14 results on '"Ojo, L."'
Search Results
2. STUDIES ON TREE POPULATION DYNAMICS, GROWTH, MORTALITY AND REGENERATION IN A FIRE TREATED DERIVED SAVANNA IN SOUTHWESTERN NIGERIA
- Author
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Ola-Adams, B. A. and Ojo, L. O.
- Published
- 1999
3. Towards global climate change mitigation: assessment of an afforestation option for Nigeria
- Author
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Siyanbola, W. O., Adesina, F. A., Pelemo, D. A., Oketola, F. O., Ojo, L. O., and Adegbulugbe, A. O.
- Published
- 2002
- Full Text
- View/download PDF
4. Measurement of tree diversity in the Nigerian rainforest
- Author
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Ojo, L. O. and Ola-Adams, B. A.
- Published
- 1996
- Full Text
- View/download PDF
5. Increasing carbon storage in intact African tropical forests
- Author
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Lewis, S.L., Lopez-Gonzalez, G., Sonké, B., Affum-Baffoe, K., Baker, T. R., Ojo, L. O., Phillips, O. L., Reitsma, M., White, L., Comiskey, J.A., Djuikouo, M.-N., Ewango, C.E.N., Feldpausch, T. R., Hamilton, A. C., Gloor, M., Hart, T., Hladik, Annette, Lloyd, J., Lovett, J.C., Makana, J.-R., Eco-Anthropologie et Ethnobiologie (EAE), and Muséum national d'Histoire naturelle (MNHN)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2009
6. Effect of Cropping on Changes in Phosphorus Fractions of Soils from Arable and Other Forest Land Use: A Greenhouse Bioassay.
- Author
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Azeez, J. O., Adetunji, M. T., and Ojo, L. O.
- Subjects
SOILS ,CROPPING systems ,LAND use ,GREENHOUSE plants ,BIOSPHERE reserves ,PHOSPHORUS ,CORN ,SOIL science ,PLANT-soil relationships - Abstract
Laboratory and greenhouse studies were conducted on six soils from natural reserves, seven plantation soils, and two arable soils from the Omo biosphere reserves in southwestern Nigeria to assess the phosphorus (P) fractions and the extent to which the soils could support five consecutive cycles of maize (Zea mays L.) harvest. The organic-P fractions constitutes about 50% of the total P, and the inorganic-P fractions in the order of abundance was iron (Fe) P>occluded P>aluminum (Al)-P>calcium (Ca) P. The residual P constituted about 20% of the total P. There were significant reductions in the inorganic-P fractions after five consecutive maize harvests; this was however, more pronounced in the available P (Bray 1). About 62% reduction in Bray 1 P was recorded after maize harvests. The reductions in the P forms after five cycles of maize harvest was Bray 1 P>Ca P>residual P>Al P>total P>Fe P>organic P>occluded P>reductant P. The capacity of the soils to support maize growth without fertilization varied widely in each of the maize cycle. Soil from natural reserves produced a significantly higher maize yield compared to most plantation soils. The arable soils investigated were depleted of their fertility after the third crop harvest. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
7. Increasing carbon storage in intact African tropical forests: Implications for the global carbon cycle.
- Author
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Lewis, Simon, Lopez-Gonzalez, G., Sonké, B., Affum-Baffoe, K., Ojo, L., White, L., Hart, T., Hladik, A., Sheil, D., Swaine, M., Taylor, D., and Phillips, O.
- Published
- 2009
- Full Text
- View/download PDF
8. Measurement of tree diversity in the Nigerian rainforest
- Author
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Ola-Adams, B. A. and Ojo, L. O.
- Subjects
CONSERVATION of natural resources ,FOREST management ,ORDINATION ,RAIN forests - Published
- 1996
9. Consistent patterns of common species across tropical tree communities.
- Author
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Cooper DLM, Lewis SL, Sullivan MJP, Prado PI, Ter Steege H, Barbier N, Slik F, Sonké B, Ewango CEN, Adu-Bredu S, Affum-Baffoe K, de Aguiar DPP, Ahuite Reategui MA, Aiba SI, Albuquerque BW, de Almeida Matos FD, Alonso A, Amani CA, do Amaral DD, do Amaral IL, Andrade A, de Andrade Miranda IP, Angoboy IB, Araujo-Murakami A, Arboleda NC, Arroyo L, Ashton P, Aymard C GA, Baider C, Baker TR, Balinga MPB, Balslev H, Banin LF, Bánki OS, Baraloto C, Barbosa EM, Barbosa FR, Barlow J, Bastin JF, Beeckman H, Begne S, Bengone NN, Berenguer E, Berry N, Bitariho R, Boeckx P, Bogaert J, Bonyoma B, Boundja P, Bourland N, Boyemba Bosela F, Brambach F, Brienen R, Burslem DFRP, Camargo JL, Campelo W, Cano A, Cárdenas S, Cárdenas López D, de Sá Carpanedo R, Carrero Márquez YA, Carvalho FA, Casas LF, Castellanos H, Castilho CV, Cerón C, Chapman CA, Chave J, Chhang P, Chutipong W, Chuyong GB, Cintra BBL, Clark CJ, Coelho de Souza F, Comiskey JA, Coomes DA, Cornejo Valverde F, Correa DF, Costa FRC, Costa JBP, Couteron P, Culmsee H, Cuni-Sanchez A, Dallmeier F, Damasco G, Dauby G, Dávila N, Dávila Doza HP, De Alban JDT, de Assis RL, De Canniere C, De Haulleville T, de Jesus Veiga Carim M, Demarchi LO, Dexter KG, Di Fiore A, Din HHM, Disney MI, Djiofack BY, Djuikouo MK, Do TV, Doucet JL, Draper FC, Droissart V, Duivenvoorden JF, Engel J, Estienne V, Farfan-Rios W, Fauset S, Feeley KJ, Feitosa YO, Feldpausch TR, Ferreira C, Ferreira J, Ferreira LV, Fletcher CD, Flores BM, Fofanah A, Foli EG, Fonty É, Fredriksson GM, Fuentes A, Galbraith D, Gallardo Gonzales GP, Garcia-Cabrera K, García-Villacorta R, Gomes VHF, Gómez RZ, Gonzales T, Gribel R, Guedes MC, Guevara JE, Hakeem KR, Hall JS, Hamer KC, Hamilton AC, Harris DJ, Harrison RD, Hart TB, Hector A, Henkel TW, Herbohn J, Hockemba MBN, Hoffman B, Holmgren M, Honorio Coronado EN, Huamantupa-Chuquimaco I, Hubau W, Imai N, Irume MV, Jansen PA, Jeffery KJ, Jimenez EM, Jucker T, Junqueira AB, Kalamandeen M, Kamdem NG, Kartawinata K, Kasongo Yakusu E, Katembo JM, Kearsley E, Kenfack D, Kessler M, Khaing TT, Killeen TJ, Kitayama K, Klitgaard B, Labrière N, Laumonier Y, Laurance SGW, Laurance WF, Laurent F, Le TC, Le TT, Leal ME, Leão de Moraes Novo EM, Levesley A, Libalah MB, Licona JC, Lima Filho DA, Lindsell JA, Lopes A, Lopes MA, Lovett JC, Lowe R, Lozada JR, Lu X, Luambua NK, Luize BG, Maas P, Magalhães JLL, Magnusson WE, Mahayani NPD, Makana JR, Malhi Y, Maniguaje Rincón L, Mansor A, Manzatto AG, Marimon BS, Marimon-Junior BH, Marshall AR, Martins MP, Mbayu FM, de Medeiros MB, Mesones I, Metali F, Mihindou V, Millet J, Milliken W, Mogollón HF, Molino JF, Mohd Said MN, Monteagudo Mendoza A, Montero JC, Moore S, Mostacedo B, Mozombite Pinto LF, Mukul SA, Munishi PKT, Nagamasu H, Nascimento HEM, Nascimento MT, Neill D, Nilus R, Noronha JC, Nsenga L, Núñez Vargas P, Ojo L, Oliveira AA, de Oliveira EA, Ondo FE, Palacios Cuenca W, Pansini S, Pansonato MP, Paredes MR, Paudel E, Pauletto D, Pearson RG, Pena JLM, Pennington RT, Peres CA, Permana A, Petronelli P, Peñuela Mora MC, Phillips JF, Phillips OL, Pickavance G, Piedade MTF, Pitman NCA, Ploton P, Popelier A, Poulsen JR, Prieto A, Primack RB, Priyadi H, Qie L, Quaresma AC, de Queiroz HL, Ramirez-Angulo H, Ramos JF, Reis NFC, Reitsma J, Revilla JDC, Riutta T, Rivas-Torres G, Robiansyah I, Rocha M, Rodrigues DJ, Rodriguez-Ronderos ME, Rovero F, Rozak AH, Rudas A, Rutishauser E, Sabatier D, Sagang LB, Sampaio AF, Samsoedin I, Satdichanh M, Schietti J, Schöngart J, Scudeller VV, Seuaturien N, Sheil D, Sierra R, Silman MR, Silva TSF, da Silva Guimarães JR, Simo-Droissart M, Simon MF, Sist P, Sousa TR, de Sousa Farias E, de Souza Coelho L, Spracklen DV, Stas SM, Steinmetz R, Stevenson PR, Stropp J, Sukri RS, Sunderland TCH, Suzuki E, Swaine MD, Tang J, Taplin J, Taylor DM, Tello JS, Terborgh J, Texier N, Theilade I, Thomas DW, Thomas R, Thomas SC, Tirado M, Toirambe B, de Toledo JJ, Tomlinson KW, Torres-Lezama A, Tran HD, Tshibamba Mukendi J, Tumaneng RD, Umaña MN, Umunay PM, Urrego Giraldo LE, Valderrama Sandoval EH, Valenzuela Gamarra L, Van Andel TR, van de Bult M, van de Pol J, van der Heijden G, Vasquez R, Vela CIA, Venticinque EM, Verbeeck H, Veridiano RKA, Vicentini A, Vieira ICG, Vilanova Torre E, Villarroel D, Villa Zegarra BE, Vleminckx J, von Hildebrand P, Vos VA, Vriesendorp C, Webb EL, White LJT, Wich S, Wittmann F, Zagt R, Zang R, Zartman CE, Zemagho L, Zent EL, and Zent S
- Subjects
- Biodiversity, Africa, Asia, Southeastern, Forests, Trees anatomy & histology, Trees classification, Trees growth & development, Tropical Climate
- Abstract
Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations
1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7 , we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
10. Asynchronous carbon sink saturation in African and Amazonian tropical forests.
- Author
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Hubau W, Lewis SL, Phillips OL, Affum-Baffoe K, Beeckman H, Cuní-Sanchez A, Daniels AK, Ewango CEN, Fauset S, Mukinzi JM, Sheil D, Sonké B, Sullivan MJP, Sunderland TCH, Taedoumg H, Thomas SC, White LJT, Abernethy KA, Adu-Bredu S, Amani CA, Baker TR, Banin LF, Baya F, Begne SK, Bennett AC, Benedet F, Bitariho R, Bocko YE, Boeckx P, Boundja P, Brienen RJW, Brncic T, Chezeaux E, Chuyong GB, Clark CJ, Collins M, Comiskey JA, Coomes DA, Dargie GC, de Haulleville T, Kamdem MND, Doucet JL, Esquivel-Muelbert A, Feldpausch TR, Fofanah A, Foli EG, Gilpin M, Gloor E, Gonmadje C, Gourlet-Fleury S, Hall JS, Hamilton AC, Harris DJ, Hart TB, Hockemba MBN, Hladik A, Ifo SA, Jeffery KJ, Jucker T, Yakusu EK, Kearsley E, Kenfack D, Koch A, Leal ME, Levesley A, Lindsell JA, Lisingo J, Lopez-Gonzalez G, Lovett JC, Makana JR, Malhi Y, Marshall AR, Martin J, Martin EH, Mbayu FM, Medjibe VP, Mihindou V, Mitchard ETA, Moore S, Munishi PKT, Bengone NN, Ojo L, Ondo FE, Peh KS, Pickavance GC, Poulsen AD, Poulsen JR, Qie L, Reitsma J, Rovero F, Swaine MD, Talbot J, Taplin J, Taylor DM, Thomas DW, Toirambe B, Mukendi JT, Tuagben D, Umunay PM, van der Heijden GMF, Verbeeck H, Vleminckx J, Willcock S, Wöll H, Woods JT, and Zemagho L
- Subjects
- Africa, Atmosphere chemistry, Biomass, Brazil, Droughts, History, 20th Century, History, 21st Century, Models, Theoretical, Temperature, Carbon Dioxide metabolism, Carbon Sequestration, Forests, Trees metabolism, Tropical Climate
- Abstract
Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions
1-3 . Climate-driven vegetation models typically predict that this tropical forest 'carbon sink' will continue for decades4,5 . Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests6 . Therefore the carbon sink responses of Earth's two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature7-9 . Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth's intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth's climate.- Published
- 2020
- Full Text
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11. Above-ground biomass and structure of 260 African tropical forests.
- Author
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Lewis SL, Sonké B, Sunderland T, Begne SK, Lopez-Gonzalez G, van der Heijden GM, Phillips OL, Affum-Baffoe K, Baker TR, Banin L, Bastin JF, Beeckman H, Boeckx P, Bogaert J, De Cannière C, Chezeaux E, Clark CJ, Collins M, Djagbletey G, Djuikouo MN, Droissart V, Doucet JL, Ewango CE, Fauset S, Feldpausch TR, Foli EG, Gillet JF, Hamilton AC, Harris DJ, Hart TB, de Haulleville T, Hladik A, Hufkens K, Huygens D, Jeanmart P, Jeffery KJ, Kearsley E, Leal ME, Lloyd J, Lovett JC, Makana JR, Malhi Y, Marshall AR, Ojo L, Peh KS, Pickavance G, Poulsen JR, Reitsma JM, Sheil D, Simo M, Steppe K, Taedoumg HE, Talbot J, Taplin JR, Taylor D, Thomas SC, Toirambe B, Verbeeck H, Vleminckx J, White LJ, Willcock S, Woell H, and Zemagho L
- Subjects
- Africa, Biomass, Carbon Cycle, Climate Change, Conservation of Natural Resources, Models, Biological, Soil, Trees anatomy & histology, Trees growth & development, Trees metabolism, Tropical Climate
- Abstract
We report above-ground biomass (AGB), basal area, stem density and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha⁻¹ (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha⁻¹) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- compared with neotropical forests. However, mean stem density is low (426 ± 11 stems ha⁻¹ greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three months of the year; a negative relationship with temperature; positive relationship with clay-rich soils; and negative relationships with C : N ratio (suggesting a positive soil phosphorus-AGB relationship), and soil fertility computed as the sum of base cations. The results indicate that AGB is mediated by both climate and soils, and suggest that the AGB of African closed-canopy tropical forests may be particularly sensitive to future precipitation and temperature changes.
- Published
- 2013
- Full Text
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12. Long-term management of the successful adult liver transplant: 2012 practice guideline by the American Association for the Study of Liver Diseases and the American Society of Transplantation.
- Author
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Lucey MR, Terrault N, Ojo L, Hay JE, Neuberger J, Blumberg E, and Teperman LW
- Subjects
- Adult, Bone Density, End Stage Liver Disease surgery, Graft Rejection, Health Promotion, Humans, Morbidity, Renal Insufficiency, Chronic etiology, Liver Transplantation adverse effects, Liver Transplantation mortality, Practice Guidelines as Topic
- Published
- 2013
- Full Text
- View/download PDF
13. A systematic review and critical evaluation of invasive Haemophilus influenzae type B disease burden studies in Asia from the last decade: lessons learned for invasive bacterial disease surveillance.
- Author
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Shetty S, Cohen AL, Edmond K, Ojo L, Loo J, O'Loughlin R, and Hajjeh R
- Subjects
- Asia epidemiology, Child, Preschool, Environmental Monitoring standards, Epidemiologic Methods, Epidemiological Monitoring, Haemophilus Infections microbiology, Humans, Incidence, Infant, Infant, Newborn, Haemophilus Infections epidemiology, Haemophilus influenzae type b isolation & purification
- Abstract
In Asia, questions regarding the burden of Haemophilus influenzae type b (Hib) disease have delayed decision-making on introduction of Hib vaccine. However, over the past decade many studies have been published regarding Hib disease burden in Asia. We conducted a systematic literature review of all reports of Hib disease burden in Asia between 1998 and 2009, and critically reviewed their methods and data quality. We identified 94 studies from 28 countries in Asia presenting data on Hib disease burden. Of the 94 studies reviewed, 49 (52%) used a case definition consistent with World Health Organization standards, and 47 (50%) described laboratory methodology used. Twenty-seven surveillance studies presented data on incidence of Hib disease, with 8 (30%) accounting for missed cases, 6 (15%) accounting for cases with missed diagnostic tests, and 2 (7%) that considered prior antibiotic use. Of the 21 studies that provided incidence data for Hib meningitis, 10 (48%) used active, prospective, population-based surveillance, and found unadjusted incidence rates of Hib meningitis ranging from a low of 0.98 per 100,000 child-years in children aged less than 5 years in China to a high of 28 per 100,000 child-years in children less than 5 years in Mongolia. Of 49 studies that reported the etiology of bacterial meningitis, 30 (60%) identified Hib as the most common cause. This review highlights the importance of using rigorous methodologies, including standardized surveillance methods and appropriate laboratory diagnostic tests, when conducting studies measuring the burden of invasive bacterial diseases including those caused by Hib. When poorly conducted, studies can underestimate disease burden and lead to inappropriate decisions about vaccine introduction.
- Published
- 2010
- Full Text
- View/download PDF
14. Lead levels in some biological samples of auto-mechanics in Abeokuta, Nigeria.
- Author
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Babalola OO, Ojo LO, and Aderemi MO
- Subjects
- Adult, Body Mass Index, Case-Control Studies, Hair chemistry, Humans, Lead blood, Male, Nigeria, Automobiles, Lead metabolism, Occupational Exposure adverse effects
- Abstract
Lead levels were determined in the blood, scalp hair and fingernails of 38, all male auto-mechanics (aged 18-45 years) from Abeokuta, South-western Nigeria. The subjects were classified into four sub-groups based on the period of exposure namely: 1-5, 6-10, 11-15, and >16 years. Thirty-two occupationally unexposed subjects (mainly office workers) served as the control. The weight, height and body mass indexes of all subjects were noted, in addition to other information obtained through structured questionnaire. The mean values of blood lead (BPb), hair lead (HPb) and fingernail lead (NPb) of the occupationally exposed subjects (n=38) were 48.50 +/- 9.08 microg/dL, 17.75 +/- 5.16 microg/g, and 5.92 +/- 3.30 microg/g respectively, while the corresponding mean values for these parameters in the control subjects (n = 32) were 33.(,5 +/- 10.09 microg/dL, 14.30 +/- 5.90 microg/g and 5.31 +/- 2.77 microg/g respectively. The differences in BPb and HPb levels of the two groups were statistically significant (P <0.05 and P <0.01 respectively), while that of NPb was not significant. The levels of lead in the biological samples appeared to have no relationship with the number of years on the job. From these results, it was obvious that the higher levels of lead in the biological samples of test subjects, compared with those of the controls were from environmental sources.
- Published
- 2005
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