Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania (original) (raw)

Fixed or mixed? Variation in tree functional types and vegetation structure in a forest-savanna ecotone in West Africa

Journal of Tropical Ecology, 2020

We analysed thirty-five 400-m2 plots encompassing forest, savanna and intermediate vegetation types in an ecotonal area in Ghana, West Africa. Across all plots, fire frequency was over a period of 15 years relatively uniform (once in 2–4 years). Although woodlands were dominated by species typically associated with savanna-type formations, and with forest formations dominated by species usually associated with closed canopies, these associations were non-obligatory and with a discrete non-specialized species grouping also identified. Across all plots, crown area index, stem basal area and above-ground biomass were positively associated with higher soil exchangeable potassium and silt contents: this supporting recent suggestions of interplays between potassium and soil water storage potential as a significant influence on tropical vegetation structure. We also found an average NDVI cover increase of ~0.15% year−1 (1984–2011) with plots dominated by non-specialized species increasing ...

Influence of soil physicochemical parameters on species composition and structure in the Togo Plateau Forest Reserve in Ghana

World Journal of Advanced Research and Reviews

Soil-Species correlation studies help in understanding the ecology of plateau ecosystems. However, this information is scarse thereby posing a challenge in their effective management in Ghana. Hence, the study on the influence of soil physicochemical parameters on species composition and structure in the six fringed communities which constitute the focus of the study: Bowuri (BO), Nkonya (NK), Akpafu (AK), Santrokofi (SA), Hohoe (HH) and Alavanyo (AL) in the Togo Plateau Forest Reserve in Ghana. Soil and vegetation parameters were recorded in a total of 180 plots (each measuring 25m × 25m) demarcated across the communities and analyzed. Canonical Correlation Analysis (CCA) results showed that pH, OC, TN, OM, TCa, TMg, TK, Na, T.E.B, ex. Acidity, ECEC, Base sat, AVI – P (ppmP), Sand and Silt were the drivers of trees, saplings and seedlings composition and structure (including density, richness, shannon, evenness and basal area (BA)) on the plateau. This vegetation attributes were se...

Effect of Anthropogenic Activities in Dry Miombo Woodlands on Wood Stock and Tree Diversity: A Case of Chenene Forest Reserve, Bahi, Tanzania

International journal of innovation and scientific research, 2014

This study assessed Woodstock, species richness, tree diversity and Importance Value Index (IVI) of Chenene Forest Reserve (CFR). Forest inventory carried out in 120 systematically selected sample plots. The forest was post stratified into disturbed and undisturbed strata. The information recorded includes: diameter at breast height, species name, Geographical Positioning System (GPS) readings, and frequency of the species. Indicators of human activities such as charcoal kilns, pitsawing, burnt area and grazing signs. Analysis of the inventory data was done using Microsoft Excel. The inventory carried out in 2011 revealed that average number of stems per hectare (N), basal areas per hectare G (m2ha-1), and volume per hectare V (m3ha-1) as 352 35.20 (SE), 6.84 0.68 (SE) and 44.68 4.47 (SE) respectively. The parameters between disturbed and undisturbed strata in this study revealed low parameters in disturbed stratum as compared to undisturbed strata were 567± 87.37 stems ha-1, Basal ...

Soil characteristics influence species composition and forest structure differentially among tree size classes in a Bornean heath forest

2019

Background and aims: Whilst several studies have shown that edaphic variability influences species composition in nutrient-poor tropical forests, the determinants of local species distributions and, in particular, how these change from younger to mature individuals in such forests are still under debate, and have been poorly explored in tropical heath forests that are among the least fertile tropical forest ecosystems. Methods: We investigated the influence of soil fertility and topography on a Bornean heath forest species composition, α-, β-diversity and tree size structure among size classes by recording all trees ≥ 1 cm DBH in 16 forest plots totalling 0.36 ha. Results: Tree species distributions generally followed gradients in available Al and soil depth; α- and β-diversity were linked to soil depth, and to some extent also to pH and the H:Al ratio. In contrast, forest structural attributes (basal area and stem density) were negatively correlated with both available and total P and a wider suite of soil nutrients, although trees ≥ 10 cm DBH were positively correlated with total P. Conclusion: Our study shows that heath forest species distribution, richness and structure is related to both edaphic and topographic characteristics and that soil acidity might have a strong influence in shaping these forests’ features. Among size classes, small trees are less influenced by soil and topography, whereas the sensitivity to these variables increases with tree size. We thus highlight that multiple edaphic factors influence different aspects of tropical forest structure, including different tree life stages, and species composition.