School of Forestry, Environmental and Geographical Sciences (SFEGS)
http://hdl.handle.net/10570/47
2024-03-29T07:27:48ZAbove-ground biomass and carbon stocks of different land cover types in Mt. Elgon, Eastern Uganda
http://hdl.handle.net/10570/3777
Above-ground biomass and carbon stocks of different land cover types in Mt. Elgon, Eastern Uganda
Buyinza, Joel
This research applied selected allometric models to estimate the Total Above Ground Biomass and Carbon stocks in three land cover types in Mt. Elgon National Park. The land cover types identified for the study included the Tropical High Forest (THF)- Normal and Degraded and Grassland fields. The vegetation in each land cover type was assessed at four category levels i.e. the mature trees (dbh >10cm), poles (5<10cm dbh), saplings (collar diameter less than 5cm) and undergrowth/ herbaceous layer (height<50cm). For tree density estimation, a 10 inch increment borer was used to extract a small cylindrical sample (4-5cm) at 140cm above the ground, from all the woody species (dbh>10cm) and poles and saplings (dbh 5-10cm) in the temporary plot. Following the extraction of wood core samples, diameter (dbh), height and crown width of each sampled tree were also measured as independent variables for calculating biomass. Tree biomass was derived using three allometric equations developed by Velle, (1997), Ketterings et al., (2001) and Brown et al., (1989). The equations were selected based on their independent variables and the land cover type where the equation was developed from. Calculation of the Mean Squared Error (MSE), the Prediction Sum of
Squares (PRESS) statistic and the Predicted R2 values of the three equations used was done, to establish the most appropriate equation for biomass and carbon estimation. For saplings of diameter less than 5cm, one sapling was uprooted and sub-samples of the foliage, bole and root components were collected and their fresh weight determined from the field. The sub-samples from the saplings and the undergrowths were oven dried to constant weight at 80°C to determine dry-to-wet matter ratios. These ratios were then used to convert the entire sample to oven-dry matter and for analysis of carbon. This study estimated the wood densities of 22 common tree species in Mt. Elgon in Kapchorwa district. The overall average wood density of 0.54 g cm-3 reported in this study is comparable to the reported values for trees in Africa which range between 0.58
and 0.67g cm-3. A comparison between the wood densities obtained from the wood samples collected from Mt. Elgon National park in this study and the published wood densities indicated an insignificant difference between the two data sets (P>0.05). The Brown et al., (1989) equation gave the least Mean Squared Error (MSE) and Prediction Sum of Squares (PRESS) and a high Predicted R2. Therefore, the best model for estimating biomass and carbon in all the land cover types is Y= exp {-2.4090 + 0.9522 ln (D2HS)} developed by Brown et al., (1989). The results indicate that the Total Above Ground Biomass (TAGB) was 652.15t/ha, 55.16t/ha and 41.7t/ha in the THF-Normal, THF-Degraded and Grasslands respectively. The TAGC in the THF-Normal was
293.65tCha-1, 25 tCha-1 in the THF-Degraded and 18.76 tCha-1 in the grassland fields. The choice of an allometric equation in any particular biomass and carbon study is important, as different equations can give rise to very different estimates when applied to
the same forest inventory data. This study also revealed that over 90% of sequestered Carbon is lost due to land cover change from THF-Normal to THF-Degraded. This calls for policy makers to come up with interventions to address forest degradation. There is need for local community sensitization on the likely negative impacts of biomass and carbon losses arising from deforestation.
A thesis submitted in partial fulfillment of the requirements for the award of the Masters of Science Degree in Agroforestry of Makerere University
2014-01-01T00:00:00ZAbove-ground biomass and carbon stocks of different land cover types in Mt. Elgon, Eastern Uganda
http://hdl.handle.net/10570/3337
Above-ground biomass and carbon stocks of different land cover types in Mt. Elgon, Eastern Uganda
Buyinza, Joel
This research applied selected allometric models to estimate the Total Above Ground Biomass and Carbon stocks in three land cover types in Mt. Elgon National Park. The land cover types identified for the study included the Tropical High Forest (THF)- Normal and Degraded and Grassland fields. The vegetation in each land cover type was assessed at four category levels i.e. the mature trees (dbh >10cm), poles (5<10cm dbh), saplings (collar diameter less than 5cm) and undergrowth/ herbaceous layer (height<50cm). For tree density estimation, a 10 inch increment borer was used to extract a small cylindrical sample (4-5cm) at 140cm above the ground, from all the woody species (dbh>10cm) and poles and saplings (dbh 5-10cm) in the temporary plot. Following the extraction of wood core samples, diameter (dbh), height and crown width of each sampled tree were also measured as independent variables for calculating biomass. Tree biomass was derived using three allometric equations developed by Velle, (1997), Ketterings et al., (2001) and Brown et al., (1989). The equations were selected based on their independent variables and the land cover type where the equation was developed from. Calculation of the Mean Squared Error (MSE), the Prediction Sum of Squares (PRESS) statistic and the Predicted R2 values of the three equations used was done, to establish the most appropriate equation for biomass and carbon estimation. For saplings of diameter less than 5cm, one sapling was uprooted and sub-samples of the foliage, bole and root components were collected and their fresh weight determined from the field. The sub-samples from the saplings and the undergrowths were oven dried to constant weight at 80°C to determine dry-to-wet matter ratios. These ratios were then used to convert the entire sample to oven-dry matter and for analysis of carbon. This study estimated the wood densities of 22 common tree species in Mt. Elgon in Kapchorwa district. The overall average wood density of 0.54 g cm-3 reported in this study is comparable to the reported values for trees in Africa which range between 0.58 and 0.67g cm-3. A comparison between the wood densities obtained from the wood samples collected from Mt. Elgon National park in this study and the published wood densities indicated an insignificant difference between the two data sets (P>0.05). The Brown et al., (1989) equation gave the least Mean Squared Error (MSE) and Prediction Sum of Squares (PRESS) and a high Predicted R2. Therefore, the best model for estimating biomass and carbon in all the land cover types is Y= exp {-2.4090 + 0.9522 ln (D2HS)} developed by Brown et al., (1989). The results indicate that the Total Above Ground Biomass (TAGB) was 652.15t/ha, 55.16t/ha and 41.7t/ha in the THF-Normal, THF-Degraded and Grasslands respectively. The TAGC in the THF-Normal was 293.65tCha-1, 25 tCha-1 in the THF-Degraded and 18.76 tCha-1 in the grassland fields. The choice of an allometric equation in any particular biomass and carbon study is important, as different equations can give rise to very different estimates when applied to the same forest inventory data. This study also revealed that over 90% of sequestered Carbon is lost due to land cover change from THF-Normal to THF-Degraded. This calls for policy makers to come up with interventions to address forest degradation. There is need for local community sensitization on the likely negative impacts of biomass and carbon losses arising from deforestation.
1
A Research thesis submitted to the School of Forestry, Environment and Geographical Sciences in partial fulfillment of the requirements for the award of Master of Science degree in Agroforestry of Makerere University
2014-01-01T00:00:00ZAbundance and nutritional compositions of ruspolia differens polymorphs from Masaka District: Uganda
http://hdl.handle.net/10570/6996
Abundance and nutritional compositions of ruspolia differens polymorphs from Masaka District: Uganda
Oipio, Moses
This study was conducted to determine the abundance and nutritional compositions of Ruspolia differens polymorphs. The objectives of the study were: 1) to compare relative abundance of different polymorphs and males and females during the first and second swarming season and; 2) to compare the nutritional values among different polymorphs and sexes. A generalized linear model of negative binomial distribution was used to test whether abundance in the different polymorphs and insect sexes were significantly different in each of the swarming seasons. One way ANOVA in SPSS was used to test whether significant differences exist in the nutritional values of (i) different polymorphs; and (ii) between sexes. Eight polymorphs were encountered in the study. Four of which were reported 46 years ago while the other four polymorphs had never been reported in Uganda. A significant difference in the relative abundance of R. differens polymorphs (P<0.05) was observed in each swarming season and not between the two swarming seasons (P>0.05). A non-significant difference in relative abundance between males and females was observed between the two swarming seasons (P>0.05). Proximate analysis showed significant differences in protein and ash (P<0.05), but not in fat, fiber, and moisture content (P>0.05) among polymorphs. Between sexes, fiber content differed significantly (P<0.05), while protein, fat, ash, and moisture content (P>0.05) did not. Ruspolia differens color and sex did not significantly influence the fatty acids detected: myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic. Calcium, zinc and iron did not significantly differ among polymorphs, while sodium, potassium and phosphorous differed significantly. Between sexes, no significant difference existed among the minerals studied: calcium, zinc, iron, sodium, potassium and phosphorus. The occurrence of polymorphs detected 46 years ago demonstrates the aspect of polymorphism maintenance, while the existence of new polymorphs suggests that this insect species is undergoing the process of evolution. The non significant difference in the relative abundance of R. differens polymorphs and insect sexes between the two swarming seasons can be attributed to the permanent adaptation of this insect species to specific environmental conditions. The nutritional composition of polymorphs most likely reflects the food sources, while that of the insect sexes is possibly influenced by the morphological and physiological differences that always occur between sexes.
2016-11-01T00:00:00ZThe abundance, distribution and community utilization of Loeseneriella apocynoides and Manilkara Obovata species in Sango Bay Forest, Rakai District
http://hdl.handle.net/10570/6286
The abundance, distribution and community utilization of Loeseneriella apocynoides and Manilkara Obovata species in Sango Bay Forest, Rakai District
Namara, Justus
The study examined the abundance, distribution and community utilization of the two woody species Loeseneriella apocynoides and Manikara obovate in Sango Bay forests. The two species are used for making fishing baskets by the people living adjacent to these forests.
The objectives of the research were:-
1. To assess the abundance and the distribution of Loeseneriella apocynoides and Manikara obovate species.
2. To determine who harvests these species and their quantities.
3. To document present methods used in harvesting these species.
4. To find out the awareness of local people towards conservation of these species.
The study consisted of two surveys, the village surveys and the forest surveys. The forest surveys were carried out in two forest reserves, Malabigambo and Namalala. The assessment involved use of 2 transects of length 1000m in Malabigambo and 2 transects of length 750m in Namalala. Plots of size 20 x 20m were established and in total there were 48 plots established with 28 in Malabigambo and 20 in Namalala Forest Reserves. The abundance and distribution was assessed in order to know what is available in the forest and where the location where harvesting can be done. For village surveys four villages neighbouring these forests were assessed which, are Mujanjabula, Mugamba, Nalubega and Mutegombwa using a questionnaire. In total 65 respondents were interviewed. From the forest surveys it was found out that these species are sparsely distributed and they generally increase with increase in distance from the edge of the forest a factor attributed to over harvesting at the edge of the forest. L. apocynoides was abundant in the diameter class <1 cm that are seedlings while M. obovate species was abundant in diameter class >5 cm which is the harvestable size. Malabigambo had more individuals of both species than Namalala.
From village surveys it was found out that men are the only ones involved in harvesting these species and they have low levels of education. The methods of harvesting included cutting stems or branches in case of M. obovate and for L. apocynoides only stems were harvested.
It was concluded that these species abundance is low and the distribution is not uniform but clumped. The methods of harvesting were not sustainable and therefore species are being depleted. It is recommended that a monitoring program should be started for these species so that the harvesting is controlled and regulated.
Thesis submitted to the School of Graduate Studies in partial fulfillment for the award of the Degree of Master of Science in Environment and Natural Resources of Makerere University.
2002-09-01T00:00:00Z