Forest fragmentation and its potential implications for the management of the Tarumã-Açu River basin, Central Amazon, Brazil

A intensificação do desmatamento e a consequente fragmentação da paisagem natural em bacias hidrográficas urbanas e periurbanas afetam todo o sistema eco-hidrológico, aumentando a necessidade de entendimento de como essas mudanças podem impactar sua sustentabilidade. Nesse sentido, o presente estudo avaliou as potenciais implicações da fragmentação florestal para a gestão da bacia do Tarumã-Açu, a partir da caracterização dos padrões estruturais e funcionais da paisagem. Para tanto, realizou-se o mapeamento e a categorização dos fragmentos florestais da bacia, a partir da classificação supervisionada (Método Bhattacharyya) de imagem Landsat/OLI, e, posteriormente, o cálculo de métricas da paisagem (área, densidade e tamanho, bordas, forma, área central, isolamento e conectividade). As métricas mostraram uma paisagem bastante fragmentada, especialmente na região do baixo curso da bacia, que concentra os menores, mais dispersos e vulneráveis fragmentos, mesmo em unidades de conservação. Já a região da cabeceira possui os maiores fragmentos, com grande quantidade de área central e alta conectividade estrutural e funcional, fundamentais para a sustentabilidade da bacia e que, portanto, merecem atenção e priorização dos gestores. Os resultados oferecem subsídios importantes e dados inéditos que podem contribuir para a elaboração do plano de gestão da bacia e para a definição de estratégias de conservação e restauração dos remanescentes florestais, indicando áreas prioritárias para implementação dessas ações.The intensification of deforestation and the consequent fragmentation of the natural landscape in urban and periurban watersheds affect the entire eco-hydrological system, increasing the need to understand how these changes can affect their sustainability. In this sense, the present study evaluated the potential implications of forest fragmentation for the management of the Tarumã-Açu basin, based on the characterization of the structural and functional patterns of the landscape. For this, we mapped and categorized the basin’s forest fragments, based on the supervised classification (Bhattacharyya Method) of Landsat/OLI image, and, subsequently, we calculated the landscape metrics (area, density and size, edge, form, core, isolation and connectivity). The metrics showed a very fragmented landscape, especially in the region of the basin’s low course, which concentrates the smallest, most dispersed, and vulnerable fragments even in conservation units. The headwater region, on the other hand, has the largest patches, with a large amount of central area and high structural and functional connectivity, which are fundamental for the sustainability of the basin and, therefore, deserve attention and prioritization by managers. The results offer important subsidies and unpublished data that can contribute to elaboration of the basin’s management plan and for the definition of conservation and restoration strategies of the forest remnants, indicating priority areas for the implementation of these actions

Viabilidade de sementes armazenadas de Himatanthus sucuuba Wood pelo teste de tetrazólio

Himatanthus sucuuba is an Amazonian tree species of importance in traditional medicine because of its therapeutic properties. Estimates of seed viability are still scarce, so it is necessary to develop rapid tests to evaluate seed quality. The objectives of this work were to adapt the methodology for the tetrazolium test and to verify the viability of the stored seeds of Himatanthus sucuuba by comparing the results from the germination and tetrazolium test. For preconditioning, the seeds were immersed in distilled water for the periods of 4, 8, 12 and 14 hours at 25°C. Subsequently, seed tissue staining was performed by immersion in a tetrazolium solution of 0.025%, 0.075% and 0.100% for 90 minutes at 40°C in the dark conditions, and the seeds were evaluated into six classes. At the same time, germination tests were conducted in a BOD chamber at 30°C, establishing criteria for viability and vigor evaluation. The experimental design was completely randomized, and the comparison of means performed by Tukey test at 5% significance. The tetrazolium test at a concentration of 0.075% at 40°C for 90 minutes was efficient to evaluate the viability and vigor of Himatanthus sucuuba seeds. The comparison between germination (78%) and tetrazolium test (70%) showed no significant difference, concluding that seeds stored for 14 months remained viableHimatanthus sucuuba é uma espécie arbórea amazônica, de importância na medicina popular devido às suas propriedades terapêuticas. As estimativas da viabilidade de sementes dessa espécie ainda são escassas, tornando-se necessário o desenvolvimento de testes rápidos que permitam a avaliação da qualidade das sementes. O objetivo deste trabalho foi adequar a metodologia para a realização do teste de tetrazólio e verificar a viabilidade das sementes armazenadas de Himatanthus sucuuba comparando os resultados dos testes de germinação e tetrazólio. Para o precondicionamento, as sementes foram imersas em água destilada por períodos de 4, 8, 12 e 14 horas a 25°C. Posteriormente, foi realizada a coloração dos tecidos, pela imersão em solução de tetrazólio 0,025%, 0,075% e 0,100% por 90 minutos a 40°C no escuro, e para a avaliação as sementes foram distribuídas em seis classes. Paralelamente, foram conduzidos testes de germinação em câmara BOD a 30°C, estabelecendo-se critérios para avaliação da viabilidade e do vigor. O delineamento experimental foi o inteiramente casualizado, e a comparação de médias foi realizada pelo teste de Tukey a 5% de significância. O teste de tetrazólio na concentração de 0,075% a 40°C durante 90 minutos mostrou-se eficiente para avaliar a viabilidade e vigor das sementes de Himatanthus sucuuba. A comparação entre a germinação (78%) e o teste de tetrazólio (70%), não mostrou diferença significativa entre eles, concluindo-se que sementes armazenadas por 14 meses permaneceram viáveis

Towards sustainability: Allowance rights for using water resources in Amazonas State of Brazil

The water use permit is one of the instruments of the National and State Policy of Water Resources in Brazil through which the government authorizes the user to withdraw water or to make hydraulic interferences in water bodies necessary for their activities, guaranteeing the right of access to these resources. In the state of Amazonas, the Water Resources Policy (PERH) was reformulated by Law 3,167 of 2007, which latter was regulated by decree 28,678 of 2009, and use permit started to being issued in 2017. The objective of this paper is to contextualize the current situation of this instrument, based on bibliographical review and on the observed practical consequences. The State Water Resources Policy (PERH) exists since 2001, but the implementation of the water use permits issuance in the state has not progressed significantly over the last 15 years. Important advances occurred only in 2016 and 2017, with the establishment of technical parameters for water use. Permits slowly started to be issued in 2017, but still disconnected from the other instruments of the Brazilian Water Resources Policy. © 2018 by author(s) and VsI Entrepreneurship and Sustainability Center

Ecological considerations on phytoplankton from the Guajará bay and from the Guamá river estuary in Pará, Brazil

Phytoplankton composition, biomass and ecology were studied from samples bimonthly collected from December/1989 to October/1990 at Guajará Bay-Pará (Brazil). Analysis was based on plankton samples collected with a 65 µm mesh net, horizontal-surface hauled. Biomass was calculated by Utermohl method (cell/liter) and chlorophyll 'a' concentration. Water salinity, temperature, transparence and pH were measured for composition. Phytoplankton was composed of 116 specific and infraspecific taxa: 1 Cyanophyceae, 45 Chlorophyceae and 70 Bacillariophyceae. Most significatives were Polymyxus coronalis, amazonic brackishwater indicator. Quantitatively phytoplankton varied from 790000 cel/l to 4790000 cel/l, being phytoflagellate the most abundant followed by diatoms, blue green and green algae. Chlorophyll 'a' varied from 1.49 mg/m3 to 23.33 mg/m3. Guajará Bay water is characterized by small salinity variation, high temperature, law transparence and pH generally acid. These parameters annual variation is related to pluviometer regime that influences the phytoplankton quantitative values

Phytoplankton dynamics in a highly eutrophic estuary in tropical Brazil

The port of Recife in northeastern Brazil is an important ecological and social area but little is known about its environmental quality. Observations, sampling and measurements of phytoplankton were performed during spring and neap tides in the dry (January-February, 2005) and rainy (June, 2005) seasons to assess the environmental quality of the port of Recife. The area had chlorophyll-a concentrations ranging from 3.30 to 54.40 mg m-3, the highest values occurring at low tide during the dry season. A total of 129 species were identified: 53 of them in the dry season and 97 in the rainy season. Diatoms were the most diverse group and comprised 75.47% of the phytoplankton collected in the dry season and 60.82% of those collected in the rainy season. The dry season was characterized by Coscinodiscus sp. and Helicotheca tamesis; the rainy season by Oscillatoria sp. and Coscinodiscus centralis. Species diversity indices varied from 1.06 to 3.74 bits cel-1. Low indices were related to the dominance of Helicotheca tamesis, Coscinodiscus centralis, Coscinodiscus sp. and Aulacoseira granulata. Seasonal forcing, rather than the estuarine flux, determined the phytoplankton community structure. The area is exposed to seasonally varying negative impacts due to metropolitan degradation and the high level of eutrophication.Para avaliar a qualidade ambiental Porto do Recife (Nordeste do Brasil), uma área ecológica e socialmente importante mas pouco investigada, observações, medições e amostragem do fitoplâncton foram realizadas durante as marés de sizígia e quadratura no período de estiagem (janeiro-fevereiro / 2005) e chuvoso (junho/2005). A área apresentou concentração de clorofila a variando de 3,30 a 54,40 mg m-3, com maiores valores registrados durante a maré baixa no período de estiagem. Um total de 129 espécies foi identificada com 53 espécies durante o período de estiagem e 97 espécies no chuvoso. As diatomáceas formaram o grupo mais diverso, com 75,47% no período de estiagem e 60,82% no chuvoso. Coscinodiscus sp. e Helicotheca tamesis caracterizaram o período de estiagem e Oscillatoria sp. e Coscinodiscus centralis o período chuvoso. A diversidade de espécie variou de 1,06 a 3,74 bits cel-1 . Os baixos índices foram relacionados com a dominância de Helicotheca tamesis, Coscinodiscus centralis, Coscinodiscus sp. e Aulacoseira granulata. A sazonalidade determinou a estrutura da comunidade fitoplanctônica, em vez do fluxo estuarino. A área é exposta sazonalmente a vários impactos negativos, devido à degradação metropolitana e ao elevado nível de eutrofização

Superação de dormência em sementes de três espécies de Parkia spp.

Knowledge of the germinative processes of seeds with resistant coats, as have some Fabaceae species, may help in seedling production and the restoration of degraded areas. Parkia seeds have a naturally slow and irregular germination due to tegument impermeability. This study aimed to evaluate different methods of overcoming physical dormancy in Parkia multijuga, P. velutina and P. panurensis seeds. Seeds were collected at the Pedro de Moura Operations Base (BOGPM), in Coari/AM, and subjected to the following treatments: control (T0), clipping (T1), clipping followed by immersion in water for 8 hours (T2), mechanical scarification of the tegument with an electric emery (T3), mechanical scarification of the tegument with an electric emery followed by immersion in water for 8 hours (T4), needle puncture in hot water (T5), needle puncture followed by immersion in hot water for 8 hours (T6), sulphuric acid immersion (H 2SO 4) for 30 minutes (T7), sulphuric acid immersion (H 2SO 4) for 20 min (T8), sulphuric acid immersion (H 2SO 4) for 15 minutes (T9). The seeds of each treatment were submitted to germination tests to evaluate the percentage germination, average time of seedling emergence, seedling emergency speed index and synchronization rate. In general, all pre-germinative treatments on the seeds of the three species increased the percentage germination compared to the control. The mechanical scarification treatments with emery eletric on the side of the seed were more effective in overcoming the dormancy of P. panurensis and P. multijuga seeds while chemical scarification with sulphuric acid with a longer period of immersion was more effective for seeds of P. panurensis and P. velutina for both seedling emergence and normal seedling formation

Diagnóstico ambiental do baixo curso do Igarapé do Gigante (Amazonas – Brasil)

The watershed is a complex system that goes beyond the drainage network, involving all the ecosystem aspects within its limits. Despite the set of ecohydrological functions that its components play in the protection of water resources, especially the vegetal cover, hydrological systems are the ecosystems that suffer the most changes due to anthropic activities, notably when inserted in the urban environment. Thus, this work aimed to perform the environmental diagnosis of the lower course of the Gigante river basin, in Manaus-AM. We carried field visits, collecting and registering information about the study area, applying check-list, interaction network and interaction matrix methods. Through the environmental diagnosis, we evaluated that the low course of the Gigante River presents areas where native vegetation has been suppressed, including permanent preservation areas, triggering several impacts of other orders, such as exposure and waterproofing of the soil, silting, introduction of exotic species, excess aquatic vegetation, effluent and solid waste. The proposed mitigation measures were to eliminate the emission of effluents and deposition of solid wastes, to remove the invasive species and to lead the natural regeneration and/or the enrichment of the area.A bacia hidrográfica constitui um sistema complexo, que vai além da rede de drenagem, envolvendo todos os aspectos ecossistêmicos compreendidos nos seus limites. Apesar do conjunto de funções eco-hidrológicas que seus componentes desempenham na proteção dos recursos hídricos, especialmente a cobertura vegetal, os sistemas hidrológicos são os ecossistemas que mais sofrem alterações em razão de atividades antrópicas, principalmente quando inseridos no meio urbano. Dessa forma, este trabalho objetivou realizar o diagnóstico ambiental do baixo curso do Igarapé do Gigante, em Manaus-AM. Para tanto, realizou-se visitas a campo, com coleta e registro de informações sobre a área de estudo, aplicando-se os métodos de check-list, rede de interação e matriz de interação. Por meio do diagnóstico ambiental, avaliou-se que o baixo curso do Igarapé do Gigante apresenta áreas onde houve a supressão da vegetação nativa, incluindo áreas de preservação permanente, desencadeando diversos impactos de outras ordens, como a exposição e impermeabilização do solo, assoreamento, introdução de espécies exóticas, excesso de vegetação aquática, aporte de efluentes e resíduos sólidos. As medidas mitigadoras propostas foram eliminar a emissão de efluentes e a deposição de resíduos sólidos, retirar as espécies invasoras e conduzir a regeneração natural e/ou o enriquecimento da área