SYNTHETIC POLYMERS ON WATER RETENTION AND PORE DISTRIBUITION IN A CLAYEY LATOSOL

The use of polymers is growing at the agricultural area, however their effects on soil porosity have been little studied. The objective of this article is to analyze the effects of applied synthetic polymers on soil porosity and water retention of a Dystroferric red Latosol. This study was conducted on undisturbed samples collected at a depth of 0.05m in a Latosol beneath native forest. The samples were saturated with distilled water and polymers HyC, HyA, HyB diluted in water according to use recommendations for coffee plantations. These samples were then submitted to matric potentials of -2, -4, -6 and -10 kPa in the suction units and -33, -100, -500 and -1500 kPa in a Richards extractor. Water retention curves were moldeled and pore size distribution estimates calculated. The data were subjected to variance analysis and the averages were compared using the Scott-knott test to a level of 5%. There was a reduction of the pore volume of size class larger than 145µm when the soil was saturated with HyA and HyB polymers. On one hand the HyB polymer promoted a reduction in the pore volume in the intermediate classes (2.9-0.6; 0,.-0.2 µm), that were responsible for providing water to the plants. On the other hand the HyC polymer promoted an increase in the soil water retention

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

Synthetic polymers on water retention and pore distribuition in a clayey Latosol

The use of polymers is increasing at the agricultural area, however their effects on soil porosity have been little studied. The objective of this article is to analyze the effects of applied synthetic polymers on soil porosity and water retention of a Dystroferric Red Latosol. This study was conducted on undisturbed samples collected at a depth of 0.05 m in a Latosol beneath native forest. The samples were saturated with distilled water and polymers HyC, HyA, HyB diluted in water according to use recommendations for coffee plantations. These samples were then submitted to matric potentials of -2, -4, -6 and -10 kPa in the suction units and -33, -100, -500 and -1500 kPa in a Richards extractor. The models were fitted and pore size distribution estimates calculated. The data were subjected to variance analysis and the averages were compared using the Scott-knott test to a level of 5 %. Decreasing of large pores volume than 145 µm, was detected with the application of polymers HyA and B. However the HyB polymer promoted a reduction in the pore volume in the intermediate classes (2.9-0.6; 0.6-0.2 µm), that are responsible for water availability to plants. On the other hand the HyC polymer promoted an increase in the soil water retention.O uso de polímeros é crescente no meio agrícola, porém seus efeitos na porosidade do solo são pouco estudados. O presente trabalho teve como objetivo analisar os efeitos da aplicação de polímeros sintéticos na porosidade e retenção de água de um Latossolo Vermelho Distroférrico muito argiloso. O estudo foi realizado em amostras indeformadas coletadas na profundidade de 0,05 m, em um Latossolo sob mata nativa. Amostras foram saturadas com água destilada e com os polímeros HyC, HyA, HyB diluídos em água conforme recomendações de uso para cultura do cafeeiro. Em seguida estas amostras de solos foram submetidas a potenciais matriciais de -2, -4, -6 e -10 kPa nas unidades de sucção e -33, -100, -500 e -1500 kPa nas câmaras de Richards. Foi realizada a modelagem de curvas de retenção de água e calculada a distribuição de poros por tamanho. Os dados foram submetidos a análises de variância e as médias comparadas pelo teste de Scott-knott ao nível de 5 %. Houve uma redução do volume de poros da classe de tamanho > 145 μm quando o solo foi saturado com os polímeros HyA e HyB. O polímero HyB promoveu uma redução do volume de poros das classes intermediárias (2,9-0,6; 0,6-0,2 μm), responsáveis pela disponibilidade de água para as plantas. Já o polímero HyC promoveu o aumento da retenção de água no solo