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The conservationist community is giving special attention to epigean insects due to their importance in the preservation of terrestrial habitats. This work analysed the diversity, richness, abundance and similarity at the soil surface of Coleoptera composition among five environments: native forest, native grassland, Pinus elliottii plantation, Eucalyptus saligna plantation and degraded area by soil use in southern Brazil, from October 2004 to October 2005. A total of 1,812 individuals were collected, attributed to 45 morph-species and 14 families. The higher richness and abundance were observed in native forest (31 species and 782 individuals) and the lower richness and abundance in degraded area (14 species, 86 individuals). Scarabaeidae was the richest family captured, with nine morph-species, and the most frequent family was Nitidulidae (1,113 individuals). According to the Shannon-Wiener index, the degraded area had smaller diversity in relation to the native forest, E. saligna and Pinus elliottii plantations. No difference in diversity between evaluated areas was found for the Simpson diversity index. The most dominant site was the degraded. The correlation between the total number of morph-species captured was not different to the degraded area and the P. elliottii monoculture (r = 0.47) and the correlation between the total individuals number was not significant between native forest and native grassland (r = 0.46) and between degraded areas and the other sites. According to the Jaccard Similarity Index, the greatest similarity for the organism composition occurred between P. elliottii plantation and E. saligna plantation, presenting 74% of overlap.

This study focuses on the morphometric analysis of seeds of Macrolobium acaciifolium from environments of Amazonian floodplains and igapó, as well as the effect of the substrates of these areas on the germination and seedling formation of the species. A biometric analysis of 200 M. acaciifolium seeds from populations of both Central Amazon environments was performed. In greenhouse, germination of seeds under their soil of origin and under vermiculite was analyzed. The seeds from igapó presented higher mean weight and thickness compared to the floodplain seeds, which, on occasion, presented higher averages of length and width. The seed germination percentage of both environments was similar, but the speed was higher for the igapó seeds, regardless of the substrate. The igapó seeds are larger than the floodplain seeds and, because they have more reserves, they are able to produce more vigorous seedlings, regardless the physical conditions of the substrate. © 2020 Fundacao Zoobotanica do Rio Grande do Sul. All rights reserved.

The distribution of the pejibaye's (Bactris gasipaes)root biomass and absorbtive area was studied in a clay textured, yellow Oxisol, near Manaus, Amazonas, Brazil. Approximately 80% of the biomass was found in the Ap horizon and 90% of this within the crown projection area. Total biomass was estimated at 72 kg, without, however, including the very large mass immediately below the stem. The root surface area increased significantly as distance from the stem increased, due to the increase in the proportion of third and fourth order roots, although its abundance per m3 diminished like that of the biomass. The total root surface area was estimated at 545 m2, of which 50% is probably active in nutrient absorbtion. The observed distribution suggested that there are absorbtive roots at least 8-9 m from the stem. Fertilizer placement should be within and just outside of the crown projection area.", 'en ; A distribuição da biomassa e da área absorvente do sistema radicular da pupunheira (Bactris gasipaes)foram estudadas num latossolo amarelo, textura argilosa, perto de Manaus, Amazonas, Brasil. Aproximadamente 80% da biomassa se encontrava no horizonte Ap, da qual 90% se encontrava dentro da área de projeção da copa. A biomassa total estimada pesou 72 kg, excluindo-se a massa logo abaixo do estipe. A área superficial das raízes aumentou significativamente conforme se afastava do estipe, devido a proporção cada vez maior de raízes terciárias e quartenárias, embora sua abundância por m3 diminuiu de forma similar à biomassa. A área superficial total estimada chegou a 545 m2, da qual se supõe que 50% é ativa na absorção de nutrientes. Supõe-se ainda que existam raízes absorventes até 8-9 m do estipe das plantas. Recomenda-se que a adubação seja feita dentro e logo fora da projeção da copa.

Wood density (WD) is an important variable for estimating tree carbon stocks in terrestrial ecosystems. WD has been little studied in savanna areas in the Brazilian Amazon. The aim of this study was to investigate variation in WD in eight tree species that occur in the open savannas of Roraima, the largest savanna area in the northern Brazilian Amazon. Variations were observed in WD in relation to species and diameter along the vertical dimension of 75 individuals sampled at six study sites. We used the direct method to obtain wood pieces from the stem and crown. The results indicated significant interspecific differences. Roupala montana Aubl. was the species with highest WD (0.674 g cm-3). Significant variation in WD was found between the stem and the woody parts of the crown, irrespective of species or sampling site. The wood density of branchs with diameter between 5 and 10 cm can be used as a predictor of individual WD for the whole tree. We conclude that the WD of the eight tree species investigated has interspecific variability and that there is a discrepancy between the WD of stem and the woody parts of the crown. Distinctions detected here provide an important tool for improving tree carbon estimates in Amazonian savannas. ; Densidade da madeira (DM) é uma variável importante para estimativas de estoques de carbono arbóreo em ecossistemas terrestres. Este tema é pobremente investigado em áreas de savana da Amazônia brasileira. O objetivo deste estudo foi investigar a DM das oito principais espécies arbóreas que ocorrem na savana aberta de Roraima, a maior área de savana do norte do bioma Amazônia. Foram verificadas as variações na DM em função da espécie e dos diferentes diâmetros observados ao longo da dimensão vertical de 75 indivíduos amostrados em seis sítios de coleta. Foi utilizado o método direto para obtenção de peças de madeira do fuste e da copa. Os resultados indicaram discrepância significativa interespecífica, sendo Roupala montana Aubl. a espécie de maior DM média (0,674 g cm-3). Foi ...

The attenuation of solar radiation in a forest medium and its relationship with the spatial distribution of the canopy elements are investigated in this work. A novel sampling technique is used for the radiation measurements inside the tall canopy covers, having a mobile support apparatus, made up of modular reticulates suspended on the top of the large trees, which allows the placement of the radiation sensors on different heights along a vertical line within the canopy. Solar radiation measurements were made at the experimental site of Reserva Jaru (10º05' S; 61º55' W), Ji-Paraná - Brazil, in the period from 30 Oct. to 24 Nov. 1999. Inversion of the solar radiation physical model allowed the establishment of the leaf area density and the average value for the leaf area index (LAI) for the local vegetation was found to be 5.6.", 'en ; A atenuação de radiação solar em meio vegetal e sua relação com a distribuição espacial dos elementos vegetais são estudadas neste trabalho. Técnicas experimentais de amostragem de radiação no interior de coberturas vegetais de grande porte são utilizadas, tendo como base dispositivos de suporte móveis constituídos por reticulados modulares suspensos na parte superior das grandes árvores, que permitem a disposição dos sensores de radiação em diferentes níveis de uma mesma vertical no interior da cobertura. As medidas de radiação solar foram realizadas no sítio experimental da Reserva Florestal Jaru (10º05' S; 61º55' W), Ji-Paraná - Brasil, no período de 30 de outubro a 24 de novembro de 1999. A inversão de modelo físico de radiação permitiu o estabelecimento da função de densidade de área foliar com um valor médio de índice de área foliar IAF de 5,6 para a vegetação do local.

A method by which a physical model of the solar radiation transfer in a vegetal medium is inverted to estimate the leaf area index (LAI) for different types of vegetation is presented here, as an alternative to the destructive experiments, which are a hard task to implement on the vegetation covers. Radiation data were obtained during the dry season - 1996, at the Embrapa Experimental Station, (BR 174 - km 54, 2º 31' S, 60º 01' W), Manaus, Brazil. The method yielded convergent values for the LAI between different adopted radiation classes with more stable estimates at time when there is a predominant diffuse radiation. The application of the inversion algorithm yields the following values for the leaf area index and respective annual foliage increments:3.5 (0.35 yr.-1) for the intact secondary forest; 2.0 (0.5 yr-1) for the palm agroforestry system; and 1.6 (0.4 yr-1) for the multi-layer ones.", 'en ; Um método de inversão de modelo físico de penetração de radiação solar em meio vegetal para estimar o índice de área foliar(IAF) é apresentado e testado neste trabalho para diferentes tipos de vegetação, como uma alternativa aos experimentos destrutivos, trabalhosos e de difícil implementação em coberturas florestais. Os dados de radiação foram obtidos durante o período seco de 1996 na Estação Experimental da Embrapa, (BR 174 - km 54, 2º 31' S, 60º 01' O), Manaus, Brasil. O método produziu valores de IAF convergentes entre as classes de radiação adotadas, com estimativas mais estáveis para ocasiões em que há predomínio de luz difusa. A aplicação do procedimento de inversão deu origem aos seguintes valores de índice de área foliar e respectivos incrementos anuais3,5 (0,35.ano-1) para a vegetação secundária intacta; 2,0 (0,5.ano-1) para o sistema agroflorestal com palmeiras; e 1,6 (0,4.ano-1) para o sistema agroflorestal multiestratificado.

The occurrence of solar radiation in forest medium and its relationship with the spatial distribution of the canopy elements are investigated in this work. Experimental sampling techniques of the radiation measurements inside tall vegetation covers are developed and tested, having as base mobile support apparatus, made of modular reticulates suspended on the top of the large trees, which allows the placement of the radiation sensors at different heights along a vertical profile within the canopy and the replication of the vertical probing at different sites. Solar radiation measurements were made at the experimental site of Reserva Ducke (02º56' S; 59º57' W), Manaus - Brazil, in the period 29 Oct. to 11 Dec. 1998. The inversion of the solar radiation physical model allowed the estimation of the leaf area density for the local vegetation. The calculated values for the leaf area index (LAI) at the three verticals with dominant diffuse radiation conditions were 6.6, 6.3 e 6.2.", 'en ; A ocorrência de radiação solar em meio florestal e a sua relação com a distribuição espacial dos elementos vegetais são investigadas neste trabalho. Técnicas experimentais de amostragem de radiação no interior de coberturas vegetais de grande porte são desenvolvidas e testadas, tendo como base dispositivos de suporte móveis constituídos por reticulados modulares suspensos na parte superior das grandes árvores, que permitem a disposição dos sensores de radiação em diferentes níveis de uma mesma vertical e a replicação das medidas em diferentes verticais no interior da cobertura. As medidas de radiação solar foram realizadas no sítio experimental da Reserva Florestal Ducke (02º56' S; 59º57' W), Manaus - Brasil, no período de 29 de outubro a 11 de dezembro de 1998. A inversão de modelo físico de radiação permitiu o estabelecimento da função de densidade de área foliar para a vegetação do local. Os valores obtidos para o índice de área foliar (IAF) nas três verticais em condições de radiação difusa foram 6,6, 6,3 e 6,2.

The irradiance and nutrient supply affect the assimilation of carbon and influence the gain and biomass partition. The aim of this research was to investigate the growth and photosynthesis in young plants of Ochroma pyramidale subjected to contrasting light environments and phosphorus fertilization. Young plants of O. pyramidale were exposed to two irradiance levels (Low: 10 to 15 and High: 1200 to 1400 μmol m-2 s-1) and two levels of P fertilization (0 and 1 mM as KH2 PO4) for 160 days. The experimental design was a completely randomized in factorial arrangement (2 x 2), with 10 replications. The greatest growth in height and diameter was observed in plants fertilized with phosphorus and under high irradiance. Concerning the allocation of dry mass, plants under high irradiance invested more in root mass ratio and plants under low irradiance in leaf mass ratio. For foliar P content, the plants fertilized with P exhibited values 137 and 54% higher than the plants not fertilized with P, under high and low irradiance, respectively. The absence of P fertilization promoted intense reduction in the efficiency of electron transport, as demonstrated by the values of photochemical efficiency of photosystem II, and photosynthetic rates. The greatest biomass production and higher photosynthetic rates in plants fertilized with phosphorus and under higher irradiance suggest that O. pyramidale plants have appropriate functional mechanisms to show a better growth and physiological performance in open fields (high irradiance), common in forest plantations or environments in recovery process.