Olfactory cues of mahogany trees to female Hypsipyla robusta

Abstract The mahogany shoot borer, Hypsipyla robusta (Moore) (Lepidoptera Pyralidae), is a serious pest insect in the tropical forests of Africa, Asia and Australia. This insect causes multiple branching of young shoots in indigenous mahogany plantations. Gravid insects are attracted to oviposition sites by volatile organic compounds (VOCs) released by their hosts. Therefore, in this study, we aimed to (i) identify and characterise the VOCs released by the shoots of Entandrophragma and Khaya mahogany and (ii) to determine the electrophysiologically active VOCs which could influence the olfactory response of H. robusta. Volatile samples were collected from shoots of Entandrophragma angolense (Welwitsch) de Candolle, Entandrophragma utile (Dawe et Sprague) Sprague, Khaya anthotheca (Welwitsch) de Candolle and Khaya ivorensis Chevalier by closed-loop-stripping-analysis. The VOCs were identified by gas-chromatography mass-spectrometry (GC-MS) and characterised by comparing their retention times with those of authentic standards. For the first time, 29 VOCs were characterised as typical of the four mahogany species studied. The VOCs included alcohols, aldehydes, alkanes, alkenes, esters, ketones, monoterpenes, alcohol sesquiterpenes and sesquiterpenes. The majority were esters (10) and sesquiterpenes (8). GC-MS/electroantennographic detection experiments revealed antennal responses of the female moth to (Z)-β-ocimene, (Z)-3-hexen-1-yl acetate, hexan-1-ol, nonanal, (Z)-3-hexen-1-yl butanoate, 2-ethyl hexan-1-ol, decanal, β-caryophyllene, (Z)-3-hexen-1-yl hexanoate and germacrene D. Dose-response experiments with three of the compounds revealed antennal responses at concentrations of 10 -7 to 10 -2 . We therefore suggest that these compounds are olfactory cues of female H. robusta and could be used in behaviour-based control of H. robusta

Fractured tenure, unaccountable authority, and benefit capture: Constraints to improving community benefits under climate change mitigation schemes in Ghana

The debate on climate change and ecosystem services has grown substantially over the past two decades. The post-Kyoto protocol period particularly has witnessed increased formulation of financial mechanisms to compensate for green efforts towards carbon sequestration and reduction in deforestation. In most cases, communities substantially depend on forests for their livelihoods or their actions have a direct bearing on the sustainability of the forests. Will the economic incentives from emerging initiatives offer new sources of income to support rural livelihoods and reduce poverty? There is some doubt about this potential, because there is enormous evidence across the world to show that forest exploitation and use has not substantially benefited local people and Ghana is no exception. This paper draws on existing evidence in Ghana to show that the lack of secure community tenure rights and the dominance of unaccountable authority-which leads to benefit capture by local elites-are critical constraints to equitable forest benefit sharing. Building on the evidence, this paper argues that unless these issues are addressed in policy and practice, the potential economic benefits from the various emerging mechanisms under climate change and ecosystem services may not benefit local people; they may even reinforce the gap between the rich and the poor

Sustainable Development Goal for Education: Teachers’ Perspectives on Climate Change Education in Senior High Schools (SHS)

Any program intended to equip the populace, particularly young people, to combat climate change and its repercussions must include education. As crucial stakeholders in education, teachers have the primary responsibility of preparing young people to deal with the effects of climate change. In two districts of Ghana’s Bono region, the study assessed SHS teachers’ viewpoints on climate change and their willingness to include climate change concerns in classes. The degree to which climate change was incorporated into the syllabi of selected disciplines was also assessed. For this study, data was collected from a hundred (n = 100) SHS teachers from 10 of the 15 schools in the study area using a simple random sampling method. The Pearson chi-square test was used to examine the association between the subject content and teachers’ desire to teach climate change. The data were analyzed using SPSS (v25). The findings demonstrated that teachers’ readiness to educate about climate change was influenced by the subjects they taught. Subjects that were not science-based provided little information on climate change to teachers. Climate change is addressed in many areas in Integrated Science and Social Studies, and it is a core topic for all students. Climate change should be taught using an interdisciplinary approach, and in-service training for teachers could be beneficial

Carbon accumulation in soil layers under degraded, intact and planted forest cover types in tropical semi-deciduous and moist evergreen forests

Tropical forest soils can contribute significantly to mitigating climate change by sequestering and storing carbon in their layers. However, in West Africa, knowledge of how much carbon is stored in deeper soil layers of various forest cover types and protected from further release into the atmosphere remains scanty. We quantified the carbon (C) and nitrogen (N) contents of tropical soils in Ghana at 0–20 cm and 20–50 cm, by comparing a degraded forest and an intact forest in the semi-deciduous forest zone, and intact forest, degraded forest, and agroforestry plantations in the moist evergreen forest zone. In semi-deciduous forests, C concentration was significantly higher for intact forest than degraded forest, but total C content of soils from the intact forest was not greater than the degraded forest due to compensating differences in bulk density. C content differed by depth for the two forests, with values at 0–20 cm of 48.1 vs 38.4 Mg ha−1 and at 20–50 cm of 20.6 vs 26.5 Mg ha−1, for degraded and intact forests respectively. In moist evergreen forests, soil C concentrations were similar between intact forest, degraded forest and plantations, yet, differed between the depths. Among the three, soils under plantations had the highest C content due to higher bulk density. For N, differences among cover types and soil depths followed similar patterns as those for C. Our results suggest the potential for formerly disturbed or degraded forests to gain more C lies primarily in live forest biomass, not in soil, especially if forests have maintained vegetative cover of some type since disturbance. The potentially large capacity for deeper soil layers to store C, and their reduced susceptibility to forest disturbance makes them an important soil carbon pool to further quantify and preserve

Tragocephala nobilis Fabricius (Coleoptera:Cerambycidae): A new insect pest threatening the domestication of Tetrapleura tetraptera (Schum and Thonn.) in Ghana

Tragocephala nobilis (Fabricius) (Coleoptera:Cerambycidae), an insect pest (herbivorous insect), was recently found on a multipurpose tropical tree species, Tetrapleura tetraptera (Schum and Thonn.) Taub, in Ghana. Although the pest has been previously reported on other tree crops such as cocoa and Coffea arabica, this is the first report on T. tetraptera. T. tetraptera is a deciduous tree crop with numerous nutritional and medicinal benefits. The pest, a long-horned beetle is found to attack T. tetraptera tree and damage is first observed as die-back of twigs and branches leading to the formation of a witches broom in the crown. This is followed by a series of tunnels created by the larvae on the main stem resulting in branch death and/or tree mortality. In view of the threat posed by the pest to T. tetraptera, a broader study is needed urgently to develop an integrated pest management strategy for T. nobilis pest in T. tetraptera plantations as the interest in its domestication as a tree crop is burgeoning in response to increasing herbal medicine and food supplements demand

Improving regeneration of mahogany: Techniques for vegetative propagation of four African mahogany species using leafy stem cuttings

Regeneration to ensure sustainable production and conservation of mahogany species globally is considered very important to foresters, investors in plantation, conservationists and timber industries worldwide. Natural regeneration of the mahoganies has been found to be far less than the rate of exploitation hence strong efforts are being made to develop other methods to regenerate mahogany seedlings to augment the low natural replacement and to ensure sustainability. This study was commissioned to investigate the effect of rooting media (river-sand, top soil and a mix of the two (50:50 v/v) on the rooting ability of four mahogany species (Khaya grandifoliola, K. ivorensis, Entandrophragma angolense and E. utile) using non-mist propagators. We investigated the effects of the source of stem cutting within a shoot (top, middle and basal position) on the rooting ability of stem cuttings from the four species in river-sand. Roots per cutting, longest root length and rooting percentage differed significantly among species in all three rooting media. Rooting ability was greatest in K. grandifoliola, which exhibited the highest average rooting percentage (73 %), longest average single root (9.9 mm) and the most roots per cutting (4.9). Rooting percentage was higher in the Khaya species than in the Entandrophragma species in all three rooting media. The mixed medium had the highest rooting percentage and the highest number of roots per rooted cutting in the two Khaya species, while the topsoil media had the best rooting percentage in the Entandrophragma species. Rooting of the two Khaya species can be maximized using a mixture of river-sand and topsoil. Cutting position within a shoot had significant impact on rooting in all four species with rooting percentage being best from middle positions in all four species. However, length of longest root and the number of roots per rooted cutting varied between the middle and basal portions. The study provides useful information for vegetative propagation of leafy stem cutting of the four African mahogany species, which could contribute to regeneration and conservation of these important timber species in the tropics. © 2014 Springer Science+Business Media Dordrecht

Variation in wood density and carbon content of tropical plantation tree species from Ghana

Most research on carbon content of trees has focused on temperate species, with less information existing for tropical trees and very little for tropical plantations. This study investigated factors affecting the carbon content of nineteen tropical plantation tree species of ages seven to twelve and compared carbon content of Khaya species from two ecozones in Ghana. For all sample trees, volume of the main stem, wood density, wood carbon (C) concentration and C content were determined. Estimated stem volume for the 12-year-old trees varied widely among species, from 0.01 to 1.04 m3, with main stem C content ranging from 3 to 205 kg. Wood density among species varied from 0.27 to 0.76 g cm−3, with faster growing species exhibiting lower density. Significant differences in wood density also occurred with position along the main stem. Carbon concentration also differed among tree species, ranging from 458 to 498 g kg−1. Differences among species in main stem C content largely reflected differences among species in estimated main stem volume, with values modified somewhat by wood density and C concentration. The use of species-specific wood density values was more important for ensuring accurate conversion of estimated stem volumes to C content than was the use of species-specific C concentrations. Significant differences in wood density did exist between Khaya species from the wet and moist semi-deciduous ecozones, suggesting climatic and site factors may also need to be considered. Wood densities for these plantation grown trees were lower than literature values reported for the same species in natural forests, suggesting that the application of data derived from natural forests could result in overestimation of the biomass and C content of trees of the same species grown in plantations

ANALYSIS OF SMALLHOLDER FORESTS FOR POVERTY ALLEVIATION AND CLIMATE CHANGE MITIGATION IN THE NKORANZA SOUTH DISTRICT OF THE BRONG AHAFO REGION OF GHANA

The study dwelt on the potential of smallholder forests for the dual purpose of providing products for the farm household while contributing to climate change mitigation in Ghana using the Kranka, Baafi and Manso integrated mahogany forests of the Nkoranza South District as case study. It employed the use of both questionnaire sourced primary and literature review sourced secondary data. Both quantitative (use of tables and charts) and qualitative methods (use of SPSS-Statistical Package for Social Scientist and the Microsoft Excel computer application software) were used in the data analysis. The study established that smallholder farmers earn less than GH₵200 a year, perceive climate change as change in rainfall pattern and increase in temperature, and are willing to manage and retain their farms for climate change mitigation longer if enabled with carbon credits. It also established that access to initial capital is main factor that could influence planting of smallholder forests for climate change, and serving carbon credits to smallholders would influence the management of their forests. The study recommends the smallholders should be provided financial assistance to enable them increase the establishment of smallholder forests and carbon credits to enable them manage the forests. (GH₵1=US$0.52493 as at February, 2013)

Citizen Science Approach for Assessing the Biodiversity and Ecosystem Service Potential of Urban Green Spaces in Ghana

Urban green spaces are linked to good human health and well-being, sustainable cities and communities, climate action, life on land and under water, as well as offering a platform for quality nature-based education. Their efficient management will no doubt be necessary if strides are to be made in efforts to protect biodiversity and enhance ecosystem service delivery in urban areas. This will, in part, require building the capacity of community members as citizen scientists to take up conservation roles. This study explored the levels of biodiversity and the proxy-based ecosystem service potential of urban green spaces in Sunyani, Ghana, using citizen science approaches. The green spaces accessed were the University of Energy and Natural Resources Wildlife Sanctuary and Arboretum, the Sunyani Parks and Gardens, the Sunyani Residency Park, and the Sunyani Senior High School Woodlot. The different levels of biodiversity (trees, arthropods) and ecosystem services were observed for the five green spaces assessed, with a significant relationship observed between arthropod communities and vegetation variables. Our results showed that citizen scientists perceived urban green spaces to supply more significant provisioning and regulating services than any other ecosystem services, even though they were highly dissatisfied with how green spaces are managed. The children’s perception of the composition of nature was slightly narrow, as they largely centered on plants and animals only. Even so, their awareness of the value of nature was high, as were the threats of human activities to nature. Citizen science approaches could complement biodiversity studies in data-deficient regions; however, collected data may require additional verification and validation from experts for conclusive and better inferences

Citizen Science Approach for Assessing the Biodiversity and Ecosystem Service Potential of Urban Green Spaces in Ghana

Urban green spaces are linked to good human health and well-being, sustainable cities and communities, climate action, life on land and under water, as well as offering a platform for quality nature-based education. Their efficient management will no doubt be necessary if strides are to be made in efforts to protect biodiversity and enhance ecosystem service delivery in urban areas. This will, in part, require building the capacity of community members as citizen scientists to take up conservation roles. This study explored the levels of biodiversity and the proxy-based ecosystem service potential of urban green spaces in Sunyani, Ghana, using citizen science approaches. The green spaces accessed were the University of Energy and Natural Resources Wildlife Sanctuary and Arboretum, the Sunyani Parks and Gardens, the Sunyani Residency Park, and the Sunyani Senior High School Woodlot. The different levels of biodiversity (trees, arthropods) and ecosystem services were observed for the five green spaces assessed, with a significant relationship observed between arthropod communities and vegetation variables. Our results showed that citizen scientists perceived urban green spaces to supply more significant provisioning and regulating services than any other ecosystem services, even though they were highly dissatisfied with how green spaces are managed. The children’s perception of the composition of nature was slightly narrow, as they largely centered on plants and animals only. Even so, their awareness of the value of nature was high, as were the threats of human activities to nature. Citizen science approaches could complement biodiversity studies in data-deficient regions; however, collected data may require additional verification and validation from experts for conclusive and better inferences