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

Effects of acetic and butyric acids on growth of rice seedlings

Este estudo teve por objetivo avaliar a fitotoxidez dos ácidos acético e butírico sobre o crescimento de plântulas de arroz (Oriza sativa L. - cv. BR IRGA 409) cultivadas em solução nutritiva. Os tratamentos constaram da adição de ácido acético e butírico e quatro concentrações (0,0, 0,1, 1,0 e 10 mM), em tubos contendo a solução Hoagland (No 2) e ajustadas a três níveis de pH (4,0, 5,0 e 6,0). As plântulas cresceram durante dez dias em câmara de crescimento a 26 ± 2°C sob uma intensidade luminosa de 6 Klux, durante doze horas. Independentemente de pH e concentração, o ácido butírico resultou mais fitotóxico que o acético, que reduziu a expansão da área radicular em 55%, enquanto o butírico, em 78%. Observou-se que 1,0 mm de ácido acético não teve efeito sobre o peso seco radicular, enquanto o butírico, em igual concentração, provocou redução de 78%. A 10 mM, os dois ácidos tiveram igual efeito inibitório sobre o crescimento radicular e da parte aérea. A elevação de pH, de 4,0 para 6,0, propiciou uma atenuação da toxidez, estimulando linearmente o crescimento de raízes e parte aérea.This study had the objective of appreciate the phytotoxic effects of acetic and butyric acids on growth of rice Oryza saliva L. cv. BR IRGA 409) seedlings cultivated in nutrient solution. The treatments consisted of addiction of acetic and butyric acids to the nutrient media to make 0.0, 0.1, 1.0 and 10 mM concentrations at three pH levels (4.0, 5.0 and 6.0). Seedlings were grown in growth chamber at 26 ± 2°C and 6 Klux light intensity with twelve hours of light and dark periods. Butyric acid was more toxic to plants than acetic acid irrespectively of acid concentration and pH. Acetic acid reduced root area expansion by 55%, and butyric acid reduced it by 78%. At 1.0 mM, acetic acid had no effect on the dry weight of roots, whereas at the same concentration butyric acid reduced root dry weight by 78%. At 10 mM, both acetic and butyric acid had the same effects in reducing the growth at root and shoots. Increasing pH from 4.0 to 6.0 alleviated the toxic effects of the acids, and linearly stimulated growth of roots and shoots

Incorporação de palha de arroz em um gleissolo e efeitos no rendimento da cultura do arroz irrigado

With the objective of verifying the effect of rice straw on flooded rice (Oryza sativa, L.) crop production, a greenhouse experiment was carried out, using soil samples of the A and Cg horizon of gleysol from Rio de Janeiro State, Brazil. The addition of rice straw decreased total production, grain production, dry matter production of plant shoots and other production parameters. The average weight of grain was not affected by rice straw incorporation and the harvest index showed a positive response up to the level of 20 ton/ha. Production levels were higher for the superficial horizon than for the subsuperficial horizon.Com o objetivo de verificar os efeitos da incorporação da palha de arroz sobre o rendimento da cultura do arroz (Oryza sativa, L.) irrigado, foi conduzido um experimento em casa de vegetação, utilizando-se amostras dos horizontes superficial (A) e subsuperficial (Cg) de um solo gley pouco húmico coletado no Vale do Rio São João (RJ). A adição de palha de arroz decresceu a produção da matéria seca total, o rendimento de grãos, a produção de matéria seca da palhada, e os componentes da produção, com exceção do peso médio de grãos. O índice de colheita revelou respostas positivas até a dose de 20 t/ha, e o horizonte superficial mostrou níveis de produção superiores aos obtidos no horizonte subsuperficial, em todos os parâmetros estudados

Lablab Purpureus Influences Soil Fertility and Microbial Diversity in a Tropical Maize-Based No-Tillage System

There are multiple mechanisms by which enhanced diversity of plant communities improves soil structure and function. One critical pathway mediating this relationship is through changes to soil prokaryotic communities. Here, nine different cropping systems were studied to evaluate how legume and grass cover crops influence soil fertility and microbial communities in a maize-based no tillage system. The soil’s bacterial and archaeal communities were sequenced (Illumina GAIIx, 12 replicates for treatment) and correlated with eight different soil features. The microbial community composition differed widely between planting treatments, with three primary “community types” emerging in multivariate space: (1) A community type associated with bare soil linked with low P, low pH, and high aluminum [Al]; (2) a community type associated with Lablab beans linked with high soil N, total organic carbon and other base cation concentrations, and high pH; and (3) a community type of all other non-lablab planting arrangements linked with higher soil P (relative to bare soil), but lower soil fertility (N and base cations). Lablab-based arrangements also expressed the highest microbial richness and alpha diversity. The inclusion of Lablab in maize-based cropping systems represents a potential alternative to reduce the use of chemical fertilizers and increase the chemical and biological quality in agricultural soils under the no-tillage system

Identification and complete sequencing of novel human transcripts through the use of mouse orthologs and testis cDNA sequences

The correct identification of all human genes, and their derived transcripts, has not yet been achieved, and it remains one of the major aims of the worldwide genomics community. Computational programs suggest the existence of 30,000 to 40,000 human genes. However, definitive gene identification can only be achieved by experimental approaches. We used two distinct methodologies, one based on the alignment of mouse orthologous sequences to the human genome, and another based on the construction of a high-quality human testis cDNA library, in an attempt to identify new human transcripts within the human genome sequence. We generated 47 complete human transcript sequences, comprising 27 unannotated and 20 annotated sequences. Eight of these transcripts are variants of previously known genes. These transcripts were characterized according to size, number of exons, and chromosomal localization, and a search for protein domains was undertaken based on their putative open reading frames. In silico expression analysis suggests that some of these transcripts are expressed at low levels and in a restricted set of tissues

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data