Modelling Above Ground Biomass Using Sentinel 2 and Planet Scope Data in Dense Tropical Montane Forests of Tanzania

Forest biomass estimation using field -based inventories at a large scale is challenging and generally entails large uncertainty in tropical regions. In this study, we investigated the performance of Sentinel 2 and Planet Scope data for above ground biomass (AGB) modelling, in the tropical rainforest of Tanzania. A total of 296 field inventory plots were measured across the west Usambara mountain forests. The results showed that, Sentinel 2-based model fitted using GLMs had better performance (cvRMSEr = 67.00 % and pseudo-R2= 20%) as compared to Planet Scope-based models (cvRMSEr = 72.1 % and pseudo-R2= 5.2%). Overall GLMs resulted into models with less prediction errors in contrast to random forest when using Sentinel 2 data. However, for the Planet Scope, there was marginal improvement when using random forest (cvRMSEr = 72.0%). Models that incorporated texture variables produced better prediction accuracy as compared to those with band values and indices only. The study has shown that, Sentinel 2 and Planet Scope remotely sensed data can be used to develop cost-effective method for AGB estimation in tropical rainforests of Tanzania

Aboveground biomass and carbon stock of Usambara tropical rainforests in Tanzania

Forest Above ground biomass (AGB) and carbon stock (AGC) estimation is important for carbon budget accounting, sustainable forest management as well as for understanding the role of forest ecosystem in the climate change mitigation. In the recent decade, there has been a growing global interest on quantifying AGB and AGC in the tropical countries. However, the information on AGB and AGC at local and subnational scales in most of the tropical forests is scattered and not consolidated. In this study, we reviewed the existing information on AGB and AGC for tropical rainforests of northern Tanzania. We used both data published in the peer-reviewed literature and data from unpublished sources provided by various sources. Our results showed that, there are three types of data sources and methods used for estimation of AGB and AGC. These included, field, geographical information system and remote sensing. Of all the methods, field based method was applied to a large extent. The average reported minimum values of AGB and AGC are 177.00 Mg ha-1 and 88.5 Mg ha-1, and the maximum average values are 872 Mg ha-1 and 436 Mg ha-1 respectively. Overall, the average values of AGB and AGC in the Usambara tropical mountain forests (UTMFs) are 351.08 Mg ha-1 and 175.54 Mg ha-1 respectively. Forest structure parameters, particularly tree sizes and number of tree stems, were the major structure parameters reported to affect the amount of AGB and AGC. To conclude, the study revealed that there is a progressive trend in the estimation of AGB and AGC in the UTMFs. However, more update and effective forest survey data and methods are needed particularly in west Usambara mountain forests block

spa typing and antimicrobial resistance of Staphylococcus aureus from healthy humans, pigs and dogs in Tanzania

The Journal Infection Developing CountriesIntroduction: Staphylococcus aureus is an opportunistic pathogen causing infections in humans and animals. Here we report for the first time the prevalence of nasal carriage, spa typing and antimicrobial resistance of S. aureus in a Tanzanian livestock community. Methodology: Nasal swabs were taken from 100 humans, 100 pigs and 100 dogs in Morogoro Municipal. Each swab was enriched in Mueller Hinton broth with 6.5% NaCl and subcultured on chromogenic agar for S. aureus detection. Presumptive S. aureus colonies were confirmed to the species level by nuc PCR and analysed by spa typing. Antimicrobial susceptibility patterns were determined by disc diffusion method. Results: S. aureus was isolated from 22 % of humans, 4 % of pigs and 11 % of dogs. A total of 21 spa types were identified: 13, 7 and 1 in human, dogs, and pigs, respectively. Three spa types (t314, t223 and t084) were shared between humans and dogs. A novel spa type (t10779) was identified in an isolate recovered from a colonized human. Antimicrobials tested revealed resistance to ampicillin in all isolates, moderate resistances to other antimicrobials with tetracycline resistance being the most frequent. Conclusion: S. aureus carrier frequencies in dogs and humans were within the expected range and low in pigs. The S. aureus spa types circulating in the community were generally not shared by different hosts and majority of types belonged to known clones. Besides ampicillin resistance, moderate levels of antimicrobial resistance were observed irrespective of the host species from which the strains were isolated

First Report on a Randomized Investigation of Antimicrobial Resistance in Fecal Indicator Bacteria from Livestock, Poultry, and Humans in Tanzania

Journal articleThis study provides an estimate of antimicrobial resistance in intestinal indicator bacteria from humans (n = 97) and food animals (n = 388) in Tanzania. More than 70% of all fecal samples contained tetracycline (TE), sulfamethoxazole (STX), and ampicillin (AMP)-resistant coliforms, while cefotaxime (CTX)-resistant coliforms were observed in 40% of all samples. The average Log10 colony forming units/g of CTX-resistant coliforms in samples from humans were 2.20. Of 390 Escherichia coli tested, 66.4% were resistant to TE, 54.9% to STX, 54.9% to streptomycin, and 36.4% to CTX. Isolates were commonly (65.1%) multiresistant. All CTX-resistant isolates contained blaCTX-M gene type. AMP- and vancomycin-resistant enterococci were rare, and the average concentrations in positive samples were low (log10 0.9 and 0.4, respectively). A low-tomoderate resistance (2.1–15%) was detected in 240 enterococci isolates to the drugs tested, except for rifampicin resistance (75.2% of isolates). The average number of sulII gene copies varied between Log10 5.37 and 5.68 with no significant difference between sample source, while cattle had significantly higher number of tetW genes than humans. These findings, based on randomly obtained samples, will be instrumental in designing antimicrobial resistance (AMR) intervention strategies for Tanzania