MULTIPLICAÇÃO E ALONGAMENTO IN VITRO DE CLONES HÍBRIDOS DE Eucalyptus globulus

Os híbridos de Eucalyptus globulus representam uma excelente alternativa para o setor de celulose e papel, em razão dos ganhos em qualidade da madeira para a fabricação de celulose. Entretanto, estes híbridos têm apresentado recalcitrância ao enraizamento adventício. Assim, a micropropagação é apontada como a técnica para o rejuvenescimento desses híbridos adultos, viabilizando a propagação clonal dos mesmos. O presente trabalho avaliou o cultivo in vitro de três clones de Eucalyptus grandis x Eucalyptus globulus e de três clones de Eucalyptus urophylla x Eucalyptus globulus, em relação à multiplicação in vitro, no meio MS suplementado com 0,5 mg L-1 de BAP e 0,01 mg L-1 de ANA, bem como o efeito das concentrações de 0,25; 0,50; 0,75 e 1,0 mg L-1 de AIB e dos meios de cultura MS e JADS no alongamento in vitro das brotações. Os clones diferiram quanto à multiplicação in vitro das brotações e apresentaram uma taxa de multiplicação média dos clones de 3,0 tufos de brotações em cada subcultivo, ao longo dos 25 subcultivos realizados. No alongamento in vitro, os clones diferiram quanto às concentrações de AIB adequadas para provocar o alongamento, bem como em relação aos meios de cultura MS e JADS. O intervalo médio entre 0,40 e 0,80 mg L-1 de AIB proporcionou o maior número e comprimento das brotações alongadas in vitro e com maior vigor.

In vitro REGENERATION OF PIGEON PEA USING LEAF EXPLANTS

Pigeon pea ( Cajanus cajan (L.) Millsp.) is a drought tolerant pulse legume, mainly grown for grain in the semi-arid tropics, particularly in Africa. Pigeon pea production in countries like Kenya is faced with a number of challenges, particularly lack of high quality seeds. The objective of this study was to develop an in vitro regeneration system for pigeon pea varieties grown in Kenya, that is amenable to genetic transformation. In vitro regeneration of pigeon pea varieties, KAT 60/8 and ICEAP 00557, commonly grown in Kenya was achieved using leaf explants from in vitro grown seedlings, through callus initiation, followed by shoot and root induction. For callus initiation, MS media supplemented with 0.5-4 mg l-1 2, 4-D and TDZ separately were tested, and IBA at 0.1, 0.5 and 1 mg l-1 was tested for rooting of shoots. Embryogenic calli was obtained on MS containing 2, 4- D; whereas TDZ induced non-embryogenic callus alone or with shoots directly on explants. Indirect shoot regeneration frequency of 6.7 % was achieved using 1 mg l-1 2, 4-D-induced embryogenic callus obtained using KAT 60/8 explants. Whereas direct shoot regeneration frequencies of 20 and 16.7% were achieved using ICEAP 00557 and KAT 60/8 explants, using 0.5 mg l-1 and 2 mg l-1 TDZ, respectively. Optimum rooting was achieved using 0.5 mg l-1 IBA; and up to 92% rooted shoots were successfully established in soil after acclimatisation. Genotype and hormone concentrations had a significant (P<0.05) influence on callus, shoot and root induction. The protocol developed can be optimised for mass production and genetic transformation of KAT 60/8 variety.

Estudo da incorporação de cascalho proveniente da perfuração de poços de petróleo em formulações para tijolos de solo-cimento

The present work is to study the characteristics and technological properties of soil-cement bricks made from binary and ternary mixtures of Portland cement, sand, water, with or without addition of gravel from the drilling of oil wells, which could be used by industry, aiming to improve its performance and reduce cost by using the residue and, consequently, increasing its useful life. The soil-cement bricks are one of the alternatives to masonry construction. These elements, after a short curing period, provide compressive strength similar to that of solid bricks and ceramic blocks, and the higher the resistance the higher the amount of cement used. We used the soil from the city of São José do Mipibu / RN, the banks of the River Baldun, cement CPIIZ-32 and residue of drill cuttings from oil wells drilling onshore wells in the town of Mossley, RN, provided Petrobras. To determine the optimum mix, we studied the inclusion of different residues (100%, 80%, 70%, 60% and 50%) where 15 bodies were made of the test piece. The assessment was made of bricks made from simple compression tests, mass loss by immersion and water absorption. The experimental results proved the efficiency and high utilization of the waste from the drilling of oil wells, making the brick-cement-soil residue with a higher strength and lower water absorption. The best result in terms of mechanical strength and water absorption for the ternary mixture was 10% soil, 14% cement and 80% residue. In terms of binary mixtures, we obtained the best result for the mix-cement residue, which was 14% cement incorporated in the residue

Avaliação da incorporação combinada dos resíduos de cascalho de perfuração de poço de petróleo e de polimento do porcelanato em cerâmica vermelha

Among the industries, those that produce ceramic porcelain for use in construction industry and oil, during the exploration and production period, play an important role in the production of waste. Much research has been carried out both by academia and the productive sector, sometimes reintroducing them in the same production line that generated them, sometimes in areas unrelated to their generation, as in the production of concrete and mortar for the construction, for example, but each one in an isolated way. In this research, the aim is to study the combined incorporation of the waste drill cuttings of oil well and the residue of the polishing of porcelain, generated in the final stage of finishing of this product in a clay matrix, for the production of red pottery, specifically bricks, ceramic blocks and tiles. The clay comes from the municipality of São Gonçalo, RN, the drilling waste is from the Natal basin, in Rio Grande do Norte, and the residue of the polishing proceeds from a ceramic porcelain of the State of Paraíba. For this purpose, we used a mixture of a plastic clay with a non-plastic, in a ratio of 50% each, settling formulations with the addition of these two residues in this clay matrix. In the formulations, both residues were incorporated with a minimum percentage of 2.5% and maximum of 12.5%, varying from 2.5% each, in each formulation, which the sum of the waste be no more than 15%. It should be noted that the residue of the polishing of ceramic porcelain is a IIa class (not inert). The materials were characterized by XRF, XRD, TG, DTA, laser granulometry and the plasticity index. The technological properties of water absorption, apparent porosity, linear shrinkage of burning, flexural tensile strength and bulk density were evaluated after the sintering of the pieces to 850 °C, 950 °C and 1050 °C, with a burning time of 3 hr, 3 hr and 30 minutes, and 3 hr and 50 minutes, respectively, with a heating rate of 10 °C/minute, for all formulations and landing of 30 minutes. To better understand the influence of each residue and temperature on the evaluated properties, we used the factorial planning and its surfaces of response for the interpretation of the results. It was found that the temperature has no statistical significance at a 95% of reliability level in flexural tensile strength and that it decreases the water absorption and the porosity, but increases the shrinkage and the bulk density. The results showed the feasibility of the desired incorporation, but adjusting the temperature to each product and formulation, and that the temperatures of 850 °C and 950 °C were the one that responded to the largest number of formulations

Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Root-depth profiles of important agricultural crops

Based on a literature review we describe root density profiles in terms of a logistic dose-response function for important global agricultural crops (wheat, maize, rice, barley, soybean, pulses, cotton, potato, sunflower, rye, rapeseed, and sugarbeet). These root density profiles can be used in 1-D macroscopic root water uptake models. For use in 1-D microscopic root water uptake models, we analyze root density data in terms of the half mean distance between roots. Based on the database there is little support for a predictive relationship between parameters of the root density distribution of agricultural crops and climate or management factors. Constancy of the shape of the root density distribution with time is shown not to hold in some experiments, but evidence is anecdotical. At present the basis to describe rooting profiles with depth only seems to allow profiles which are constant in time and with depth. The correlation between half mean distance and drought sensitivity is investigated and conclusions will be presented.

Taming transitive permission attack via bytecode rewriting on Android application

Google Android is popular for mobile devices in recent years. The openness and popularity of Android make it a primary target for malware. Even though Android's security mechanisms could defend most malware, its permission model is vulnerable to transitive permission attack, a type of privilege escalation attacks. Many approaches have been proposed to detect this attack by modifying the Android OS. However, the Android's fragmentation problem and requiring rooting Android device hinder those approaches large-scale adoption. In this paper, we present an instrumentation framework, called SEAPP, for Android applications (or “apps”) to detect the transitive permission attack on unmodified Android. SEAPP automatically rewrites an app without requiring its source codes and produces a security-harden app. At runtime, call-chains are built among these apps and detection process is executed before a privileged API is invoked. Our experimental results show that SEAPP could work on a large number of benign apps from the official Android market and malicious apps, with a repackaged success rate of over 99.8%. We also show that our framework effectively tracks call-chains among apps and detects known transitive permission attack with low overhead. Copyright © 2016 John Wiley & Sons, Ltd.

Walker Evans: documentary detachment, narrative sequences and telling juxtapositions

This paper will re-examine the long established position of Evans as the quintessential detached documentary style photographer. I propose that is only part of the story. Evans was the inventor of the clinically detached and knowing ‘documentary style’. However, we will see that his magazine portfolios and his portfolios in book form; function quite differently. I will argue they employ a surprisingly engaged pictorial narrative form that echoes his personal scrapbook arrangements of magazine cuttings, and international magazine tropes of the time. Evans arranges his otherwise detached documents in satirical juxtapositions and telling sequences. I will argue that the Vitruvius of the vernacular is after all, also an engaged and engaging storyteller.

Konstruktive und funktionale Entwicklung eines selbststeuernden Unterflurbewässerungsverfahrens

Unter Einfluss des gegenwärtigen Klimawandels sowie dem Anstieg der Erdbevölkerung ist der effiziente Umgang mit den vorhandenen Wasserressourcen ein zentrales Thema in der Bewässerungslandwirtschaft. Die Unterflurbewässerung ist ein seit Jahrtausenden bekanntes Verfahren, bei dem das Bewässerungswasser unterhalb der Erdoberfläche aufgebracht wird und der Pflanze direkt im Wurzelraum zur Verfügung steht. Die Gefäßbewässerung ist ein selbststeuerndes Verfahren wobei die Wassergabe aus dem unglasierten Tongefäß aufgrund der im umgebenden Boden anliegenden Saugspannung erfolgt. Diese wassersparende und dem Wasserbedarf der Pflanze angepasste Bewässerungsweise ist Grundlage der Überlegungen und Untersuchungen der vorliegenden Arbeit. Ausgehend von dem Gedanken der Kombination der Vorteile der Gefäßbewässerung mit denen moderner Materialien, die eine maschinelle Installation ermöglichen und eine lange Lebensdauer aufweisen, wurde die Entwicklung einer selbststeuernden Bewässerung verfolgt. Materialrecherchen und eine Auswahl als geeignet identifizierter Materialien führten zu Laboruntersuchungen an Hand derer die Darcy-Eigenschaften (linearer Zusammenhang zwischen Volumenstrom und anliegendem Druck) überprüft wurden. Membranen erwiesen sich danach als geeignet, so dass an einer ausgewählten Schlauchmembran weitergehende Untersuchungen zum Einsatz für die Bewässerung vorgenommen wurden. Diese umfassten Langzeitlaborversuche im Boden zur Untersuchung der Entwicklung der Durchlässigkeit der Schlauchmembran über die Zeit, sowie zum Nachweis der Selbststeuerung des Systems. Mit den gewonnenen Ergebnissen war es möglich großmaßstäbliche Versuche im Gewächshaus zu realisieren, bei der die Schlauchmembran im Vergleich zur Tropfbewässerung hinsichtlich Wasserverbrauch und Ernteertrag an Standorten in Deutschland und Algerien getestet wurde. Diese Gewächshausversuche zeigten vielversprechende Ergebnisse für die Membranschlauchbewässerung mit im Vergleich zur Tropfbewässerung erhöhten Erträgen bei gleichzeitig geringerem Wasserverbrauch. Dies wurde besonders bei Verwendung von Bewässerungswasser mit erhöhtem Salzgehalt deutlich. Sorgfältiger Beachtung bedarf die Wasserqualität, da die Membranschlauchbewässerung auf Wasserverunreinigungen mit Durchflussverminderung reagiert, die sich nachteilig auf die Pflanzenentwicklung auswirkt. Aufgabe weiterer Forschungen muss es demnach sein, technische Verfahren zu entwickeln, die die langfristige Leistungsfähigkeit der Membran im Bewässerungsbetrieb aufrechterhalten.

Nitrogen requirements at bulb initiation for production of intermediate-day onions

Nitrogen requirements at bulb initiation for production of intermediate-day onions Article in Acta horticulturae · October 2016 DOI: 10.17660/ActaHortic.2016.1142.11 1st Rui Machado 16.44 · Universidade de Évora 2nd David R. Bryla 30.16 · United States Department of Agriculture Abstract Nitrogen requirements at bulb initiation for production of intermediate-day onions Authors: R.M.A. Machado, D.R. Bryla Keywords: Allium cepa, crop growth, nitrogen uptake, soil nitrate Abstract: The effect of nitrogen application on growth, nitrogen (N) uptake, yield, and quality of intermediate-day onion (Allium cepa 'Guimar') was evaluated in the field in southern Portugal. Plants were fertilized with 30 kg ha-1 N at transplanting, 10 kg ha-1 N at 29 days after transplanting (DAT) during early leaf growth, and with 0, 20, 40 and 60 kg ha-1 N at 51 DAT at the initiation of bulbing. The root system of plants in each treatment were concentrated in the top 0.1 m of soil and limited to 0.3 m depth but neither root length density nor rooting depth were affected by N application during later stages of bulb development. Leaf and bulb dry matter, on the other hand, increased linearly with N rate during bulb growth (85 DAT) and at harvest (114 DAT), respectively. Soil nitrate-N (NO3-N) at 0-0.3 m depth likewise increased linearly with N rate during bulb growth but declined from 15-30 mg kg-1 at bulbing to >10 mg kg-1 in each treatment by harvest. A substantial amount of N in the plants, which ranged from 302-525 mg, was taken up from the soil. Application of 60 kg ha-1 N resulted in luxury consumption. Yield (fresh bulb weight) increased from 0.19 kg plant-1 with no N at bulbing to as much as 0.28 kg plant-1 with 60 kg ha-1 N. Bulbs harvested from plants fertilized 40-60 kg ha-1 N averaged 8.2-8.5 cm in diameter, while those from plants with no N at bulbing averaged only 7.2 cm in diameter. Application of N fertilizer is thus recommended at bulbing to increase N uptake, yield, and bulb size of intermediate-day onions, particularly in dry Mediterranean climates where many onions are produced. Other components of quality, including neck diameter, bulb water content, total soluble solids, and juice pH, were not affect by N applied at bulbing.

Identification of endophytic bactéria from micropropagated yacon (Smallanthus sonchifolius) crowing under autotrophic and Heterotrophic systems.

Yacon, Smallanthus sonchifolius, an Andean species. is a rich source of dictetíc oligofructans with low glucose content. proteins and phenolic compounds. These constituents have shown efficacy in the prevention of diet-related ehronic diseases, including gastroin-testinal disorders and diabetes |1,2|. Yacon is part of a research program at the National Center for Natural Products Research (NCNPR) and University of Mississippi Field Station to develop new alternative root crops for Mississippi while attempting to im-prove the diet of low incorne families. Yacon can be easily propa-gated by cultings. Virus and nematode infections have been re-ported on plants propagated by cuttings in Brazil. a country that hás adopted Yacon as specialty crop [3|. We have developed two culture systems. autotrophic and heterotrophic, to produce healthy plants. Herem we describe the presence of endophytic bactéria m micropropagated Yacon. In auxin free media, new roots were induced. Overa 15day period. the average root mduction per expiam was 5.45 to 8.75 under autotrophic and heterotrophic cul-tures, respectively. Root lenglh vaned between 3 and 60mrn. The presence of root hairs and lateral roots was noticed only in auto-trophic condilions. These beneficiai bactéria were identified and chemically ctiaracterized. Acknowledgement: This research work was partially supported by the USDA/ARS Cooperative Research Agreement No. 58-6408-2-009. Referentes; |1) Terada S. et ai. (2006] Yakugaku Zasshi 126(8): 665-669. (2| Valentová K. Ulri-chová j. (2003) Biomedical Papers 147: 119-130. [3| Mogor C. et ai, (2003) Acta Horticulturea 597: 311 -313.

Enraizamento de estacas de seis espécies nativas de mata de galeria: Bauhinia rufa (Bong.) Steud., Calophyllum brasiliense Camb., Copaifera langsdorffii Desf., Inga laurina (Sw.) Willd., Piper arboreum Aubl. e Tibouchina stenocarpa (DC.) Cogn.

Tecnicas de propagacao por meio de enraizamento de estacas tem sido amplamente empregadas na fruticultura, floricultura e silvicultura. No entanto, no Brasil, poucos estudos tem sido feitos com especies nativas. Neste estudo foi testado o enraizamento de estacas caulinares de seis especies nativas de Mata de Galeria do bioma Cerrado: Copaifera langsdorffii Desf. (copaiba), Tibouchina stenocarpa (DC.) Cogn. (quaresmeira), Piper arboreum Aubl. (pimenta-de-macaco), Inga laurina (Sw.) Willd. (inga), Calophyllum brasiliense Camb. (landim) e Bauhinia rufa (Bong.) Steud. (unha-de-vaca). Foi estudada a influencia de diferentes concentracoes de acido indolbutirico, AIB (0, 1000, 2000 e 4000 ppm), em talco, e tratamento com agua sob gotejamento no enraizamento de estacas basais e/ou apicais, conforme a especie, em duas epocas do ano, final das chuvas (marco-maio/98) e inicio da seca (junho/98). Com P. arboreum tambem foi feito um tratamento onde as estacas foram enraizadas usando agua como substrato. Os resultados mostraram que as especies apresentaram diferentes habilidades para formar raizes adventicias em estacas. As estacas de C. langsdorffii e T. stenocarpa nao formaram raizes em qualquer das epocas realizadas, enquanto P. arboreum e I. laurina formaram raizes nas estacas apicais coletadas nas duas epocas (chuvosa e seca). Porem, as estacas basais de P. arboreum formaram menos raizes do que as apicais e as estacas basais de I. laurina nao enraizaram. Ja em C. brasiliense observaram-se altas taxas de sobrevivencia das estacas coletadas nas duas epocas (final das chuvas e inicio da seca), mas nao houve enraizamento. Por ultimo, as estacas de B. rufa enraizaram somente nas coletas realizadas na estacao chuvosa. Os tratamentos auxinicos (AIB) nao tiveram efeitos sobre a percentagem final de enraizamento das estacas de P. arboreum (apicais e basais), de I. laurina (apicais) e de B. rufa, bem como sobre a porcentagem final de sobrevivencia das estacas de C. brasiliense. Entre as especies estudadas, as estacas apicais de P. arboreum apresentaram os percentuais de enraizamento mais elevados: de 63% a 83% no periodo chuvoso e de 63% a 90% no periodo seco. Nas estacas basais o enraizamento foi menor, variando de 7% a 20%, no periodo chuvoso, e de 0 a 13%, no periodo seco. A epoca de coleta afetou a sobrevivencia e o peso seco das estacas apicais de P. arboreum, mas nao o numero de estacas enraizadas. Ja nas estacas basais, onde a capacidade de enraizamento foi menor, a epoca de coleta afetou o enraizamento das estacas, mas nao a sobrevivencia. Nas estacas basais houve uma grande mortalidade das estacas nas duas epocas estudadas (chuva e seca). Em geral, os melhores resultados de enraizamento ocorreram na epoca seca para as estacas apicais e na epoca chuvosa para as estacas basais. A utilizacao de agua de torneira como substrato proporcionou resultados satisfatorios no enraizamento das estacas basais de P. arboreum tanto em copos (200 ml) com agua colocados na casa de vegetacao (87%) quanto no tanque com agua corrente (77%). Em I. laurina a epoca de coleta influenciou a sobrevivencia das estacas apicais. As estacas coletadas na estacao chuvosa apresentaram melhores resultados sobrevivencia do que aquelas coletadas na estacao seca. Nas coletas feitas no final da epoca chuvosa obteve-se uma media de 15% de enraizamento e uma variacao de 3 a 23% de estacas enraizadas conforme os tratamentos. Na seca a media foi de 7% e a variacao foi de 0 a 13%. No periodo seco as medidas de peso seco das raizes foram mais inferiores do que na epoca chuvosa. A maioria das estacas vivas de I. laurina que nao enraizaram formaram calos, sugerindo que um periodo maior de observacao pode levar a maiores percentuais de enraizamento. Em C. brasiliense a epoca de coleta influenciou a sobrevivencia das estacas, de forma que no periodo chuvoso a porcentagem media de sobrevivencia (81%) foi maior do que na epoca seca (71%). Bauhinia rufa teve uma baixa capacidade de enraizamento por meio de estacas coletadas nas duas epocas do ano: apenas 3% das estacas enraizaram quando tratadas com 1000 e 4000 ppm de AIB; nos outros tratamentos nao ocorreu enraizamento. Pelos resultados, sugere-se que P. arboreum e uma especie de facil enraizamento por meio de estacas apicais, nas duas datas estudadas (no final das chuvas e inicio da seca), mas o uso de estacas basais nestas datas e inviavel. Sugere-se tambem que, devido aos baixos percentuais de enraizamento, nas duas epocas (chuva e seca), I. laurina e B. rufa sao especies de dificil enraizamento por meio de estacas apicais e basais com folhas. Ja C. Brasiliense, C. langsdorffii e T. stenocarpa nao enraizaram e podem ser consideradas especies de dificil enraizamento, nestas duas epocas estudadas (chuvosa e seca).

Strategies to enhance the productivity of rainfed off-season maize.

In Brazil, off-season rainfed maize is usually affected by limited water due to irregularities in rainfall. Alternatives to mitigate these effects include ground cover to reduce evaporation losses and the use of cultivars with a deeper rooting system. We conducted a study in Goias, Brazil, to evaluate the influence of different crop management strategies to mitigate the effect of limited water in maize yield. Modeling was used to simulate scenarios that consisted of 0, 3.5 and 5.0 t ha-1 of soybean residue left on the soil surface combined with cultivar ideotypes with 0.30 m, 0.50 m 0.70 m deep rooting system grown with 60 and 340 kg ha-1of nitrogen. The results showed that maintaining residue in the soil surface in combination with the use of cultivars with deeper rooting systems favored higher yields of off-season maize. Our results also indicated that a cultivar with rooting system in the top 0.50 m of the soil fertilized with a high nitrogen rate tended to be more efficient in the use of the soil available water

Sodium hypochlorite sterilization of culture medium in micropropagation of Gerbera hybrida cv. Essandre.

Micropropagation requires controlling contamination that might compromise the success of the process. Thermal sterilization is traditionally used; however, costs deriving from equipment acquisition and maintenance render this technique costly. With the purpose of finding an alternative to thermal sterilization, this research aimed at assessing the efficiency and ideal concentration of sodium hypochlorite for sterilization of culture media and glassware used during rooting of micropropagated Gerbera hybrida cv. Essandre. Two experiments were carried out. In the first one, treatments consisted of control I (no sterilization), control II (thermal sterilization), and total active chlorine concentrations of 0.0005, 0.001, 0.002 and 0.003%. In the second experiment, based on the results observed in the first experiment, treatments consisted of control I (thermal sterilization) and II (chemical sterilization), and total active chlorine concentrations of 0.002, 0.0025 and 0.003%. Plant behavior was assessed based on the length of aerial part and roots, number of roots, and dry biomass of plants. Results showed that the addition of an active chlorine concentration of 0.003% to culture media provided total control of contaminants, and there were no significant differences regarding the variables analyzed between plants obtained with thermal sterilization and with sodium hypochlorite sterilization. Thus, chemical sterilization can be used as a replacement for thermal sterilization of nutrition media for rooting of gerbera in vitro.

Canopy-scale biophysical controls of transpiration and evaporation in the Amazon Basin.

Canopy and aerodynamic conductances (gC and gA) are two of the key land surface biophysical variables that control the land surface response of land surface schemes in climate models. Their representation is crucial for predicting transpiration (λET) and evaporation (λEE) flux components of the terrestrial latent heat flux (λE), which has important implications for global climate change and water resource management. By physical integration of radiometric surface temperature (TR) into an integrated framework of the Penman?Monteith and Shuttleworth?Wallace models, we present a novel approach to directly quantify the canopy-scale biophysical controls on λET and λEE over multiple plant functional types (PFTs) in the Amazon Basin. Combining data from six LBA (Large-scale Biosphere-Atmosphere Experiment in Amazonia) eddy covariance tower sites and a TR-driven physically based modeling approach, we identified the canopy-scale feedback-response mechanism between gC, λET, and atmospheric vapor pressure deficit (DA), without using any leaf-scale empirical parameterizations for the modeling. The TR-based model shows minor biophysical control on λET during the wet (rainy) seasons where λET becomes predominantly radiation driven and net radiation (RN) determines 75 to 80 % of the variances of λET. However, biophysical control on λET is dramatically increased during the dry seasons, and particularly the 2005 drought year, explaining 50 to 65 % of the variances of λET, and indicates λET to be substantially soil moisture driven during the rainfall deficit phase. Despite substantial differences in gA between forests and pastures, very similar canopy?atmosphere "coupling" was found in these two biomes due to soil moisture-induced decrease in gC in the pasture. This revealed the pragmatic aspect of the TR-driven model behavior that exhibits a high sensitivity of gC to per unit change in wetness as opposed to gA that is marginally sensitive to surface wetness variability. Our results reveal the occurrence of a significant hysteresis between λET and gC during the dry season for the pasture sites, which is attributed to relatively low soil water availability as compared to the rainforests, likely due to differences in rooting depth between the two systems. Evaporation was significantly influenced by gA for all the PFTs and across all wetness conditions. Our analytical framework logically captures the responses of gC and gA to changes in atmospheric radiation, DA, and surface radiometric temperature, and thus appears to be promising for the improvement of existing land?surface?atmosphere exchange parameterizations across a range of spatial scales.