The Challenge Of Including Chemodiversity, And The Potential Economic Use Of New Natural Compounds And Processes, In The Biota/fapesp Program

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Aspects of arbuscular mycorrhizal fungi in an atlantic forest chronosequence parque estadual turístico do Alto Ribeira (petar), SP

Mycorrhizal colonization was assessed in roots of trees within an Atlantic Forest chronosequence, located in the southeastern of São Paulo State, Brazil, inside Tourist State Park of the High Ribeira Valley (PETAR). The phytosociological survey was carried out in three adjacent areas, all on calcareous soil, which correspond to different time intervals during which they have been left abandoned following a slash-and-burn agricultural perturbation. Early Phase (EP) with 15 years; Mid Phase (MP) with 25 years; and Late Phase (LP) with more than 36 years without clear-cut. The inventory indicated a continuum of tree species substitution, which is dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. (Mimosoideae) in the earlier successional phases. Mycorrhizal colonization, estimated by the occurrence of the mycorrhizal structures in the tree species roots, diminished during the season with less rain (winter), and showed no significant differences between successional phases in the wet season (summer). Rather, the mycorrhizal colonization was correlated with occurrence of the tree’s successional status: being positively correlated with occurrence of pioneer species, and negatively correlated with late secondary species. Mycorrhizal colonization was also correlated negatively with soil organic matter and base saturation. Twenty five species of arbuscular mycorrhizal fungi belonging to four genera were identified. Six species were only identified to generic level. The species Glomus etunicatum Becker & Gerd. represented 10% of the total number of spores and occurred in all phases and seasons, while the genus Glomus represented 57% of the total of spores found in the rhizosphere. The diversity indices evaluated for the mycohrriza community were: H’ = 2.3, J’ = 0.97 and R = 4.12. These results are a contribution to the knowledge of The Atlantic Forest biodiversity and may have implications to support programs regarding rehabilitation of degraded vegetation in one of the World’s most threatened Biomes.Foi levantada a ocorrência de colonização por micorriza nas raízes das espécies arbóreas que dirigem a sucessão secundária sobre solo calcário em uma área localizada no Parque Estadual Turístico do Alto Ribeira (PETAR), sudeste do Estado de São Paulo, Brasil. O levantamento fitossociológico foi realizado em três áreas justapostas correspondentes a diferentes idades de abandono após cultivo de subsistência sobre um solo calcário: Fase Inicial com 15 anos; Fase Intermediaria com 25 anos e Fase Tardia com mais de 36 anos sem corte raso. O inventário indicou a predominância de espécies da família das leguminosas, especialmente Piptadenia gonoacantha (Mimosoideae) nos estágios iniciais de sucessão. A ocorrência de colonização por micorriza nas raízes das espécies arbóreas decresceu ao longo da sucessão durante a estação com menos chuva (inverno). Durante o período de verão, estação mais úmida, a colonização não apresentou diferenças significativas entre as fases de sucessão. A colonização por micorriza nas raízes apresentou correlação com a ocorrência de diferentes estratégias de regeneração entre as espécies arbóreas: positivamente com o aumento de ocorrência de espécies pioneiras e negativamente com espécies secundárias tardias. A colonização apresentou também correlação negativa com o conteúdo de matéria orgânica e saturação de bases no solo. Foram identificadas 25 espécies de fungos micorrizicos arbusculares pertencentes a quatro gêneros, e seis espécies apenas foram identificadas ao nível de gênero. A espécie Glomus etunicatum Becker & Gerd. representou 10 % dos esporos encontrados na rizosfera das amostras analisadas, tendo ocorrido em todas as fases sucessionais e estações. O gênero Glomus representou 57% do total de esporos. Os índices de diversidade para a comunidade de fungos micorrizicos indicaram os seguintes valores: H’ = 2.3, J’ = 0.97 e R = 4.12. Estes resultados são importantes contribuições para um melhor conhecimento da biodiversidade da Mata Atlântica e podem ser decisivos no sucesso de ações para a reabilitação de áreas degradadas neste que é um dos biomas mais ameaçados do planeta.11

Seed germination and growth of Calophyllum brasiliense (Clusiaceae), a typical species of flooded forests

Soil waterlogging and the subsequent reduction in the amount of oxygen available for the respiration of the root system selected, along the evolutive process, plants able to thrive in seasonally or permanently flooded areas. In neotropical plants there are many types of adaptations to flooding. In this paper we present the results of the work carried out with seeds and seedlings of C brasiliense subjected to hypoxia during germination and early development. C brasiliense seeds are not photoblastic and survive up to three months burried in a water saturated substrate, but germination only takes place in well-drained soils. Soil waterlogging does not inhibit seedling growth and there are no apparent morphological changes of the aerial part of flooded plants. New and aerated roots that make plant survival possible replace old and spoiled roots. In contrast to many typical species of flood-prone areas where growth is inhibited by oxygen stress. C. brasiliense seedlings seem to be well adapted to their waterlogged environment. Seed dispersion, the absence of photoblastic response as well as seed and seedling capacity of surviving and growing in waterlogged soils contribute to the wide geographic distribution of C. brasiliense always associated with areas subjected to soil waterlogging.A saturação hídrica do solo e a conseqüente diminuição na quantidade de oxigênio disponível para o sistema radicular selecionaram, ao longo do processo evolutivo, plantas capazes de sobreviverem à inundação sazonal ou permanente. Nas espécies neotropicais as adaptações que permitem suportar este estresse são bastante diversificadas. Neste trabalho foram estudados a germinação das sementes e o crescimento inicial das plantas de Calophyllum brasiliense, em condições de hipoxia. As sementes de C brasiliense não são fotoblásticas, sobrevivem ao menos três meses submersas, mas germinam apenas em solo bem drenado. A inundação não inibe o crescimento da planta. Não houve mudanças morfológicas na parte aérea das plantas, mas a substituição das raízes formadas no período pré-inundação por um sistema radicular eficiente talvez seja o principal motivo que permita o crescimento normal das plantas em áreas inundadas. Ao contrário de algumas espécies de locais sujeitos ao alagamento, cujas plantas têm o crescimento inibido pelo estresse, o ciclo de vida de C brasiliense está adaptado à inundação temporária ou permanente. A diversificação da forma de dispersão, a indiferença em relação à luz e a capacidade de sobreviver e crescer em solo inundado são características que contribuem para a ampla distribuição geográfica da espécie, sempre associada a áreas alagáveis.113120Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Experiences from the Brazilian Atlantic Forest:\ud ecological findings and conservation initiatives

The Brazilian Atlantic Forest hosts one of the world’s most diverse and threatened tropical forest\ud biota. In many ways, its history of degradation describes the fate experienced by tropical forests\ud around the world. After five centuries of human expansion, most Atlantic Forest landscapes are\ud archipelagos of small forest fragments surrounded by open-habitat matrices. This ‘natural\ud laboratory’ has contributed to a better understanding of the evolutionary history and ecology of\ud tropical forests and to determining the extent to which this irreplaceable biota is susceptible to\ud major human disturbances.We share some of the major findings with respect to the responses of\ud tropical forests to human disturbances across multiple biological levels and spatial scales and\ud discuss some of the conservation initiatives adopted in the past decade. First, we provide a short\ud description of the Atlantic Forest biota and its historical degradation. Secondly, we offer\ud conceptual models describing major shifts experienced by tree assemblages at local scales and\ud discuss landscape ecological processes that can help to maintain this biota at larger scales. We\ud also examine potential plant responses to climate change. Finally, we propose a research agenda\ud to improve the conservation value of human-modified landscapes and safeguard the biological\ud heritage of tropical forests.C.A.J. was supported by grants from the BIOTA/FAPESP Program (FAPESP 03/12595-7, 10/50811-7, 12/51872-5) and CNPq (403710/2012-0). J.P.M. (307934/2011-0) and M.T. (304598/2011-9) thank the Brazilian Science Council (Conselho Nacional de Desenvolvimento Cientıfico) for their research fellowships. We thank Leandro Reverberi Tambosi for providing Fig. 1, and the three ad hoc reviewers for their constructive critical evaluation of the manuscript which resulted in a much improved final version

Soil and floristic composition of native vegetation remnants relationship in the municipality of Ribeirão Preto, SP

Aiming to establish the relationship between soil characteristcs and floristic composition, 95 fragments of natural vegetation were visited, and their floristic composition was determined by the expedite survey method. A total of 509 tree species belonging to 71 botanic families were found. A detrended correspondence analysis (DCA) and a cluster analysis using relative Sørensen distance showed three floristic groups associated with particular soil types. A multi-response permutation procedure (MRPP) indicated the groups consistence. A main group associated with the basalt derived soils, Purple Latosol and Lytholic soil, could be slipt into two subgroups according to the rock desintegration degree: mesophilous and decidous forest, respectively. The other two groups were linked to the Dark Red and Yellow Red Latosol, the cerradão, and to the Hydromorfic Soil, the swamp forest. Each group presented a characteristic floristic composition. Considering the most abundant tree species, meanly 65% of them showed differential occurrence in the different soil types. A high proportion of species ocurred in few fragments, and each forest remnant presented somewhat regionally rare species. The observed association between soil and remnants floristic composition could contribute to the establishment of criterion for fragment conservation as well as in determining the proper species to choose in vegetation recomposition projects.Visando o estabelecimento da relação entre as características do solo e a composição florística, foi efetuado levantamento florístico em 95 fragmentos de vegetação natural em Ribeirão Preto. Foram registradas 509 espécies arbóreas pertencentes a 71 famílias botânicas. Uma análise de correspondência retificada (DCA) e uma análise de agrupamentos utilizando a distância relativa de Sørensen indicaram a existência de três grupos florísticos, associados aos tipos de solos. A aplicação de um procedimento de permutação (MRPP) indicou que os grupos são consistentes. Um grupo maior associado aos solos derivados do basalto, Latossolo Roxo e Litossolo, pôde ser subdividido em dois subgrupos de acordo com o grau de decomposição da rocha, identificados como mata mesófila e mata decídua, respectivamente. Outros dois grupos foram identificados, um associado ao Latossolo Vermelho Escuro e Vermelho Amarelo, cerradão, e outro ao solo Hidromórfico, mata paludícola. Cada grupo apresentou uma composição florística característica. Considerando as espécies arbóreas mais comuns, cerca de 65% tendem a ocorrer de forma diferenciada entre os tipos de solos. Elevada proporção das espécies ocorreu em pequeno número de fragmentos, e cada remanescente apresentou alguma espécie considerada regionalmente rara. A associação observada entre o solo e a composição florística dos remanescentes poderá contribuir para o estabelecimento de critérios para conservação dos fragmentos de vegetação, bem como na indicação das espécies apropriadas para plantio nos projetos de recomposição da vegetação em diferentes regiões da cidade.541562Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Trabalho de casa, auto–eficácia e rendimento em Matemática

O Trabalho de Casa (TPC) é uma estratégia instrutiva amplamente utilizada na Escola de muitos países. O TPC é um processo complexo que é afectado por múltiplos factores de ordem cognitiva, motivacional, social e contextual. A investigação tem-se centrado no tempo despendido na realização das tarefas de TPC, no entanto os resultados de vários estudos e as críticas metodológicas sugerem a necessidade de direccionar a pesquisa para outras variáveis. O objectivo deste estudo é a análise do poder preditivo da auto-eficácia percebida na Matemática e de três dimensões menos exploradas na literatura do TPC (e.g., número de TPC prescritos, taxa de completamento, e correcção percebida do TPC) sobre o rendimento a matemática, em alunos portugueses do 5.º e 6.º ano de escolaridade (10 e 11 anos). Os resultados sugerem que o rendimento a matemática se encontra explicado, positiva e significativamente, pelas variáveis escolhidas. As conclusões sugerem a urgência de repensar o TPC como ferramenta educativa promotora do sucesso académico.Homework is a well known teaching strategy in schools all over the world. Considered as a very complex process, homework is said to be affected by numerous factors, being these cognitive, motivational, social or even contextual. Several studies have privileged time spent on homework has main variable, however homework research findings and new approach perspectives suggest the need to study other important and impacting variables. The goal of the present study is analyzing Math perceived self-efficacy and three other dimensions rarely approached in homework literature (e.g. number of Math homework assignments, completion rate and perceived correction of homework assigned) as predictors of middle school students’ (aged 10-11) Math achievement. Data suggest that Math achievement is positive and significantly explained by the chosen variables. Findings stress the importance of rethinking homework as a renewed instructional tool designed to achieve success

Test Anxiety: Associations with personal and family variables

La ansiedad ante los exámenes es un comportamiento muy frecuente, sobre todo entre la población escolar que afronta una presión social muy centrada en la obtención de un gran éxito académico. Pocos estudios han analizado las relaciones entre la ansiedad ante los exámenes, la postergación académica (academic procrastination), variables personales y familiares y las notas en matemáticas. En este trabajo se analiza el impacto de variables sociopersonales tales como el nivel de estudios de la madre y del padre, el número de hermanos y el número de cursos suspensos utilizando ANOVAS en dos muestras independientes de 533 y 796 sujetos de los 3 primeros cursos de la Educación Secundaria Obligatoria. Los datos, similares en los dos estudios, revelan que la ansiedad ante los exámenes es superior en las chicas y disminuye con el aumento del nivel de estudios de la madre y del padre, del número de cursos suspensos y de las notas en matemáticas. La ansiedad ante los exámenes y la conducta de postergación se correlacionan positiva y significativamente. Los resultados son discutidos en función de los hallazgos de las investigaciones previas. Se analizan las implicaciones para la práctica educativa.Test anxiety is a common behavior among students facing social pressure centered on mastery. Only a few studies have analyzed the relations between test anxiety, academic procrastination, personal and family variables and math grades. This work focus on the analysis of the impact of students’ social-personal variables such as parents’ education level, number of siblings and under-achievement by performing ANOVAs in two samples of 533 and 796 students from junior high-school. Corroborating the findings in other studies, the data stress that test anxiety is higher in girls and decreases when students’ parents have higher educational levels, with the number of courses flunked, and when students’ math grades were lower. Test anxiety and procrastination correlate positive and significantly. Findings are discussed and compared with those of previous researches. The implications for teaching practice are also analyzed

Trait interactions effects on tropical tree demography depend on the environmental context

Although functional traits are defined based on their impact on demographic parameters, trait-demography relationships are often reported as weak. These weak relationships might be due to disregarding trait interactions and environmental contexts, which should modulate species trait-demography relationships. We applied different models, including boosted regression tree (BRT) models, to investigate changes in the relationship between traits and demographic rates of tropical tree species in plots along an elevational gradient and among time intervals between censuses, analyzing the effect of a strong drought event. Based on a large dataset of 18,000 tree individuals from 133 common species, distributed among twelve 1-ha plots (habitats) in the Atlantic Forest (Brazil), we evaluated how trait interactions and the environmental context influence the demographic rates (growth, mortality, and recruitment). Functional traits, trait-trait, and trait-habitat interactions predicted demography with a good fit through either BRTs or linear mixed-models. Changes in growth rates were best related to size (diameter), and mortality rates to habitats, while changes in recruitment rates were best related to the specific leaf area. Moreover, the influence of traits differed among time intervals, and for demographic parameters, habitat affected growth and mortality by interacting with diameter. Here, we provide evidence that trait-demography relationships can be improved when considering the environmental context (space and time) and trait interactions to cope with the complexity of changes in the demography of tropical tree communities. Thus, to expand predictions of demography based on functional traits, we show that it is useful to fully incorporate the concept of multiple trait-fitness optima, resulting from trait interactions in different habitats and growth conditions.We thank the Brazilian National Research Council (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for the scholarships conceded to the first author (CNPq 141781/2016-5 and CAPES 88881.189491/2018-01) and for the productivity fellowship to FAMS (CNPq 310168/2018-0). This study was financed by research funding of the projects: “Functional Gradient” (Biota/FAPESP 03/12595-7), “PELD/BIOTA” and “ECOFOR” (Processes 2012/51509-8 and 2012/51872-5, within the BIOTA/FAPESP Program), “EcoSpace” (Edital Universal CNPq 459941/2014-3), “Sustainable Landscapes Brazil” project (US Forest Service, USAID, US Department of State and EMBRAPA), and “Sustainable Landscapes” (NASA-Goddard). This study was also supported by CNPq (PELD CNPq 403710/2012-0), British Natural Environment Research Council/NERC (NE/K016431/1) and FAPESP as part of a doctoral fellowship (FAPESP 11/11604-0). CPC was financed by the Estonian Research Council (PSG293)

Nitrogen input by bamboos in neotropical forest: a new perspective

Background Nitrogen (N) is an important macronutrient that controls the productivity of ecosystems and biological nitrogen fixation (BNF) is a major source of N in terrestrial systems, particularly tropical forests. Bamboo dominates theses forests, but our knowledge regarding the role of bamboo in ecosystem functioning remains in its infancy. We investigated the importance of a native bamboo species to the N cycle of a Neotropical forest. Methods We selected 100 sample units (100 m2 each) in a pristine montane Atlantic Forest, in Brazil. We counted all the clumps and live culms of Merostachys neesii bamboo and calculated the specific and total leaf area, as well as litter production and respective N content. Potential N input was estimated based on available data on BNF rates for the same bamboo species, whose N input was then contextualized using information on N cycling components in the study area. Results With 4,000 live culms ha−1, the native bamboo may contribute up to 11.7 kg N ha−1 during summer (January to March) and 19.6 kg N ha−1 in winter (July to September). When extrapolated for annual values, M. neesii could contribute more than 60 kg N ha−1y−1. Discussion The bamboo species’ contribution to N input may be due to its abundance (habitat availability for microbial colonization) and the composition of the free-living N fixer community on its leaves (demonstrated in previous studies). Although some N is lost during decomposition, this input could mitigate the N deficit in the Atlantic Forest studied by at least 27%. Our findings suggest that M. neesii closely regulates N input and may better explain the high diversity and carbon stocks in the area. This is the first time that a study has investigated BNF using free-living N fixers on the phyllosphere of bamboo