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Rhodospatha rupicola (Araceae), una nueva especie reófita de la Amazonia colombiana
No full textA new species of the genus Rhodospatha (Araceae) from the Colombian Amazon is described and illustrated. The new species is restricted to the Caquetá department between 300–520 m altitude, growing mainly as a rheophyte on rocks along small rivers, creeks and waterfalls. This life-form has been not recorded in Rhodospatha before. © 2019, Universidad Nacional de Colombia. All rights reserved
Brazil's Native Vegetation Protection Law Jeopardizes Wetland Conservation: A Comment on Maltchik et al.
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Tree rings and rainfall in the equatorial Amazon
No full textThe Amazon basin is a global center of hydroclimatic variability and biodiversity, but there are only eight instrumental rainfall stations with continuous records longer than 80 years in the entire basin, an area nearly the size of the coterminous US. The first long moisture-sensitive tree-ring chronology has been developed in the eastern equatorial Amazon of Brazil based on dendrochronological analysis of Cedrela cross sections cut during sustainable logging operations near the Rio Paru. The Rio Paru chronology dates from 1786 to 2016 and is significantly correlated with instrumental precipitation observations from 1939 to 2016. The strength and spatial scale of the precipitation signal vary during the instrumental period, but the Rio Paru chronology has been used to develop a preliminary reconstruction of February to November rainfall totals from 1786 to 2016. The reconstruction is related to SSTs in the Atlantic and especially the tropical Pacific, similar to the stronger pattern of association computed for the instrumental rainfall data from the eastern Amazon. The tree-ring data estimate extended drought and wet episodes in the mid- to late-nineteenth century, providing a valuable, long-term perspective on the moisture changes expected to emerge over the Amazon in the coming century due to deforestation and anthropogenic climate change. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature
Dry leaf or twig mantis? A new genus and species of Acanthopidae with sexually dimorphic cryptic strategies (Insecta: Mantodea)
No full textEcophysiology and growth of Bertholletia excelsa Bonpl. in response to thinning, liming and phosphorus addition
Get PDFBertholletia excelsa has a high potential for timber production, and although it is widely planted in the Amazon, information on management practices of this species in planting condition is scarce. Understanding of the effects of thinning, liming and phosphate fertilization on the ecophysiology and growth of native species is fundamental for the definition of management strategies. Thus, the objective of this research was to investigate how the thinning, liming and phosphate fertilization, as well as the combination between these treatments in the dry and rainy season influence the ecophysiology and growth of B. excelsa. The study was carried out in a planting, located in the area of the Agronomic Company Fazenda Aruanã, Itacoatiara, AM. The planting was submitted simultaneously to two levels of thinning (removal of 0 and 50% of the basal area of the stand), liming (application of 0 and 2.0 Mg ha-1 of dolomitic limestone) and phosphate fertilization (application of 0 and 150 kg ha-1 of super triple phosphate). The experimental design was in randomized blocks with six treatments (1- Control; 2-Liming; 3-Liming + Phosphorus; 4-Thinning; 5-Thinning + Liming; 6- Thinning + Liming + Phosphorus) and eight replications. The treatments were compared in relation to light, water and nutrients availability, leaf and fine-root morphology, elementary stoichiometry at the soil-plant interface, photosynthesis and resource use efficiency for two years (2016-2018). Thinning increased light availability from 51 to 423 μmol m-2 s -1 . Liming boosted soil pH from 4.2 to 5.3 and phosphorus fertilization increased soil P from 2.1 to 88.2 mg kg -1 . Trees under thinning showed the highest growth rates (9.0 mm year-1 ) independent of liming or phosphate fertilization application. Light was the site factor that exerted the greatest effect on the ecophysiology and growth of B. excelsa, but when light availability was low the pH and P availability in soil exerted the greatest effects on growth. The higher growth rates of trees under thinning were influenced by changes in leaf morphology, N and P concentrations, increase in photosynthetic rates, and efficiency in the use of light, N and P. While the higher growth rates of trees under liming treatment and phosphorus fertilization were influenced by changes in fine-root morphology, Ca, Mg and P concentrations, increase of photosynthetic rates, and efficiency in the use of light, N and P. The highest growth rates were observed in the rainy season, while the highest photosynthetic rates were observed in the dry season. Thus, it is concluded that although soil conditions (pH and P availability) have an effect on the growth of B. excelsa, light is the most limiting factor, and thinning is indicated to increase the light availability and, consequently, yield of the plantations formed by this species.Bertholletia excelsa é uma espécie de elevado potencial para a produção de madeira e, embora seja amplamente plantada na Amazônia, informações sobre práticas de manejo dessa espécie em condição de plantio são escassas. O entendimento dos efeitos do desbaste, calagem e fertilização fosfatada sobre a ecofisiologia e o crescimento de espécies nativas é fundamental para definição de estratégias de manejo. Assim, o objetivo desta pesquisa foi investigar como o desbaste, a calagem e a fertilização fosfatada, bem como a combinação entre esses tratamentos em períodos de baixa e alta precipitação influenciam a ecofisiologia e o crescimento de B. excelsa. O estudo foi realizado em plantio, localizado na área da Empresa Agropecuária Fazenda Aruanã, Itacoatiara, AM. O plantio foi submetido simultaneamente a dois níveis de desbaste (retirada de 0 e 50% da área basal do povoamento), calagem (aplicação de 0 e 2,0 Mg ha-1 de calcário dolomítico) e fertilização fosfatada (aplicação de 0 e 150 kg ha-1 de fosfato super triplo). O delineamento experimental foi em blocos casualizados com seis tratamentos (1-Controle, 2-Calagem, 3-Desbaste, 4-Calagem + Fósforo, 5-Calagem + Desbaste e 6-Calagem + Fósforo + Desbaste) e oito repetições. Os tratamentos foram comparados quanto à disponibilidade de recursos, morfologia de folhas e raízes finas, estequiometria elementar na interface solo-planta, fotossíntese e eficiência no uso de recursos durante dois anos (2016-2018). O desbaste aumentou a disponibilidade de luz de 51 para 423 µmol m-2 s -1 . A calagem aumentou o pH do solo de 4,2 para 5,3 e a fertilização fosfatada aumentou o P no solo de 2,1 para 88,2 mg kg -1 . As árvores sob tratamento de desbaste apresentaram as maiores taxas de crescimento (9.0 mm ano -1 ) independente da aplicação da calagem ou da fertilização fosfatada. A luz foi o fator de sítio que exerceu maior efeito sobre a ecofisiologia e crescimento de B. excelsa, mas quando a disponibilidade de luz foi baixa o pH e a disponibilidade de P no solo exerceram os maiores efeitos sobre o crescimento. As maiores taxas de crescimento das árvores sob tratamento de desbaste foram influenciadas por mudanças na morfologia de folhas, concentrações de N e P, aumento das taxas fotossintéticas e eficiência no uso de luz, N e P. Ao passo que as maiores taxas de crescimento das árvores sob tratamento de calagem e fertilização fosfatada foram influenciadas por mudanças na morfologia de raízes finas, concentrações de Ca, Mg e P, aumento das taxas fotossintéticas e eficiência no uso de luz, N e P. As maiores taxas de crescimento foram observadas no período de maior precipitação, enquanto que as maiores taxas fotossintéticas foram observadas no período de menor precipitação. Desta forma, conclui-se que embora as condições edáficas (pH e disponibilidade de P) exerçam efeito sobre o crescimento de B. excelsa, a luz é o fator mais limitante, sendo indicada a realização do desbaste para aumentar a disponibilidade de luz e, consequentemente, o crescimento das plantações formadas por esta espécie
Der Sandwich-Effekt:Einengung von Habitaten durch Staudaemme gefaehrdet die groessten und artenreichsten Flussauen der Erde
No full textThe role of fertile anthropogenic soils in the conservation of native and exotic agrobiodiversity in Amazonian homegardens
No full textAmazonian dark earths (ADE) are anthropogenic soils mostly created between 500 and 2500 years ago by pre-Columbian populations. ADE are currently used by local people for different agricultural and agroforestry systems. Because of their high fertility they may play an important role in the conservation of non-native agrobiodiversity. This study aimed to investigate the variation in richness and abundance of exotic and native species in homegardens along the ADE-background soil continuum. We conducted floristic inventories in 70 homegardens located in 7 riverside communities along the lower and middle Madeira River, Central Amazonia. Each species sampled was classified according to its origin: native Amazonian, American (from outside Amazonia) and non-American, and each individual was classified according to its form of establishment: cultivated or spontaneous. The floristic diversity was significantly related to soil fertility, texture and homegarden size. We found a positive relationship between soil fertility and richness of species and landraces. Homegardens on more fertile soils tended to have a higher richness and abundance of cultivated non-American species, as well as a higher richness and abundance of spontaneously established American species. Homegardens at the fertile end of the fertility gradient provided conditions for the establishment and growth of many species, especially exotic species, that are generally more nutrient-demanding than Amazonian species. Our results show that homegarden agroecosystems on ADE favour experimentation with the introduction of a wide range of species from various regions of the globe. © 2017, Springer Science+Business Media B.V
Measures for sustainable forest management in the tropics – A tree-ring based case study on tree growth and forest dynamics in a Central Amazonian lowland moist forest
Get PDFThe conservation of tropical forests is recognized as one of the most important challenges for forestry, ecology and politics. Besides strict protection, the sustainable management of natural forests should be enhanced as a key part of the foundation for the maintenance of tropical rain forest ecosystems. Due to methodological reasons it has been complicated to attain reliable growth data to plan sustainable felling cycles and rotation periods. Tree ring analyses enable the estimation of growth rates over the entire life span of trees and their age as well as giving hints from forest dynamics in previous centuries. For tree ring analysis, stem disk samples were taken from three important commercial tree species (Cariniana micrantha, Caryocar villosum and Manilkara huberi) in the upland (terra firme) forests of the Precious Woods Amazon logging company near Itacoatiara, Brazil. Based on radiocarbon estimates of individual growth zones, the annual nature of tree rings was proven for the three species. Tree rings were measured and the results used together with height estimates to model diameter, height and volume growth. The age of the eldest tree, a C. micrantha, was 585 yrs with 165 cm in diameter. The species’ diameter increments range from 0.20±0.12 cm yr-1 to 0.29±0.08 cm yr-1. At first sight, this is considerably lower than increments reported from other Amazonian or African timber species. Considering the respective wood density there is no significant difference in growth performance of dominant timber species across continents. The interpretation of lifetime tree ring curves indicate differences in shadow tolerance among species, the persistence of individuals in the understory for up to 150 years and natural stand dynamics without major disturbances. Management criteria should be adapted for the measured growth rates as they differed considerably from the Brazilian standards fixed by laws (felling cycle of 25–35 years and a common minimum logging diameter of 50 cm). Felling cycles should be increased to 32–51 years and minimum logging diameters to 63–123 cm depending on the species. © 2019 Worbes, Schöngart. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
