We experimentally evaluated how different temperatures affect germination of individual seedlings of Dipteryx alata, and estimated the impact of climate change on the species using ecological niche modeling. A total of 240 seeds were randomly distributed among three different temperature treatments (32 ºC, 36 ºC, and 40 ºC), and monitored for 35 days. We measured seven seed traits and estimated the ecological niche of D. alata using a consensus of four methods. The treatment with the highest temperature produced smaller and lighter seedlings. The consensus of ecological niche modeling indicated that are expected to reduce the areas with climates favorable for D. alata in future scenarios. Thus, our two results (experiment and ecological niche modeling) are concordant, and both indicate the impact of global warming on germination (initial stage of the plant) and potential geographic distribution. Moreover, in geographic context, our experiment and ecological niche modeling indicated that north, northwest and central regions of the "Cerrado" are predicted to have lower morphological traits of germination and loss climate favorable area, since these regions are predicted to have higher temperatures (nearly 40 ºC) in future climatic scenarios.
O paricá, Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby, é uma espécie florestal largamente utilizada em reflorestamentos. Entretanto, os danos causados por insetos podem reduzir a área fotossintética, interferindo no crescimento. Portanto, o objetivo deste trabalho foi avaliar a capacidade de recuperação de paricá em idades precoces, pela simulação de desfolha. Foi utilizado o delineamento experimental em blocos casualizados, divididos em quatro experimentos, com quatro repetições, separados em dois períodos (30 e 60 dias após emergência) e pela porcentagem de folhas e folíolos. Ao completar 30 e 60 dias após emergência foram realizadas as desfolhas e após mais 30 dias, nas duas fases, avaliou-se altura da planta, diâmetro do caule e recuperação foliar. Os dados foram submetidos à análise de variância e regressão para os percentuais de desfolha. Sob desfolha artificial, o paricá apresentou baixa redução de crescimento e boa capacidade de recuperação de danos, sendo assim considerado tolerante às diferentes porcentagens de danos testadas.
The development of activities in the forestry sector is constantly evolving. The constant search for improvements in the production system in order to increase production and reduce costs are, therefore, necessary to maintain the growth of forestry. The forest harvesting stage corresponds to a large part of the financial amount spent on the activity and, therefore, it becomes the target of constant studies aiming at its improvement and evolution. The objective of this study is to carry out a technical analysis of the operation of a forest machine skidder operating in the drag of a eucalypts stand in the whole tree system. The technical analysis encompasses factors such as the study of times and movements, operational efficiency and productivity, evaluating the performance of the machinery for three different drag branch distances. In the study of times and movements, the operations “travel without load” and “travel with load” were the operations that demanded the longest total cycle time. The operational efficiency of the machinery approached 90% and the productivity of the skidder decreased according to the increase in the distance from the skidding branch, being in the order of 19.36 m³. hˉ¹ for the 100-meter skid road, 14.01 m³. hˉ¹ for the 200-meter skid road and 8.35 m³. hˉ¹ for the 300-meter skid road.
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