Evaluacion de la probabilidad de ocurrencia de fuegos en rodales de Pinus pinaster Ait en Portugal

Maritime pine (Pinus pinaster Ait.) is an important conifer from the western Mediterranean Basin extending over 22% of the forest area in Portugal. In the last three decades nearly 4% of Maritime pine area has been burned by wildfires. Yet no wildfire occurrence probability models are available and forest and fire management planning activities are thus carried out mostly independently of each other. This paper presents research to address this gap. Specifically, it presents a model to assess wildfire occurrence probability in regular and pure Maritime pine stands in Portugal. Emphasis was in developing a model based on easily available inventory data so that it might be useful to forest managers. For that purpose, data from the last two Portuguese National Forest Inventories (NFI) and data from wildfire perimeters in the years from 1998 to 2004 and from 2006 to 2007 were used. A binary logistic regression model was build using biometric data from the NFL Biometric data included indicators that might be changed by operations prescribed in forest planning. Results showed that the probability of wildfire occurrence in a stand increases in stand located at steeper slopes and with high shrubs load while it decreases with precipitation and with stand basal area. These results are instrumental for assessing the impact of forest management options on wildfire probability thus helping forest managers to reduce the risk of wildfire

Response of tropical maize to supplemental irrigation strategies.

Water is one of the most important factors influencing crop production in rainfed cropping systems. In tropical regions, supplemental irrigation reduces the risk of yield losses associated to water deficit due to insufficient rainfall. Water deficit in regions with irregularities in rainfall may be overcome with the use of supplemental irrigation, a technique based on the application of water at amounts below the crop?s evapotranspiration (ETc). We investigated the potential of supplemental irrigation as a strategy to increase yield of maize grown under tropical conditions. We used the CSM-CERES-Maize model of the Decision Support System for Agrotechnology Transfer (DSSAT) to simulate irrigation strategies of maize in six counties in the state of Minas Gerais, Brazil. Our results indicate significant differences on simulated crop yield in response to supplemental irrigation. As a consequence, water productivity was improved with reductions of 10% and 15% of full irrigation depths in one of the six counties while in two the water productivity was higher when full irrigation was applied

A three-step approach to post-fire mortality modelling in maritime pine (Pinus pinaster Ait.) stands for enhanced forest planning in Portugal

Maritime pine (Pinus pinaster Ait) is a very important timber-producing species in Portugal with a yield of ~67.1 million m3 year21. It covers ~22.6 per cent of the forest area (710.6 × 103 ha). Fire is the most significant threat to maritime pine plantations. This paper discusses research aiming at the development of post-fire mortality models for P. pinaster Ait stands in Portugal that can be used for enhanced integration of forest and fire management planning activities. Post-fire mortality was modelled using biometric and fire data from 2005/2006 National Forest Inventory plots and other sample plots within 2006–2008 fire perimeters. A three-step modelling strategy based on logistic regression methods was used. Firstly, the probability of mortality to occur after a wildfire in a stand is predicted and secondly, the degree of mortality caused by a wildfire on stands where mortality occurs is quantified. Thirdly, mortality is distributed among trees. The models are based on easily measurable tree characteristics so that forest managers may predict post-fire mortality based on forest structure. The models show that relative mortality decreases when average d.b.h. increases, while slope and tree size diversity increase the mortalityinfo:eu-repo/semantics/publishedVersio

Período crítico de interferência de plantas daninhas na cultura dos citros no Município de Manaus.

Este trabalho teve por objetivo determinar o período crítico de interferência das plantas infestantes com as plantas de laranjeiras

Modelagem do crescimento de culturas: aplicações à cultura do milho.

Características gerais dos modelos de culturas; Principais modelos de culturas; Possibilidades de aplicação dos modelos de cultura; Aplicação no manejo da cultura; Aplicação na análise da resposta de culturas à irrigação e no planejamento do uso de recursos hídricos; Aplicação no manejo de nitrogênio; Aplicação na avalização de risco climático e no prognóstico de safras; Aplicação na análise da sustentabilidade de sistemas de sucessão de culturas; Aplicação em estudos de variabilidade espacial e em manejo sítio-específico; Aplicação no planejamento de uso da terra e dos recursos naturais; Aplicação na genética e melhoramento e na análise da interação genótipo x ambiente; Aplicação na simulação do efeito de pragas, doenças e plantas daninhas; Aplicação nos estudos de mudanças climáticas; Aplicação como ferramenta de educação e transferência de tecnologia; Limitações dos modelos de crescimento de culturas; Potencialidades de aplicação de modelos de simulação de culturas no Brasil.bitstream/CNPMS-2010/22537/1/Doc-91.pd

Eficiência de farinha de ossos calcinada, em formulações organominerais, para o feijão-caupi.

A correção e a manutenção da fertilidade do solo são essenciais para a sustentabilidade dos sistemas agrícolas de produção. A solubilidade das fontes de fósforo é de grande importância para determinação da sua eficiência. O objetivo do presente trabalho foi avaliar o efeito de fertilizantes fosfatados granulados, produzidos com farinha de ossos calcinada, sobre o desenvolvimento do feijão-caupi. Foi conduzido experimento em casa de vegetação utilizando vasos com 5 dm3 de solo, dois solos com teores diferentes de argila (23% e 38%), três formulações organominerais granuladas NPK, produzidas com farinha de ossos de bovinos (08-20-10; 02-20-10 e 01-20-00) e três sucessões de cultivo com soja, milho e feijão-caupi. Observou-se maior acúmulo de matéria seca da parte aérea (MSPA) para o feijão caupi quando cultivado no solo de menor teor de argila e a sequência observada com as diferentes formulações para acúmulo de MSPA foi 08-20-10> 02-20-10 > 01-20-00. Os resultados evidenciam a viabilidade de utilização de fertilizantes organominerais granulados produzidos com farinha de ossos para crescimento de plantas de caupi

Bulk-sensitive photoemission spectroscopy of A_2FeMoO_6 double perovskites (A=Sr, Ba)

Electronic structures of Sr_2FeMoO_6 (SFMO) and Ba_2FeMoO_6 (BFMO) double perovskites have been investigated using the Fe 2p->3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have strongly mixed Mo-Fe t_{2g} character, suggesting that the Fe valence is far from pure 3+. The Fe 2p_{3/2} XAS spectra indicate the mixed-valent Fe^{3+}-Fe^{2+} configurations, and the larger Fe^{2+} component for BFMO than for SFMO, suggesting a kind of double exchange interaction. The valence-band PES spectra reveal good agreement with the LSDA+U calculation.Comment: 4 pages, 3 figure

Intake and digestibility of river buffalo steers (Bubalus bubalis) fed different levels of palm kernel cake: effect of diet neutral detergent fiber, digestible energy, crude protein and extract ether.

Proceeding of World Buffalo Congress, 9., 2010, Buenos Aires

The effect of feeder system and diet on welfare, performance and meat quality, of growing-finishing Iberian × Duroc pigs under high environmental temperatures

The present study investigated the replacement of 5% of starch (ST) by 5% of sunflower oil (SO), with or without feed restriction, in the diet of growing-finishing Iberian × Duroc pigs exposed to heat stress conditions. The effects of these strategies on the welfare, performance and meat quality of the animals were evaluated. Seventy-two crossbred males [51.00 ± 6.29 kg body weight (BW)] were housed in collective pens and randomly distributed according to their initial BW in climate-controlled rooms under heat stress conditions (30–32 °C; 35%–50% humidity). The experiment was carried out in a randomized block design, in a 2 × 2 factorial design composed of two diets (control or oil) and two feed management (ad-libitum and restriction) types. The investigated treatments were: 1) control diet (5% ST × 0% SO) with ad-libitum feed intake, 2) oil diet (replacement of 5% of ST by 5% SO) with ad-libitum feed intake, 3) control diet with restriction feed intake, and 4) oil diet with restriction feed intake. The pigs’ behavior and dirtiness score were observed daily, and their performance was assessed weekly. Furthermore, three blood samples were collected from each animal for hemogram analysis during the period of study. The analysis of meat and carcass quality was performed 24 h post-mortem once the animals had reached an average BW of 130–140 kg. Statistical analyses were performed using the PROC MIXED and PROC GENMOD procedures of the Statistical Analysis System (SAS). The diet-regimen interaction produced no effects (P > 0.05) on the analyzed variables, except for behavior. Animals on the control diet associated with ad-libitum feed management spent more time in the lateral decubitus position and showed reduced activity. In addition, pigs fed ad-libitum and those that received the control diet displayed the highest level of dirtiness during the experiment. Evaluation of performance revealed that pigs receiving the oil diet showed reduced feed intake (P < 0.05) with no difference in average daily gain and consequently presented better feed conversion values compared to animals on the control diet. Furthermore, the oil diet resulted in a higher (P < 0.05) carcass yield as well as a higher oleic fat content in the meat. Pigs on restricted feeding management with lower body and carcass weights produced higher values of leanness percentage and carcass compared to animals in the ad-libitum group. In conclusion, the replacement of 5% of starch by 5% of sunflower oil in the pigs’ diet during high ambient temperatures improved the animals’ welfare, feed efficiency, and carcass characteristics.info:eu-repo/semantics/acceptedVersio