Multiple dormancy and maternal effect on Miconia ferruginata (Melastomataceae) seed germination, Serra de Caldas Novas, Goiás, Brazil

Species with mostly asexual reproduction are interesting subjects for germination studies since variation would be more easily linked to environmental factors. Miconia ferruginata DC. is an apomictic treelet in Brazilian cerrado areas on rocky outcrops. Germination of seeds collected from individuals occurring in the Serra de Caldas Novas State Park, Goiás, was studied in three experiments under controlled conditions. Germination characteristics differed among individuals and were correlated with altitude and soil Al content. Seeds from plants growing at lower altitudes, with lower soil aluminium content, presented malformed seeds with absence of embryo which rendered lower, but better synchronized germination. The nested analysis showed that from the total variance, 78.14% for germinability, 54.56% for uncertainty of the germination process, and 68.30% for the quantity of seeds without embryo was attributed to the altitudinal effect. Individuals nested within altitude contributed up to 16.93% for the total variance. It means that there is low variability among individuals of the same altitude and high variability among individuals from different points of the slope, making clear that for the studied population the environmental effect is stronger than the genetic component to determine the seed quality. The testa of the seeds provides a mechanical dormancy which seems to be associated also with phenolic compounds, which help to disperse germination through time. Photoblastism was also registered for seeds of this species.

Aspectos estruturais da comunidade arbórea em remanescentes de floresta estacional decidual, em Corumbá, MS, Brasil

(Aspectos estruturais da comunidade arbórea em remanescentes de floresta estacional decidual, em Corumbá, MS, Brasil). Um estudo comparativo da estrutura da comunidade arbórea entre dois remanescentes de floresta decídua foi conduzido em diferentes altitudes: florestas deciduais de terras baixas (FEDTB) e submontana (FEDSM), localizados em Corumbá, MS, Centro Oeste brasileiro. Amostraram-se indivíduos arbóreos com CAP ³ 15 cm, utilizando-se método de quadrantes. Foram demarcados 80 pontos em FEDTB e em FEDSM 78 pontos foram distribuídos por altitude: 180 m (18 pontos), 220, 260 e 300 m de altitude (20 pontos cada). Em FEDTB foram amostradas 34 espécies, sendo que Calycophyllum multiflorum Griseb., Ceiba pubiflora (A. St.-Hil.) K. Schum. e Anadenanthera colubrina (Vell.) Brenan apresentaram os maiores valores de importância. Na área de FEDSM foram amostradas 33 espécies, sendo que Anandenanthera colubrina, Ceiba pubiflora e Acosmium cardenasii H. S. Irwin & Arroyo foram as mais importantes. O padrão de distribuição das espécies variou ao longo do gradiente altitudinal. Em ambas as áreas, o índice de diversidade de Shannon foi de 2,9 e a Equitabilidade de 0,8, onde as famílias mais representativas foram Fabaceae (8 spp.) e Rubiaceae (4 spp). As florestas estudadas apresentaram baixa densidade de indivíduos por hectare em relação a outros estudos, exceto na área a 300 m. A comunidade arbórea apresentou 22,46% de indivíduos perfilhados e em fases iniciais de sucessão. O dossel variou de 6 a 12 m, com indivíduos emergentes de até 18 m. Estes remanescentes representam fonte de diversidade biológica para a região do Pantanal sendo importantes componentes dos corredores naturais da região.

Development of hypogene and supergene alteration and copper mineralization patterns, Sar Cheshmeh porphyry copper deposits, Iran /

The formation of the Sar Cheshmeh porphyry Cu-Mo deposit is related to the culmination of calc-alkaline igneous activity in the Kerman region. The deposit comprises a suite of Late Cenozoic intrusive sub-volcanic and extrusive rocks emplaced into a folded series of Eocene andesitic lavas and pyroclastic sediments. The earliest stage of magmatism was emplacement of a large granodiorite stock about 29 m.y.b.p. This was followed by intrusion of two separate porphyritic bodies at 15 (Sar Cheshrneh porphyry) and 12 m.y.b.p. (Late porphyry) and a series of sub-volcanic dikes between 12 and 9 m.y.b.p. Magmatic activity terminated with multi-phase extrusion of a Pelean dacitic dome complex between 10 and 2.8 m.y.b.p. The country rocks and the earlier porphyritic intrusions are pervasively altered to biotite-rich potassium silicate (metasomatic and hydrothermal) sericite-clay, phyllic and chlorite-clay, argillic assemblages. These grade outwards to an extensive propylitic zone. Within the ore body, the later intra-. and post-mineral dikes only reach the propylitic grade. At least three different sets of quartz veins are present, including a sericite-chlorite-quartz set which locally retrogrades pervasive secondary biotite to sericite. In the hypogene zone, metasomatic and hydrothermal alteration is related to all stages of magmatism but copper mineralization and veining are restricted to a period of 15 to 9 m.y.b.p.related to the early intrusive phases. The copper mineralization and silicate alteration do not fit a simple annular ring model but have been greatly modified by, 1. The existence of an ititial, outer ring, of metasomatic alteration overprinted by an inner.ring of hydrothermal alteration and, 2. later extensive dilating effects of intra- and post-mineral dikes. The hydrothermal clay mineral assemblage in the hypogene zone is illite-chlorite-kaolinite-smectite (beidellite). Preliminary studies indicate that the amount of each of these clays varies vertically and that hydrothermal zonation of clay minerals is possible. However, these minerals alter to illite-kaolinite assemblages in the supergene sulfide zone and to more kaolinite-rich assemblages in the supergene leached zone. Hydrothermal biotite breaks down readily in the supergene zone and is not well preserved in surface outcrops. The distribution of copper minerals in the supergene sulfide enrichment zone is only partly related to rock type being more dependent on topography and the availability of fractures.

Patterns of faunal change at an upper Cambrian trilobite extinction event, Nolichucky Formation, Tennessee and Virginia

During the Upper Cambrian there were three mass extinctions, each of which eliminated at least half of the trilobite families living in North American shelf seas. The Nolichucky Formation preserves the record of one of these extinction events at the base of the Steptoean Stage. Sixty-six trilobite collections were made from five sections In Tennessee and Virginia. The lower Steptoean faunas are assigned to one low diversity, Aphelaspis-dominated biofacies, which can be recognized in several other parts of North America. In Tennessee, the underlying upper Marjuman strata contain two higher diversity biofacies, the Coosella-Glaphyraspis Biofacies and the Tricrepicephalus-Norwoodiid Biofacies. At least four different biofacies are present in other parts of North America: the Crepicephalus -Lonchocephalus Biofacies, the Kingstonia Biofacies, the Cedaria Biofacies, and the Uncaspis Biofacies. A new, species-based zonation for the Nolichucky Formation imcludes five zones, three of which are new. These zones are the Crepicephalus Zone, the Coosella perplexa Zone, the Aphelaspis buttsi Zone, the A. walcotti Zone and the A. tarda Zone. The Nolichucky Formation was deposited within a shallow shelf basin and consists largely of subtidal shales with stormgenerated carbonate interbeds. A relative deepening is recorded In the Nolichucky Formation near the extinction, and is indicated In some sections by the appearance of shale-rich, distal storm deposits above a carbonate-rich, more proximal storm deposit sequence. A comparable deepening-upward sequence occurs near the extinction in the Great Basin of southwestern United States and in central Texas, and this suggests a possible eustatic control. In other parts of North America, the extinction IS recorded In a variety of environmental settings that range from near-shore to slope. In shelf environments, there is a marked decrease in diversity, and a sharp reduction in biofacies differentiation. Although extinctions do take place in slope environments, there IS no net reduction in diversity because of the immigration of several new taxa.

Sedimentology and stratigraphy of the Lower Silurian Grimsby formation, in subsurface, Lake Erie and Southwestern Ontario

Since the first offshore Lake Erie well was drilled in 1941, the Grimsby and Thorold formations of the Cataract Group have been economically important to the oil and gas industry of Ontario. The Cataract Group provides a significant amount of Ontario's gas production primarily from wells located on Lake Erie. The Grimsby - Thorold formations are the result of nearshore estuarine processes influenced by tides on a prograding shelf and are composed of subtidal channel complexes, discrete tidal channels, mud flats and non-marine deposits. Deposition was related to a regressive - transgressive cycle associated with eustatic sea level changes caused by the melting and resurgence of continental glaciation centred in Africa in the Late Ordovician/Early Silurian. Grimsby deposition began during a regression with the deposition of subtidal channel complexes incised into the marine deposits of the Cabot Head Formation. The presence of mud drapes and mud couplets suggest that these deposits were influenced by tides. These deposits dominate the lower half of the Grimsby. Deposition continued with a change from these subtidal channel complexes to laterally migrating, discrete, shallow tidal channels and mud flats. These were in turn overlain by the non-marine deposits of the Thorold Formation. Grimsby - Thorold deposition ended with a major transgression replacing siliciclastic deposition with primarily carbonate deposition. Sediment was sourced from the east and southeast and associated with a continuation of the Taconic Orogeny into the Early Silurian. The fluvial head of the estuary prograded from a shoreline that was located in western New York and western Pennsylvania running NNE-SSW and then turning NW-SE and paralleling the present day Lake Erie shoreline. iii The facies attributed to the Grimsby - Thorold formations can be ascribed to the three zones within the tripartite zonation suggested by Dalrymple et ale (1992) for estuaries, that is, a marine-dominated facies, a mixed energy facies, and a facies that is dominated by fluvial processes. Also, sediments within the Grimsby - Thorold are commonly fining upwards sequences which are common in estuarine settings whereas deltaic deposits are normally composed of coarsening upwards sequences in a vertical wedge shape with coarser material near the head. The only coarsening observed was in the Thorold Formation and attributed to non-marine deposition by palynological evidence. The presence of a lag deposit at the base of the sediments of the Grimsby Thorold formations suggests that they were incised into the Cabot Head Formation. Further, the thickness of Early Silurian sediments located between the top of the Queenston Formation, where Early Silurian sedimentation began, to the top of the Reynales - Irondequoit formation are constant whether the Grimsby - Thorold formations are present or not. Also, cross-sections using a sand body located in the Cabot Head Formation for correlation further imply that the Grimsby Formation has been incised into the previous deposits of the Cabot Head.

Ribbed moraines and subglacial geomorphological signatures of interior-sector palaeo-ice sheet dynamics

Transverse, subglacial bedforms (ribbed moraines) occur frequently in southern Keewatin, Nunavut, Canada, where they record a complex glacial history, including shifting centers of ice dispersal and fluctuating basal thermal regimes. Comprehensive mapping and quantitative morphometric analysis of the subglacial bedform archive in this sector reveals that ribbed moraines are spatially clustered by size and assume a broad range of visually distinct forms. Results suggest that end-member morphologies are consistent with a dichotomous polygenetic origin, and that a continuum of forms emerged through subsequent reshaping processes of variable intensity and duration. Translocation of mobile, immobile and quasi-mobile beds throughout the last glacial cycle conditioned the development of a subglacial deforming bed mosaic, and is likely responsible for the patchy zonation of palimpsest and inherited landscape signatures within this former core region of the Laurentide Ice Sheet. Comparison against field evidence collected from central Norway suggests that bedforming processes can be locally mediated by pre-existing topography.

L’histoire postglaciaire de la végétation et des feux dans la région du Lac Mégantic

La région du lac Mégantic est probablement la première zone à s'être déglacée au Québec, ce qui lui confère un intérêt particulier. L'analyse pollinique et anthracologique des sédiments des trois lacs situés à ses abords, soit les lacs Clinton, Dubuc et des Joncs ont permis de reconstituer l'histoire locale et régionale de la végétation et des feux. La présence d'un gradient altitudinal a entrainé des décalages surtout dans l'instauration des premières phases forestières. La région s'est déglacée vers 13 500 ans AA, et une toundra s'y est installée. Le début de l'afforestation est marqué par l'arrivée du sapin baumier et de l'épinette noire. Par la multiplication de leurs populations, la forêt s'est fermée vers 10 000 ans AA pour constituer une forêt boréale qui fût alors perturbée par plusieurs épisodes de feux. Vers 8000 ans AA, les nouvelles conditions climatiques favorisent les espèces feuillues et instaurent une érablière à bouleau jaune et une diminution de la fréquence des feux. Les résultats obtenus permettent d'enrichir les connaissances paléophytogéographiques et anthracologiques du Québec.

Some observations on the ecology and biochemical aspects of the seaweeds of Kerala coast

In the present thesis , observations on the ecology of seaweed flora of Kerala, their distribution and zonation pattern, monthly/seasonal density of seaweeds at each station, frequency of occurrence, standing crop, monthly/seasonal/place-wise data on physico—chemical characters of ambient waters at the stations and their influence on seaweed density have been made. This data will help us in the farming of economically important seaweeds, by providing information on the ideal conditions of seaweed biomass production. Biochemical observations on protein, carbohydrate and lipid contents of different species of nutritive value. Seaweeds with high content of proteins, carbohydrates and lipids can be recommended for food and feed formulations after subjecting them to toxicological studies. The study on monthly/seasonal/placewise variation in biochemical composition of seaweeds will provide necessary information on the appropriate time and place of harvesting the algal species for exploiting its constituents .

Hydrogeological, Geophysical And Geochemical Studies In Parts Of Coastal And Midland Areas, Central Kerala - A Gis Approach

The present study deals with the different hydrogeological characteristics of the coastal region of central Kerala and a comparative analysis with corresponding hard rock terrain. The coastal regions lie in areas where the aquifer systems discharge groundwater ultimately into the sea. Groundwater development in such regions will require a precise understanding of the complex mechanism of the saline and fresh water relationship, so that the withdrawals are so regulated as to avoid situations leading to upcoming of the saline groundwater bodies as also to prevent migration of sea water ingress further inland. Coastal tracts of Kerala are formed by several drainage systems. Thick pile of semi-consolidated and consolidated sediments from Tertiary to Recent age underlies it. These sediments comprise phreatic and confined aquifer systems. The corresponding hard rock terrain is encountered with laterites and underlined by the Precambrian metamorphic rocks. Supply of water from hard rock terrain is rather limited. This may be due to the small pore size, low degree of interconnectivity and low extent of weathering of the country rocks. The groundwater storage is mostly controlled by the thickness and hydrological properties of the weathered zone and the aquifer geometry. The over exploitation of groundwater, beyond the ‘safe yield’ limit, cause undesirable effects like continuous reduction in groundwater levels, reduction in river flows, reduction in wetland surface, degradation of groundwater quality and many other environmental problems like drought, famine etc.

Studies on some aspects of mangrove ecosystem in a tropical estuary"

The situation in the backwaters of Kerala, which reportedly had about 70,000 ha of mangroves, is unique in the sense that there has been a total conversion to other uses such as paddy cultivation, coconut plantation, aquaculture, harbour development and urban development In order to save and restore what is left over national and international organisations are mounting pressure on scientists and policy makers to work out ways and means conserving and managing the mangrove ecosystems. In this context, it has been observed in recent years that mangrove vegetation has remained intact in isolated pockets of undisturbed areas in the Cochin estuarine system and also that there is resurgence of mangroves in areas of accretion and silting. The candidate took up the present study with a view to make an inventory of the existing mangrove locations, the areas of resurgence, species composition, zonation and other ecological parameters to understand their dynamism and to suggest a mangement plan for this important coastal ecosystem

Resource use pattern and agroecosystem functioning in Rawanganga micro-watershed in Garhwal Himalaya, India

Agro-ecological resource use pattern in a traditional hill agricultural watershed in Garhwal Himalaya was analysed along an altitudinal transect. Thirty one food crops were found, although only 0.5% agriculture land is under irrigation in the area. Fifteen different tree species within agroforestry systems were located and their density varied from 30-90 trees/ha. Grain yield, fodder from agroforest trees and crop residue were observed to be highest between 1200 and 1600 m a.s.l. Also the annual energy input- output ratio per hectare was highest between 1200 and 1600 m a.s.l. (1.46). This higher input- output ratio between 1200-1600 m a.s.l. was attributed to the fact that green fodder, obtained from agroforestry trees, was considered as farm produce. The energy budget across altitudinal zones revealed 95% contribution of the farmyard manure and the maximum output was in terms of either crop residue (35%) or fodder (55%) from the agroforestry component. Presently on average 23%, 29% and 41% cattle were dependent on stall feeding in villages located at higher, lower and middle altitudes respectively. Similarly, fuel wood consumption was greatly influenced by altitude and family size. The efficiency and sustainability of the hill agroecosystem can be restored by strengthening of the agroforestry component. The approach will be appreciated by the local communities and will readily find their acceptance and can ensure their effective participation in the programme.

Possible solution of some essential zero problems in compositional data analysis

One of the tantalising remaining problems in compositional data analysis lies in how to deal with data sets in which there are components which are essential zeros. By an essential zero we mean a component which is truly zero, not something recorded as zero simply because the experimental design or the measuring instrument has not been sufficiently sensitive to detect a trace of the part. Such essential zeros occur in many compositional situations, such as household budget patterns, time budgets, palaeontological zonation studies, ecological abundance studies. Devices such as nonzero replacement and amalgamation are almost invariably ad hoc and unsuccessful in such situations. From consideration of such examples it seems sensible to build up a model in two stages, the first determining where the zeros will occur and the second how the unit available is distributed among the non-zero parts. In this paper we suggest two such models, an independent binomial conditional logistic normal model and a hierarchical dependent binomial conditional logistic normal model. The compositional data in such modelling consist of an incidence matrix and a conditional compositional matrix. Interesting statistical problems arise, such as the question of estimability of parameters, the nature of the computational process for the estimation of both the incidence and compositional parameters caused by the complexity of the subcompositional structure, the formation of meaningful hypotheses, and the devising of suitable testing methodology within a lattice of such essential zero-compositional hypotheses. The methodology is illustrated by application to both simulated and real compositional data

A Comparative study of germination strategies of two species of genus Allium sect. Allium

Germination experiments were performed with seeds of two species of genus Allium section Allium, a rare and endangered species A. pyrenaicum and a common A. sphaerocephalon. Different pre-treatments and a photoperiod of 24 h darkness were applied in order to simulate different germination conditions. Both species showed a high percentage of viable seeds a part of which were dormant. An elevate percentage of dormant seeds could be caused by a later collection time. Low altitude populations had more mortality than the others, possibly caused by the hard summer conditions during flowering and fruiting time. Comparisons between dates of species coexistence localities only show inter-population variability and it could be caused by the detected dormancy. Darkness accelerates germination, possibly for elongation radicle stimulation. Heat-shock pre-treatments decreased germination time in seeds from localities where fire is a probable event. The rarity of A. Pyrenaicum not seems to be caused by restricted germination requirements but is attributable to distinct habitat preferences, related to his altitudinal range of distribution

26 propuestas para el fin de semana : rutas para andar por los espacios naturales de la Comunidad de Madrid

Se describen los ecosistemas m??s representativos de la Comunidad de Madrid a trav??s de rutas por la geograf??a madrile??a. Se aporta informaci??n no solo sobre los itinerarios de las mismas sino tambi??n sobre los componentes hist??ricos y culturales de cada una de ellas. Cada una de las rutas cuenta con varias partes: un cuadro inicial, el texto descriptivo y explicativo, el perfil altitudinal, un mapa y alg??n cuadro tem??tico especial de la ruta.

Jupiter's and Saturn's convectively driven banded jets in the laboratory

The banded patterns of cloud and wind are among the most striking features of the atmospheres of Jupiter and Saturn, but their dynamical origin remains poorly understood. Most approaches towards understanding zonation so far (also in the terrestrial oceans) have used highly idealized models to show that it might originate from dynamical anisotropy in a shallow turbulent fluid layer due to the planetary β-effect. Here we report the results of laboratory experiments, conducted on a 14-m diameter turntable, which quantitatively confirm that multiple zonal jets may indeed be generated and maintained by this mechanism in the presence of deep convection and a topographic β-effect. At the very small values of Ekman number (≤2 × 10−5) and large local Reynolds numbers (≥2000, based on jet scales) achieved, the kinetic energy spectra suggest the presence of both energy-cascading and enstrophy-cascading inertial ranges in addition to the zonation near twice the Rhines wave number.