Predicting of biomass in Brazilian tropical dry forest: a statistical evaluation of generic equations

Abstract

Dry tropical forests are a key component in the global carbon cycle and their biomass estimates depend almost exclusively of fitted equations for multi-species or individual species data. Therefore, a systematic evaluation of statistical models through validation of estimates of aboveground biomass stocks is justifiable. In this study was analyzed the capacity of generic and specific equations obtained from different locations in Mexico and Brazil, to estimate aboveground biomass at multi-species levels and for four different species. Generic equations developed in Mexico and Brazil performed better in estimating tree biomass for multi-species data. For Poincianella bracteosa and Mimosa ophthalmocentra, only the Sampaio and Silva (2005) generic equation was the most recommended. These equations indicate lower tendency and lower bias, and biomass estimates for these equations are similar. For the species Mimosa tenuiflora, Aspidosperma pyrifolium and for the genus Croton the specific regional equations are more recommended, although the generic equation of Sampaio and Silva (2005) is not discarded for biomass estimates. Models considering gender, families, successional groups, climatic variables and wood specific gravity should be adjusted, tested and the resulting equations should be validated at both local and regional levels as well as on the scales of tropics with dry forest dominance.

Stump regrowth and estimation of reconstituting Caatinga shrub-tree biomass under forest management

“…The original DBH was estimated from the selected model, based on the DAB of the stumps remaining in the field. The equation of Silva and Sampaio (2008) was used for Caatinga vegetation located about 70 km from the studied area (Equation 2) and validated for the present study by Lima et al (2017).…”

Path Analysis Applied to Evaluation of Biomass Estimates in Subtropical Forests at Brazil

“…The relationship between the total biomass and dbh allows to identify that the variance between diameter classes increases with the dbh growth (Figure 2A), therefore stratification in diameter classes is appropriated to reduce errors. A similar relationship (BT and base diameter) can be seen in the article by Lima et al (2017), in which they deal with the modeling of total biomass of trees in dry tropical forest in the state of Pernambuco, Brazil, and the maximum dbh is 35 cm due to the forest typology. In a study with the species Betula platyphylla Suk., Wang et al (2018) found a similar relationship between wood biomass and dbh, considering a maximum dbh of 15 cm.…”

Estimativas de biomassa aérea e volume lenhoso de Sabiá (Mimosa caesalpiniifolia Benth.) em povoamento com 12 anos de idade

“…No âmbito das ciências florestais, equações alométricas são entendidos como modelos matemáticos baseados em regressão estatística que utilizam dados de biomassa ou volume lenhoso obtidos em experimentos de campo, onde as árvores são colhidas, pesadas ou cubadas. Estas informações são utilizadas para obter coeficientes que ajustam os valores das medidas de peso ou volume cubados a algum atributo dendrométrico (tal como DAP, altura, densidade da madeira, etc), com a finalidade de produzir um modelo matemático com poder preditor estatisticamente satisfatório (Chave et al 2005;Sampaio et al 2010;De Lima et al 2017).…”

“…Entretanto, embora a determinação da biomassa aérea e do volume de espécies arbóreoarbustivas da Caatinga já tenha sido abordada em outros trabalhos (Silva e Sampaio 2008;Sampaio et al 2010;De Lima et al 2017;Barreto et al 2018;Dalla Lana et al 2018), as pesquisas que visam estudar esses parâmetros em plantios homogêneos e, especificamente, com povoamentos de Mimosa caesalpiniifolia Benth (Sabiá) são pouco comuns, ainda mais quando se considera condições particulares de cada sítio e a necessidade de ajustes específicos aos dados locais, para incidir em menor erro nas estimativas.…”