RESUMO

The structural breakdown of skeletal remains follows a lengthy decomposition process, progressing from the appearance of cracking along the bone to complete loss of shape and skeletal integrity, that can occur in as early as 6 years or as long as 30. The length of time a set of skeletal remains takes to decompose depends heavily upon its micro-environment, the local context in which decomposition agents act on remains. Critical changes in the micro-context can drastically increase or slow the process. The burial of remains below the surface has been found to effectively shut out many of the most destructive decaying agents, such as the natural elements and insect and animal activity. This causes an increase in the amount of time needed to breakdown the skeletal remains. A better understanding of the decomposition process in varying micro-contexts is important for the ability to correctly estimate time since burial. This can aid not only in understanding of archaeological remains, but also in the identification of individuals in modern forensic and human rights cases. This study details the observations made during the excavation and analysis of burials on the Isla de Coiba off the coast of Panama. The excavation took place during the summer 2003 in an effort to identify several individuals who were believed to be part of the 'disappeared', people who went missing and believed to have been murdered under orders by the Torrijos and Noriega military regimes. Through the fieldwork analysis a decomposition timeline, specific for the Coiba micro-environment, was created. This new set of stages can be used to estimate time since burial in other areas whose local context is similar to that found on Coiba.

Assuntos

RESUMO

Mangrove forest is an important ecosystem that provides many services, but in Panama, as in other countries, they are under threat due to a variety of human activities. Nowadays, large areas of mangroves continue to be lost without been described and lack of management strategies. This study focused on the mangrove structure in the two largest islands, Isla del Rey and Isla San Jose, of Las Perlas Archipelago (LPA), Pacific Panama. Assessment of Landsat satellite imagery revealed loss of mangroves in the LPA of 965ha in the period 1974-1986, and 248ha in the period 1986-2000. The majority of the loss (>77%) from the two study islands was due to timber extraction and agricultural development. In May 2006, permanent plots following the CARICOMP protocol were established at two sites on Isla del Rey (R1 and R2) and one site on Isla San Jose (SJ) where standardized metrics such as species, height and diameter at breast height of adult trees and seedlings were recorded. Forest structure differed at the three sites, although R1 and R2 were most similar. At R1, Laguncularia racemosa was the important species and R2 was dominated by Pelliciera rhizophorae. Examination of the forest structure and classified imagery indicated that these sites are spatially dynamic and appear to be rejuvenating. The forest structure would indicate that the sites have been growth-limited previously by human activities and possibly by other factors. SJ was dominated by Rhizophora mangle and appears to have a mature forest with large adult trees and few seedlings. It does not appear to have shown the same extent of spatial regrowth as the other two sites between 1986 and 2000 and is relatively static. The establishment of permanent plots and monitoring will be useful as part of the management plan, as the LPA shows a variety of mangrove structures and could be subject to further coastal development. Rev. Biol. Trop. 58 (3): 857-869. Epub 2010 September 01.

Los bosques de manglar son ecosistemas importantes que proveen muchos servicios, pero éstos están bajo la amenaza de una variedad de actividades humanas y grandes áreas de manglar continúan perdiéndose en Panamá. Este estudio está enfocado en la estructura de manglar de las dos islas más grandes del Archipiélago de Las Perlas en el Pacifico Panameño (LPA), la Isla del Rey y la Isla San José. La evaluación de las imágenes del satélite Landsat revela la pérdida de manglares en LPA de 965ha en el periodo entre 1974-1986, y de 286ha en el periodo 1986-2000. La mayor parte de la pérdida (>77%) en las dos islas estudiadas fue debida a la extracción de madera y al desarrollo agrícola. En mayo de 2006, se establecieron parcelas permanentes siguiendo el protocolo de CARICOMP en dos sitios en la isla del Rey (R1 y R2) y un sitio en la Isla San José (SJ) donde especies, altura y diámetro a la altura de la copa de árboles adultos y jóvenes fueron registradas. La estructura del bosque difirió en los tres sitios, sin embargo R1 y R2 fueron los más similares. En R1, Laguncularia racemosa fue la especie más dominante y Pelliceria rhizophora en R2. El análisis de la estructura del bosque y de imágenes clasificadas indicó que estos sitios son espacialmente dinámicos y parecen estar regenerándose. La estructura del bosque indica que el crecimiento en los sitios ha estado limitado por las actividades humanas y posiblemente por otros factores. SJ fue dominado por Rhizophora mangle y parece tener un bosque maduro con árboles adultos grandes y pocos jóvenes. Éste sitio no parece mostrar la misma extensión de rebrote espacial de los otros dos sitios entre 1986-2000 y es relativamente estático. El establecimiento de parcelas permanentes y el monitoreo serán útiles en la implementación del plan de manejo, ya que los manglares del LPA tienen una variedad estructural y podrían estar sujetos a un mayor desarrollo costero.

Assuntos

RESUMO

Mangrove forest is an important ecosystem that provides many services, but in Panama, as in other countries, they are under threat due to a variety of human activities. Nowadays, large areas of mangroves continue to be lost without been described and lack of management strategies. This study focused on the mangrove structure in the two largest islands, Isla del Rey and Isla San Jose, of Las Perlas Archipelago (LPA), Pacific Panama. Assessment of Landsat satellite imagery revealed loss of mangroves in the LPA of 965ha in the period 1974-1986, and 248ha in the period 1986-2000. The majority of the loss (>77%) from the two study islands was due to timber extraction and agricultural development. In May 2006, permanent plots following the CARICOMP protocol were established at two sites on Isla del Rey (R1 and R2) and one site on Isla San Jose (SJ) where standardized metrics such as species, height and diameter at breast height of adult trees and seedlings were recorded. Forest structure differed at the three sites, although R1 and R2 were most similar. At R1, Laguncularia racemosa was the important species and R2 was dominated by Pelliciera rhizophorae. Examination of the forest structure and classified imagery indicated that these sites are spatially dynamic and appear to be rejuvenating. The forest structure would indicate that the sites have been growth-limited previously by human activities and possibly by other factors. SJ was dominated by Rhizophora mangle and appears to have a mature forest with large adult trees and few seedlings. It does not appear to have shown the same extent of spatial regrowth as the other two sites between 1986 and 2000 and is relatively static. The establishment of permanent plots and monitoring will be useful as part of the management plan, as the LPA shows a variety of mangrove structures and could be subject to further coastal development.

Assuntos

RESUMO

Las Perlas Archipelago (LPA) is located off the Pacific Coast of Panama and was designated as a marine protected area (MPA) in 2007. This baseline study of the shallow and deeper sedimentary habitats of the islands partly informed the MPA designation. Ninety-two grab stations and twenty trawl stations were sampled. Sediment grab sample results were interpolated to produce a map that showed the area to be dominated by mud (1246 km2, 40%) and sand/shell sediments (780 km2, 25%). A total of 201 taxa were recorded and over 5800 individual specimens were processed, revealing that the sediments hold varying community compositions, with annelids being the dominant group (73%) followed by crustaceans (14%). Relationships were evident between community, feeding guilds, and sediment types, which give an indication of communities that can be expected in similar sediments in other areas of the Tropical Eastern Pacific. A study of this scale and level of detail is rare for this biogeographic region and provides a valuable, comprehensive appreciation of the LPA's benthos.

Assuntos