Aufforstungsmaßnahmen unterstützen. Wissen über biophysikalische Variablen, Strahlungsbilanz und Energieaufteilung während des Rotationszyklus der Ölpalme können verwendet werden, um neue Managementpraktiken einzubeziehen, die die extreme ökologischen und mikroklimatischen Bedingungen in der Anfangsphase der Ölpalmplantagen reduzieren könnten. ; Over the last decades, Indonesia has experienced dramatic land transformations with an expansion of oil palm plantations at the expense of tropical forests. Indonesia is currently one of the regions with the highest transformation rate of the land surface worldwide related to the expansion of oil palm plantations and other cash crops replacing forests on large scales. As vegetation is a modifier of the climate near the ground these large-scale land transformations have major impacts on surface biophysical variables such as land surface temperature (LST), albedo, vegetation indices (e.g. the normalized difference vegetation index, NDVI), on the surface energy balance and energy partitioning. Despite the large historic land transformation in Indonesia toward oil palm and other cash crops and governmental plans for future expansion, this is the first study so far to quantify the impacts of land transformation on biophysical variables in Indonesia. To assess such changes at regional scale remote sensing data are needed. As a key driver for many ecological functions, LST is directly affected by land cover changes. We analyze LST from the thermal band of a Landsat image and produce a high-resolution surface temperature map (30 m) for the lowlands of the Jambi province in Sumatra (Indonesia), a region which experienced large land transformation towards oil palm and other cash crops over the past decades. The comparison of LST, albedo, NDVI, and evapotranspiration (ET) between seven different land cover types (forest, urban areas, clear cut land, young and mature oil palm plantations, acacia and rubber plantations) shows that forests have lower surface temperatures than the other land cover types, indicating a local warming effect after forest conversion. LST differences were up to 10.1 ± 2.6 ºC (mean ± SD) between forest and clear-cut land. The differences in surface temperatures are explained by an evaporative cooling effect, which offsets an albedo warming effect. Young and mature oil palm plantations differenced in their biophysical. To study the development of surface biophysical variables during the 20 – 25 years rotation cycle of oil palm plantations, we used three Landsat images from the Jambi province in Sumatra/Indonesia covering a chronosequence of oil palm plantations. Our results show that differences between oil palm plantations in different stages of the oil palm rotation cycle are reflected in differences in the surface energy balance, energy partitioning and biophysical variables. During the oil palm plantation lifecycle the surface temperature differences to forest gradually decrease and approach zero around the mature oil palm plantation stage of 10 years. Concurrently, NDVI increases and the albedo decreases approaching typical values of forests. The surface energy balance and energy partitioning show a development patterns related to biophysical variables and the age of the oil palm plantations. Newly established and young plantations (< 5 years) have less net radiation available than mature oil palm plantations, yet have higher surface temperatures than mature oil palm plantations. The changes in biophysical variables, energy balance and energy partitioning during the oil palm rotation cycle can be explained by the previously identified evaporative cooling effect in which the albedo warming effect is offset. A main determinant in this mechanism is the vegetation cover during the different phases in the oil palm rotation cycle. NDVI as a proxy for vegetation cover showed a consistent inverse relation with the LST of different aged oil palm plantations, a trend that is also observed for different land use types in this study. On a regional and longer time scale, the analysis of the LST trend between 2000 and 2015 based on MODIS data shows that the average daytime surface temperature in the Jambi province increased by 1.05 ºC, which followed the trend of observed land cover changes and exceed the effects of climate warming. In order to assess the full climate effects of oil palm expansion the surface energy balance, energy partitioning and biophysical processes play an important role and the full rotation cycle of oil palm plantations need to be considered. Based on our result we construct the rotation cycle of oil palm plantations and the changes that occur during the development of oil palm vegetation. This study provides evidence that the expansion of oil palm plantations and other cash crops leads to changes in biophysical variables, warming the land surface and thus enhancing the increase of air temperature because of climate change. By using high-resolution Landsat data we were able to include the effects of land use change on biophysical variables. Understanding the effects of land cover change on the biophysical variables may support policies regarding conservation of the existing forests, planning and expansion of the oil palm plantations and possible afforestation measures. Knowledge of biophysical variables, radiation balance and energy partitioning during the rotation cycle of oil palm can be used to including new management practices that could reduce the extreme environmental and microclimatic conditions in the initial phase of the oil palm plantations.