Transpiração em espécie de grande porte na Floresta Nacional de Caxiuanã, Pará Transpiration in large size species in Caxiuanã National Forest, in the State of Pará, Brazil

Durante o experimento "O Impacto da Seca Prolongada nos Fluxos de Água e Dióxido de Carbono em uma Floresta Tropical Amazônica" (ESECAFLOR) realizou-se este trabalho. Trata-se de um subprojeto do Experimento de Grande escala da Biosfera-Atmosfera da Amazônia (LBA), localizado na Estação Científica Ferreira Pena, dentro da Floresta Nacional de Caxiuanã, Pará (1º 42- 30-- S; 51º 31-45-- W; 62 m altitude). A região tem floresta bem preservada, com dossel médio de 35 m. As espécies predominantes em terra-firme, são: Eschweilera coriacea (Mata-matá branco), Voucapoua americana (Acapu) e Protium pallidum (Breu Branco). Medidas foram realizadas entre 03 a 16 de dezembro de 2000 e 12 a 25 de janeiro de 2003, objetivando-se determinar a transpiração de dois exemplares de Eschweilera coriacea, mediante os efeitos da seca provocada. A área do ESECAFLOR compreende duas parcelas, cada uma com 1 ha, parcela A (controle) e parcela B (exclusão da chuva). Para o fluxo de seiva, o método foi o Balanço de Calor no Tronco, com sistema Sap Flow meter, P4.1; entre os períodos analisados, a transpiração média registrou aumento de 56% na árvore A237 (parcela A) e redução de 68% na árvore B381 (parcela B).<br>During the "Long-term impact of drought on water and carbon dioxide fluxes in Amazonian Tropical Rainforest Experiment" (ESECAFLOR), this study was carried out, which is a subproject of Large Scale Biosphere Atmosphere Experiment in Amazônia (LBA), located in the Ferreira Penna Scientific Station (FPSS) in the Caxiuanã National Forest (CNF) in Pará State (1º 42- 30-- S; 51º 31-45-- W; 62 m altitude). The region has a well-preserved forest, with canopy of 35 m. The predominate tree species in the landscape are Eschweilera coriacea (White Matá-matá), Voucapoua americana (Acapu) and Protium pallidum (White Pitch). Sap flow measurements were made in the wet season (03-16 December 2000 and 12-25 January 2003), to evidence the effect of long term induced drought, aiming to determinate the transpiration of Eschweilera coriacea. The ESECAFLOR site consists of two different areas with 1 ha each. Plot A (control) and Plot B (rainfall exclusion). The Trunk Heat Balance (THB) method was applied to sap flow measurements, by Sap Flow Meter P4.1 system. Between analysed periods, the mean transpiration of E. Coriacea increased 56% in the tree A237 (control plot) and decreased 68% in B381 (drought plot)

The ALICE transition radiation detector: Construction, operation, and performance

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection. © 2017 CERN for the benefit of the ALICE Collaboration