Plant species, biomass and environmental characteristics of relevés along the North America Arctic bioclimate gradient

Question: How do interactions between the physical environment and biotic properties of vegetation influence the formation of small patterned-ground features along the Arctic bioclimate gradient? Location: At 68° to 78°N: six locations along the Dalton Highway in arctic Alaska and three in Canada (Banks Island, Prince Patrick Island and Ellef Ringnes Island). Methods: We analysed floristic and structural vegetation, biomass and abiotic data (soil chemical and physical parameters, the n-factor [a soil thermal index] and spectral information [NDVI, LAI]) on 147 microhabitat releves of zonalpatterned-ground features. Using mapping, table analysis (JUICE) and ordination techniques (NMDS). Results: Table analysis using JUICE and the phi-coefficient to identify diagnostic species revealed clear groups of diagnostic plant taxa in four of the five zonal vegetation complexes. Plant communities and zonal complexes were generally well separated in the NMDS ordination. The Alaska and Canada communities were spatially separated in the ordination because of different glacial histories and location in separate floristic provinces, but there was no single controlling environmental gradient. Vegetation structure, particularly that of bryophytes and total biomass, strongly affected thermal properties of the soils. Patterned-ground complexes with the largest thermal differential between the patterned-ground features and the surrounding vegetation exhibited the clearest patterned-ground morphologies.

The paradisus londinensis : or coloured figures of plants cultivated in the vicinity of the metropolis /

Some copies have text for plates 118-123 although plates were never issued.

Field identification cards /

A set of individual identification cards for rare and sensitive plant species found in the southeastern United States including Puerto Rico. Categories include forbs, shrubs, ferns, and trees. Each card has a color picture on one side and a description and map on the reverse. The description includes: family, flowering date, habitat, and identifying characteristics.

Atividades biológicas de extratos salinos de sementes de plantas da caatinga contra Aedes Aegypti e investigação da participação de proteínas bioativas

Dengue fever, currently the most important arbovirus, is transmitted by the bite of the Aedes aegypti mosquito. Given the absence of a prophylactic vaccine, the disease can only be controlled by combating the vector insect. However, increasing reports of resistance and environmental damage caused by insecticides have led to the urgent search for new safer alternatives. Twenty - um plant s eed extracts from the Caatinga were prepared , tested and characterized . Sodium phosphate ( 50 mM pH 8.0) was used as extractor. All extracts showed larvicidal and ovipositional deterrence activity . Extracts of D. grandiflora, E. contortisiliquum, A. cearenses , C. ferrea and C. retusa were able to attract females for posture when in low co ncentration . In the attractive concentrations, the CE of E. contortisiliquum and A. cearenses were able to kill 52% and 100% of the larvae respectively . The extracts of A. cearenses , P. viridiflora, E. velutina, M. urundeuva and S. brasiliensis were also pupicides, while extracts of P. viridiflora, E. velutina, E. contortisiliquum , A. cearenses, A. colubrina, D. grandiflora , B. cheilantha , S. spectabilis, C. pyramidalis, M. regnelli e G. americana displayed adulticidal activity. All extracts were toxic to C. dubia zooplankton . The EB of E. velutina and E. contortisiliquum did not affect the viability of fibroblasts . In all extracts were identified at least two potential insecticidal proteins such as enzyme inhibitors, lectins and chitin - binding proteins and components of secondary metabolism . Considering all bioassays , the extracts from A. cearenses, P. viridiflora, E. contortisiliquum , S. brasiliensis, E. velutina and M. urundeuva were considered the most promising . The E. contortisiliquum extracts was the only one who did not show pupicida activity, indicating that its mechanism of action larvicide and adulticidal is related only to the ingesti on of toxic compounds by insect , so it was selected to be fragmenting. As observed for the CE , th e protein fractions of E. contortisiliquum also showed larvicidal activity, highlighting that F2 showed higher larvicidal activity and lower en vironmental toxicity than the CE source. The reduction in the proteolytic activity of larvae fed with crude extra ct and fractions of E. contortisiliquum suggest ed that the trypsin inhibitors ( ITEc) would be resp onsible for larvicidal activity . However the increase in the purification of this inhibitor resulted in loss of larvicidal activity , but the absence of trypsin inhibitor reduced the effectiveness of the fractions , indicating that the ITEC contributes to the larvicidal activity of this extract. Not been observed larvicidal activity and adulticide in rich fraction vicilin, nor evidence of the contribution o f this molecule for the larvicidal activity of the extract. The results show the potential of seeds from plant extracts of Caatinga as a source of active molecules against insects A. aegypti at different stages of its development cycle, since they are comp osed of different active compounds, including protein nature, which act on different mechanisms should result in the death of insec

Dinâmica de uma floresta tropical manejada na Amazônia oriental

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Florestal, 2016.

Rubiaceae em um remanescente de floresta atlântica no Rio Grande do Norte, Brasil

Empresa de Pesquisa Agropecuária do Rio Grande do Norte

Caracterização macroscópica de cincos espécies madeireiras de Leguminoseae disponíveis na xiloteca da Embrapa Amazônia Oriental, Belém, PA.

Identificação taxonômica é o meio mais seguro para a comercialização de madeiras, pois o constante estudo sobres as espécies comerciais são essenciais para se evitar enganos nas transações comerciais. O trabalho teve como objetivo caracterizar espécies de madeiras comerciais de leguminoseae. As amostras foram selecionadas na xiloteca da EMBRAPA e descritas macroscopicamente. As espécies selecionadas foram as Alexa grandiflora Ducke, Diplotropis purpurea (Rich.) Amsh, Dipteryx odorata (Aubl.) Willd, Hymenolobium excelsum Ducke, e Parkia pendula (Willd.) Benth. ex Walp. O parênquima mais frequente foi do tipo aliforme losangular; a visibilidade dos parênquimas e dos poros apresentaram-se visíveis a olho nu na maioria; frequência dos poros entre poucos e muito poucos, com exceção da D. odorata que eram numerosos; ocorrência de estratificação dos raios somente nas espécies de H. excelsum e D. odorata. Como são madeiras com um intenso fluxo de comercialização, a descrição macro de seus caracteres taxonômicos podem auxiliar a evitar nomenclatura equivocadas dessas especies de grande representatividade no estado.