Variações espaço-temporais na abertura do dossel em diferentes tipologias vegetais sob efeito de fogo

Atlantic and Brazilian savanna phytogeographic domains stand out the high level of threating from forest remnants, making the ecological study of these important areas for both the Domains conservation. In nature, disturbances events are common, but human activities can aggravate the occurrence of these phenomena, for example, increasing the frequency of fire events in natural environments. Even the higher layer in the forest, the canopy, suffers directly and indirectly affected by this disturbance. Besides, canopies characteristics are decisive factor acting in the regeneration dynamics of vegetal community, regulating luminosity that reach inferior low layers of vegetation. This study aims to capture the variations in canopy gaps in an ecotone area between Savanna and Atlantic Domains in order to identify how these changes occur between the analyzed vegetation types and which is the fire influence in the upper layer of the forest. We captured variations in the forest gaps after a fire event utilizing hemispheric photos. The photos have been taking for three years in an interval of six months. We found out that similar phytophysiognomies showed similar levels of canopy coverage and displayed an oscillation pattern. Finally, it appears that fire proved to be an indirect modifier of the canopy, since the characteristics of the vegetation itself have the ability to control the impacts of this type of disturbance.Os domínios fitogeográficos Atlântico e dos Cerrados brasileiros destacam-se pelo alto grau de ameaça de seus remanescentes, fazendo com que o estudo de sua ecologia seja de suma importância para a conservação desses domínios. Apesar da existência de distúrbios ecológicos naturais, a ação humana pode agravar a ocorrência desses fenômenos, como por exemplo: o aumento da frequência do fogo em ambientes naturais. Mesmo o dossel, camada superior da vegetação, é prejudicado direta ou indiretamente pela ação desse distúrbio. Além disso, as características do dossel são determinantes para a dinâmica de regeneração das comunidades vegetais, pois suas condições regulam os níveis de luminosidade que chegam às camadas inferiores da vegetação. Assim, este trabalho buscou estudar as variações na abertura do dossel de um mosaico vegetacional inserido em uma área de contato entre os domínios Atlântico e dos Cerrados, com o intuito de identificar como se dão essas alterações entre as tipologias vegetais analisadas e qual a influência da ocorrência de fogo nas oscilações no estrato superior da vegetação. Para isso, o estudo acompanhou as mudanças na abertura do dossel, com o uso de fotografias hemisféricas, em diferentes unidades vegetacionais por três anos, a partir da ocorrência de um evento de fogo no local. Os resultados obtidos mostraram que fitofisionomias semelhantes apresentaram níveis de abertura do dossel parecidos, da mesma forma que exibiram um padrão de oscilação similar entre si. Por fim, depreende-se que o fogo se mostrou como um modificador indireto do dossel, uma vez que as próprias características da vegetação têm a capacidade de controlar os impactos desse tipo de distúrbio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost