Litterfall in primary and secondary forests (‘capoeira’) in eastern Brazilian Amazonia was measured fortnightly from August 1979 to October 1980. The nutrient contents of the litter (N, P, K, Ca and Mg) were determined.Litterfall differed between the two forest types (primary forest − 8.04 t ha−1 yr−1; secondary forest − 5.04 t ha−1 yr−1). The value obtained for primary forest was similar to those reported elsewhere in Brazil (mean = 8 t ha−1 yr−1) and from other regions of S. America (mean = 7.20 t ha−1 yr−1).Prediction of net primary production from litterfall at the primary forest site gave rise to values of 14.47 and 26.53 t ha−1 yr−1. Estimates of net primary production in ‘capoeira’ ranged from 9.07 to 16.63 t ha−1 yr−1.Seasonality of litterfall was more marked in ‘capoeira’ than primary forest but in both cases was less pronounced than elsewhere in Brazil.Nutrient concentrations were highest in ‘capoeira’ litter, a finding which accords with results from other tropical sites; nevertheless input of nutrients per unit area of forest floor was greatest in the primary forest.

RESUMO Foram estudados os micro-artrópodos do solo, bem como a cobertura vegetal, fauna de cobertura, respiração edáfica, além de fatores físico-químicos do solo e climáticos, em pastagens artificiais de terra firme próximo a Manaus. De janeiro a dezembro de 1977 foram realizadas 21 amostragens, perfazendo 1304 unidades com 12,56 cm2de área e até 5 cm de profundidade. A fauna foi extraída pelo método Berlese-Tullgren, modificado. Acari o Collembola foram os grupos dominantes do solo em todos os ambientes. Foram encontrados até 22 grupos de artrópodes na pastagem e 26 grupos na floresta. Na pastagem, as densidades de Acari variam de 32.000 a 73.000/m2e de Collembola de 4.000 a 35.000/m2, Na floresta, urna única estimativa deu como resultado 49.000/m2para Acari e 12.000/m2para Collembola. A pastagem extensiva e o sistema rotacional não apresentaram diferenças na fauna do solo. Diferenças foram encontradas entre pastagens formadas por diversas gramíneas e com diferentes idades, e também entre pastagem e floresta primária, principalmente com relação ao número de grupos encontrados. As populações de artrópodes encontram-se agregadas e as de Acari e Collembola em particular são descritas satisfatoriamente pelo distribuição binomial negativa. A respiração edáfica sob Setaria sp. apresentou-se com média de 455,7 (dia) e 448,1 (noite) mg/CO2/m2/h e sob diversas espécies de Solanaceae de 507,0 (dia) e 483,6 (noite) mg/CO2/m2/h.

Resumo Este trabalho trata da correlação entre os fatores temperatura do ar, umidade relativa, umidade do solo e precipitação e os índices de agregação (K da binomial negativa) de população de Acari e Collembola sob Setaria sp. em pastagem rotacional e extensiva. Os artrópodes foram extraídos do solo usando-se funis de Berlese — Tullgren modificado e as coletas foram feitas de janeiro a dezembro de 1977. Verificou-se que cs índices de agregação indicam uma menor agregação em Acari que em Collembola e que as correlações com os fatores físicos estudados não explicam totalmente o comportamento dos animais. Observou-se uma maior influência dos fatores estudados sobre as populações de Acari. A variável que mais influência exerce é a precipitação.

-The Plant Breeding Brazilian Association (SBMP, in Portuguese) and the Center for Strategic Studies and Management in Science, Technology and Innovation (CGEE, in Portuguese) The third chapter of the book Competences in genetic plant breeding in Brazil (Ramalho et al. 2010), presents the results of the assessment on the current status of the competences in the area of plant breeding in Brazil during the last two years. This work was conducted via electronic consultation to the list of SBMP associated members, the participants of the Plant Breeding Brazilian Meetings and to other unlisted breeders. The dissemination of the results of this survey aims to make available the names of the current plant breeders to the scientific community in Brazil, as well as their academic qualification, research area, species/products studied, and other relevant information. The data of this assessment are presented so as not to repeat information on the academic qualification of plant breeders in Brazil and their private enterprise profile, topics that will be addressed by other speakers of this panel.Of 3,299 scientists consulted, 689 who replied to the questionnaire, worked for 178 private and public institutions. Most of the professionals who did not reply worked for private institutions.The 178 institutions cited were classified by the participants as: Governmental, Other Governmental Institution, Enterprise, or Public Research Institution, Public Institution of Higher Education, Private Institution of Higher Education, Association, Co-operative, Private Enterprise, and Non-Governmental Organization. The majority (86.6 %) of the professionals were involved with plant breeding programs at public institutions. The highest concentration of professionals was found in Public Research Institutions (39.4 %) and Universities (44.6 %).An even distribution was found in the academic qualification (undergraduate, Master's and Doctorate levels) of the responding participants and, as expected, there is a predominance of agronomists (74.1 %) with a graduate degree (49.3 % with a Master's, and 44.3 % with a doctorate) in plant breeding.With respect to the nature of the activity (research, teaching, rural extension and consultancy), the highest plant breeding production is found to be concentrated in research and teaching. Two hundred and fourteen professionals, corresponding to 31 % of all the participants, are exclusively involved in research.The largest number of respondents declared to be involved on the following areas: Plant breeding programs,