Forest In Uganda Research Articles

Response of tropical forest productivity to seasonal drought mediated by potassium and phosphorus availability

Tropical forest productivity is increasingly reported to be nutrient limited, which may affect its response to seasonal droughts. Yet experimental evidence on nutrient limitation from Afrotropical forests remains rare. We conducted an ecosystem-scale, full factorial nitrogen (N)–phosphorus (P)–potassium (K) addition experiment in a moist forest in Uganda to investigate nutrient controls on fine litter production and foliar chemistry. The eight factorial treatments were replicated four times in 32 plots of 40 × 40 m each. During the three-year nutrient additions, we found K and P limitations on leaf litter production, exhibiting strong links to ecosystem responses to seasonal drought. Specifically, leaf litterfall consistently decreased in dry seasons with K additions, whereas P additions caused a reduction only during prolonged drought in the first year. Leaf litterfall was not significantly affected by N additions. Furthermore, K additions delayed the timing of leaf litterfall peak, underscoring the crucial role of K in regulating stomatal aperture and signalling during water-stress conditions and suggesting a prolonged leaf lifespan. Foliar N increased with N and P additions whereas K was the most resorbed nutrient. We conclude that the productivity and resilience of tropical forests, particularly under drier conditions, may depend on terrestrial K and P availability.

The Role of Remote Sensing in Forest Cover Changes in Butambala District, Central Uganda

Natural forests in Uganda have experienced changes which must be quantified to inform future forest resource management and avoid the danger of reduced ecosystem service benefits. The primary purpose of this study was to assess forest changes in Butambala District by employing remote sensing techniques and GIS tehniques. The original contribution is the capacity to detect Central Forest Reserve cover decline using remote sensing in the study area for a 27-year period (1995-2020). Landsat 5 and Sentinel 2 images were processed using a supervised image classification approach to identify and quantify land use/cover changes. The study results indicated that the district has undergone land cover/use changes over the last 27 years. The prevailing changes in the district from 1995 to 2022 were expansions of built-up areas from (0.54% to 4.22%), agriculture from (42.38% to 79%), and decreases in grassland from (29.9% to 0%), natural forest cover from (14.07% to 5.9%), wetland from (8.24% to 7.9%), tree plantation from (4.87% to 3.3%). The changes threaten the environment and quality of life of people. Therefore, there is need to take critical and practical measures to regulate land use and landcover changes and conserve natural resources in Butambala District

Composition of non‐volant small mammals inhabiting a degradation gradient in a lowland tropical forest in Uganda

A study aimed at assessing the structure of rodent and shrew assemblages inhabiting a degradation gradient while considering rainfall patterns, was conducted in one of few remaining lowland tropical forests in eastern Africa. We collected a unique dataset of rodents and shrews, representing 24 species (19 rodents, 5 shrews). The most abundant species alternated in dominance as species abundance significantly fluctuated across the study period following a degradation gradient. While only generalist species were observed near the degraded forest edge, habitat specialists such as Deomys ferrugineus, Malacomys longipes and Scutisorex congicus, were observed in the primary forest interior suggesting a significant association between species and their associated habitats and habitat attributes. There was also an observed correlation between rainfall patterns and species abundance. Capturing more species in adjacent fallows and along the degraded forest edge suggests that many species are able to live in degraded habitats that offer a variety of food resources. The study has highlighted the importance of habitat heterogeneity through species associations and also recommend an assessment of the effect of habitat homogeneity due to the proliferation of paper mulberry on small mammal community.

Broussonetia papyrifera invasion reduces the abundance and basal area of selected native timber species in a tropical moist forest in Uganda

Broussonetia papyrifera invasion reduces the abundance and basal area of selected native timber species in a tropical moist forest in Uganda

The form and function of chimpanzee buttress drumming

Many animal species use vocal and nonvocal acoustic signals to communicate over large distances. Wild chimpanzees, Pan troglodytes , drum on the buttress roots of trees, generating low-frequency sounds that can reach distances of over 1 km. Buttress drumming is produced in bouts of beats and is often accompanied by pant hoots, the species-typical long-distance vocalization. We investigated whether individual differences exist in the acoustic structure of drumming bouts produced by male chimpanzees of the Waibira community in the Budongo Forest in Uganda, and whether individual, contextual and social factors affected their use of drumming. We found individual differences in drumming bouts produced by seven male chimpanzees during travel events as well as in their timing within the pant hoot, and discriminated specific patterns of beats for some chimpanzees. In contrast, we found no evidence for individual differences in the acoustic structure of drumming bouts produced by four males during displays. Together these findings suggest that chimpanzees may be able to choose to encode identity within individual drumming ‘signatures’. Chimpanzees drummed less frequently as their party size increased. We found no evidence that the age of the signaller or the presence of preferred social partners, higher-ranking males or females in oestrus affected the use of drumming. These findings suggest there may be flexibility in buttress drumming across social and behavioural contexts and provide support for the hypothesis that, by encoding individual identity, long-distance drumming may be used to facilitate chimpanzee fission–fusion social dynamics. • Chimpanzees produce low-frequency sounds by drumming on buttress roots of trees. • Drumming is used across contexts with apparently long- and short-distance functions. • Chimpanzee drums encode individual signatures in travel events but not in displays. • Patterns of production suggest drumming coordinates fission–fusion dynamics.

ZIKA VIRUS AN EPIDEMIOLOGICAL PROFILE

Known scientifically ZIKV, constituted in viruses when so enveloped in the unsegmented single RNA chain of the flaviviridae family and flavivirus genus then discovered and isolated in 1947 the Zika virus emerged in the Zika forest in Uganda in monkey-reso and discovered in humans in 1968. Its main means of transmission is by the Aedes Aegypti mosquito and also by sexual intercourse, blood contact, breast milk and amniotic fluid. In Brazil the zika virus was featured during the World Cup in 2014 because many foreigners are from different nations. Treatment is symptomatic means that there is no specific treatment just to relieve symptoms and protect yourself from mosquito bites so it does not carry the disease to other people. In order to carry out this bibliographic review, the Scienc Direct, SciELO, Medline, Capes Periodicals, Google Scholar and Brazilian Ministry of Health databases were used, being considered articles in the Portuguese language according to the quality and relevance of the proposed theme of this review. This work did not pretend to bring something new but to highlight the great health problem that this pathology can cause to the human being and in all its biogenesis.

Responses of tree growth and biomass production to nutrient addition in a semi-deciduous tropical forest in Africa.

Experimental evidence of nutrient limitations on primary productivity in Afrotropical forests is rare and globally underrepresented yet are crucial for understanding constraints to terrestrial carbon uptake. In an ecosystem-scale nutrient manipulation experiment, we assessed the early responses of tree growth rates among different tree sizes, taxonomic species, and at a community level in a humid tropical forest in Uganda. Following a full factorial design, we established 32 (eight treatments × four replicates) experimental plots of 40 × 40 m each. We added nitrogen (N), phosphorus (P), potassium (K), their combinations (NP, NK, PK, and NPK), and control at the rates of 125 kg N ha-1 year-1 , 50 kg P ha-1 year-1 and 50 kgK ha-1 year-1 , split into four equal applications, and measured stem growth of more than 15,000 trees with diameter at breast height (dbh) ≥1cm. After 2 years, the response of tree stem growth to nutrient additions was dependent on tree sizes, species and leaf habit but not community wide. First, tree stem growth increased under N additions, primarily among medium-sized trees (10-30 cm dbh), and in trees of Lasiodiscus mildbraedii in the second year of the experiment. Second, K limitation was evident in semi-deciduous trees, which increased stem growth by 46% in +K than -K treatments, following a strong, prolonged dry season during the first year of the experiment. This highlights the key role of K in stomatal regulation and maintenance of water balance in trees, particularly under water-stressed conditions. Third, the role of P in promoting tree growth and carbon accumulation rates in this forest on highly weathered soils was rather not pronounced; nonetheless, mortality among saplings (1-5cm dbh) was reduced by 30% in +P than in -P treatments. Although stem growth responses to nutrient interaction effects were positive or negative (likely depending on nutrient combinations and climate variability), our results underscore the fact that, in a highly diverse forest ecosystem, multiple nutrients and not one single nutrient regulate tree growth and aboveground carbon uptake due to varying nutrient requirements and acquisition strategies of different tree sizes, species, and leaf habits.

Lack of serological and molecular evidences of Zika virus circulation in non-human primates in three states from Brazil.

BACKGROUND Zika virus (ZIKV) was discovered in 1947 with the virus isolation from Rhesus monkey (Macaca mulatta) in Uganda forest, Africa. Old World Primates are involved in a sylvatic cycle of maintenance of this arbovirus, however a limited knowledge about the role of New World primates in ZIKV transmission cycles has been established.OBJECTIVE This work aimed to investigate the presence of enzootic circulation of ZIKV in New World Primates from three Brazilian states: São Paulo, Paraíba, and Paraná.METHODS We analyzed 100 non-human primate samples collected in 2018 and 2020 from free-ranging and captive environments from São Paulo (six municipalities belonging to Sorocaba region), Paraíba (João Pessoa municipality), and Paraná (Foz do Iguaçu municipality) using reverse transcriptase quantitative polymerase reaction (RT-qPCR) assays, indirect enzyme-linked immunosorbent assay (ELISA), and plaque reduction neutralization test (PRNT).FINDINGS All samples (n = 141) tested negative for the presence of ZIKV genome from tissue and blood samples. In addition, all sera (n = 58) from Foz do Iguaçu’ non-human primates (NHPs) were negative in serological assays.MAIN CONCLUSION No evidence of ZIKV circulation (molecular and serological) was found in neotropical primates. In addition, the absence of antibodies against ZIKV suggests the absence of previous viral exposure of NHPs from Foz do Iguaçu-PR.

Livelihood outcomes after two decades of co-managing a state forest in Uganda

Collaborative forest management (CFM) is widely promoted because of its purported ability to deliver both conservation and livelihoods improvement goals. It is especially attractive to developing countries where livelihood improvement is a key focus of national governments (that have simultaneously made global conservation commitments). Uganda has embraced CFM in its policy framework and promoted it for nearly two decades. However, there is dearth of empirical evidence on livelihoods outcomes for communities as a result of CFM. Using a dataset collected among forest-fringe communities around Budongo central forest reserve (CFR) – a state forest where CFM has been implemented since the early 2000s, we ran a propensity score matching (PSM) to establish suitable counterfactuals and adapted the Sustainable Livelihoods Framework (SLF) to assess changes in livelihood outcomes for CFM participants. Our results show that CFM has increased access to legally-sourced forest products from the state forest and privately (on-farm). However, it has reduced the participants' dependence on forest environmental income while no significant changes in total household income were recorded. The de-jure status of the CFM groups has served as a source of security for CFM participants to access credit. CFM has also offered a platform for conservation and development partners to promote alternative livelihoods schemes that target increased dependence on on-farm income. In order to achieve the envisioned livelihood benefits, conservation and development initiatives should focus on improving household income and promoting sustainable non-farm business models among the CFM groups.

Restoration of Citropsis articulata, a Species at Risk from Medicinal Overharvesting in a Ugandan Rainforest Reserve

Citropsis articulata, the African cherry orange, is considered to be threatened in Ugandan forests as a result of its purported aphrodisiac properties. This study, part of an ongoing effort to address restoration needs of Mabira Central Forest Reserve in Uganda, demonstrates the feasibility of restoring depleted C. articulata populations using seedlings transplanted from nursery-grown seeds. Phenology of 20 Mabira forest plants was monitored with the aim of collecting seeds. One hundred and fifty-six ripe fruits were collected, and 233 of the extracted seeds were planted in pots in a nursery during January–March 2019. During November-December 2019, seedlings were planted near the sites from which fruits were collected. Seed germination success rate was 89%, and fifteen months after transplanting, in situ survival was 100%. These results suggest that depleted C. articulata populations may be restored in situ using nursery-grown seeds.

Data from: The effect of Broussonetia papyrifera invasion on the regeneration of selected native timber species in a tropical moist forest in Uganda

Data from: The effect of Broussonetia papyrifera invasion on the regeneration of selected native timber species in a tropical moist forest in Uganda

Occurrence of Citropsis articulata in Tropical Forests in Uganda: Implication for Ex Situ Conservation

Citropsis articulata is a medicinal plant that is increasingly threatened by unsustainable methods of harvesting and habitat degradation. Owing to the fact that this plant species is highly utilized for herbal medicine and is currently restricted to a few forest reserves in Uganda, this has significant implications for ex situ conservation. Therefore, the aim of this study was to assess how physiographical factors influence the occurrence and distribution of C. articulata in the three forest reserves in Uganda, namely, Budongo, Mabira, and Kibale National Park. The study was carried out in 15 compartmental sites in each of the three forests. In each compartmental site, 4 plots of 60 m × 60 m were systematically established, and within each plot, 4 subplots each of size 20 m × 20 m were randomly setup. A total of 240 subplots were assessed for occurrence of Citropsis articulata in each forest. The results indicated a significant (p<0.05) variation in the density of C. articulata with the highest recorded in Kibale National Park. Citropsis articulata generally occurred at moderate altitudinal landscapes (overall elevation = 1200.0 ± 20.73 m) with soils that are moderately acidic (overall pH = 5.7 ± 0.10), low in salinity (overall salinity = 84.0 ± 3.84 mg/l), and moderate levels of macro- and micronutrients. Citropsis articulata was generally associated with plant communities dominated by canopy tree species of genera such as Chryosphyllum, Celtis, Markhamia, Cynometra, Lasiodiscus, Trilepisium, Funtumia, and Diospyros, thus suggesting that C. articulata is a shade-tolerant species. Establishing the ecological requirements of this plant species among other things informs the potential for ex situ production of this plant. This will not only provide alternative sources of plant harvest but also go a long way in relieving the current harvest pressures exerted on the conserved wild populations of this plant species.

Woodlot management and livelihoods in a tropical conservation landscape

In biodiversity hotspots, there is often tension between human needs and conservation, exacerbated when protected areas prevent access to natural resources. Forest-dependent people may compensate for exclusion by managing unprotected forests or cultivating planted woodlots. Outside Bwindi Impenetrable National Park in Uganda, household wood product needs are high and population growth puts pressure on the environment. We investigated the role of privately and collectively managed woodlots in provisioning wood products and supporting local livelihoods. We found that households relied heavily on woodlots for daily needs and as resources during time of need. We also found that locally relevant social institutions, called stretcher groups, played a role in the management of woodlots, providing shared community resources. Privately and collectively owned woodlots support local livelihoods and wood product needs in the region. Long-term management of forests in Uganda should consider the value of woodlots and the mechanisms required to support them.

Recovery of seedling community attributes during passive restoration of a tropical moist forest in Uganda

AbstractAimThere has been a debate about the effectiveness of passive restoration for recovering tropical forests, but few studies quantify the success of passive restoration. The aim of this study was to better understand tropical forest succession under a passive restoration scenario. We compared floristic and functional attributes of seedlings in a passively restored and an old‐growth forest, and assessed the effect of restoration age and distance from the old‐growth forest on seedling attributes.LocationKibale National Park, western Uganda.MethodsWe measured seedlings in a passively restored and an old‐growth forest in 2011, 2014 and 2017. We determined species diversity, structure and composition and searched the literature for functional traits. We used generalized linear mixed‐effects models to compare seedling attributes between the restored and old‐growth forest and determine the influence of restoration age and distance from the old‐growth forest.ResultsSeedling species abundance, evenness, basal area and height were similar between the restored and old‐growth forest. Wood density and abundance of seedlings of different dispersal modes, habitat types, fruit size categories, and regeneration strategies were also similar between the restored and old‐growth forest. However, richness, diversity and composition of seedlings were different. We found a positive effect of restoration age on species abundance and abundance of non‐zoochorous, medium‐fruited, forest‐dependent, non‐pioneer light demander and shade‐tolerant species, and a negative effect on evenness, wood density, abundance of pioneers and compositional dissimilarity. Basal area of seedlings and the abundance of zoochorous and forest‐dependent species declined while compositional dissimilarity increased with distance from the old‐growth forest.ConclusionsOur results provide empirical evidence on the potential of passive restoration to recover the structure and functionality of tropical forests in a relatively short period of time. We demonstrate that the effect of restoration age and distance from the old‐growth forest is not straightforward and depends on the attributes measured.

Status of Nahan’s Partridge Ptilopachus nahani (Dubois, 1905) (Aves: Galliformes: Odontophoridae) in Uganda

We carried out a survey of Nahan’s Partridge Ptilopachus nahani in the Ugandan forests of Mabira, Bugoma, and Budongo from December 2016 to December 2017, using a point count method employing a call playback technique. The aim was to establish the population status of this globally threatened species, which was last surveyed in 2003. Separate analyses of the number of groups per point and those involving use of the Distance Program yielded the same density estimates, indicating that either method reliably estimates the density of the species. The density estimates for the three reserves were 31.6, 25.2, and 13.3 groups per km2 for Bugoma, Budongo, and Mabira forest reserves, respectively. In the last 14 years, it appears that the density of the species for Uganda has increased from 16.3 to 23.4 groups per km2, which when extrapolated translates to 16,000 and 23,000 groups, respectively. This represents a 44% increase in density, or a group growth rate of 450 per year. The lowest density and population increment was registered in Mabira and we attribute this to the apparently high incidence of disturbance and degradation of this forest compared to the other two. Since Mabira, Bugoma, and Budongo are the only remaining large tropical rainforest reserves in Uganda, strengthening their conservation or upgrading their conservation status to national parks is required to save the species.

Desideratum: a developmentalist view of Zika virus infection

Zika virus was first isolated from the blood of a rhesus macaque during a study on yellow fever transmission in the Zika forest in Uganda in the late 1940s.1 In the following years, the virus, transmitted through Aedes mosquitos, remained, besides reports on local case series, almost unrecognised until the 2007 outbreak in the Federated States of Micronesia. It was another 8 years later that the 2015–16 epidemic in Brazil suddenly brought Zika virus into the spotlight because of unexpected severe neurological complications.

Modelling for the Reduction and Spread Transmission of the Dynamics and Control of Zika virus Disease: Using Ordinary Differential Equations

The Zika virus is a flavivirus which upon infection in humans causes an illness known as Zika fever. It is commonly identified by popular rash, mild fever and arthritis. The Zika virus (ZIKV) was first identified and isolated from the Zika forest in Uganda in 1947. This paper focuses on human recovery from treatment and death of mosquitoes from insecticides in order to reduce the spread of the virus. This shows that the ZIKV is endemic in a population when the illness exists and is a threat to a population if there is no control. Therefore, the model formulated is unique for analysis. The result of this study shows that the treatment technique without insecticides has no significant reduction in the infected vectors and hosts. The stability of the disease shows stable with R o > 1. Finally, the best option is to use an insecticide to reduce the spread of the virus on both infected hosts and vectors. Keywords : Zika Virus, Modelling, Transmission, Dynamics and Analysis

Aspectos clínicos da cavidade oral de pacientes com a síndrome congênita do zika: revisão da literatura

RESUMO: O vírus Zika pertence a família Flaviviridae, gênero Flavivírus e foi descoberto em 1947 nos macacos rhésus, na floresta Zika em Uganda na África, daí a origem do nome Zika. Inicialmente apresentava os mesmos sintomas febris da dengue. Teve seu primeiro relato em humanos em 1960 ainda na África. Na década de 1970 o vírus se espalhou e chegou a Indonésia, India, Paquistão e Malásia. Seu principal vetor no Brasil é o mosquito Aedes aegypti. Entre o final de 2014 e início de 2015, surgiu um surto de uma doença exantemática clinicamente diferente da dengue. A confirmação da presença do vírus Zika no Brasil ocorreu em março de 2015. Coincidentemente em agosto do mesmo ano começaram a nascer crianças com microcefalia neonatal no estado de Pernambuco e em outros estados do Nordeste brasileiro. Diante desse surto desconhecido de microcefalia, o Ministério da Saúde declarou emergência nacional. Logo após, foi estabelecida uma relação causal entre o vírus Zika e a série de alterações congênitas que posteriormente foi denominada Síndrome Congênita do Zika. Em aproximadamente 90% dos casos, a microcefalia está associada a alterações neurológicas. O presente estudo teve como ênfase a seguinte questão norteadora: Existem alterações clínicas orais em pacientes acometido pela Síndrome Congênita do Zika? Tendo como objetivo relatar os aspectos clínicos da cavidade oral em pacientes com a Síndrome Congênita do Zika, através de um levantamento bibliográfico. Trata-se de uma revisão da literatura, realizada em publicações feitas a partir de 2014, utilizando as plataformas de pesquisa PubMed, Lilacs, Scielo, BVS e Google Acadêmico. Esses resultados apontam que podem existir alterações na cavidade oral em crianças com Síndrome Congênita do Zika, demonstrando que os efeitos causados pelo vírus Zika estão além dos danos neurológicos. Por se tratar de uma Síndrome recém-descoberta, os dados referentes aos achados clínicos orais em crianças com Síndrome Congênita do Zika são poucos e ainda precisam ser mais pesquisados. Sugerimos que sejam feitos estudos com exames complementares pra reforçar e até aumentar os achados clínicos das crianças com Síndrome Congênita do Zika.
 PALAVRAS-CHAVE: Microcefalia, Zika Vírus, Saúde Bucal.

Introduction to the special issue: Tool use among Ugandan forest fragment chimpanzees

Version anglaise Chimpanzees are considered to be one of the most frequent tool users in the animal kingdom (McGrew, 1992). They usually use tools manufactured from natural materials, such as sticks, stones, leaves or grass, for obtaining food and for exploring their environment (including tools for extracting, probing, and pounding) (Whiten et al., 1999). Additionally, tools may be used in social contexts and for cleaning their bodies (Goodall, 1986). While tool use is widespread among chimp...

The Zika Virus Epidemic Four Years After: Where are We?

Zika virus (ZIKV), an emerging arthropod-borne, single-stranded RNA virus, member of the Spondweni serocomplex (genus Flavivirus, family Flaviviridae), was first isolated in 1947 from a sentinel (monkeys held captive with the purpose of identifying yellow fever activity) rhesus monkey in a forest in Uganda. After its discovery, ZIKV was associated only with few sporadic mild cases in humans in Africa and Asia over the next 60 years.[1] However, since 2007, when the first outbreak of ZIKV outside Africa and Asia was reported in the Federated States of Micronesia (Yap), it has been identified in subsequent outbreaks in French Polynesia, Pacific islands, and more recently, from 2015, Brazil was the first country in the Western Hemisphere to confirm autochthonous transmission of ZIKV associated with an outbreak of “dengue-like syndrome” cases.[2]