Does biomass production depend on plant community diversity?

In order to ensure the sustainability of agroecosystems, biodiversity must be a priority. Agroforestry, which includes trees, is an example of such diverse systems. We evaluated plant diversity and aboveground biomass production to assess whether areas under fallow following traditional cultivation return to their initial condition. Also, plant diversity and aboveground biomass production were assessed in agroforestry systems (AFS) to determine if these were similar to unmanaged ecosystems. Another objective of the study was to observe the influence of plant diversity on aboveground biomass production in plant communities and also in the population of the dominant species, Cordia oncocalyx. Plant diversity was evaluated by assessing species richness, as well as using Shannon’s (H0) and Pielou’s (J0) indices. Aboveground plant biomass was evaluated in two AFS: agrosilvopastoral (ASP) and silvopastoral (SP), and also in a traditionally managed agricultural system (AG), areas that had been under fallow for six years (F6) and nine years (F9) and an area of unmanaged caatinga (CAT) vegetation. We observed that the ASP system had a lower diversity and number of species, especially tree species. However, it sustained the same total biomass production as CAT and fallow areas. The SP system, despite having lower H0 and J0 indices as well as lower total biomass production, had a similar number of species to CAT and cropped and fallow systems AG, F6 and F9. Plant biomass in F6 and F9 had recovered to productivity levels of unmanaged CAT vegetation; however the diversity indices were not restored to the same level. Plant diversity did not have an effect on the productivity of the agroecosystems. Likewise, annual biomass production by C. oncocalyx is not dependent upon diversity, but it is influenced by the growth stage of individuals

Density and distribution of Xylocopa nests (Hymenoptera: Apidae) in Caatinga areas in the surroundings of Passion fruit crops.

Due to their importance as pollinators of many plant species, this study aimed to know the nest density, spatial distribution, and nesting substrates used by Xylocopa species in the Caatinga, a xerophilous vegetation f Northeastern Brazil. Three areas of Caatinga in the surroundings of passion fruit crops were sampled. The bee species found in these areas were Xylocopa grisescens Lepeletier and Xylocopa frontalis (Olivier). All nests were in Commiphora leptophloeos (Burseraceae) trees (n=113). Phytosociological analysis showed that this tree species presented the highest absolute density (212.5 individuals/ha) and index of importance value (52.7). The distribution pattern of the C. leptophloeos was aggregated. The nests were located in dead and dried branches with an average diameter of 5.3±2.0 cm (n=43). The mean number of nests/tree was 3.1± 2.8 (n=113). The less disturbed area showed 6.7 nests/ha and 4.2 nests/tree. In the disturbed areas, 0.9 nests/ha and 2.4 to 2.7 nests/tree were observed. The availability of substrate for nesting in the studied areas and its importance as a limiting factor for nesting are discusse

Um exemplo de aplicação da carta de zoneamento edafoclimático para o Estado do Paraná para plantios florestais: P. tecunumanii.

A escolha de área para plantios florestais, comerciais ou experimentais é fundamental para o sucesso dos plantios. A carta de unidades geoclimáticas do Estado do Paraná foi composta com base em análise estatística de dados climáticos e na geomorfologia do estado. Associado a esta carta foi elaborada uma ?tabela de pertinência? onde as tipologias estão divididas, de forma hierárquica, com as devidas caracterizações climáticas. A partir dela foi composto o zoneamento edafoclimático, com base no mapa de solos do estado, e nele foram elencados critérios de solos que são especificamente favoráveis ao plantio de espécies florestais. De acordo com estes critérios, os solos foram agrupados e assim foi composto o mapa de solos. Cada uma das 22 zonas geoclimáticas foi cruzada, em ambiente SGI, com o mapa de solos, formando 22 cartas edafoclimáticas resultantes. A partir desta carta pode-se alocar todos os plantios de espécies florestais, desde que se conheçam suas preferências edafoclimáticas. Para o P. tecunimanii foram definidas seis áreas preferenciais, três intermediárias, recomendadas para experimentação, e o restante são áreas restritas ao plantio, ou seja, inadequadas ao plantio

Parâmetros leucocitários de caprinos da raça Moxotó criados no semi-árido cearense.

A influência de algumas variáveis ambientais sobre a fisiologia animal podem ocasionar evidentes oscilações nos elementos constituintes do hemograma em especial do leucograma. Diante da importância das raças caprinas nativas criadas na região Nordeste, objetivou-se com esse estudo conhecer os valores do leucograma de caprinos da raça Moxotó criados no semi-árido cearense, visando determinar os parâmetros específicos para a raça, durante os períodos seco e chuvoso. Foram avaliados 15 animais, sendo cinco machos e dez fêmeas. As colheitas de sangue, num total de 60 amostras, foram realizadas no período da manhã, nos meses de abril e setembro, durante dois anos. Foi possível observar que os valores médios obtidos neste estudo encontram-se dentro da faixa de normalidade citada na literatura, exceto para os valores de bastões, segmentados do machos no período chuvoso e eosinófilos das fêmeas no período seco e chuvoso, que estão acima dos valores considerados normais. Foi observada diferença estatística significativa entre os machos e fêmeas no período seco quanto aos valores de leucócitos totais e segmentados. Observou-se também diferença estatística significativa entre os períodos seco e chuvoso quanto aos valores absolutos de monócitos. Apesar deste estudo, ainda é necessária a realização de maispesquisas com um número maior de animais para a determinação dos parâmetros normais

Anticipating economic market crises using measures of collective panic

Sem informaçãoPredicting panic is of critical importance in many areas of human and animal behavior, notably in the context of economics. The recent financial crisis is a case in point. Panic may be due to a specific external threat or self-generated nervousness. Here we show that the recent economic crisis and earlier large single-day panics were preceded by extended periods of high levels of market mimicry-direct evidence of uncertainty and nervousness, and of the comparatively weak influence of external news. High levels of mimicry can be a quite general indicator of the potential for self-organized crises.Predicting panic is of critical importance in many areas of human and animal behavior, notably in the context of economics. The recent financial crisis is a case in point. Panic may be due to a specific external threat or self-generated nervousness. Here we show that the recent economic crisis and earlier large single-day panics were preceded by extended periods of high levels of market mimicry-direct evidence of uncertainty and nervousness, and of the comparatively weak influence of external news. High levels of mimicry can be a quite general indicator of the potential for self-organized crises.107127Sem informaçãoSem informaçãoSem informaçã

OSIRIS Software: The Mask Designer Tool

OSIRIS is a Day One instrument that will be available at the 10m GTC telescope which is being built at La Palma observatory in the Canary Islands. This optical instrument is designed to obtain wide-field narrow-band images using tunable filters and to do low-resolution spectroscopy in both long-slit and multislit modes. For the multislit spectroscopy mode, we have developed a software to assist the observers to design focal plane masks. In this paper we describe the characteristics of this Mask Designer tool. We discuss the main design concepts, the functionality and particular features of the software.Comment: 6 figures; accepted for publication in Experimental Astronom

Influência dos períodos, seco e chuvoso, sobre os parâmetros clínicos em caprinos das raças Canindé e Moxotó.

Os caprinos têm um sistema de termorregulação que visa manter a temperatura corporal constante dentro de certos limites, independente da temperatura ambiente. Quando esses limites são estabelecidos, eles são usados em diversos mecanismos fisiológicos para manter a temperatura corporal (TC) dentro dos limites normais. Assim, a produção animal pode diminuir devido ao estresse térmico causado por temperaturas elevadas, especialmente em áreas semi-áridas como o Nordeste do Brasil. Este trabalho teve como objetivo avaliar o comportamento fisiológico de diferentes grupos genéticos de caprinos nativos de acordo com a resposta fisiológica das varáveis temperatura retal (TR), frequência respiratória (FR), batimentos cardíacos (BC) e movimentos ruminais (MR), e estabelecer os parâmetros fisiológicos para estas raças sob as condições do semiárido do Nordeste do Brasil. Foram selecionados aleatoriamente 30 animais, sendo cinco machos e dez fêmeas da raça Canindé e cinco machos e dez fêmeas da raça Moxotó, dos quais foram aferidos as variáveis BC, FR e TR nos meses de abril e setembro/2007 e 2008. Observou-se influência significativa (P<0,05) do período do ano no BC, na FR e na TR na raça Canindé, sendo observados valores mais elevados de BC e TR no período chuvoso. Na raça Moxotó observou-se uma diferença significativa (P<0,05) quanto ao BC e TR entre os períodos estudados, sendo observadas na estação seca maiores valores para estas variáveis. Também se observou nesta raça, uma correlação negativa (47%) entre a temperatura ambiente (TA) e TR no período seco, enquanto que no período chuvoso, essa correlação foi positiva (28%). A correlação entre TA e BC foi negativa (21%) no período chuvoso e, positiva (25%) no período seco. Na raça Canindé observou-se correlação negativa (39%) entre TA e movimento ruminal (MR) na época chuvosa, enquanto que no período seco, essa correlação foi positiva (33%). Os parâmetros clínicos avaliados neste estudo encontram-se dentro da normalidade para a espécie caprina no semi-árido nordestino e a raça Moxotó apresentou comportamento condizente com uma maior tolerância ao clima da região e um maior grau de adaptabilidade. Influence of the dry and rainy periods on clinical parameters in Canindé and Moxotó goat. Goats have a thermoregulatory system which maintains a constant body temperature within certain limits regardless the room temperature. When these limits are established, they are used in various physiological mechanisms maintaining body temperature within normal limits. Thus the animal production may fall due to thermal stress caused by high temperatures, especially in tropical areas like Northeast of Brazil. This work aimed to evaluate the physiological behavior from different goats genetic groups through physiological answers of rectal temperature (RT), respiratory frequency (RF), heart beat (HB) and ruminal movements (RM) and also to establish the physiological values for these breeds under semi arid conditions from Northeast of Brazil. It was randomly selected 30 animals, five males and ten females Canindé and five males and ten females Moxotó breed. It was obtained the HB, RF and RT in April and September/2007 and 2008. It was observed a significant influence (P<0.05) of the period of the year on HB, RF and RT in Canindé breed, being observed higher values of HB and RT in the rainy period. In Moxotó it was observed a significant difference (P <0.05) in HB and RT between the periods studied, being observed in the dry season the highest HB and RT. The correlation between air temperature (AT) and RT was negative (47%) in the dry period to Moxotó, whereas in the rainy season the correlation was positive (28%). Also the correlation between AT and HB was negative (21%) in the rainy period and positive (25%) in the dry season. In Canindé breed it was observed negative correlation (39%) between AT and RM in the rainy season, while in the dry period this correlation was positive (33%). According to this study the clinical parameters are within the normal range for the goat specie in the Northeast semi-arid and the Moxotó breed showed a pattern consistent with better tolerance to the regional climate and a higher degree of adaptability

Soil quality, resistance and resilience in traditional agricultural and agroforestry ecosystems in Brazil's semiarid region.

Agroforestry represents an alternative to traditional agricultural systems in semiarid regions, since it effectively provides soil coverage and improves the amount and quality of soil organic matter. The sustainability of agricultural systems can be assessed by evaluating soil quality, resistance and resilience. Therefore, this work evaluated soil quality, resistance and resilience under traditional cropping and agroforestry systems. The study took place at an experimental station in Brazil’s semiarid northeast region. Studied land use systems include agrosilvopastoral, silvopastoral and traditional cropping, as well as areas under traditional fallow for six and nine years and unaltered ecosystem. Small trenches were dug randomly to collect soil from three depth increments. Soil Quality (SQ) was assessed using chemical, physical and biological indicators. Based on these indicators, resistance, resilience and soil quality indices were calculated. The index quality of the soil was generated using soil water retention, nutrient supply and biological activity promotion functions. Comparisons of index means indicate that agroforests maintained SQ, while traditional fallow systems resulted in improved SQ up to levels similar to the unaltered ecosystem. Traditional cropping lead to a reduction in SQ, resistance and resilience. Agroforestry systems are sustainable. Fallow can improve soil quality, soil resistance and resilience