Basal area

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Stand structure and recent climate change constrain stand basal area change in European forests: a comparison across  boreal, temperate and Mediterranean biomes

Stand structure and recent climate change constrain stand basal area change in European forests: a comparison across boreal, temperate and Mediterranean biomes

the NFIs included in the study: (a) stand basal area (m 2 ha -1 ), (b) mean d.b.h. (mm), (c) water availability (%), (d) minimum temperature (ºC), (e) absolute temperature anomaly (ºC), and (f) relative precipitation anomaly (%) in the Spanish, German and Finish NFIs at a spatial resolution of 0.2 x 0.2 degrees.

59 Lee mas

Model Selection and Fitting for Basal Area Increment in a Vietnamese Tropical Forest

Model Selection and Fitting for Basal Area Increment in a Vietnamese Tropical Forest

approaches would be imminent to model forest structure. Hung (2018) reveals that, several mathematical functions; both linear and non-linear are expressed to cement relationship between two or more variable/parameters. Notably logistic function using R statistical application (Hung and Doi, 2017; R Core Team, 2019). In regression, Height and Diameter (h-d) are integral part of growth and yield models as basic variable input (Temesgen et al., 2007; Lida et al., 2012; Riofrío et al., 2019) as dependent and independent in the analysis. Mate et al., (2014) argued about h-d per species are probably the best fit for growth/biomass models in combination with stand composition variables such as Basal Area (Riofrío et al., 2019), crown architecture (Pretzsch et al., 2015) including the relationship with wood density (Iida et al., 2012) giving rise to improved model coefficients. This argument could be said to be unanimous as growth models developed for tropical and temperature forest structures relies on similar variables. 1.2 Problem Statement and Justification
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63 Lee mas

Allan P. Drew, Jeremy D. Boley, Yinghao Zhao, Mark H. Johnston y Frank H. Wadsworth
SESENTA Y DOS AÑOS DE CAMBIO DE ESTRUCTURA Y COMPOSICIÓN FORESTAL HÚMEDA SUBTROPICAL EN EL VERDE, PUERTO RICO (en inglés)

Allan P. Drew, Jeremy D. Boley, Yinghao Zhao, Mark H. Johnston y Frank H. Wadsworth SESENTA Y DOS AÑOS DE CAMBIO DE ESTRUCTURA Y COMPOSICIÓN FORESTAL HÚMEDA SUBTROPICAL EN EL VERDE, PUERTO RICO (en inglés)

Losses of tall P. montana as a result of Hurricane Hugo were significant as the 1943 population lost 11 of 21 individu- als, but large amounts of ingrowth accrued so that the net result was increased numbers. Zimmerman et al. (1994) noted that P. mon- tana, the most common species on the LFDP, had 8.8% mortality from Hurricane Hugo, mostly due to broken stems presumably oc- curring as surrounding trees fell on the palms. Their plot had 9.0% mortality, overall, for palms plus trees >10cm dbh. Species rich- ness, density and basal area on plot EV-3 are similar to those reported for the LFDP. How- ever, species richness is low relative to other humid tropical forests at low to middle eleva- tions (Thompson et al., 2004).
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7 Lee mas

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Lower total densities in Panamá in rela- tion to Iguanita could be indicative of a more mature mangrove stand, as it is considered that as a mangrove forest matures density decreases while tree diameter increases (Cin- trón & Schaeffer-Novelli 1984). However, tree density and diameter comparisons between both stands may not be appropriate given that preliminary analysis of Iguanita showed domi- nance by Rhizophora within the sampled area, and Panamá was dominated by Avicennia (of which tree height and diameter data was not comparable given critical variation in total trees encountered). Furthermore, Rhizophora tree heights did not vary between stands but diam- eters were higher at Iguanita, while Lagun- cularia trees were taller at Iguanita but had similar diameters at both stands. Nonetheless, basal area at both sites (Iguanita=25.1 & Pan- amá= 2.7m 2 /0.1ha) was higher than at Santa
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12 Lee mas

Estimación de la densidad forestal mediante imágenes Landsat ETM+ en la región sur del Estado de México

Estimación de la densidad forestal mediante imágenes Landsat ETM+ en la región sur del Estado de México

Aboveground biomass and other forest parameters (e.g. volume, basal area, carbon and leaf area index) are estimated using the direct and indirect methods. The former consists of a destructive sampling; however, it is very slow and costly, which makes its large scale application complicated. The latter is based on: i) statistical techniques (allometric equations and biomass expansion factor) (Ayala et al., 2002) relating variables that can be easily measured (normal diameter and total height) in forest inventories with variables that are difficult to measure (e.g. volume and biomass) (Návar, 2009; Aquino et al., 2015); and ii) models obtained from combinations of data derived from the forest inventory and from remote sensing (Labrecque et al., 2006; Hall et al., 2006).
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18 Lee mas

Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

surveys and no evidence of tree harvesting before and within consecutive surveys were selected. From those plots, only trees > = 10 cm diameter at breast height (DBH) were included in the dataset to standardise tree selection between the different inventories. The 14 most representative tree species in terms of abundance and distribution were selected as focal trees: Abies alba (needle-leaved evergreen, temperate mountains), Acer pseu- doplatanus (broad-leaved deciduous, temperate), Betula pendula (broad-leaved deciduous, boreal-temperate), Betula pubescens (broad-leaved deciduous, boreal-temperate), Carpinus betulus (broad-leaved deciduous, temperate), Castanea sativa (broad-leaved deciduous, temperate), Fagus sylvativa (broad-leaved deciduous, temperate), Juniperus thurifera (needle-leaved evergreen, Mediterranean mountains), Picea abies (needle-leaved evergreen, boreal-alpine), Pinus halepensis (needle-leaved evergreen, Mediterranean), Pinus sylvestris (needle-leaved evergreen, boreal-alpine-temperate), Quercus pyrenaica (broad-leaved deciduous, Mediterranean- temperate transition), Quercus robur (broad-leaved deciduous, temperate), and Quercus ilex (broad-leaved ever- green, Mediterranean). These species represent more than one third of the total stand basal area measured in the Figure 3. (a) Location of forest inventory plots across the study area (Europe) and (b) potential evapotranspiration (units) throughout the study area. Own preparation based on (a) plot coordinates included in the National Forest Inventories considered, and (b) Potential Evapotranspiration data available in CGIAR-CSI GeoPortal 60 using
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10 Lee mas

Modelado de atributos de rodales forestales utilizando imágenes de satélite Landsat ETM+ y QuickBird en el oeste de Turquía

Modelado de atributos de rodales forestales utilizando imágenes de satélite Landsat ETM+ y QuickBird en el oeste de Turquía

with the results of the related previous studies in literatu- re. Based on the objectives, the hypothesis of the research is that QuickBird images would be able to present better estimation of forest structural parameters as compared with Landsat ETM+ images. The objectives, along with the hypothesis, are tested with the measurements of the forest structural parameters (stand volume, basal area, tree density and quadratic mean diameter) from sample plots and the interpretation of the band digital number and some vegetation indices values generated from Landsat ETM+ and QuickBird satellite images of each sample plot. METHODS
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12 Lee mas

Occlusion probability in operational forest inventory field sampling with ForeStereo

Occlusion probability in operational forest inventory field sampling with ForeStereo

Relaskop-based sampling and correction of occlusions with Poisson attenuation model 577.. 2008) depends on the DBH of the apparent trees and on the basal area factor 578. sele[r]

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Determinación de la estructura de rodales de Fagus orientalis coetáneos en Turquía

Determinación de la estructura de rodales de Fagus orientalis coetáneos en Turquía

For sample areas, mean diameter weighted by basal area of stands is used as a basis for calculation of mean dia- meter. Stand mean height was calculated via mean height weighted by basal area. The number of trees per hectare was calculated by multiplying the number of trees thicker than 8 cm in sampling areas with hectare conversion co- efficient. Stand basal area was found through addition of basal areas of single trees at the site and their multiplica- tion for conversion to hectare. Stand top height was calcu- lated by means of arithmetic mean of highest trees in the sampling area pursuant to 100-tree per hectare calculation. The volume estimates in the sampling area made use of a volume equation developed by (Carus 1998) on Oriental Beech, given in equation number (1) below. Upon con- version of total single tree volumes in hectare via double- entry tree volume equations, we attained stand volumes. In the model, “d” signifies diameter at breast height while “h” shows tree height.
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14 Lee mas

Patterns and drivers of tree mortality in Iberian forests: climatic effects are modified by competition

Patterns and drivers of tree mortality in Iberian forests: climatic effects are modified by competition

We selected six predictor variables from an initial set of 31 available, in order to focus the analyses on the key drivers of mortality and to avoid convergence problems within the MCMC algorithm associated with including closely correlated variables. The selection of environmental variables was made by performing a Principal Component Analysis in R [39], and retaining variables highly correlated with the two first axis; mean annual temperature (mat, uC) and annual precipitation (ap, mm) were selected as representative of the climatic conditions for each tree (see Fig. S2 and Appendix S1 for full details). We tested single-predictor models comparing different biotic and competition variables (see Appendix S1) and selected: diameter at breast height (D, mm), species dominance index (sdi, proportion)) and basal area of larger trees (B L , m 2 /ha). We fitted models using different edaphic
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10 Lee mas

Interactions among patch area, forest structure and water fluxes in a fog inundated forest ecosystem in semi arid Chile

Interactions among patch area, forest structure and water fluxes in a fog inundated forest ecosystem in semi arid Chile

The lower tree basal area of the small patches may be a direct consequence of their size and resultant greater perimeter ⁄ area ratio (i.e. edge effects). Here, edge effects have an important influence on three interdependent ecosystem components: (i) tree regeneration, (ii) tree mortality and (iii) microclimate. First, smaller patches have lower tree regenera- tion associated with higher rates of insect and mammal herbivory (del-Val et al. 2006, 2007) and unsuitable microcli- matic condition (see below). This is reflected in the positive scaling of total tree basal area and patch area, which is a prod- uct of higher tree size and density. In large forest patches, there are more trees that can reach larger sizes on average (Gutierrez et al. 2008), and this pattern is not exclusively related to the presence of an additional species in larger patches (i.e. D. winteri), but to all tree species in the patch. Secondly, it has been shown that tree mortality can be higher along patch edges due to canopy damage and tree falls caused by wind turbulence (Ferreira & Laurance 1997; Laurance et al. 2000). A similar pattern of mortality may be occurring in our forest mosaic, where smaller patches of rather elon- gated shapes have half of the basal area per hectare of larger patches. Furthermore, mortality can be strongly associated with the leeward edge of patches due to fog shadow effects (del-Val et al. 2006). Thirdly, higher overall air temperature in small forest patches is common to other fragmented forests (Kapos 1989; Saunders, Hobbs & Margules 1991; Laurance et al. 2002; Cadenasso et al. 2003). The fact that small patches show higher thermal amplitude (greater difference between maximum and minimum air temperatures) implies
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10 Lee mas

COMPOSICIÓN FLORÍSTICA DE MELASTOMATÁCEAS Y SU RELACIÓN CON EL ÁREA BASAL

COMPOSICIÓN FLORÍSTICA DE MELASTOMATÁCEAS Y SU RELACIÓN CON EL ÁREA BASAL

We studied the species composition of Melastomataceae and its relation with basal area of trees in different forest types of Allpahuayo-Mishana Reserved Zone, Loreto, Peru, as part of the “Use of biological inventories to reveal geographic distribution patterns of lowland Amazonian species” course organized by the Peru-Finland Biological Diversity of the Peruvian Amazon project (BIODAMAZ), with the support of the Peruvian Amazonian Research Institute (IIAP) and the Peruvian Amazonian National University (UNAP). We report 49 species for the area, of which six may be new, and with Miconia as the most abundant genus. The greatest richness in species was found in forest on clay soil, with 34 species, contrasting with the poorly-drained forest on white sand that had only two species (Clidemia epibaterium and Tococa guianensis). There was no relation found between species composition of Melastomataceae and the basal area.
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7 Lee mas

Productividad y estructura vertical de un bosque templado con incidencia de incendios forestales

Productividad y estructura vertical de un bosque templado con incidencia de incendios forestales

The natural productivity of forest ecosystems results in goods and services for society, and it is estimated that the global timber harvest for 2009 in the country was 42.98 million m 3 (Caballero, 2010). Pinus patula Schiede ex Schltdl. & Cham and Pinus pseudostrobus Lindl. are two of the forest species preferred from their high increases in commercial plantations in several countries (Caballero, 2000). There is little quantitative research on the relationship between structural complexity and tree diversity with the productivity of temperate forest ecosystems; however, some studies have shown that diversity indexes are reduced with the increase in basal area removed and average productivity tends to increase with increasing removal (Návar and González, 2009).
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19 Lee mas

Increased Drought Impacts on Temperate Rainforests from Southern South America: Results of a Process Based, Dynamic Forest Model

Increased Drought Impacts on Temperate Rainforests from Southern South America: Results of a Process Based, Dynamic Forest Model

current values by 1.1 to 1.5 in steps of 0.1. These two parameters were first varied separately (keeping the second parameter constant) and then both together. Parameter variations produced a total of 36 climate scenarios, i.e. six levels of each of the two rainfall parameters, including the current climate scenario (Table 3). In addition, we assessed the impact of warming trends on potential evapotranspiration, and its influence on other hydrologic components and forest structure. To this end, we ran an additional scenario including temperature changes expected for year 2100, with parameters 1/l and g kept at their current values (Table 3). We considered four output variables computed at yearly temporal scale: total basal area, above-ground biomass, evapo- transpiration (computed as the sum of canopy transpiration and interception) and soil moisture. The latter is dynamically linked to forest processes such as annual gross biomass production of each tree (PB, cf. Eq. 8, see also Fig. S1). We described changes in forest structure at different successional stages based on simulations for Figure 6. Sensitivity of total basal area (a, b) and above-ground biomass (c, d) predicted by the model under increased drought in a young-secondary (YS) and an old-growth (OG) North Patagonian forest. Results are the percentage of change between the average under current climate (indicated in Table 4) and the average under future scenarios. Results are the average of 30 simulations per scenario for YS and OG. The axes of the figures are as in Figure 5.
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15 Lee mas

Implementacin de la estrategia basal plus en la pctica clnica

Implementacin de la estrategia basal plus en la pctica clnica

En líneas generales, se recomienda man- tener los mismos AO que el paciente lle- vaba previamente con la pauta de insulina basal, aunque podría ser un buen momen- to para replantearnos el tratamiento. En general, al inicio de la insulinización se recomienda retirar las glitazonas, por la mayor retención hídrica y el aumento de peso asociado a esta opción. La metformi- na se debe mantener siempre, indepen- dientemente de la pauta de insulina admi- nistrada. Los tratamientos basados en las incretinas, y los secretagogos de acción prolongada (sulfonilureas), se pueden mantener si se añade una sola dosis de in- sulina prandial. Aunque algunos prefi eren retirar los secretagogos, otros piensan que su retirada temprana podría implicar un importante aumento de las necesidades de insulina 4,5,10
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8 Lee mas

Decomposing recruitment limitation for an avian dispersed rain forest tree in an anciently fragmented landscape

Decomposing recruitment limitation for an avian dispersed rain forest tree in an anciently fragmented landscape

4. Lower density and basal areas of reproductive female trees, in addition to shorter fruiting periods and lower seed yields, led to strong source limitation in small patches. Three bird species accounted for the bulk of visits to fruiting trees, but were less active in smaller patches. Dispersal curves were strongly leptokurtic with maximum dispersal distances related to the shape of patches. Important pro- portions (5 – 40%) of genotyped seeds in all patches were immigrants. However, seeds arrived mainly at patch edges or below reproductive trees where germination and survival are reduced. Fewer seed- lings originated from experimentally added seeds in small patches subjected to greater edge effects. 5. Synthesis. In summary, we provide evidence for source, dispersal and establishment limitation of this dioecious tree in an aridity-driven fragmented landscape. Small fragment size and edge effects had negative impacts on fecundity and seedling establishment. Although bird-mediated seed dis- persal favoured immigration between patches, recruitment from such seeds will be unlikely because of low quality of deposition sites.
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10 Lee mas

Manejo de la hiperglucemia en pacientes hospitalizados

Manejo de la hiperglucemia en pacientes hospitalizados

insulina basal y de los bolos prandiales deben ajustarse con base en la dosis total de insulina de corrección administrada en las últimas 24 horas. Cuando la insulina de corrección es requerida antes de la mayoría de los alimentos, a menudo es necesario incrementar la dosis de insulina basal. Cuando la glucosa sanguínea persiste consistentemente elevada a una hora determinada, se debe ajustar la dosis de insulina prandrial que precede a la medición. 29 Una forma de realizar el ajuste de la dosis

8 Lee mas

"Revisión de los dispositivos tecnológicos utilizados en el tratamiento y control de la Diabetes Mellitus. Revisión bibliográfica

"Revisión de los dispositivos tecnológicos utilizados en el tratamiento y control de la Diabetes Mellitus. Revisión bibliográfica

El desarrollo de la diabetes tipo 1 es variable y comienza con la aparición de autoanticuerpos como respuesta a la interacción entre genética, estado inmunitario y factores ambientales (fase preclínica). Se produce la pérdida progresiva de masa de células beta como resultado de la insulitis o inflamación de los islotes de Langerhans (característica histológica principal de la enfermedad) y comienza a alterarse el metabolismo de los HC, donde la glucemia basal alcanza niveles superiores a los 200 mg/dl (fase clínica) (9). Posteriormente se encuentra la fase de remisión o “luna de miel”, donde hasta en un 62% de los casos se presenta una remisión parcial (más duradera a mayor edad). Con la destrucción progresiva de las células beta aparece la última fase de la diabetes (fase establecida) donde la sintomatología de la enfermedad se hace evidente.
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Un Hegetotheriidae (Mammalia, Notoungulata) basal del Mioceno temprano de Patagonia

Un Hegetotheriidae (Mammalia, Notoungulata) basal del Mioceno temprano de Patagonia

Hegetotheriidae constituye uno de los clados más derivados dentro del Orden Notoungulata. Ya diversificado en el Oligoceno tardío, sus representantes, muchos de aspecto gliriforme, son conspicuos componentes de las faunas de mamíferos terrestres sudamericanas hasta el Pleistoceno. Sin embargo, es limitado aún el conocimiento de la diversidad de hegetotéridos para la Edad Mamífero Colhuehuapense (Mioceno temprano). Aquí se describe un nuevo hegetotérido, Hegetotheriopsis sulcatus n. gen. et sp., representado por un fragmento craneano con gran parte de la dentadura procedente de capas colhuehuapeses de la Formación Sarmiento en Bryn Gwyn, Patagonia central. Varios fragmentos mandibulares con dientes procedentes de ésta y otras localidades presuntamente contemporáneas en el norte de Patagonia, se asignan tentativamente a este nuevo taxón. Hegetotheriopsis sulcatus presenta una combinación única de caracteres craneanos y dentarios, algunos previamente conocidos para los notoungulados arqueohirácidos (interpretados como el grupo hermano de Hegetotheriidae) y otros que tipifican a los hegetotéridos. El análisis filogenético, basado en la matriz de datos de estudios previos, señala que Hegetotheriopsis sulcatus constituye el hegetotérido más tempranamente divergente hasta ahora conocido, por lo que no puede ser clasificado dentro de Hegetotheriinae ni Pachyrukhinae, las dos subfamilias en las que tradicionalmente se incluyen a todos los hegetotéridos. La presencia en niveles de edad Colhuehuapense de este taxón, más basal que otros conocidos para capas del Oligoceno tardío (Edad Mamífero Deseadense), introduce un linaje fantasma de al menos 4 millones de años en el registro paleontológico de estos mamíferos.
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AREA DE COBERTURA VEGETAL TOTAL AREA DEL MUNICIPIO

AREA DE COBERTURA VEGETAL TOTAL AREA DEL MUNICIPIO

PROSP TAB 2 INDICADORES PARA EL EOT DE VIRACACHÁ ASPECTOS BIOFISICOS INDICADORES POR COMPONENTE NOMBRE DEL INDICADOR.. DEFINICIÓN UNIDAD DE MEDIDA UNIDAD OPERACIONAL STATUS C[r]

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