Phytomass structure of natural plant communities on spodosols in southern Venezuela: The tall Amazon Caatinga forest

Abstract

The phytomass structure of the evergreen lowland forest vegetation (Tall Amazon Caatinga) supported by tropaquods near San Carlos de Rio Negro, Federal Amazon Territory of Venezuela was studied in 13 10 m X 10 m plots. The plots were laid out subjectively to cover a low topographical gradient along which the forest on tropaquod is grading into a low woodland (Bana, or Low Amazon Caatinga). The phytomass was estimated by destructive sampling.The total living phytomass (dry matter) varies between I99 t/ha in one plot including a natural gap, to 822 t/ha in a plot located near a blackwater creek draining the 10 ha study site in which the vegetation was surveyed. Dead aboveground phytomass (dry matter) varies between 2 and 37 t/ha. The average leaf area index is 5. t. Leaves are sclerophyllous. The mesophyll leaf size class is dominant.Compared with other Amazonian rainforests the Tall Amazon Caatinga is lower in aboveground phytomass and wood volume, respectively, but its root average proportion is 2.4 times greater.One hundred and thirty species (dbh 1>1 cm) were recorded in all plots, 14--45 species per plot composed the aboveground phytomass. 20 species each had a relative frequency of 50 or more percent. 7 of these species plus 10 less frequent ones each represented 10 or more percent of the basal area in at least 1 plot. Sixteen species each contributed l0 or more percent to the aboveground phytomass, in at least 1 plot. There is only 1 species (Micranda sprucei, Euphorbiaceae) which was observed in all plots. Its contribution to basal area and aboveground phytomass is considerable. M. sprucei is also the dominant species of the top canopy layer.

Phytomass structure of natural plant communities on spodosols in southern Venezuela: the Bana woodland

“…The average dry above-ground phytomass in the Tall Caatinga is 280 t/ha (Klinge & Herrera, 1983). The average root contribution to total phytomass is 34% in the Tall Caatinga.…”

“…This is reflected by the basal area values. Comparing the Bana values for both basal area and above-ground phytomass to those for Tall Amazon Caatinga (Klinge & Herrera, 1983), it is observed that the basal area in the Bana with relatively low biomass is disproportionately high. This observation provides evidence that towards Open Bana the radial growth of the boles of Bana trees increases progressively relatively to their height growth ( Fig.…”

“…Other vegetation types between the Rio Negro and Casiquiare in Venezuela are Mixed tropical rainforest growing on oxisols (Uhl, 1980;Uhl & Murphy, 1981), and Tall Amazon Caatinga on growing tropaquods (Klinge, 1978;Herrera, 1979;Klinge & Herrera, 1983;Herrera et al, in press). On ultisols, Eperua purpurea forest (N. Dezzeo & W. Franco, unpubl.…”

Forest floor biomass, litter fall and nutrient return in Central Himalayan oak forests

“…A considerable amount of data on above-ground litter production exists for various parts of the world (e.g., Bray & Gorham 1964;Bongers etal. 1985;Klinge & Herrera 1983;Meentemeyer etaL 1982;Proctor 1983).…”

Revisión de métodos para el monitoreo de biomasa y carbono vegetal en ecosistemas forestales tropicales

“…Para determinar y monitorear el almacenamiento de carbono orgánico en sistemas forestales y agroforestales, se debe estimar la diferencia de carbono almacenado en suelos y en la biomasa para sitios con el proyecto y sin este sobre un período de tiempo específico; la diferencia en la cantidad de carbono almacenado es el carbono secuestrado por el proyecto. Existen dos técnicas de monitoreo que pueden ser usadas para evaluar el carbono fijado en proyectos forestales (Araujo, Higuchi & de Carvalho, 1999;Brown, 1999;Brown, Gillespie & Lugo, 1989, Brown & Lugo, 1984Chave et al, 2004;Chave et al, 2014;Cifuentes et al, 2015;Francis, 2000;Jordan & Uhl, 1978;Klinge & Herrera, 1983;Petrokofsky et al, 2012;Saldarriaga, West, Tharp & Uhl, 1988;Schlegel, 2001) y recomendadas por el IPCC (1996): -Modelaje o método indirecto: se calcula la biomasa del árbol con ecuaciones o modelos matemáticos calculados por medio de análisis de regresión entre variables de los árboles, tales como el diámetro a la altura del pecho (dap), la altura comercial (h c ) y total (h t ), el crecimiento diamétrico, el área basal y la densidad específica de la madera. También puede estimarse la biomasa a partir del volumen del fuste, y usar luego la densidad básica de la madera para calcular el peso seco y un factor de expansión para calcular el peso total del árbol.…”