Moe S.R.,Norwegian University of Life Sciences |
Loe L.E.,Norwegian University of Life Sciences |
Jessen M.,Norwegian University of Life Sciences |
Okullo P.,Nabuin Zonal Agricultural Research and Development Institute
Journal of Applied Ecology | Year: 2016
Invasion of exotic species is a global challenge and the potential for adverse effects on local biodiversity is particularly high in protected areas. Protected African savanna areas support globally important biodiversity. At the same time, forest plantations are widespread throughout Africa and exotic tree species frequently invade natural areas. To evaluate the potential invasiveness of plant species, it is pertinent to know to what extent, if at all, consumption by native herbivore assemblages differentially affects exotic and indigenous plants. We studied how two globally widespread exotic trees Eucalyptus grandis and Grevillea robusta and two common indigenous trees Milicia excelsa and Maesopsis eminii responded to natural herbivory by large herbivores and termites. We experimentally exposed 720 tree seedlings to: (i) no large herbivores or termites; (ii) termites only; (iii) large herbivores only; and (iv) both large herbivores and termites. When exposed to large herbivores and termites, the total survival was much higher for the exotics with 45% (E. grandis) and 63% (G. robusta) compared to the indigenous species (both 20%). Exposure to large herbivores affected early seedling survival of natives more than the exotics. Apart from the indigenous M. excelsa, survival did not decrease when seedlings were exposed to termites. Large herbivores retarded seedling growth for all species. The exotic E. grandis was the only species capable of growth when exposed to large herbivores. Exposure to termites had only a small, but significant effect resulting in a 7% size difference in all species. Synthesis and applications. Our results highlight how browsing might, for some tree species, adversely affect native seedling survival and growth more than exotic species in protected African savanna. If exotic species are to be used in plantations, managers should consider planting tree species and varieties that are sensitive to ungulate browsing. This will not compromise economic gain because large herbivores are generally less common in plantations. Consequently, local ungulates could function as biological control agents outside plantations and reduce the potential risk of exotic plants proliferating in protected areas. Our results highlight how browsing might, for some tree species, adversely affect native seedling survival and growth more than exotic species in protected African savanna. If exotic species are to be used in plantations, managers should consider planting tree species and varieties that are sensitive to ungulate browsing. This will not compromise economic gain because large herbivores are generally less common in plantations. Consequently, local ungulates could function as biological control agents outside plantations and reduce the potential risk of exotic plants proliferating in protected areas. Journal of Applied Ecology © 2016 British Ecological Society.
Otuba M.,Swedish University of Agricultural Sciences |
Otuba M.,Nabuin Zonal Agricultural Research and Development Institute |
Johansson K.E.,Swedish University of Agricultural Sciences
Journal of Tropical Forest Science | Year: 2016
The aim of this study was to determine if the number of understorey species in Eucalyptus plantation was less compared with that in plantations of other common tropical and subtropical species. Meta study was used to collect information for assessing the differences in the number of understorey plant species. The number of understorey plant species in the Eucalyptus plantation was in higher compared with that of the six other species. Thus, it could be concluded that the generally-held perception of fewer understorey species in Eucalyptus plantation was not applicable. © Forest Research Institute Malaysia.
Egeru A.,University of Nairobi |
Egeru A.,Makerere University |
Osaliya R.,University of Nairobi |
MacOpiyo L.,University of Nairobi |
And 6 more authors.
International Journal of Environmental Studies | Year: 2014
Semi-arid areas show climatic variability on a spatio-temporal scale. There are few studies on the long-term trends and intensity of this variability from East Africa. We used National Ocean and Atmospheric Administration re-analysis climate data (1979-2009) in this study. Rainfall exhibited a non-significant long-term trend. The climate of the area is variable (coefficient of variation-CV >35.0%) with spatio-temporal oddities in rainfall and temperature. A rise in minimum (0.9 °C), maximum (1.6 °C) and mean (1.3 °C) temperature occurred between 1979 and 2009. There were more months with climate variability indices below the threshold (<1.0) from 1979 to 1994 than between 1995 and 2009, with wetness intensity increasingly common after 2000, leading to the observed reduction in the recurrence of multi-year drought events. More extreme wet events (rainfall variability index >2.6) were experienced between 2004 and 2009 than between 1984 and 2003. We consider that the use of spatio-temporal climatic information for timely adjustment to extreme climate variability events is essential in semi-arid areas. © 2014 © 2014 Taylor & Francis.
Byaruhanga C.,Nabuin Zonal Agricultural Research and Development Institute |
Okwee-Acai J.,Makerere University
Veterinary Parasitology | Year: 2013
A study was conducted between April and July, 2011 to determine and compare the efficacy of albendazole (ABZ), levamisole (LVM) and ivermectin (IVM) against gastrointestinal nematodes in naturally infected Mubende and Boer crossbred goats at the National Semi-arid Resources Research Institute in Serere, Uganda. Forty Mubende goats and 31 Boer crosses were each blocked by age and sex and randomly assigned to four groups. The first group of each breed served as the untreated control, the second was treated with albendazole (5. mg/kg BW), the third with levamisole hydrochloride and oxyclozanide (7.5 and 15. mg/kg BW) and the fourth with ivermectin (0.2. mg/kg BW). Each group included 7-11 animals. Treatments were administered with doses of goats in albendazole and ivermectin, and doses of sheep in levamisole, as recommended by the manufacturers. In the treated groups, goats received anthelmintics basing on individual weights. Fecal egg counts, expressed as eggs per gram and larval cultures were done on day zero before treatment and on day 13 after anthelmintic treatment. Efficacy for each anthelmintic was determined by the Fecal Egg Count Reduction Test (FECRT). In Mubende goats, ABZ, LVM, and IVM reduced FEC by 28.5%, 91%, and 98%, respectively. In Boer crosses, ABZ, LVM, and IVM reduced FEC by 11%, 84.88% and 78.47%, respectively. At a 95% CI, only IVM was more effective in Mubende goats than Boer crosses (. t=. 2.564, p<. 0.05). This may indicate occurrence of anthelmintic resistance in the goat farming sector in Uganda. Further studies need to be done to clarify the state of efficacy of the commonly used anthelmintics covering different agro ecological zones and species of animals in Uganda. © 2013 Elsevier B.V.
Byaruhanga C.,Nabuin Zonal Agricultural Research and Development Institute |
Ndukui J.N.,Makerere University |
Olinga S.,Nabuin Zonal Agricultural Research and Development Institute |
Egayu G.,Nabuin Zonal Agricultural Research and Development Institute |
And 2 more authors.
Livestock Research for Rural Development | Year: 2015
This study was conducted in three districts (Moroto, Nakapiripirit and Napak) of Karamoja Region, Uganda, to identify and document indigenous knowledge of the pastoralists regarding the control of helminthosis and ticks. Participatory methods in form of focus group discussions (30) with livestock keepers (9-12 per group) in 30 settlement areas (manyattas), and key informant interviews (20) were employed to establish the ethnoveterinary practices including local plant names, life form, parts used, method of preparation and administration. Interviews were supplemented with field observations and plant collection trips. Samples of each plant were identified and documented at the Makerere University Herbarium and National Museums of Kenya. Fourteen plant species from 13 genera and 10 botanical families were recorded as being used for control of ticks and helminthosis. Most frequently used plants for ticks were Azadirachta indica A. Juss and Adenium obesum (Forssk) Roem. & Schult (39 and 23% consensus, respectively). Dalbergia melanoxylon Guill & Perr. and Azadirachta indica A. Juss were frequently used for control of helminthosis (47 and 33% consensus, respectively). Most plants were in form of shrubs (57%). Most frequently used part of the plant was roots (43%). Non-plant practices included daily handpicking of ticks from animals, burning of bushes, smearing animals with mud and application of a mixture of ash and urine. This study contributes to the ethnoveterinary knowledge in the control of ticks and helminthosis of livestock, and provides a basis for further pharmacological studies, particularly those involving the use of plants. Apart from Azadirachta indica, Nicotiana tabacum and Balanites aegyptiaca, other plant species are reported for the first time, in Uganda, for the control of ticks and helminthosis. © 2015, Fundacion CIPAV. All rights reserved.