Allometry and biomass distribution in replanted mangrove plantations at Gazi Bay, Kenya

Abstract

ABSTRACT1. This study reports above-ground biomass of 5 and 8 years old mangrove plantations in Kenya. Trees with stem diameter greater than 5.0 cm inside 100 m 2 sample plots were harvested, and then separated into stems (trunks), branches, leaves and prop roots.2. Mean above-ground biomass was calculated at 20.25 t dry matter ha À1 for Rhizophora mucronata Lam., 11.7 t dry matter ha À1 for Avicennia marina (Forsk.) Vierh., 6.7 t dry matter ha À1 for Sonneratia alba Sm. and 3.7 t dry matter ha À1 for Ceriops tagal (Perr.) C. B. Robinson. In A. marina and R. mucronata, stems (52.19%) and prop-roots (30.28%), respectively, accounted for the highest proportion of the above-ground dry weight. While in S. alba and C. tagal, branch biomass represented the highest percentage of biomass, 48.20% and 43.62%, respectively.3. The total above-ground biomass of R. mucronata was best estimated from regression equations using a combination of height and diameter above stilt root as the independent variables. For A. marina, C. tagal and S. alba there was no simple correlation found between the above-ground biomass and tree height or stem diameter.4. Comparison of the regression models with those developed elsewhere gave different biomass values in these plots, further reinforcing the need for the use of site-specific allometric equations for biomass estimation.

Above- and belowground tree biomass models for three mangrove species in Tanzania: a nonlinear mixed effects modelling approach

“…A review by Komiyama et al (2008) identified 13 species-specific and two common (i.e., multi-species) models for prediction of aboveground biomass of mangroves, while nine speciesspecific models and one common model were identified for belowground biomass. Additional studies on mangroves that developed models for prediction of biomass not present in this review also exist (e.g., Kairo et al 2009;Kauffman and Donato 2012;Sitoe et al 2014). With the exception of the models developed by Kairo et al (2009) in Kenya and Sitoe et al (2014) in Mozambique, most of the models have been developed for mangroves in Asia.…”

“…Additional studies on mangroves that developed models for prediction of biomass not present in this review also exist (e.g., Kairo et al 2009;Kauffman and Donato 2012;Sitoe et al 2014). With the exception of the models developed by Kairo et al (2009) in Kenya and Sitoe et al (2014) in Mozambique, most of the models have been developed for mangroves in Asia. The relatively few existing models for belowground biomass may be associated with the labor-intensive nature of sampling belowground biomass for mangrove tree species (Njana et al 2015).…”

“…For example, the aboveground model by Chave et al (2005) is based on mangrove data from a limited geographical area (French Guiana and Guadeloupe); thus, the model does not represent mangroves found in Africa and it does not include any dominant species found in Africa. Similarly, the aboveground biomass models from mangroves in Kenya and Mozambique are both based on data from one site, and they have limited sample size (e.g., n=5, Kairo et al 2009; n = 31 for six species, Sitoe et al 2014) and tree size ranges (dbh up to 42 cm, Sitoe et al 2014). Trees with dbh > 40 cm are likely to be found in Tanzania (e.g.…”

“…Thus, model tests on real data are preferable, but this is of course seldom possible since suitable data would mostly be collected for calibrating local models, which renders the use of the alien model unnecessary. However, Njana et al (2015) tested selected existing belowground biomass models on relevant data from Tanzania, both common (Komiyama et al 2005) and species-specific (Tamai et al 1986;Comley and McGuinness 2005;Kairo et al 2009). The results revealed large prediction errors for both the common (26-63 %) and species-specific (55-63 %) models.…”

Ecological Variability and Carbon Stock Estimates of Mangrove Ecosystems in Northwestern Madagascar

“…Mangrove ecosystems also support high floral and faunal biodiversity [9,[12][13][14] and sequester significant amounts of CO 2 [15,16]. While numerous studies have measured above-ground biomass in mangrove trees (e.g., [17][18][19][20][21][22][23][24][25][26]), comparatively few have quantified above-and below-ground carbon (C) pools, including soil (i.e., [15,[27][28][29][30][31][32][33][34]); however, it is the deep, organic material enriched soils that contain the vast majority of C stocks [35][36][37][38]. Factoring in soil, mangroves have been found to be amongst the most carbon-dense forests in the tropics, with similar or greater above-and exceptionally larger below-ground stocks compared with the terrestrial systems reported in several studies [15,27,[32][33][34]39].…”