Race diversity in dryland maize (Zea mays L.) landraces from southern Nuevo León, Mexico

Objective: To analyze the race diversity and geographic distribution of the native maize landraces currently cropped at southern Nuevo León, México. Design/Methodology/Approach: Data was obtained from 41 accessions which represent the commercial production in the dry land area, where fertilization and pest control are scarcely used. Landraces were classified according to the CONABIO guidelines for ear traits. Results: The measured accessions correspond to seven maize races and to seven interracial crosses. The two most frequent maize races were Ratón and Cónico Norteño, mostly located in the dry areas with less rain. Study Limitations/Implications: Three races, Celaya, Tablilla de Ocho and Elotes Cónicos, had not been previously reported; while two formerly reported races Tabloncillo and Olotillo, were no longer found. This study did not include the grain-colored accessions. Findings/Conclusions: Three collections stood out for producing large ears with large kernels, thus showing a high yield potential. The maize landraces harvested in dryland areas might offer advantages to be grown under harsh environments or be used as gene donors for drought tolerance.

Responses of the mangrove ecosystem to Holocene environmental change in the Sundarban Biosphere Reserve, India

The Sundarban Mangrove Forest in the Sundarban Biosphere Reserve, located at the mouth of the Ganga–Brahmaputra Delta in India, is the most diverse mangrove ecosystem in the world. Sediment cores were taken from two widely separated islands in that reserve: Chamta (CMT) and Sudhyanyakhali (SDK). Pollen analysis and radiocarbon dating were used to study the Holocene development and dynamics of this unique ecosystem. Modern pollen rain study reveals a strong relation between modern pollen rain and the present vegetation, as well as a high rate of Phoenix palludosa pollen production.The pollen records indicate that man-grove existed at CMT from ~5960 and at SDK from ~1520 cal yr BP. Changes in relative sea level, including the frequency and intensity of inundation as well as fluctuating precipitation, have been the major factors along with geomorphic processes that control the development and dynamics of the mangrove in the area during the Holocene. The mid Holocene mangrove at CMT declined, to be progressively replaced by successive communities, and eventually reached climax stage, while the SDK site is transitional in nature. The mangrove responds rapidly to changes in environmental conditions at both locations. Because of large-scale anthropogenic interventions, it is unlikely that similar rapid responses will occur in the future.

KAJIAN KONDISI ATMOSFER SAAT KEJADIAN HUJAN EKSTREM DI PADANG SUMATERA BARAT (STUDI KASUS TANGGAL 14 FEBRUARI 2018)

<p class="AbstractEnglish"><strong>Abstract:</strong> Padang's West Sumatra region has an equatorial rain pattern, where every year there are two peaks of rain. On February 14, 2018, there has been extreme rain in the Padang area, West Sumatra reaching 193 mm / day. In this extreme rain study using ECMWF reanalysis data, HIMAWARI -8 satellite data, and observation data on the Minangkabau Meteorological Station, Padang. The data is processed using tables, and images then analyzed descriptively. Based on the results of the analysis, it was found that the extreme rainfall occurring in the Padang region of West Sumatra was due to the pattern of closed angina seen around the area around West Sumatra, the highest humidity values were wet to 200 mb, cloud cover patterns that support extreme rainfall, and is supported by divergence and vertical velocity as well as unstable air conditions in the West Sumatra region and beyond. The lowest cloud top temperature reaches -74.5° C, it is indicated that the clouds formed at the time of the incident are convective clouds that are multi-cell.</p><p class="KeywordsEngish"><strong>Abstrak:</strong> Wilayah Sumatera Barat tepatnya Padang memiliki pola hujan ekuatorial, dimana setiap tahun terdapat dua puncak hujan. Pada tanggal 14 Februari 2018, telah terjadi hujan ekstrem di wilayah Padang, Sumatera Barat mencapai 193 mm/hari. Dalam penelitian hujan ekstrem ini menggunakan data reanalysis ECMWF, data satelit HIMAWARI -8, serta data observasi permukaan Stasiun Meteorologi Minangkabau, padang. Data tersebut diolah dengan menggunakan tabel, dan gambar kemudian dianalisa secara deskriptif. Berdasarkan hasil analisis didapatkan bahwa kejadian hujan ekstrem yang terjadi di wilayah Padang, Sumatera Barat tersebut dikarenakan adanya pola angin tertutup yang terlihat di sekitar wilayah sekitar Sumatera Barat, nilai kelembaban relatif tinggi yakni basah hingga lapisan 200 mb, pola tutupan awan yang mendukung untuk untuk terjadinya hujan ekstrem, dan didukung oleh divergensi dan kecepatan vertikal juga kondisi udara yang labil di wilayah Sumatera Barat dan sekitarnya. Suhu puncak awan terendah mencapai -74,5^oC, diindikasikan bahwa awan-awan yang terbentuk pada saat kejadian adalah awan konvektif yang bersifat multi sel.</p>

Estudo Pluvial no Nordeste do Brasil Utilizando Análise Multivariada (Rain Study in Northeast Brazil Using Multivariate Analysis)

O objetivo deste trabalho foi estudar a dinâmica de variabilidade climática espacial e temporal da pluviosidade nos nove estados do Nordeste Brasileiro, utilizando as técnicas multivariadas de Análise de Componentes Principais (ACP) e Análise de Agrupamento (AA). Foram utilizadas médias mensais da precipitação pluvial e de mais 11 índices climáticos pluviais definidos pela OMM (Organização Meteorológica Mundial) obtidas a partir de dados diários de 258 estações meteorológicas e/ou postos pluviométricos, fornecidos pela antiga rede de postos da SUDENE/DCA, referentes a um período de 47 anos (1960-2006). Com base nesses dados, foram aplicadas as técnicas de ACP e AA à média pluvial e aos 11 índices pluviais. Na ACP, nove índices climáticos e a média pluvial foram representados por três componentes principais e estas explicaram mais de 90% da variância original dos dados. Na AA, nove índices apresentaram quatro grupos homogêneos de atuação. Palavras - chave: Componentes principais, agrupamento, índices pluviais. Rain Study in Northeast Brazil Using Multivariate Analysis ABSTRACTThe aim of this work was to study the dynamics of spatial and temporal climatic variability in rainfall in the nine states of Northeast Brazil, using the multivariate techniques of Principal Component Analysis (PCA) and Cluster Analysis (CA). We used monthly averages of rainfall and 11 climate indices over rain defined by WMO (World Meteorological Organization) obtained from daily data from 258 meteorological stations and/or climatic stations, supplied by the former service station network SUDENE/DCA, referring a period of 47 years (1960-2006). Based on these data, we applied the techniques the average PCA and CA rain and 11 rain indices. In ACP, nine climate indices and average rainfall were represented by three principal components and these accounted for more than 90% of the variance of the original data. In AA, nine indices showed four homogeneous groups of activity.Keywords: Principal components; cluster; rain indices.