Niveles altos del mar y la especiación de comunidades costeras: oportunidades para los nuevos territorios en el sur de Sudamérica.

La fluctuación del nivel durante el Holoceno indujo la emergencia de nuevas áreas geográficas limitadas a algunos factores condicionantes como el régimen de salinidad, hábitats y sustratos. En la costa argentina, algunos organismos han sido favorecidos por esos factores. El caracol risoideo, Heleobia australis (D’Orbigny 1835), colonizó {reas estuarinas (planicies de fango, lagunas costeras, estuarios) de cambios significativos en relación con el régimen salino. El roedor Ctenomys australis (Rusconi 1934) se ha especializado para vivir en barreras medanosas, ambientes significativamente diferentes a los que ocupaban los antecesores de esta familia. En Patagonia, las ensenadas entre cabos han cambiado en su disponibilidad de sedimento durante los estadíos altos del mar durante el Cuaternario. Las comunidades bentónicas estuvieron así más relacionadas a los cambios en la composición del fondo que a los de la temperatura superficial. Los saltos del nivel durante el Holoceno han causado similares efectos rápidos cuando el mar superó cierto nivel causando la inundación aproximadamente rápida de una depresión emergida previamente.The sea-level fluctuation during the Holocene has induced the emergence of new geographical extensions constrained by some conditioning factors as salinity regimes, habitats and substrates. At the coast of Argentina, some organisms have taken advantage of these factors. A genera of the rissoidean snail, Heleobia australis (D?Orbigny 1835), has colonised estuarine areas (mudflats, coastal lagoons, estuaries) with significant changes in regard to the salinity regime. The rodent Ctenomys australis (Rusconi 1934) has specialized to live on barrier dunes, environments significantly different from those occupied by the ancient lineages of this family. In Patagonia, embayments between headlands have changed in their sediment availability during the different highstands of the Quaternary. Benthic communities were therefore more related to the changes of the bottom composition of these marine terraces than to sea surface temperatures. The Holocene jumps of the sea level could have caused similar rapid effects when the sea surpassed certain levels causing the approximately-sudden flood of a former subaerial depression.Fil: Isla, Federico Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Rejuvenation of Tea Gardens of Himachal through R&D Activities - A Report*

78-85Most of the tea gardens in Himachal Pradesh (India) were in dilapidated state due to negligence since decades. In 1983, with the establishment of this lab of Council of Scientific and Industrial Research (CSIR) in Palampur, the activities of rejuvenation of the tea industry in Kangra valley were initiated on the basis of intensive extension work and research. As a sequel, the tea production in this state increased by about 2.5 times during the past 15 years. The quality of the tea of this region also distinctly improved along with production. This paper presents a report on the strategies and status of development in these tea gardens

Effect of Methods and Systems of Plucking on Productivity and Quality of China Hybrid Tea

146-150A study was conducted for 5 years during 1988-92 to evaluate the performance of different methods and systems of plucking involving four types of hand plucking (standard plucking, black plucking, fish leaf plucking and mother leaf plucking) and two types of machine plucking (hand shears and one man power operated Japanese machine). The study revealed that in comparison to standard plucking, black plucking and fish plucking resulted in on an average 21 and 14% higher yield, respectively. Hand shears and power operated machine though resulted in 27-28% higher yield but caused reduction (about 50%) in crop quality in terms of its fineness. Average labour requirement with the Japanese machine and hand shears was found to be 17% (range 9-23%) and 59% (range 36-75%), respectively of the standard plucking

A survey of abandoned and neglected Tea Plantations in Sikkim for assessing the possibility of their Rejuvenation and Extension

25-29Sikkim is one of the hilly states in India where tea is cultivated. The developed as well as abandoned and neglected tea plantations exist in the state. A survey of the abandoned and neglected tea plantations in the state revealed that the soil and weather parameters suit the requirements for tea cultivation, and such plantations could be revived by adopting the rejuvenation technology package developed for tea gardens in hills at Institute of Himalayan Bioresource Technology which has been successfully implemented for development of such type of plantations in Himachal Pradesh