Multidisciplinary design and flight testing of a remote gas/particle airborne sensor system

The main objective of this paper is to describe the development of a remote sensing airborne air sampling system for Unmanned Aerial Systems (UAS) and provide the capability for the detection of particle and gas concentrations in real time over remote locations. The design of the air sampling methodology started by defining system architecture, and then by selecting and integrating each subsystem. A multifunctional air sampling instrument, with capability for simultaneous measurement of particle and gas concentrations was modified and integrated with ARCAA’s Flamingo UAS platform and communications protocols. As result of the integration process, a system capable of both real time geo-location monitoring and indexed-link sampling was obtained. Wind tunnel tests were conducted in order to evaluate the performance of the air sampling instrument in controlled nonstationary conditions at the typical operational velocities of the UAS platform. Once the remote fully operative air sampling system was obtained, the problem of mission design was analyzed through the simulation of different scenarios. Furthermore, flight tests of the complete air sampling system were then conducted to check the dynamic characteristics of the UAS with the air sampling system and to prove its capability to perform an air sampling mission following a specific flight path

Biomaterializar: madera de Amomyrtus, una oportunidad para la diversificación productiva sustentable del bosque templado

The background information presented in this paper explores a productive alternative for the temperate forest of Chile and Argentina. Los antecedentes a exponer en este documento exploran una alternativa productiva para el bosque templado de Chile y Argentina. O histórico a ser apresentado neste documento explora uma alternativa produtiva para as florestas temperadas do Chile e da Argentina.&nbsp

La agricultura familiar en un territorio de interfase rural-urbana : El caso del partido de Luján, PBA

El partido de Luján -localizado en el norte de la provincia de Buenos Aires y al oeste del Gran Buenos Aires (GBA)-, se destaca por presentar una particular configuración territorial producto de las transformaciones sociodemográficas y productivas de las últimas décadas que impactan en el paisaje y los usos de la tierra, generando tensiones/conflictos entre una ruralidad ag roproductiva y otra residencial. En efecto, en el partido de Luján se conjugan dos fuerzas en equilibrio inestable: los procesos de urbanización provenientes del GBA y los procesos de agriculturización/sojización que se extienden desde la zona núcleo de la agricultura. De este modo, el ámbito rural se complejiza a partir de la instalación de nuevos espacios residenciales, la expansión de la agricultura de commodities, el desarrollo de nuevas actividades agropecuarias capital intensivas y el corrimiento de actividades de abasto. Los productores agropecuarios de Luján desarrollan diferentes estrategias productivas y laborales, que muchas veces tensionan la coexistencia entre usos del suelo. Dentro de este universo, la agricultura familiar se destaca por su tradición en el partido vinculada a las producciones de abasto, pero también por el arribo reciente de pequeños productores con diferentes trayectorias. En este trabajo presentamos resultados del relevamiento de encuestas y entrevistas realizado durante 2017 en el partido de Luján, analizando el peso de los agricultores familiares en la estructura agraria local, sus estrategias de resistencia frente a las dinámicas del capital en expansión y los conflictos generados, así como las trayectorias de los nuevos productores que se suman a este subgrupo.Facultad de Humanidades y Ciencias de la Educació

La agricultura familiar en un territorio de interfase rural-urbana : El caso del partido de Luján, PBA

El partido de Luján -localizado en el norte de la provincia de Buenos Aires y al oeste del Gran Buenos Aires (GBA)-, se destaca por presentar una particular configuración territorial producto de las transformaciones sociodemográficas y productivas de las últimas décadas que impactan en el paisaje y los usos de la tierra, generando tensiones/conflictos entre una ruralidad ag roproductiva y otra residencial. En efecto, en el partido de Luján se conjugan dos fuerzas en equilibrio inestable: los procesos de urbanización provenientes del GBA y los procesos de agriculturización/sojización que se extienden desde la zona núcleo de la agricultura. De este modo, el ámbito rural se complejiza a partir de la instalación de nuevos espacios residenciales, la expansión de la agricultura de commodities, el desarrollo de nuevas actividades agropecuarias capital intensivas y el corrimiento de actividades de abasto. Los productores agropecuarios de Luján desarrollan diferentes estrategias productivas y laborales, que muchas veces tensionan la coexistencia entre usos del suelo. Dentro de este universo, la agricultura familiar se destaca por su tradición en el partido vinculada a las producciones de abasto, pero también por el arribo reciente de pequeños productores con diferentes trayectorias. En este trabajo presentamos resultados del relevamiento de encuestas y entrevistas realizado durante 2017 en el partido de Luján, analizando el peso de los agricultores familiares en la estructura agraria local, sus estrategias de resistencia frente a las dinámicas del capital en expansión y los conflictos generados, así como las trayectorias de los nuevos productores que se suman a este subgrupo.Facultad de Humanidades y Ciencias de la Educació

La agricultura familiar en un territorio de interfase rural-urbana : El caso del partido de Luján, PBA

El partido de Luján -localizado en el norte de la provincia de Buenos Aires y al oeste del Gran Buenos Aires (GBA)-, se destaca por presentar una particular configuración territorial producto de las transformaciones sociodemográficas y productivas de las últimas décadas que impactan en el paisaje y los usos de la tierra, generando tensiones/conflictos entre una ruralidad ag roproductiva y otra residencial. En efecto, en el partido de Luján se conjugan dos fuerzas en equilibrio inestable: los procesos de urbanización provenientes del GBA y los procesos de agriculturización/sojización que se extienden desde la zona núcleo de la agricultura. De este modo, el ámbito rural se complejiza a partir de la instalación de nuevos espacios residenciales, la expansión de la agricultura de commodities, el desarrollo de nuevas actividades agropecuarias capital intensivas y el corrimiento de actividades de abasto. Los productores agropecuarios de Luján desarrollan diferentes estrategias productivas y laborales, que muchas veces tensionan la coexistencia entre usos del suelo. Dentro de este universo, la agricultura familiar se destaca por su tradición en el partido vinculada a las producciones de abasto, pero también por el arribo reciente de pequeños productores con diferentes trayectorias. En este trabajo presentamos resultados del relevamiento de encuestas y entrevistas realizado durante 2017 en el partido de Luján, analizando el peso de los agricultores familiares en la estructura agraria local, sus estrategias de resistencia frente a las dinámicas del capital en expansión y los conflictos generados, así como las trayectorias de los nuevos productores que se suman a este subgrupo.Facultad de Humanidades y Ciencias de la Educació

Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

Funding: Data collection was largely funded by the UK Natural Environment Research Council (NERC) project TREMOR (NE/N004655/1) to D.G., E.G. and O.P., with further funds from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001) to J.V.T. and a University of Leeds Climate Research Bursary Fund to J.V.T. D.G., E.G. and O.P. acknowledge further support from a NERC-funded consortium award (ARBOLES, NE/S011811/1). This paper is an outcome of J.V.T.’s doctoral thesis, which was sponsored by CAPES (GDE 99999.001293/2015-00). J.V.T. was previously supported by the NERC-funded ARBOLES project (NE/S011811/1) and is supported at present by the Swedish Research Council Vetenskapsrådet (grant no. 2019-03758 to R.M.). E.G., O.P. and D.G. acknowledge support from NERC-funded BIORED grant (NE/N012542/1). O.P. acknowledges support from an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. R.S.O. was supported by a CNPq productivity scholarship, the São Paulo Research Foundation (FAPESP-Microsoft 11/52072-0) and the US Department of Energy, project GoAmazon (FAPESP 2013/50531-2). M.M. acknowledges support from MINECO FUN2FUN (CGL2013-46808-R) and DRESS (CGL2017-89149-C2-1-R). C.S.-M., F.B.V. and P.R.L.B. were financed by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001). C.S.-M. received a scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq 140353/2017-8) and CAPES (science without borders 88881.135316/2016-01). Y.M. acknowledges the Gordon and Betty Moore Foundation and ERC Advanced Investigator Grant (GEM-TRAITS, 321131) for supporting the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk), within which some of the field sites (KEN, TAM and ALP) are nested. The authors thank Brazil–USA Collaborative Research GoAmazon DOE-FAPESP-FAPEAM (FAPESP 2013/50533-5 to L.A.) and National Science Foundation (award DEB-1753973 to L. Alves). They thank Serrapilheira Serra-1709-18983 (to M.H.) and CNPq-PELD/POPA-441443/2016-8 (to L.G.) (P.I. Albertina Lima). They thank all the colleagues and grants mentioned elsewhere [8,36] that established, identified and measured the Amazon forest plots in the RAINFOR network analysed here. The authors particularly thank J. Lyod, S. Almeida, F. Brown, B. Vicenti, N. Silva and L. Alves. This work is an outcome approved Research Project no. 19 from ForestPlots.net, a collaborative initiative developed at the University of Leeds that unites researchers and the monitoring of their permanent plots from the world’s tropical forests [61]. The authros thank A. Levesley, K. Melgaço Ladvocat and G. Pickavance for ForestPlots.net management. They thank Y. Wang and J. Baker, respectively, for their help with the map and with the climatic data. The authors acknowledge the invaluable help of M. Brum for kindly providing the comparison of vulnerability curves based on PAD and on PLC shown in this manuscript. They thank J. Martinez-Vilalta for his comments on an early version of this manuscript. The authors also thank V. Hilares and the Asociación para la Investigación y Desarrollo Integral (AIDER, Puerto Maldonado, Peru); V. Saldaña and Instituto de Investigaciones de la Amazonía Peruana (IIAP) for local field campaign support in Peru; E. Chavez and Noel Kempff Natural History Museum for local field campaign support in Bolivia; ICMBio, INPA/NAPPA/LBA COOMFLONA (Cooperativa mista da Flona Tapajós) and T. I. Bragança-Marituba for the research support.Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Ψ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Ψ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Ψ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.Publisher PDFPeer reviewe

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

Hyperdominance in Amazonian Forest Carbon Cycling

While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’ species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region