Search results for "Basal area"
showing 8 items of 18 documents
Response of water and nutrient fluxes to improvement fellings in a tropical montane forest in Ecuador
2009
Abstract Management of natural forests might be one option to reduce the high deforestation rate in Ecuador. We therefore evaluated the response of water and nutrient cycles in a natural tropical montane forest to improvement fellings with the aim of favoring economically valuable target trees which will later be harvested with additional ecosystem impacts not considered here. The study was conducted at ca. 1900–2200 m above sea level in the south Ecuadorian Andes on the east-exposed slope of the east cordillera. In June 2004, one of two paired ca. 10-ha large catchments was thinned by felling 10.2% of the initial basal area (dbh ≥ 10 cm) on 30% of the catchment. The stems remained in situ.…
Optimizing the Sampling Area across an Old-Growth Forest via UAV-Borne Laser Scanning, GNSS, and Radial Surveying
2022
Aboveground biomass, volume, and basal area are among the most important structural attributes in forestry. Direct measurements are cost-intensive and time-consuming, especially for old-growth forests exhibiting a complex structure over a rugged topography. We defined a methodology to optimize the plot size and the (total) sampling area, allowing for structural attributes with a tolerable error to be estimated. The plot size was assessed by analyzing the semivariogram of a CHM model derived via UAV laser scanning, while the sampling area was based on the calculation of the absolute relative error as a function of allometric relationships. The allometric relationships allowed the structural …
Structural analysis of woody species in Mediterranean old fields.
2008
The first part of this study provides an overview on Sicilian olive systems. Subsequently, the study describes the different typologies of cultivated agroforestry systems present in South-Eastern Sicily employing olive trees in association with other Mediterranean tree species, in particular for the production of firewood, coal and animal food (downy or pubescent oak, holm oak, cork oak), but also in association with forage or grazing species (oat, barley, vetch, etc.) or cereals. The study shows that Sicilian agroforestry systems are much more diversified than it was known so far. In the second part, the study describes the spontaneous colonization processes by plants, observed in abandone…
The Effect of Bark Stripping by Deer (Cervus elaphus L.) on Biometric Parameters of the Scots Pine
2022
Bark stripping by red deer (Cervus elaphus L.) is one of the most acute instances of damage wrought by these animals in a forest. Because of its location, bark stripping causes damage to the thickest and most valuable part of the tree trunk, which lowers the quality of the wood due to technical flaws. The research was conducted in 25 sampling sites of pine stands aged 35 years in a mixed, fresh forest habitat in south-western Poland. The study was aimed at assessing the influence of bark damage by deer on biometric parameters of pine stands (Pinus sylvestris L.). The assessment involved the diameter at breast height, height, basal area and volume of the tree stands. The results revealed a s…
Edaphyc characteristics and floristic composition of the seasonally dry forest la menta and timbes, Piura Region, Peru
2011
Con el objetivo de contribuir al conocimiento de los ecosistemas naturales del país, se determinó las características edáficas y la composición florística del bosque estacionalmente seco (La Menta, 04º 43' 55" LS y 80º 04' 55" LO, provincia de Piura y Timbes, 04º 44' 58" LS y 80º 03' 33" LO, provincia de Ayabaca), ambos en la región Piura, Perú. El área de estudio abarcó una extensión aproximada de 6 000 hectáreas en un rango altitudinal entre 350 m a 1 350 m. En cada bosque se muestrearon 5 transectos de 10 x 50 m a intervalos de 20 m, sumando un total de 2 500 m². El análisis de suelo reveló niveles bajos de materia orgánica, nitrógeno y potasio y medios de fósforo asimilable. Estos suelo…
Structural variables drive the distribution of the sensitive lichen Lobaria pulmonaria in Mediterranean old-growth forests
2015
a b s t r a c t We tested the hypothesis that structural variables related to old-growth features affect the distribution of Lobaria pulmonaria in a Mediterranean National Park of Italy. A total of 36 plots, with old-growth characteristics and representing overall three forest types (beech- oak- and mixed- forests) were studied. The lichen was absent in about half of the sites, suggesting that the selection of old-growth forests based solely on structural features is not sufficient to predict the presence of this species, which therefore proves to be rather sensitive and selective. Its abundance was related to high tree circumference and basal area, and to availability of deadwood, confirmi…
Temperature variability in the Iberian Range since 1602 inferred from tree-ring records
2017
Abstract. Tree rings are an important proxy to understand the natural drivers of climate variability in the Mediterranean Basin and hence to improve future climate scenarios in a vulnerable region. Here, we compile 316 tree-ring width series from 11 conifer sites in the western Iberian Range. We apply a new standardization method based on the trunk basal area instead of the tree cambial age to develop a regional chronology which preserves high- to low-frequency variability. A new reconstruction for the 1602–2012 period correlates at −0.78 with observational September temperatures with a cumulative mean of the 21 previous months over the 1945–2012 calibration period. The new IR2Tmax reconstr…
Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela
2014
El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…