Fire Responses to the 2010 and 2015/2016 Amazonian Droughts

Extreme droughts in Amazonia cause anomalous increase in fire occurrence, disrupting the stability of environmental, social, and economic systems. Thus, understanding how droughts affect fire patterns in this region is essential for anticipating and planning actions for remediation of possible impacts. Focused on the Brazilian Amazon biome, we investigated fire responses to the 2010 and 2015/2016 Amazonian droughts using remote sensing data. Our results revealed that the 2015/2016 drought surpassed the 2010 drought in intensity and extent. During the 2010 drought, we found a maximum area of 846,800 km2 (24% of the Brazilian Amazon biome) with significant (p ≤ 0.05) rainfall decrease in the first trimester, while during the 2015/2016 the maximum area reached 1,702,800 km2 (47% of the Brazilian Amazon biome) in the last trimester of 2015. On the other hand, the 2010 drought had a maximum area of 840,400 km2 (23% of the Brazilian Amazon biome) with significant (p ≤ 0.05) land surface temperature increase in the first trimester, while during the 2015/2016 drought the maximum area was 2,188,800 km2 (61% of the Brazilian Amazon biome) in the last trimester of 2015. Unlike the 2010 drought, during the 2015/2016 drought, significant positive anomalies of active fire and CO2 emissions occurred mainly during the wet season, between October 2015 and March 2016. During the 2010 drought, positive active fire anomalies resulted from the simultaneous increase of burned forest, non-forest vegetation and productive lands. During the 2015/2016 drought, however, this increase was dominated by burned forests. The two analyzed droughts emitted together 0.47 Pg CO2, with 0.23 Pg CO2 in 2010, 0.15 Pg CO2 in 2015 and 0.09 Pg CO2 in 2016, which represented, respectively, 209%, 136%, 82% of annual Brazil’s national target for reducing carbon emissions from deforestation by 2017 (approximately 0.11 Pg CO2 year-1 from 2006 to 2017). Finally, we anticipate that the increase of fires during the droughts showed here may intensify and can become more frequent in Amazonia due to changes in climatic variability if no regulations on fire use are implemented

Genomic evaluation for novel stayability traits in Nellore cattle.

Cow stayability plays a major role on the overall profitability of the beef cattle industry, as it is directly related to reproductive efficiency and cow's longevity. Stayability (STAY63) is usually defined as the ability of the cow to calve at least three times until 76 months of age. This is a late-measured and lowly heritable trait, which consequently constrains genetic progress per time unit. Thus, the use of genomic information associated with novel stayability traits measured earlier in life will likely result in higher prediction accuracy and faster genetic progress for cow longevity. In this study, we aimed to compare pedigree-based and single-step GBLUP (ssGBLUP) methods as well as to estimate genetic correlations between the proposed stayability traits: STAY42, STAY53 and S TAY64, which are measured at 52, 64 and 76 months of cow's age, considering at least 2, 3 and 4 calving, respectively. ssGBLUP yielded the highest prediction accuracy for all traits. The heritability estimates for STAY42, STAY53, STAY63 and STAY64 were 0.090, 0.151, 0.152 and 0.143, respectively. The genetic correlations between traits ranged from 0.899 (STAY42 and STAY53) to 0.985 (STAY53 and STAY63). The high genetic correlation between STAY42 and STAY53 suggests that besides being related to cow longevity, STAY53 is also associated with the early-stage reproductive efficiency. Thus, STAY53 is recommended as a suitable selection criterion for reproductive efficiency due to its higher heritability, favourable genetic correlation with other traits, and measured earlier in life, compared with the conventional stayability trait, that is STAY63

Tomato seedling production in substrate containing coconut fiber and mushroom culture waste AB S TR ACT

Tomato seedling production in substrate containing coconut fiber and mushroom culture waste Revista Brasileira de Ciências Agrárias, vol. 3, núm. 3, julio-septiembre, 2008, pp. 237-241 Universidade Federal Rural de Pernambuco Pernambuco, Brasil Tomato seedling production in substrate containing coconut fiber and mushroom culture waste AB S TR ACT The objective of this research was to evaluate the ratio of coconut fiber and mushroom culture waste in the tomato seedling production. A greenhouse experiment was carried out in the randomized block experimental design, with seven treatments and four replications: T1 -Commercial Substrate Hortimix®; T2 -0% coconut fiber dry matter (CF) + 100% dry matter of mushroom culture waste (MW); T3 -20% (CF) + 80% (MW); T4 -40% (CF) + 60% (MW); T5 -60% (CF) + 40% (MW); T6 -80% (CF) + 20% (MW); T7 -100% (CF) + 0% (MW). Stem diameter, seedling height, emergence speed, germination percentage, shoot and root fresh matter and shoot and root dry matter were evaluated. It was evidenced, for all the studied characteristics, with exception of the speed of germination-aid seedling emergence and of the germination percentage, significant differences between substrate containing coconut fiber and mushroom culture residue and the commercial substratum, the best results presented by the last one. The increase in the proportion of mushroom residue in relation to the coconut fiber provided tomato seedling with better characteristics than the others. Key words: organic substrate, recycling, organic manure, germination Produção de mudas de tomate em substrato contendo fibra de coco e resíduo de cultivo de cogumelo RES UMO Visou-se, com o presente trabalho, avaliar proporções de fibra de coco e de resíduo proveniente do cultivo de cogumelo como substratos para a produção de mudas de tomate. O experimento foi conduzido em casa de vegetação, tendo-se utilizado o delineamento em blocos inteiramente casualizados, com sete tratamentos e quatro repetições: T 1 -Substrato comercial Hortimix ® ; T 2 -0% matéria seca de fibra de coco (FC) + 100% matéria seca de resíduo proveniente do cultivo de cogumelo (RC); T 3 -20% FC + 80% RC; T 4 -40% FC + 60% RC; T 5 -60% + 40% RC; T 6 -80% FC + 20% RC; T 7 -100% FC + 0% RC. Avaliaram-se o diâmetro do caule, a altura da planta, o índice de velocidade de emergência, a percentagem de germinação, a matéria fresca da parte aérea e da raiz, e a matéria seca da parte aérea e da raiz. Constataram-se, para todas as características estudadas, com exceção do índice de velocidade emergência e da percentagem de germinação, diferenças significativas entre os substratos contendo fibra de coco e resíduo do cultivo de cogumelo e o substrato comercial, em que este último apresentou os melhores resultados. O aumento da proporção de resíduo de cogumelo em relação à fibra de coco proporcionou a produção de mudas com melhores características que as demais

The VISCACHA survey : III. Star clusters counterpart of the Magellanic Bridge and Counter-Bridge in 8D

Context. The interactions between the Small and Large Magellanic Clouds (SMC and LMC) created the Magellanic Bridge; a stream of gas and stars pulled out of the SMC towards the LMC about 150 Myr ago. The tidal counterpart of this structure, which should include a trailing arm, has been predicted by models but no compelling observational evidence has confirmed the Counter-Bridge so far. Aims. The main goal of this work is to find the stellar counterpart of the Magellanic Bridge and Counter-Bridge. We use star clusters in the SMC outskirts as they provide a 6D phase-space vector, age, and metallicity which help characterise the outskirts of the SMC. Methods. Distances, ages, and photometric metallicities were derived from fitting isochrones to the colour-magnitude diagrams from the VISCACHA survey. Radial velocities and spectroscopic metallicities were derived from the spectroscopic follow-up using GMOS in the CaII triplet region. Results. Among the seven clusters analysed in this work, five belong to the Magellanic Bridge, one belongs to the Counter-Bridge, and the other belongs to the transition region. Conclusions. The existence of the tidal counterpart of the Magellanic Bridge is evidenced by star clusters. The stellar component of the Magellanic Bridge and Counter-Bridge are confirmed in the SMC outskirts. These results are an important constraint for models that seek to reconstruct the history of the orbit and interactions between the LMC and SMC as well as constrain their future interaction including with the Milky Way

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors