scholarly journals Wood specific gravity of trees and forest types in the southern Peruvian Amazon

2000 ◽  
Vol 30 (4) ◽  
pp. 589-589 ◽  
Author(s):  
Deborah W. WOODCOCK
Keyword(s):  
Specific Gravity ◽  
Tropical Forest ◽  
Alluvial Soil ◽  
Peruvian Amazon ◽  
Forest Age ◽  
Forest Types ◽  
High Terrace ◽  
Carbon Stores ◽  
High Degree ◽  
Terrestrial Biomass

Estimates of terrestrial biomass depend critically on reliable information about the specific gravity of the wood of forest trees. The study reported on here was carried out in the southern Peruvian Amazon and involved collection of wood samples from trees (70 spp.) in intact forest stands. Results demonstrate the high degree of variability in specific gravity (ovendry weight/green volume) in trees at single locations. Three forest types (swamp, high terrace forest with alluvial soil, and sandy-soil forest) had values close to the average reported for tropical forest woods (.69). Two early successional forest types, which make up as much as 12% of the total vegetated area in this part of the Amazon, had values significantly lower (.40). An increase in specific gravity with increasing age of the tree, which has been reported in some spe cies of tropical-forest woods, is seen in a positive relationship between specific gravity and di ameter for a species prevalent in one plot. Increases in specific gravity with tree and forest age may be significant in estimating changes in carbon stores over time.

WOOD CHARACTERISTICS OF AMAZON FOREST TYPES

IAWA Journal ◽  
2000 ◽  
Vol 21 (3) ◽  
pp. 277-292 ◽  
Author(s):  
D.W. Woodcock ◽  
G. Dos Santos ◽  
C. Reynel
Keyword(s):  
Specific Gravity ◽  
Vessel Diameter ◽  
Floodplain Forest ◽  
Small Samples ◽  
Vessel Element ◽  
Amazon Forest ◽  
Forest Types ◽  
Swamp Forest ◽  
Climate Controls ◽  
Pattern Of Variation

The Tambopata region of the southern Peruvian Amazon supports a high diversity of both woody plants and forest types. Woods collected from low riverside vegetation, floodplain forest, clay-soil forest on an upper terrace, sandy-soil forest, and swamp forest provide an opportunity to test for significant differences in quantitative anatomical characters among forest types. Vessel-element length in floodplain-forest trees is significantly greater than in the other forest types. Specific gravity is lower in the two early-successional associations (low riverine forest and mature floodplain forest). Vessel diameter and density do not show significant differences among forest types and may be responding to overall climate controls. These two characters, however, show a pattern of variation within a transect extending back from the river along a gradient of increasing substrate and forest age; in addition, sites characterized by frequent flooding or presence of standing water lack vessels in the wider-diameter classes. The six characters analyzed show distributions that are, with the exception of wood specific gravity, significantly nonnormally distributed, a consideration that may be important in representing characteristics of assemblages of taxa. The degree of variability seen in some of the quantitative characters shows the importance of either basing analysis on adequate sample sizes or identifying robust indicators that can be used with small samples.

scholarly journals Effects of topography, soil type and forest age on the frequency and size distribution of canopy gap disturbances in a tropical forest

2013 ◽  
Vol 10 (11) ◽  
pp. 6769-6781 ◽  
Author(s):  
E. Lobo ◽  
J. W. Dalling
Keyword(s):  
Tropical Forest ◽  
Size Distribution ◽  
Soil Type ◽  
Scale Up ◽  
Area Fraction ◽  
Environmental Drivers ◽  
Gap Size ◽  
Forest Age ◽  
Gap Formation ◽  
Canopy Disturbance

Abstract. Treefall gaps are the major source of disturbance in most tropical forests. The frequency and size of these gaps have important implications for forest ecosystem processes as they can influence the functional trait distribution of tree communities, stand-level aboveground biomass and productivity. However, we still know little about the relative importance of environmental drivers of gap disturbance regimes because existing studies vary greatly in criteria used for defining gaps, in the spatial extent of the study area, and the spatial resolution of canopy height measurements. Here we use lidar (light detecting and ranging) to explore how forest age, topography and soil type affect canopy disturbance patterns across a 1500 ha tropical forest landscape in central Panama. We characterize disturbance based on the frequency distribution of gap sizes (the "gap size distribution"), and the area of the forest affected by gaps (the "gap area fraction"). We found that slope and forest age had significant effects on the gap size distribution, with a higher frequency of large gaps associated with old-growth forests and more gentle slopes. Slope and forest age had similar effects on the gap area fraction, however gap area fraction was also affected by soil type and by aspect. We conclude that variation in disturbance patterns across the landscape can be linked to factors that act at the fine scale (such as aspect or slope), and factors that show heterogeneity at coarser scales (such as forest age or soil type). Awareness of the role of different environmental factors influencing gap formation can help scale up the impacts of canopy disturbance on forest communities measured at the plot scale to landscape and regional scales.

scholarly journals Effects of topography, soil type and forest age on the frequency and size distribution of canopy gap disturbances in a tropical forest

2013 ◽  
Vol 10 (4) ◽  
pp. 7103-7133 ◽  
Author(s):  
E. Lobo ◽  
J. W. Dalling
Keyword(s):  
Tropical Forest ◽  
Size Distribution ◽  
Soil Type ◽  
Scale Up ◽  
Area Fraction ◽  
Environmental Drivers ◽  
Gap Size ◽  
Forest Age ◽  
Gap Formation ◽  
Canopy Disturbance

Abstract. Treefall gaps are the major source of disturbance in most tropical forests. The frequency and size of these gaps have important implications for forest ecosystem processes as they can influence the functional trait distribution of tree communities, stand-level above-ground biomass and productivity. However, we still know little about the relative importance of environmental drivers of gap disturbance regimes because existing studies vary greatly in criteria used for defining gaps, in the spatial extent of the study area, and the spatial resolution of canopy height measurements. Here we use LiDAR (light detecting and ranging) to explore how forest age, topography and soil type affect canopy disturbance patterns across a 1500 ha tropical forest landscape in central Panama. We characterize disturbance based on the frequency distribution of gap sizes (the "gap size distribution"), and the area of the forest affected by gaps (the "gap area fraction"). We found that slope and forest age had significant effects on the gap size distribution, with a higher frequency of large gaps associated with old-growth forests and more gentle slopes. Slope and forest age had similar effects on the gap area fraction, however gap area fraction was also affected by soil type and by aspect. We conclude that variation in disturbance patterns across the landscape can be linked to factors that act at the fine scale (such as aspect or slope), and factors that show heterogeneity at coarser scales (such as forest age or soil type). Awareness of the role of different environmental factors influencing gap formation can help scale-up the impacts of canopy disturbance on forest communities measured at the plot scale to landscape and regional scales.

scholarly journals Mitigating Tropical Forest Fragmentation with Natural and Semi-Artificial Canopy Bridges

Diversity ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 66 ◽  
Author(s):  
Diego Balbuena ◽  
Alfonso Alonso ◽  
Margot Panta ◽  
Alan Garcia ◽  
Tremaine Gregory
Keyword(s):  
Natural Gas ◽  
Tropical Forest ◽  
Forest Fragmentation ◽  
Gas Pipeline ◽  
Peruvian Amazon ◽  
Right Of Way ◽  
Natural Gas Pipeline ◽  
Linear Infrastructure ◽  
Linear Infrastructures

Fragmentation caused by linear infrastructures is a threat to forest-dwelling wildlife globally. Loss of canopy connectivity is particularly problematic for highly arboreal species such as those of the Neotropics. We explored the use of both natural canopy bridges (NCBs) and a semi-artificial one over a natural gas pipeline right-of-way (RoW) in the Peruvian Amazon to provide more information on both a proven and a novel solution to the problem of fragmentation. We monitored seven NCBs over 14 months and found crossing rates higher than previously recorded (57.70 crossings/100 trap nights by 16 species). We also constructed a semi-artificial canopy bridge (SACB) out of a liana and found it to be used quickly (seven days after installation) and frequently (90.23 crossings/100 trap nights—nearly nightly) by five species (two procyonids, one didelphid, one primate, and one rodent). This information contributes to our knowledge of mitigation solutions for fragmentation. As linear infrastructure grows globally, more solutions must be developed and tested.

Operational biomass recovery of small trees: equations for six central Ontario tree species

2015 ◽  
Vol 45 (3) ◽  
pp. 372-377 ◽  
Author(s):  
Matt Thiel ◽  
Nathan Basiliko ◽  
John Caspersen ◽  
Jeff Fera ◽  
Trevor Jones
Keyword(s):  
Pinus Strobus ◽  
Size Class ◽  
Forest Types ◽  
White Pine ◽  
Breast Height ◽  
Biomass Equations ◽  
Bioenergy Feedstocks ◽  
Biomass Recovery ◽  
The Difference ◽  
High Degree

Accurate estimates of the amount of biomass that can be recovered at the roadside are needed to make informed decisions about whether to implement an increased utilization harvesting system to supply additional bioenergy feedstocks. Current estimates of recovery are based on total aboveground biomass equations that do not always account for the volume lost to the unharvested stumps or to tops and branches broken during forestry operations. The study took place in a white pine (Pinus strobus L.) mixedwood forest at the Petawawa Research Forest in central Ontario. Equations to describe recoverable biomass were developed from 371 cut and skidded trees, which ranged from 3 to 24 cm in diameter at breast height, across six species. For each species and diameter size class, we evaluated the difference between estimates produced by locally developed equations and those from published equations produced for other locations and forest types. Our recovered biomass estimates were generally higher than the Canadian national averages but within the observed range of published values from across North America. We report that small trees are recovered nearly in their entirety, with little breakage and loss during operations. The high degree of variability among estimates produced by the various equations poses one of the biggest challenges in accurately estimating roadside biomass in an operational setting.

Effects of climate and forest age on plant and caterpillar diversity in the Yucatan, Mexico

2014 ◽  
Vol 30 (5) ◽  
pp. 419-434 ◽  
Author(s):  
Tijl Essens ◽  
Euridice Leyequién ◽  
Carmen Pozo ◽  
Henricus F. M. Vester ◽  
Hector A. Hernández-Arana
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Forest Type ◽  
Species Turnover ◽  
Herbivorous Insect ◽  
Forest Age ◽  
Forest Types ◽  
Humid Forest ◽  
Species Numbers ◽  
Explained Variation

Abstract:Understanding patterns in plant and herbivorous insect diversity across spatial and temporal scales is fundamental to ecology, but comparative multi-taxonomic studies in tropical seasonally dry forests remain scarce. In 36 sites, distributed over three forest age classes (5–10 y, 10–30 y, >100 y) and three seasonal forest types (dry, intermediate, humid), we sampled plants of different stem diameter classes while caterpillars were sampled across vertically distributed forest layers during three seasons over the year. We recorded 299 plant species and 485 caterpillar morphospecies. For large woody plants, species numbers showed a gradually increasing trend with forest age in the intermediate and humid forest types, while the main portion of explained variation in overall species turnover was accounted for by the forest type × forest age interaction (21.3–23.1% of 44.4–48.7%). Ordinations and multivariate pairwise comparisons suggested a faster but also very distinct successional development of species diversity of large plants in the driest compared with humid and intermediate forest types. In contrast, highest species numbers of small plants in the undergrowth was often found in the 5–10 y-old vegetation across forest types, whereas forest type was the major factor in overall species turnover (contributing 24.2% of 48.7% explained variation). Caterpillar species turnover was most correlated to species turnover of small plants; however, variation in caterpillar species diversity appears to be mostly regulated by seasonal cues, and to a lesser extent by patterns of regional turnover and local diversity of undergrowth plant species.

scholarly journals Generic Composition, Structure and Diversity of Secondary Forests at Amisconde, the Pacific Slope of the Cordillera de Talamanca, Costa Rica

2015 ◽  
pp. 1069-1079
Author(s):  
D A P Hooftman
Keyword(s):  
Elevation Gradient ◽  
Forest Composition ◽  
Primary Forest ◽  
Forest Belt ◽  
Forest Age ◽  
Forest Types ◽  
Elevation Gradients ◽  
Positive Correlation ◽  
Composition Structure ◽  
Cordillera De Talamanca

Most Costa Rican forests have been intensively studied in recent years. One exception is the transition zone from lowland wet forest to the high elevatíon Quercus forest belt al Ihe pacific slopes of the Cordillera de Talamanca. An inventory of secondary forest composition, structure and diversity was done on a specific slope (l150- 2300-m elevation) in the conservation and development project Amisconde. Thirteen plots of 500 m2 were evenly spread a10ng an elevation gradient. Specimens were collected of a11 woody individuals (> 3 cm DBH), dried, placed in a herbarium of morphospecies and afterwards identified. In total 90 genera within 49 families were found. The vegetation was separated in three forest types using TWINSPAN c1assification. Forest types were elevatíon based. Elevation and forest age showed (overall) no correlatíon with diversity using ANOVA, with the single exceptíon of a positíve correlatíon of the number of genera and elevatíon. This was opposite to the negative correlations mostly found on elevatíon gradients. The main factors for this positíve correlation were the level of recent disturbance and the distance to primary forest, in combination wíth forest age

scholarly journals Variation in wood physical properties within stems of Guazuma crinita, a timber tree species in the Peruvian Amazon

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
Lady L. Tuisima-Coral ◽  
Joel E. Odicio-Guevara ◽  
John C. Weber ◽  
David Lluncor-Mendoza ◽  
Bohdan Lojka
Keyword(s):  
Specific Gravity ◽  
Physical Properties ◽  
Tree Species ◽  
Basic Density ◽  
Agroforestry Systems ◽  
Peruvian Amazon ◽  
Transport And Transformation ◽  
Stem Wood ◽  
Timber Tree ◽  
Old Trees

An understanding of wood physical properties and the interrelationships that govern them is required for efficient utilization of timber tree species. Guazuma crinita is a fast-growing timber tree of agroforestry systems in the Peruvian Amazon. The aim of this study was to assess variation in wood physical properties within the G. crinita stem. Wood samples were obtained from the base, middle and top of the stem of 12 randomly selected eight-year-old trees from six provenances in order to determine wood moisture content, density, specific gravity, radial, tangential and volumetric shrinkage and the coefficient of anisotropy. Pearson correlations between physical properties were also determined. The highest basic density was 459 kg/m3 from Tournavista provenance. Mean basic density and specific gravity were 430 kg/m3 and 0.45 respectively. There was statistically significant variation (p ≤ 0.05), due to stem level within the trees. The moderate values of density and anisotropy coefficient (1.56) suggest that G. crinita is a stable wood; these are important advantages in terms of costs of the processes of transport and transformation. Given the variation found in the limited tree samples of this study, we recommend further analysis with larger samples from different provenances and planting zones.Variación de las propiedades físicas en troncos de Guazuma crinita, una especie maderable en el Amazonas Peruano El entendimiento de las propiedades físicas de la madera y de las interrelaciones que las gobiernan es necesario para el uso eficiente de las especies maderables. Guazuma crinita es una especie arbórea de rápido crecimiento en sistemas agroforestales del Amazonas peruano. El objetivo de este estudio fue determinar la variación de las propiedades físicas de la madera en el fuste de árboles G. crinita. Las muestras de madera fueron obtenidas de la base, parte media y parte superior del tronco de 12 árboles de ocho años de edad aleatoriamente seleccionados, de seis lugares de procedencia. Con ellas se determinó: contenido de humedad, densidad, densidad relativa, contracciones radial, tangencial y volumétrica y coeficiente de anisotropía; se determinaron también las correlaciones de Pearson entre las propiedades físicas. La densidad básica mayor fue 459 kg/m3, de la procedencia de Tournavista. Las densidades básica y relativa promedio fueron 430 kg/m3 y 0.45, respectivamente. Se encontró variación estadísticamente significativa (p ≤ 0.05) entre alturas en el fuste. La madera moderadamente densa y el coeficiente de anisotropía (1.56) sugieren que G. Crinita es una madera estable, lo que representa importantes ventajas en términos de costos por transporte y proceso de transformación. Debido a la variación encontrada en las limitadas muestras de árboles de este estudio, se recomienda la realización de más análisis con mayores muestras y de diferentes sitios y plantaciones.

Mapping secondary tropical forest and forest age from SPOT HRV data

1999 ◽  
Vol 20 (18) ◽  
pp. 3625-3640 ◽  
Author(s):  
D. S. Kimes ◽  
R. F. Nelson ◽  
W. A. Salas ◽  
D. L. Skole
Keyword(s):  
Tropical Forest ◽  
Forest Age ◽  
Secondary Tropical Forest
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