Browsing by Autor "Alejandro Araujo Murakami"

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Dinámica del bosque, incorporación y almacenamiento de biomasa y carbono en el Parque Nacional Noel Kempff Mercado
(2006) Alejandro Araujo Murakami; Luzmila Arroyo Padilla; Timothy J. Killeen; Mario Saldias Paz
Estructura, composición y variabilidad del bosque subandino xérico en un sector del Valle del río Tuichi, Anmi Madidi, La Paz (Bolivia)
(2004) Alfredo Fuentes Claros; Alejandro Araujo Murakami; Héctor Cabrera Condarco; Freddy Canqui; Leslie Cayola; Carla Maldonado; Narel Paniagua
Se evaluaron 1.3 has. de bosque subandino xerico en el valle del Tuichi donde se midieron todas las lenosas con DAP > 2.5 cm en parcelas de 0.1 has. Se registraron 4709 tallos en total, con un promedio de 362.2± 132.3/0.1 ha. El promedio del area basal fue de 2.9± 1.1 m2/0.1 ha. Se encontraron 171 especies y 50 familias, con promedios de 48±7.5 especies y 24.8±3.8 familias por parcela. Las especies de mayor importancia ecologica (IVI) fueron Phyllostylon rhamnoides, Anadenanthera colubrina y Trichilia catigua; las familias con mayor IVIF fueron Fabaceae, Meliaceae y Ulmaceae. El Analisis de Componentes Principales diferencio dos grupos de parcelas o comunidades: una comunidad de cimas y laderas caracterizada por Zanthoxylum fagara, Astronium urundeuva y Erythrina amazonica; y otra comunidad de fondos de valle y terrazas caracterizada por Chrysophyllum gonocarpum, Randia armata y Gallesia integrifolia. Biogeograficamente predominan especies de bosques estacionalmente secos del arco pleistocenico, reforzando la teoria de la existencia durante el Pleistoceno de una formacion de bosques secos mucho mas extensa que la actual; le siguen en orden de importancia elementos de bosques humedos de tierras bajas y por ultimo elementos andinos que concentran los endemismos y caracterizan a esta formacion. Palabras claves: Bosque seco subandino Madidi, estructura, composicion, variabilidad, biogeografia. ABSTRACT We present detailed information on structure and floristic composition of the xeric subandean forest in a sector of the Tuichi valley, in the Madidi Natural Area of Integrated Management, La Paz-Bolivia. We evaluated 1.3 has. of forest where we measured all the woody plants with DBH > 2.5 cm, in plots of 0.1 ha. A total of 4709 stems with means of 362.2± 132.3/0.1 ha were recorded. The total basal area was of 37.7 m2 with means of 2.9±1.1 m2/0.1 ha (S.D.). We recorded 171 species in 50 families, with means of 48±7.5 species and 24.8±3.8 families per plot. The species of greatest ecological importance (IVI) were Phyllostylon rhamnoides, Anadenanthera colubrina and Trichilia catigua; the families with greatest IVIF were Fabaceae, Meliaceae and Ulmaceae. A Principal Component Analysis distinguished two groups of plots or plant communities: a community found on top and slopes of ridges characterized by Zanthoxylum fagara, Astronium urundeuva and Erythrina amazonica; and the other a community found in the valley bottoms and terraces was characterized by Chrysophyllum gonocarpum, Randia armata and Gallesia integrifolia. Biogeographycally predominates species of seasonally dry forests of the pleistocenic arc, reinforcing the theory of the existence during the Pleistocene of one formacion of dry forests much more extensive that in the present; they follow in importance order elements of humid lowland forests and finally Andean elements that concentrate the endemism and characterize this formation. Key words: Madidi subandean dry forest, structure, composition, variability, biogeography.
Evaluación del estado de conservación de los bosques montanos en los Andes tropicales
(2012) Natalia Tejedor‐Garavito; Esteban Álvarez‐Dávila; Sandra Lorena Franco Arango; Alejandro Araujo Murakami; Cecilia Blundo; Tatiana Erika Boza Espinoza; M. A. la Torre Cuadros; Jackeline Gaviria; Nelcy Patricia Vargas Gutiérrez; Peter M. Jørgensen
Autores del artículo: N. Tejedor Garavito, E. Álvarez, S. Arango Caro, A. Araujo Murakami, C. Blundo, T.E. Boza Espinoza, M.A. La Torre Cuadros, J. Gaviria, N. Gutíerrez, P.M. Jørgensen, B. León, R. López Camacho, L. Malizia, B. Millán, M. Moraes, S. Pacheco, J.M. Rey Benayas, C. Reynel, M. Timaná de la Flor, C. Ulloa Ulloa, O. Vacas Cruz, A.C. Newton.
Fine root dynamics across pantropical rainforest ecosystems
(Wiley, 2021) Walter Huaraca Huasco; Terhi Riutta; Cécile A. J. Girardin; Fernando Hancco Pacha; Beisit L. Puma Vilca; Sam Moore; Sami W. Rifai; Jhon del Águila Pasquel; Alejandro Araujo Murakami; Renata Freitag
Fine roots constitute a significant component of the net primary productivity (NPP) of forest ecosystems but are much less studied than aboveground NPP. Comparisons across sites and regions are also hampered by inconsistent methodologies, especially in tropical areas. Here, we present a novel dataset of fine root biomass, productivity, residence time, and allocation in tropical old-growth rainforest sites worldwide, measured using consistent methods, and examine how these variables are related to consistently determined soil and climatic characteristics. Our pantropical dataset spans intensive monitoring plots in lowland (wet, semi-deciduous, and deciduous) and montane tropical forests in South America, Africa, and Southeast Asia (n = 47). Large spatial variation in fine root dynamics was observed across montane and lowland forest types. In lowland forests, we found a strong positive linear relationship between fine root productivity and sand content, this relationship was even stronger when we considered the fractional allocation of total NPP to fine roots, demonstrating that understanding allocation adds explanatory power to understanding fine root productivity and total NPP. Fine root residence time was a function of multiple factors: soil sand content, soil pH, and maximum water deficit, with longest residence times in acidic, sandy, and water-stressed soils. In tropical montane forests, on the other hand, a different set of relationships prevailed, highlighting the very different nature of montane and lowland forest biomes. Root productivity was a strong positive linear function of mean annual temperature, root residence time was a strong positive function of soil nitrogen content in montane forests, and lastly decreasing soil P content increased allocation of productivity to fine roots. In contrast to the lowlands, environmental conditions were a better predictor for fine root productivity than for fractional allocation of total NPP to fine roots, suggesting that root productivity is a particularly strong driver of NPP allocation in tropical mountain regions.
Methods to estimate aboveground wood productivity from long-term forest inventory plots
(Elsevier BV, 2014) Joey Talbot; Simon L. Lewis; Gabriela López‐González; Roel Brienen; Abel Monteagudo; Timothy R. Baker; Ted R. Feldpausch; Yadvinder Malhi; Mark C. Vanderwel; Alejandro Araujo Murakami
Soil pyrogenic carbon in southern Amazonia: Interaction between soil, climate, and above-ground biomass
(Frontiers Media, 2022) Edmar Almeida de Oliveira; Ted R. Feldpausch; Beatriz Schwantes Marimon; Paulo S. Morandi; Oliver L. Phillips; Michael I. Bird; Alejandro Araujo Murakami; Luzmila Arroyo; Carlos A. Quesada; Ben Hur Marimon
The Amazon forest represents one of the world’s largest terrestrial carbon reservoirs. Here, we evaluated the role of soil texture, climate, vegetation, and distance to savanna on the distribution and stocks of soil pyrogenic carbon (PyC) in intact forests with no history of recent fire spanning the southern Amazonia forest-Cerrado Zone of Transition (ZOT). In 19 one hectare forest plots, including three Amazonian Dark Earth (ADE, terra preta) sites with high soil PyC, we measured all trees and lianas with diameter ≥ 10 cm and analyzed soil physicochemical properties, including texture and PyC stocks. We quantified PyC stocks as a proportion of total organic carbon using hydrogen pyrolysis. We used multiple linear regression and variance partitioning to determine which variables best explain soil PyC variation. For all forests combined, soil PyC stocks ranged between 0.9 and 6.8 Mg/ha to 30 cm depth (mean 2.3 ± 1.5 Mg/ha) and PyC, on average, represented 4.3% of the total soil organic carbon (SOC). The most parsimonious model (based on AICc) included soil clay content and above-ground biomass (AGB) as the main predictors, explaining 71% of soil PyC variation. After removal of the ADE plots, PyC stocks ranged between 0.9 and 3.8 Mg/ha (mean 1.9 ± 0.8 Mg/ha –1 ) and PyC continued to represent ∼4% of the total SOC. The most parsimonious models without ADE included AGB and sand as the best predictors, with sand and PyC having an inverse relationship, and sand explaining 65% of the soil PyC variation. Partial regression analysis did not identify any of the components (climatic, environmental, and edaphic), pure or shared, as important in explaining soil PyC variation with or without ADE plots. We observed a substantial amount of soil PyC, even excluding ADE forests; however, contrary to expectations, soil PyC stocks were not higher nearer to the fire-dependent Cerrado than more humid regions of Amazonia. Our findings that soil texture and AGB explain the distribution and amount of soil PyC in ZOT forests will help to improve model estimates of SOC change with further climatic warming.
Spatial patterns of above-ground structure, biomass and composition in a network of six Andean elevation transects
(Taylor & Francis, 2013) Cécile Girardin; William Farfán-Ríos; Karina García; Kenneth J. Feeley; Peter M. Jørgensen; Alejandro Araujo Murakami; Leslie Cayola Pérez; Renate Seidel; Narel Paniagua; A C.
Background: The Amazon to Andes transition zone provides large expanses of relatively pristine forest wilderness across environmental gradients. Such elevational gradients are an excellent natural laboratory for establishing long-term interactions between forest ecosystems and environmental parameters, which is valuable for understanding ecosystem responses to environmental change. Aims: This study presents data on elevational trends of forest structure (biomass, basal area, height, stem density), species richness, and composition from six elevational transects in the Andes. Methods: We analysed the spatial patterns of forest structure, above-ground biomass and composition from 76 permanent plots, ranging from lowland Amazonian rain forest to high-elevation cloud forests in Ecuador, Peru, and Bolivia. Results: Forest above-ground woody biomass stocks ranged from 247 Mg ha−1 (Peru, 210 m) to 86 Mg ha−1 (Peru, 3450 m), with significantly decreasing trends of tree height and biomass and an increasing trend of stem density with increasing elevation. We observed an increase in forest richness at three taxonomic levels at mid-elevation, followed by a decrease in richness within the cloud immersion zone. Conclusions: The transects show an increase in stem density, a decline in tree height and above-ground coarse wood biomass and a hump-shaped trend in species richness with increasing elevation. These results suggest that environmental change could lead to significant shifts in the properties of these ecosystems over time.
Thinner bark increases sensitivity of wetter Amazonian tropical forests to fire
(Wiley, 2019) A. Carla Staver; Paulo Brando; Jos Barlow; Douglas C. Morton; C. E. Timothy Paine; Yadvinder Malhi; Alejandro Araujo Murakami; Jhon del Águila Pasquel
Abstract Understory fires represent an accelerating threat to Amazonian tropical forests and can, during drought, affect larger areas than deforestation itself. These fires kill trees at rates varying from < 10 to c. 90% depending on fire intensity, forest disturbance history and tree functional traits. Here, we examine variation in bark thickness across the Amazon. Bark can protect trees from fires, but it is often assumed to be consistently thin across tropical forests. Here, we show that investment in bark varies, with thicker bark in dry forests and thinner in wetter forests. We also show that thinner bark translated into higher fire‐driven tree mortality in wetter forests, with between 0.67 and 5.86 gigatonnes CO 2 lost in Amazon understory fires between 2001 and 2010. Trait‐enabled global vegetation models that explicitly include variation in bark thickness are likely to improve the predictions of fire effects on carbon cycling in tropical forests.