Effects of conspecifics and rocks on seedling recruitment of Brachystegia spiciformis Benth.in a dry miombo woodland in southern Africa

2021 ◽  
Vol 113 ◽  
pp. 103777
Author(s):  
Donald Mlambo ◽  
Francis Tafadzwa Chiparange
2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ezekiel Edward Mwakalukwa ◽  
Henrik Meilby ◽  
Thorsten Treue

Tools to accurately estimate tree volume and biomass are scarce for most forest types in East Africa, including Tanzania. Based on a sample of 142 trees and 57 shrubs from a 6,065 ha area of dry miombo woodland in Iringa rural district in Tanzania, regression models were developed for volume and biomass of three important species,Brachystegia spiciformisBenth. (n = 40),Combretum molleG. Don (n = 41), andDalbergia arbutifoliaBaker (n = 37) separately, and for broader samples of trees (28 species,n = 72), shrubs (16 species,n = 32), and trees and shrubs combined (44 species,n = 104). Applied independent variables were log-transformed diameter, height, and wood basic density, and in each case a range of different models were tested. The general tendency among the final models is that the fit improved when height and wood basic density were included. Also the precision and accuracy of the predictions tended to increase from general to species-specific models. Except for a few volume and biomass models developed for shrubs, all models hadR2values of 96–99%. Thus, the models appear robust and should be applicable to forests with similar site conditions, species, and diameter ranges.


IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 385-399 ◽  
Author(s):  
Valérie Trouet ◽  
Kristof Haneca ◽  
Pol Coppin ◽  
Hans Beeckman

The value of growth rings as proxy data for climate reconstruction was studied in two miombo woodland species in eastern Africa. Growth rings, marked by terminal parenchyma, were visually detectable on carefully prepared stem discs of Isoberlinia tomentosa and Brachystegia spiciformis, dominant species of the miombo woodland in north-western Tanzania. However, the presence of multiple growth ring anomalies rendered cross-dating of the growth ring series between trees difficult. Cross-dating succeeded for eight out of thirteen samples for Isoberlinia tomentosa, but was unsuccessful for Brachystegia spiciformis. A mean series of 38 years was calculated for Isoberlinia tomentosa only. Monthly precipitation, monthly maximum air temperature and monthly SOI-value (Southern Oscillation Index) correlated significantly with tree ring widths of the mean series. These correlations are strong indicators of the annual character of the growth rings. They also suggest that Isoberlinia tomentosa provides an appropriate paleoclimatic record for dendroclimatic reconstruction.


2020 ◽  
Vol 11 (1) ◽  
pp. 12-19
Author(s):  
Narciso Fernando Bila ◽  
Rosilani Trianoski ◽  
Márcio P. Da Rocha ◽  
José Reinaldo Moreira Da Silva ◽  
Setsuo Iwakiri ◽  
...  

This study aimed to evaluate the effect of machining operations on the surface quality of the messassa wood (Brachystegia spiciformis and Julbernadia globiflora) for use in the furniture industry. The wood cames from Mozambican Miombo Woodland. The following machining operations were performed: planing, shaping, milling, tearing and boring based on technical standard. The wood had a surface quality approval rating above 70% in all tested machining operations. A perfect surface quality was obtained with a feed speed of 6 m.min-1 in planing. Brachystegia spiciformis had easy workability and extremely well performance compared to Julbernadia globiflora. Nevertheless, both wood species have great potential for use in higher value-added products such as furniture and frame production.


2021 ◽  
Author(s):  
Henry Zimba ◽  
Miriam Coenders-Gerrits ◽  
Banda Kawawa ◽  
Bart Schilperoort ◽  
Imasiku Nyambe ◽  
...  

<p>Evaporation is a major constraining factor of water availability at the land surface which makes its assessment a highly significant prerequisite for application in hydrological, agricultural, climate studies and many other disciplines at various scales. However, its importance and calculation procedures have largely been crafted around and often limited to crop productivity. The overarching consequence of this is inaccurate estimates of evaporation for other land surfaces and particularly for forest systems. Due to limited field evaporation observations attention has been focused on the application of satellite-based products. However, in the case of Africa, and the Miombo ecosystem in particular, the number of flux towers is extremely limited (very few if any) which makes it extremely difficult to evaluate available satellite-based evaporation products. In this study we used the energy balance Bowen ratio approach to estimate field evaporation in a dense Miombo Woodland which we then used to evaluate four energy balance evaporation models. The models evaluated included the MOD16, SEBS, SSEBop and WaPOR. Furthermore, cluster analysis was used to assess the similarity of the models in simulating evaporation. The results show that at daily and dekadal scale the simulated evaporation by the four models significantly varied from field evaporation observations. However, less variations were observed at monthly scale.  Furthermore, all four models overestimated evaporation during the dry season (June-September) with RMSE ranges between 0.21 – 0.38 mm.day<sup>-1</sup> and 6.64 - 9.91 mm.month<sup>-1</sup>. Based on the RMSE and biases the MOD16 (RMSE = 6.64 mm.month<sup>-1</sup>; Bias = 2.04 mm.month<sup>-1</sup>), SEBS (RMSE = 8.69 mm.month<sup>-1</sup>; Bias = 5.72 mm.month<sup>-1</sup>) and WaPOR (RMSE = 7.44 mm.month<sup>-1</sup>; Bias = 6.67 mm.month<sup>-1</sup>) ranked higher than the SSEBop (RMSE = 9.91 mm.month<sup>-1</sup>; Bias = 9.84 mm.month<sup>-1</sup>) in simulating evaporation in the Miombo Woodland. Three clusters were observed with the SEBS and WaPOR grouped together indicating their close similarity in simulating evaporation in the Miombo ecosystem while the MOD16 and SSEBop were each grouped separately. Results of this study could aid the interpretation of these evaporation models in Miombo Woodland covered basins such as the Zambezi River Basin in Southern Africa. This could help in monitoring basin water availability and ecosystem reactions and feedbacks to climate change and anthropogenic impacts.</p>


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