scholarly journals Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
JAMES G. KAIRO ◽  
MICHAEL NJOROGE GITHAIGA ◽  
KIPLAGAT KOTUT ◽  
FRANCIS KARIUKI

Abstract. Githaiga MN, Kotut K, Kariuki F, Kairo JG. 2019. Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya. Bonorowo Wetlands 9: 18-32. The goal of this study was to determine the forest structure and estimate biomass accumulation above and below ground in the mangrove forest of Gazi Bay. The western, middle, and eastern forest blocks of the Gazi Bay mangrove forest were investigated for forest structure, whereas the western forest block was determined for biomass accumulation. To calculate below-ground biomass accumulation, in-growth cores of 80 cm long, 20 cm broad, and 60 cm deep were employed. Above-ground biomass accumulation was calculated using data on tree height and stem diameter at breast height (DBH-130). Leaf phenology was observed by tagging shoots. At the start, environmental variables were measured every four months for a year across four mangrove species zones. The linear regeneration sampling approach was used to determine the composition and distribution pattern of natural regeneration (LRS). Salinity revealed a strong negative connection with above-ground biomass accumulation among the soil environment characteristics studied. Sonneratia alba had the highest biomass accretion rate of 10.5 1.9 t ha-1 yr-1 among the four forest zones. Rhizophora mucronata (8.5 0.8 t ha-1 yr-1), Avicennia marina (5.2 1.8 t ha-1 yr-1), and Ceriops tagal (2.6 1.5 t ha-1 yr-1) were the next most abundant species. Above-ground and below-ground biomass accumulation differed significantly among zones (F (3, 8) = 5.42, p = 0.025) and (F (3, 8) = 16.03, p = 0 001), respectively. There was a significant difference in total biomass accumulation across zones (F (3, 8) =15.56, p = 0.001). For the entire forest, a root : shoot biomass accumulation ratio of 2 : 5 was calculated. This study's findings provide more accurate estimates of mangrove carbon capture and storage, which can be used in carbon credit discussions in the emerging carbon market.

Biologia ◽  
2006 ◽  
Vol 61 (20) ◽  
Author(s):  
Miroslav Svoboda ◽  
Karel Matějka ◽  
Jiří Kopáček

AbstractThis paper presents data on species composition, biomass, and element pools (C, N, P, Ca, Mg, Na, K, Al, Fe, Mn) of the understory vegetation of spruce forests in the catchments of lakes Čertovo jezero (CT) and Plešné jezero (PL) in the Bohemian Forest (Šumava, Czech Republic). Calamagrostis villosa was the most abundant species in the CT catchment, while Vaccinium myrtillus was the most abundant species in the PL catchment. The catchments weighted mean (CWM) of above-ground biomass of the understory vegetation was 288 and 723 g m−2 in the CT and PL catchments, respectively. The significant difference in the biomass between the catchments was caused by the much higher abundance of V. myrtillus in the PL catchment. The CWM of below-ground biomass of the fine roots was 491 and 483 g m−2 in the CT and PL catchments, respectively. The respective CWM element pools of biomass in the CT and PL catchments were: C (33 and 51 mol m−2), N (0.8 and 1.0 mol m−2), P (24 and 34 mmol m−2), Ca (53 and 113 mmol m−2), Mg (24 and 41mmol m−2), Na (3.7 and 6.5 mmol m−2), K (83 and 109 mmol m−2), Al (50 and 42 mmol m−2), Fe (13.3 and 7.3 mmol m−2), and Mn (4.2 and 8.8 mmol m−2).


Prediction equations have been worked out on the basis of 17 trees felled for Eucalyptus hybrid for different tree components on the basis of diameter and height (D2 H) which was found to be best suited as depended variable over D & D2 (Diameter at Breast Height 1.37 m). The correlation coefficient (r2 ) values of all the tree components are significant where as these values for AGB (Above Ground Biomass), BGB (Below Ground Biomass) and Total Biomass (TB) is highly significant. These developed prediction equations are validated by comparing the predicted values of total biomass of overall average trees felled with their actual / calculated biomass. The differences of predicted and actual biomass ranged from 6.8 to 38.5 % of different diameter classes in the felled Eucalyptus trees. Generally differences between predicted and actual biomass in percentages of 10 – 30 % is universally acceptable in forest management.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Gerong Wang ◽  
Yue Sun ◽  
Mo Zhou ◽  
Naiqian Guan ◽  
Yuwen Wang ◽  
...  

Abstract Background Herbs are an important part of the forest ecosystem, and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances. Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone, this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning. Results The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity, they were mainly determined by seasonal changes. Across the entire growing season, the species with the highest importance values in thinning treatments included Carex pilosa, Aegopodium alpestre, Meehania urticifolia, and Filipendula palmata, which dominated the herb layer of the coniferous and broad-leaved mixed forest. The number of species, Margalef index, Shannon-Wiener index and Simpson index all had their highest values in May, and gradually decreased with months. Pielou index was roughly inverted “N” throughout the growing season. Thinning did not increase the species diversity. Thinning can promote the total biomass, above- and below-ground biomass. The number of plants per unit area and coverage were related to the total biomass, above- and below-ground biomass. The average height had a significantly positive correlation with herb biomass in May but not in July. However, it exerted a significantly negative correlation with herb biomass in September. The biomass in the same month increased with increasing thinning intensity. Total herb biomass, above- and below-ground biomass showed positive correlations with Shannon-Winner index, Simpson index and Pielou evenness index in May. Conclusions Thinning mainly changed the light environment in the forest, which would improve the plant diversity and biomass of herb layer in a short time. And different thinning intensity had different effects on the diversity of understory herb layer. The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.


2020 ◽  
pp. 1-7
Author(s):  
Brandon R. Hays ◽  
Corinna Riginos ◽  
Todd M. Palmer ◽  
Benard C. Gituku ◽  
Jacob R. Goheen

Abstract Quantifying tree biomass is an important research and management goal across many disciplines. For species that exhibit predictable relationships between structural metrics (e.g. diameter, height, crown breadth) and total weight, allometric calculations produce accurate estimates of above-ground biomass. However, such methods may be insufficient where inter-individual variation is large relative to individual biomass and is itself of interest (for example, variation due to herbivory). In an East African savanna bushland, we analysed photographs of small (<5 m) trees from perpendicular angles and fixed distances to estimate above-ground biomass. Pixel area of trees in photos and diameter were more strongly related to measured, above-ground biomass of destructively sampled trees than biomass estimated using a published allometric relation based on diameter alone (R2 = 0.86 versus R2 = 0.68). When tested on trees in herbivore-exclusion plots versus unfenced (open) plots, our predictive equation based on photos confirmed higher above-ground biomass in the exclusion plots than in unfenced (open) plots (P < 0.001), in contrast to no significant difference based on the allometric equation (P = 0.43). As such, our new technique based on photographs offers an accurate and cost-effective complement to existing methods for tree biomass estimation at small scales with potential application across a wide variety of settings.


2016 ◽  
Vol 8 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Sudam Charan SAHU ◽  
H.S. SURESH ◽  
N.H. RAVINDRANATH

The study of biomass, structure and composition of tropical forests implies also the investigation of forest productivity, protection of biodiversity and removal of CO2 from the atmosphere via C-stocks. The hereby study aimed at understanding the forest structure, composition and above ground biomass (AGB) of tropical dry deciduous forests of Eastern Ghats, India, where as a total of 128 sample plots (20 x 20 meters) were laid. The study showed the presence of 71 tree species belonging to 57 genera and 30 families. Dominant tree species was Shorea robusta with an importance value index (IVI) of 40.72, while Combretaceae had the highest family importance value (FIV) of 39.01. Mean stand density was 479 trees ha-1 and a basal area of 15.20 m2 ha-1. Shannon’s diversity index was 2.01 ± 0.22 and Simpson’s index was 0.85 ± 0.03. About 54% individuals were in the size between 10 and 20 cm DBH, indicating growing forests. Mean above ground biomass value was 98.87 ± 68.8 Mg ha-1. Some of the dominant species that contributed to above ground biomass were Shorea robusta (17.2%), Madhuca indica (7.9%), Mangifera indica (6.9%), Terminalia alata (6.9%) and Diospyros melanoxylon (4.4%), warranting extra efforts for their conservation. The results suggested that C-stocks of tropical dry forests can be enhanced by in-situ conserving the high C-density species and also by selecting these species for afforestation and stand improvement programs. Correlations were computed to understand the relationship between above ground biomass, diversity indices, density and basal area, which may be helpful for implementation of REDD+ (reduce emissions from deforestation and forest degradation, and foster conservation, sustainable management of forests and enhancement of forest carbon stocks) scheme.


1970 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Anita Pokharel ◽  
Madhu Chhetri ◽  
Chiranjibi P Upadhyaya

Limited information is available on the species composition, above ground biomass and its relations to grazing in a trans-Himalayan rangeland. Its assessment is essential for long term conservation and management. In the present study, we compared species composition, phenology, diversity index and biomass between controlled (without grazing) and open (free grazing) plots to assess the effects of grazing in the selected experimental sites of Upper Mustang during July and November 2005. Species encountered were classified as high, medium, low and non palatable and in three life form categories-grasses, shrubs and forbs. The experimental sites are dominated by forbs (80%) followed by grasses (15%) and shrubs (5%). Disturbance caused by grazing affects the phenological characteristics of the plant community. Result also reveals that species diversity, maximum possible diversity, evenness and species richness was higher in the grazed plots during July and November. A comparison of the aboveground biomass in July showed that mean percentage biomass of high, medium and low palatable species is higher in ungrazed plots. In November, the percentage biomass of only medium palatable species was higher in ungrazed plots and rest of the category is higher in grazed plots. Significant difference in July, a peak growing seasons for most of the plant species in the region reveals that the pasture has impact of livestock grazing. Keywords: Biomass, diversity, grazing effect, rangeland, species Banko Janakari: A journal of forestry information for Nepal Vol.17(1) 2007 pp.25-31


2015 ◽  
Vol 34 (2) ◽  
pp. 137-146
Author(s):  
Saulius Marcinkonis ◽  
Birutė Karpavičienė ◽  
Michael A. Fullen

AbstractThe aim of the present study is to evaluate the long-term effects of long-term piggery effluent application on semi-natural grassland ecotop-phytotop changes (above- and below-ground phytomass production, and carbon and nitrogen allocation in grassland communities) in relation to changes (or variability) in topsoil properties. Analysis of phytomass distribution in piggery effluent irrigated grassland communities showed that dry biomass yield varied from 1.7−5.3 t ha-1. Variability in soil and plant cover created a unique and highly unpredictable site specific system, where long-term anthropogenic influences established successor communities with specific characteristics of above- and below-ground biomass distribution. These characteristics depend more on grassland communities than on soil chemical properties. Families of grasses (Poaceae) dominated the surveyed communities and accumulated most carbon and least nitrogen, while legumes accumulated most nitrogen and lignin and least carbon. Carbon concentrations in above-ground biomass had minor variations, while accumulation of nitrogen was strongly influenced by species diversity (r = 0.94, n = 10, p <0.001) and production of above-ground biomass


2019 ◽  
Vol 11 (7) ◽  
pp. 1941 ◽  
Author(s):  
Yuzhe Li ◽  
Jiangwen Fan ◽  
Hailing Yu

Grasslands in northern China form an important ecological barrier that prevents and controls desertification. The Beijing–Tianjin Sand Source Control (BTSSC) Project has been implemented to restore grassland in order to control sand sourced pollution. This study aimed to understand the impacts of four applied restoration practices on the productivity, composition, and species diversity of vegetation communities in the BTSSC Project. The results indicated the following: (1) All the restoration practices tended to increase the height and cover of communities, and the effect was most obvious where grazing was excluded; (2) total biomass (87%), above-ground biomass (164%) and below-ground biomass (58%) only increased consistently when grazing was excluded from the steppe; (3) fenced and grazing exclusion practice significantly increased the abundance of species in communities, but all the practices tended to decrease the evenness of species; and, (4) the correlation analysis revealed that the Shannon–Wiener diversity index, and Pielou evenness index, showed significant negative correlations with the above-ground biomass of grassland communities after restoration, while no significant relationships were shown in reference plots. Our comparison of applied practices in the BTSSC project revealed that grazing exclusion might be a high priority for more successful restoration in this region.


Land ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 209
Author(s):  
Frederick Gyasi Damptey ◽  
Klaus Birkhofer ◽  
Paul Kofi Nsiah ◽  
Enrique G. de la Riva

The ongoing global deforestation resulting from anthropogenic activities such as unsustainable agriculture and surface mining threatens biodiversity and decreases both soil carbon and above-ground biomass stocks. In this study, we assessed soil properties and below- and above-ground biomass attributes in a restored former gravel mine area in Ghana two decades after active restoration with potted plants and fresh topsoil. We compared conditions to four alternative land-use types (unrestored abandoned gravel mine, arable land, semi-natural forest, and natural forest) representing pre- and post-disturbance as well as natural reference states. We hypothesized that soil properties and related levels of below- and above-ground biomass in the restored area share similarities with the natural reference systems and thereby are indicative of a trajectory towards successful restoration. Eight replicated subareas in each land-use type were assessed for a set of soil parameters as well as below- and above-ground biomass attributes. The soil properties characteristic for the restored area differed significantly from pre-restoration stages, such as the abandoned gravel site, but did not differ significantly from properties in the natural forest (except for bulk density and base saturation). Above-ground biomass was lower in the restored area in comparison to the reference natural forests, while differences were not significant for below-ground biomass. Silt and effective cation exchange capacity were closely related to above-ground biomass, while below-ground biomass was related to soil organic carbon, bulk density, and potassium concentration in soils. Our results suggest that major steps towards successful restoration can be accomplished within a relatively short period, without the wholesale application of topsoil. Improving soil conditions is a vital tool for the successful development of extensive vegetation cover after surface mining, which also affects carbon sequestration by both above- and below-ground biomass. We emphasize that the use of reference systems provides critical information for the monitoring of ecosystem development towards an expected future state of the restored area.


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