A three level system for estimating the biomass of Castanea sativa Mill. coppice stands in north-west Spain

Sweet chestnut agroforestry systems in North-western Spain: Classification, spatial distribution and an ecosystem services assessment

“…The tree density values were chosen considering the traditional C. sativa AFS, in which the open structure maximizes the amount of light reaching the trees. The density of coppice stands of this species is therefore > 400 trees/ha (Menéndez-Miguélez et al, 2013). The diameter (dg) of sweet chestnut in the coppiced stands in the study area ranges between 9.56 and 30.98 cm (Menéndez-Miguélez et al, 2013;, while in plantations of this species younger than 25 years, the diameter is < 35 cm (Álvarez-Álvarez et al, 2010).…”

“…Two criteria were considered: i) the type of woodland in relation to tree density (cleared stands <400 trees/ha derived from traditional management for fruit production, and dense stands ≥ 400 trees/ha derived from abandonment of the previous type); and ii) the type of dominant trees in the stand (in relation to diameter and height). The values of these variables, shown below, were chosen on the basis of recent studies characterizing C. sativa coppice stands in the area (Menéndez-Miguélez et al, 2013;. As the target ecosystem of the present study was the C. sativa agro-ecosystem, we restricted our investigation to those stands in which this species was the most common tree.…”

“…The low density of chestnut wood in comparison with other species (Quercus spp., Fagus sylvatica and Fraxinus excelsior) may be related to the lower importance of this species as firewood. However, there is a growing interest in the use of C. sativa for energetic purposes as a result of the higher levels of biomass production (Menéndez-Miguélez et al, 2013). AFS types 4 and 5 (high density of trees in coppice stands) represent the stages of the AFS with the highest potential to supply this increasingly important ES (Nunes et al, 2013).…”

“…Although man-made, these AFS are included in the Habitats Directive (Directive 92/43 Annex 1: "Castanea sativa woodlands"; EC, 1992) and show a high species richness for moderate intensity of use (Guitián et al, 2011). Some coppice stands devoted to traditional chestnut production have been almost totally abandoned, and most stands were destined for production of high quality timber and biomass (Menéndez-Miguélez et al, 2013). These pure chestnuts forests are regenerated from adventitious and dormant buds and typically include a high density of stems per hectare.…”

Aboveground Dendromass Estimation of Juvenile Paulownia Sp.

“…The models for total aboveground biomass, or total dendromass, are usually derived in two stages Menéndez-Miguélez et al, 2013). In the first stage, models for each particular biomass fraction are developed and in the next stage, they are combined in a system of equations that are fitted simultaneously taking into account the system additivity, which requires that the estimate of the total biomass equals the sum of the estimates of the individual compartments (Parresol, 1999;Burkhart & Tomé, 2012).…”