scholarly journals Vertical and horizontal distribution of pollination systems in cerrado fragments of central Brazil

2007 ◽  
Vol 50 (3) ◽  
pp. 503-514 ◽  
Author(s):  
Fernanda Quintas Martins ◽  
Marco Antônio Batalha
Keyword(s):  
Spatial Distribution ◽  
Significant Variation ◽  
Horizontal Distribution ◽  
Bee Pollination ◽  
Vertical Variation ◽  
Pollination System ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Vertical And Horizontal Distribution ◽  
Pollination Systems

In fragments of the cerrado, we determined the frequency of pollination systems and analyzed their spatial distribution. We placed 38 transects, sampling 2,280 individuals and 121 species. As expected in Neotropical regions, bee-pollination was the most frequent pollination system. We found a decrease in the frequency of plants pollinated by beetles towards the fragment interior. Similarly, we found significant variation in relation to height just for the bats; there was an increase in the frequency of plants pollinated by bats towards the higher heights. In general, we found no horizontal and vertical variation in the pollination systems, probably as consequence of the more open physiognomy of the cerrado vegetation.

scholarly journals Spatial distribution of cases of fatal yellowing on organic oil palm plantation

2016 ◽  
Vol 37 (5) ◽  
pp. 3047
Author(s):  
José Nilton da Silva ◽  
Paulo Roberto Silva Farias ◽  
Anderson Gonçalves da Silva ◽  
Fábio Júnior de Oliveira ◽  
Ricardo Salles Tinôco
Keyword(s):  
Spatial Distribution ◽  
Spatial Analysis ◽  
Oil Palm ◽  
Spatial Dispersion ◽  
Horizontal Distribution ◽  
Quadrant Analysis ◽  
Line Number ◽  
Analysis Techniques ◽  
Oil Palm Plantation ◽  
Vertical And Horizontal Distribution

This work studied the spatial dispersion of cases of fatal yellowing (FY) in an oil palm plantation in Acará, Pará State, Brazil. Data were collected monthly from two areas, divided in 16 quadrants each, for a 24 month period (2012-2013). In each quadrant, 138 plants were evaluated. The number of diseased plants was counted in twenty planting lines, and the spatial pattern of the disease was analyzed. The following spatial analysis techniques were used: common sequences of “runs”, “doublets” and quadrants. We also determined the levels of disease aggregation in the sectors. Plants with FY had a spatial distribution aggregated in a lower line number when using the “run” analysis than when using the “doublets” method. Aggregation of FY cases was observed in 30% of the evaluated lines. The quadrant analysis confirmed the existence of case aggregation, with vertical and horizontal distribution. The existence of disease forming foci suggests that FY probably has biotic origin. Additional studies are required to confirm this hypothesis.

Spatial distribution of zooplankton biomass size fractions in a bog lake: abiotic and (or) biotic regulation?

1998 ◽  
Vol 76 (5) ◽  
pp. 805-823 ◽  
Author(s):  
Stéphane Masson ◽  
Bernadette Pinel-Alloul
Keyword(s):  
Spatial Distribution ◽  
Spatial Heterogeneity ◽  
Size Structure ◽  
Vertical Axis ◽  
Horizontal Distribution ◽  
Zooplankton Biomass ◽  
Relative Importance ◽  
Size Fractions ◽  
Anoxic Waters ◽  
Vertical And Horizontal Distribution

Although spatial heterogeneity of zooplankton has been explained by variations in abiotic and biotic factors as well as their cascading interactions, few studies have paid attention to the relative importance of these processes in structuring the vertical and horizontal distribution of zooplankton within a lake. The main objective of this study was to determine the relative importance of abiotic and biotic processes in the regulation of the vertical and horizontal distribution of four size fractions (53-100, 100-202, 202-500, and >500 µm) of the zooplankton biomass in a bog lake (Lake Geai, Quebec). Spatial heterogeneity of zooplankton biomass was found in both the horizontal and the vertical dimensions of the lake, and spatial patterns were quite similar for all size fractions. On the horizontal axis, spatial heterogeneity was stronger in the epilimnetic stratum. Zooplankton biomass was mainly aggregated in the east side of the lake in an area of higher conductivity and greater density of small chaoborid larvae. On the vertical axis, zooplankton biomass was concentrated in the epilimnetic waters and decreased with depth. This vertical pattern of distribution might be due to the avoidance of cold and anoxic waters and a high density of large chaoborid larvae in the hypolimnion. In general, invertebrate predation has been identified as the primary factor regulating zooplankton biomass distribution in Lake Geai. However, the size structure of chaoborid predators was more important than their density in the control of the spatial distribution of zooplankton.

scholarly journals Spatial distribution of soil organic carbon by digital mapping: the case of the Medio Aguanaval river sub-basin

2021 ◽  
Vol 13 (2) ◽  
pp. 227-245
Author(s):  
Georgina Pérez-Rodríguez ◽  
◽  
Armando López-Santos ◽  
Miguel Agustín Velásquez-Valle ◽  
José Villanueva-Díaz ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Horizontal Distribution ◽  
Digital Mapping ◽  
Lack Of Information ◽  
Static Modeling ◽  
Vertical And Horizontal Distribution ◽  
Soc Stocks ◽  
Selection Of

ntroduction: Carbon is found mainly in geological reservoirs, oceans, atmosphere and land. Soil organic carbon (SOC) is determined by the quantity and vertical distribution of vegetation, intrinsic soil properties and climate, but variability is influenced by anthropogenic interference. SOC stocks are not static; modeling their spatial, vertical and horizontal distribution involves the creation of baseline estimates to quantify these stocks. Objective: To estimate the magnitude of SOC stocks in the Medio Aguanaval River sub-basin (ScRMA) and to analyze the sensitivity of four interpolation methods to minimize the error of digital mapping for the ScRMA. Methodology: The study consisted of five stages: 1) search, download and analysis of soil data, 2) data processing, 3) selection of verification sites, 4) laboratory analysis and 5) processing of data from verification sites. Results: SOC values ranged from 9 to 133 t·ha-1, with a mean of 36.31 t·ha-1 and standard deviation of 23.83 t·ha-1. The ordinary exponential Kriging interpolator was the best representation for SOC of the ScRMA based onstatistics. The results of the analysis of the verification sites yielded a mean SOC of 24.4 t·ha-1. Limitations of the study: Soil profile density for the region and the lack of information on bulk density. Originality: The baseline distribution of SOC at the sub-basin level was used to analyze its dynamics. Conclusions: The highest concentration of SOC (61 to 129 t·ha-1) was found in the municipalities of Cuencamé and Santa Clara, while the lowest records (10 to 30 t·ha-1) were located in the municipalities of Torreón and Viesca.

Spatial distribution of flying Tribolium castaneum (Coleoptera: Tenebrionidae) in a rice warehouse

1995 ◽  
Vol 85 (3) ◽  
pp. 355-359 ◽  
Author(s):  
S.H. Ho ◽  
K.S. Boon
Keyword(s):  
Spatial Distribution ◽  
Distribution Pattern ◽  
Tribolium Castaneum ◽  
Horizontal Distribution ◽  
Insect Species ◽  
Factors Influencing ◽  
Vertical And Horizontal Distribution ◽  
Coleoptera Tenebrionidae

AbstractThe vertical and horizontal distribution of Tribolium castaneum (Herbst) in a rice warehouse was studied using flight traps hung around selected stacks of bagged rice. Traps hung at 4 m or higher from the floor caught more T. castaneum than other insect species in the warehouse. At 6 m height, the traps caught mainly this species and were easy to maintain. The horizontal distribution pattern of T. castaneum sampled at 6 m was not homogeneous. The factors influencing distribution are discussed.

Pollination ecology of Caryocar brasiliense (Caryocaraceae) in Central Brazil cerrado vegetation

1993 ◽  
Vol 9 (2) ◽  
pp. 199-211 ◽  
Author(s):  
Rogério Gribel ◽  
John D. Hay
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Seed Set ◽  
Floral Biology ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Glossophaga Soricina ◽  
Caryocar Brasiliense ◽  
Anoura Geoffroyi ◽  
Phyllostomus Discolor

ABSTRACTThe floral biology, breeding system and pollination of Caryocar brasiliense were studied in the cerrado vegetation of Central Brazil. The large, yellowish-cream, brush-like flowers are pollinated mainly by glossophagine bats (Glossophaga soricina and Anoura geoffroyi). Three non-glossophagine bats (Phyllostomus discolor, Vampyrops lineatus and Carollia perspicillata) and two short probosisced hawk moths (Erinyis ello and Pseudosphinx tetrio) may also act as occasional pollinators. Caryocar brasiliense is self-compatible although it sets significantly more fruits when crossed than when selfed. The natural fruit set (fruit/flower ratio) and seed set (seed/ovule ratio) are 3.1% and 1.0% respectively. Most of the fruits and seeds are formed through the action of the flower visitors, despite the fact that about 20% of the non-visited flowers receive self pollen on at least one stigma.

scholarly journals The length of the dry season may be associated with leaf scleromorphism in cerrado plants

2015 ◽  
Vol 87 (3) ◽  
pp. 1691-1699 ◽  
Author(s):  
MARCELO C. SOUZA ◽  
AUGUSTO C. FRANCO ◽  
MUNDAYATAN HARIDASAN ◽  
DAVI R. ROSSATTO ◽  
JANAÍNA F. DE ARAÚJO ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Specific Leaf Area ◽  
Woody Species ◽  
Dry Season ◽  
Core Region ◽  
The Other ◽  
Low Fertility ◽  
Fertility Rates ◽  
Cerrado Vegetation ◽  
Central Brazil

Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP). We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA) between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake.

Behavior and Distribution of Nonylphenol Ethoxylates and their Metabolites in Sediments of Nansi Lake, China

2011 ◽  
Vol 356-360 ◽  
pp. 1733-1738
Author(s):  
Fang He ◽  
Aya Obara ◽  
Shi Long Wang ◽  
Li Guo Wang
Keyword(s):  
Water Flow ◽  
Flow Direction ◽  
Sediment Cores ◽  
Sewage Treatment ◽  
Vertical Direction ◽  
Total Content ◽  
Horizontal Distribution ◽  
Nansi Lake ◽  
Increasing Trend ◽  
Vertical And Horizontal Distribution

The vertical and horizontal distribution of NPEOn and their metabolites of NP and NPEnC in the Upper Nansi Lake, North China were investigated using LC-MS and LC-MS/MS methods, sampling at three sites (St.1, St.2 and St.3) along the water flow direction. The total content of NPEOn (n=1–15) bound onto the sediment of this lake changed in the range of 60.7–631.5 μg/kg-dry with the horizontal flow direction and the vertical direction of the sediment cores with sediment thickness up to 35 cm. Compared to the presence levels of all detected NPEOn species, the content of NP was much higher, falling in 26.5–1,998.4 μg/kg-dry. A general increasing trend of the NP content along the water flow direction of this lake was revealed. NPEnC showed a roughly increasing trend from the upstream to the downstream, with the total concentrations being obviously lower than NPEOn and NP and falling in 2.13–23.1 μg/kg-dry. The short chain NPEOn dominant in NPEO mixtures in these sedimentary cores indicated that this lake received some effluents from STPs, and the sewage treatment ratio is relatively low in this area. Furthermore, the computed magnitudes of NPEO 1-2/NPEO1-15, NP/NPEO 1-15 and NPEC 1-10/NPEO 1-15 suggested that the non-oxidative hydrolytic transformation seemed to be a major process occurring within the sediment phase of Nansi Lake, while the oxidative hydrolytic transformation pathway was probably less involved.

scholarly journals Multiple incursion pathways for Helicoverpa armigera in Brazil show its genetic diversity spreading in a connected world

2019 ◽  
Author(s):  
Jonas A. Arnemann ◽  
Stephen H. Roxburgh ◽  
Tom Walsh ◽  
Jerson V.C. Guedes ◽  
Karl H.J. Gordon ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gene Flow ◽  
South America ◽  
New World ◽  
Flow Patterns ◽  
South American ◽  
Southern Brazil ◽  
American Continent ◽  
Central Brazil ◽  
South American Continent

AbstractThe Old World cotton bollworm Helicoverpa armigera was first detected in Brazil with subsequent reports from Paraguay, Argentina, Bolivia, and Uruguay. This pattern suggests that the H. armigera spread across the South American continent following incursions into northern/central Brazil, however, this hypothesis has not been tested. Here we compare northern and central Brazilian H. armigera mtDNA COI haplotypes with those from southern Brazil, Uruguay, Argentina, and Paraguay. We infer spatial genetic and gene flow patterns of this dispersive pest in the agricultural landscape of South America. We show that the spatial distribution of H. armigera mtDNA haplotypes and its inferred gene flow patterns in the southwestern region of South America exhibited signatures inconsistent with a single incursion hypothesis. Simulations on spatial distribution patterns show that the detection of rare and/or the absence of dominant mtDNA haplotypes in southern H. armigera populations are inconsistent with genetic signatures observed in northern and central Brazil. Incursions of H. armigera into the New World are therefore likely to have involved independent events in northern/central Brazil, and southern Brazil/Uruguay-Argentina-Paraguay. This study demonstrates the significant biosecurity challenges facing the South American continent, and highlights alternate pathways for introductions of alien species into the New World.

scholarly journals Wątrobowce (Hepaticae) Beskidu Żywiecko-Orawskiego (Karpaty Zachodnie) [Liverworts (Hepaticae) of the Beskid Żywiecko-Orawski Range (Polish Western Carpathians)]

2014 ◽  
Vol 79 ◽  
pp. 1-144 ◽  
Author(s):  
Henryk Klama
Keyword(s):  
Endangered Species ◽  
Habitat Preferences ◽  
Horizontal Distribution ◽  
Western Carpathians ◽  
Vulnerable Species ◽  
Floristic Analysis ◽  
Vertical And Horizontal Distribution

The study area comprises two mountain groups – Wielka Racza and Pilsko – situated in western part of the Beskid Żywiecko-Orawski Range in Polish Western Carpathians. The flora of this area includes 111 species of liverworts and 2 species of hornworts. 81 species of liverworts and 2 species of hornworts were found in the area of the Wielka Racza group, 108 species of liverworts and 2 species of hornworts – in the area of the Pilsko group. The species new for the Polish part of the Beskid Żywiecki Range were found (27), as well as for the whole Range including the Slovakian part (22) and for the Western Beskids (2). Moreover, 20 species rare in the Western Beskids as well as 11 species rare in the whole area of the Western Carpathians were recorded. 6 species regarded as threatened in the Polish flora occur in the study area. Four of them belong to the category of endangered species (E):<em> Fossombronia wondraczekii, Frullania tamarisci, Porella baueri</em> and <em>P. platyphylla</em>, the remaining two belong to the category of vulnerable species (V): <em>Geocalyx graveolens</em> and <em>Metzgeria conjugata</em>. A particular attention should be payed to the species threatened on European scale: <em>Lophozia ascendens</em> (R category), <em>Porella baueri</em> (T) and <em>Scapania parvifolia</em> (T). The floristic analysis of habitats covered by liverworts as well as habitat groups of liverworts and habitat preferences of particular species arę presented in the paper. The phytogeographic characteristics of the flora is also given, including vertical and horizontal distribution of liverworts in the study area.

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