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Item Climate change and the potential distribution of the invasive shrub, leucaena leucocephala (lam.) de wit in Africa(2023) Obiakara, M.C.; Olubode, O.S.; Chukwuka, K.S.Leucaena leucocephala, previously known as ‘miracle tree’ because of its numerous agroforestry uses has become a seri¬ous invasive species in tropical regions. Despite the risks associated with the spread of L. leucocephala, changes in its distribution with respect to climate are poorly understood, particularly in Africa where it has been widely introduced in more than 30 countries. To provide first-line information for the management of L. leucocephala, we examined its poten-tial distribution in Africa using ecological niche modelling. We identified bioclimatic variables that determine the global distribution of L. leucocephala, and calibrated niche models using MaxEnt and species occurrences recorded between 1973 and 2013. The potential distribution of this species was estimated from model projections in Africa based on cur¬rent and future climatic conditions. We tested the hypothesis of niche conservatism for L. leucocephala by comparing its climatic niche in Africa to that of its native range. Under current conditions, L. leucocephala is constrained between 30° S and 20° N in Africa, with the broadest distribution in East Africa. High rainfall areas in Central Africa with no known records of this species hitherto, were found to be highly suitable for its establishment. We predicted a significant decre¬ment in the extent of areas at risk of invasion by L. Leucocephala under changing climates in Africa. Our results revealed that the study species occupies a similar but non-identical climatic niche in Africa in relation to its native niche. Climate change is likely to impede the spread of L. leucocephala in Africa.Item Evaluation of depredation activities of vertebrate pest species in cassava cultivation at sasa-ajibode, Ibadan, Oyo state, Nigeria(2022) Badmus, H.A.; Olubode, O.S.; Onaolapo, E.E.Cassava is the fourth most important food crop in developing countries, after rice, maize, and wheat. African giant rats (Cricetomys gambianus), cane rats/grasscutter (Thryonomys swinderianus), and birds such as bush fowl (Francolinus bicalcaratus), among others, cause considerable damage to cassava crops. The present study was conducted on an existing cassava farm located at Shasha- Ajibode, Akinyele Local Government of Ibadan, Oyo state. Systematic sampling was used to collect quantitative and qualitative damages in the study area. Data were analyzed using Analysis of variance (ANOVA) and means were separated using Least Significant Difference (LSD) at the level of significance of P≤0.05. The results showed that there were evidences of root damage done in plot 1 (21.67%), plot 2 (14.00%), and plot 3 (20.00%) at 14 Weeks After Planting (WAP). Plot 2 had the highest total stem cut percentage (36.36%) while plot 1 and 2 had the same percentage of total stem cut (31.82%). It was revealed that the position of the plots had no significant effect on the damage level caused by the vertebrate pests on cassava roots and stems. It can be inferred that even though the damage level was not significant, attention should be given to managing those rodent populations and damages so that they do not escalate to causing unbearable economic loss.Item Peri-urban agricultural expansion and forest loss in lapite, Ibadan, its implication for floristic composition and species invasion(2023) Olubode, O.S.; Oni, T.E.Peri-urban agriculture in developing countries is in increasing demand for food as a result of increasing population. It offers an alternative land-use for income generation to ameliorate urban poverty and contributing to global food security. Peri-urban agriculture however causes forest loss, degradation, and species invasion. This study investigated the extent of forest loss, species composition, and importance of invasive species in peri-urban agriculture at Moniya, Akinyele local government area, Ibadan, Oyo State in the wet season of 2019. The study site was located at Lapite, Moniya, Ibadan on N 07° 34.253, E 003° 54.633; 235 m above sea level. Ten farmlands (sizes: 1120 m2 and 3750 m2) were evaluated within 70.4 hectares. Systematic sampling for herbaceous and woody flora was conducted using plot sizes of 10 × 10 m and one square meter quadrats, respectively. Land-use cover change from 1998-2018 was assessed with Arc GIS 10 on USGS Landsat imageries. Enumerated floristic data were analyzed for species composition, relative important value (RIV), and invasive species were noted. One hundred and thirty-two (132) herbaceous species in 38 families were enumerated with RIV ranging from 0.02% - 13.9%. Talinum fruticosum had the highest RIV (13.58%). Twenty woody species in 13 families were enumerated with RIV of 1.33% to 23.2%. Elias guineensis had the highest RIV. Five invasive species were identified. Leucaena leucocephala had the highest occurrence among invasive woody species (RIV=13.38). Alternanthera sessilis was the most (RIV= 2.5%) occurring invasive species. GIS analysis indicated bare/deforested areas increased from 8.33% in 1998 to 46.23% in 2018. Loss of cover and species invasion was attributed to the expansion of agricultural areas and might increase the impact of climate change in the area. Peri-urban agricultural activities in Moniya should be regulated to prevent the further incursion of invasive species and forest loss with associated benefits.Item Vegetation communities and floristic diversity of eleyele and dandaru wetland in Ibadan, Southwest, Nigeria(Science Association of Nigeria, 2021) Woghiren, A.I.; Olubode, O.S.Wetlands are globally important biodiversity hotspots and are facing rapid loss in floristic diversity and major changes in the functioning of these ecosystems due to various anthropogenic activities. However, wetlands located in large cities in developing nations are often unattended despite major yet often subtle changes in the functioning of the ecosystems. Recognizing this, the study was conducted in two wetland ecosystems, Eleyele and Dandaru wetlands in Ibadan city, southwestern Nigeria, to assess, document and determine the degradation or otherwise of the diversity and stand distribution of herbaceous and wood flora of the wetlands. The study was carried out on the wetlands of Eleyele (Lat, 7O25148.38″N, Long, 3O51145.18″E; elevation of 200 m ASL) in 2012. Systematic survey was carried out to assess the herbaceous and woody (girth ≥ 10 cm) components of the wetlands following Kent (2012) and Cox (1990) methods. Forty – five plotless sampling points of fifteen 5 m line transects, and twenty–one 10 m ×10 m plots were used for the respective surveys. Species presence and densities were used to compute Relative Importance Values and Diversity Indices following Kent (2012), Hammer et al. (2001) and Hill (1994). Topsoil was collected from the top 0 – 15 cm with a soil auger, bulked and analysed following AOAC (1984) methods. The wetland of Dandaru had higher diversity and was in a better floristic and edaphic health than Eleyele Lake wetland. This study recommends that Eleyele Lake wetland should be protected from anthropogenic activities that may lead to the loss of species.Item Vegetation communities and floristic diversity of eleyele and dandaru wetland in Ibadan, Southwest, Nigeria(Science Association of Nigeria, 2021) Woghiren, A.I.; Olubode, O.S.Wetlands are globally important biodiversity hotspots and are facing rapid loss in floristic diversity and major changes in the functioning of these ecosystems due to various anthropogenic activities. However, wetlands located in large cities in developing nations are often unattended despite major yet often subtle changes in the functioning of the ecosystems. Recognizing this, the study was conducted in two wetland ecosystems, Eleyele and Dandaru wetlands in Ibadan city, southwestern Nigeria, to assess, document and determine the degradation or otherwise of the diversity and stand distribution of herbaceous and wood flora of the wetlands. The study was carried out on the wetlands of Eleyele (Lat, 7O25148.38″N, Long, 3O51145.18″E; elevation of 200 m ASL) in 2012. Systematic survey was carried out to assess the herbaceous and woody (girth ≥ 10 cm) components of the wetlands following Kent (2012) and Cox (1990) methods. Forty – five plotless sampling points of fifteen 5 m line transects, and twenty–one 10 m ×10 m plots were used for the respective surveys. Species presence and densities were used to compute Relative Importance Values and Diversity Indices following Kent (2012), Hammer et al. (2001) and Hill (1994). Topsoil was collected from the top 0 – 15 cm with a soil auger, bulked and analysed following AOAC (1984) methods. The wetland of Dandaru had higher diversity and was in a better floristic and edaphic health than Eleyele Lake wetland. This study recommends that Eleyele Lake wetland should be protected from anthropogenic activities that may lead to the loss of species.Item Seed pre-treatment and early growth performance of piliostigma thonningii (schum.) milne-redhead under nitrogen amendment in Old Oyo national Park, Nigeria(2023) Olubode, O.S.Survival of wildlife in protected areas is dependent on innate attributes and response of vegetation to climate change. Piliostigma thonningii holds promise for wildlife conservation in Old Oyo National Park, but its population is threatened by physical dormancy. There is dearth of information on long-term benefits of its seed pretreatment and early growth response to nitrogen fertilizer. This study assessed effects of acid scarification on germination and early growth of P. thonningii under different nitrogen application rates. Seeds harvested from three purposively selected seasonal wetlands in Old Oyo National Park (OONP) were treated with 1N H2SO4 at durations ranging from 0 – 120 minutes in three replicates. Germinated seeds were enumerated over a 14-day period. Top soils from the wetlands were randomly sampled using soil auger in three replicates for physical and chemical analyses, and for early growth study with Urea fertilizer at rates 0, 50 and 100 kg/ha in experimental pots in completely randomized design. Growth and dry matter were assessed using ANOVA at P.05. Germination commenced in control treatments at 14 days after plating (DAP) and was low (13.3%). Germination progressively increased in acid treatment. At 5 DAP for soaking for 30 minutes gave 46.67%; while it was 96.67% at 40 minutes at 14 DAP. Higher soaking times gave 100% germination by 14 DAP, but with low growth vigor. The response of P. thonningii to Urea application was significantly higher in number of leaves at 12 weeks than in other rates. Other growth parameters are not significantly different at all rates. The biomass yield of P. thonningii was 1.98 g 0.21and 2.6 g 0.36 root and shoot dry weights at 6 weeks after sowing (WAS); and 7.3 g 0.04 root and 6.4 g 0.95 shoot dry weights at 12 WAS. Piliostigma thonningii can restore and improve wildlife abundance to mitigate climate change effects in the Park.Item Phytosociology of the herbaceous flora of university of ibadan oil palm plantation, University of Ibadan, Ibadan, Southwest, Nigeria(2023) Olubode, O.S.Plantation agriculture perturbs native flora of ecosystems. This impacts vegetation biodiversity, through species invasion and shift in weeds population dynamics. Oil palm plantations are common in tropical landscapes, and can cause long-term floristic changes. There is paucity of knowledge on inventory and potential impacts of the plantation on community structure of plants. This study investigated herbaceous flora diversity and phytosociology as indicators of appropriateness of management strategy in the University of Ibadan oil palm plantation. The study site is located in a lowland rainforest at the Teaching and Research Farm, University of Ibadan, Ibadan, Nigeria on 07°27`253`N latitude and longitude 03°53`427`E. A systematic sampling was employed to enumerate herbaceous flora of a hectare mega plot. The hectare was laid along 100 m transects at 10 m intervals, with 10 m separating each transect. Each transect was laid to cut across middle of 9 m x 9 m x 9 m plant spacing for oil palm. Data were collected on species composition, frequency and density for determination of relative importance value (RIV), species diversity, ordination and classification. The plantation consisted of 32 herbaceous species in 15 plant families. Commelina erecta had the highest RIV (12.621) while Alchornea cordifolia had the least (RIV=0.288). Diversity indices indicated high species richness (Simpson Index = 0.909) among enumerated species and species co-dominance (D = 0.091) Ordination biplots indicated three distinct vegetation structures (Secondary, wetland, dryland/fallow). Classification model showed Commelina erecta had widest coverage of 92% in distribution at the site followed by Commelina benghalensis at 88%. The Oil palm plantation is heterogeneous in species composition, and was not detrimentally invaded. Weeding regimes and other agronomic practices in the plantation should be ecologically integrated to conserve its native vegetation.Item Assessment of bitter yam (dioscorea dumentorum [kunth] pax) production in Oyo state, Nigeria(2023) Olubode, O.S.; Fasola, I.A.; Gbadamosi, I.T.Production of bitter yam (Discoreae dumentorum [Kunth.] Pax) is low in Oyo State, Nigeria. Two varieties are mainly cultivated, but there is limited information on factors responsible for low production and varietal preferences among farmers. This study investigated the demography, farming practices and differential proximate compositions as probable causes of low production of bitter yam in Oyo State. One hundred and twenty (120) copies of structured questionnaire were administered to selected respondents. Multistage sampling was used in selecting respondents in Oyo state from local government areas constituting four agricultural zones and 12 villages to collect demographic, production-related information, and constraints to production. Data were analyzed using descriptive statistics as well as analysis of variance (ANOVA). The result revealed that although bitter yam cultivation in Oyo state was male dominated (70%), majority of the farmers were old (57%), married (72%) and poorly educated (55%). Its production was for subsistence, and it was mainly grown in intercrop with other yam species. Ranked production constraints indicated poor marketability as the most extremely severe constraint, followed by labour unavailability and storage inadequacies. White bitter yam variety with superior basic proximate composition than Yellow Yam was preferred for cultivation. Subsistence production of bitter yam in Oyo state could be up-scaled through government intervention via farmer-centered education and public awareness and provision of infrastructure to facilitate cultivation, transportation, and storage.Item Landscape ecological risk assessment and transformation processes in the Guinean-Congolese climate zone in Benin Republic(2023) Anagonou, S.P.G.; Ewemoje, T.A.; Toyi, S.S.M.; Olubode, O.S.The landscape of Ramsar site 1018 in Benin Republic is increasingly modified by different types of land use. Understanding these changes dynamics is essential for efficient resource management. The aim of the research is to identify the spatial configuration of landscapes using landscape indices, which are the indicators and guide for agricultural policy. Fragstats 4 software helped for computing landscape metrics. Landsat imagery were analysed using Arcmap 10.7.1 and ENVI 5.3 software. The landscape of the Ramsar site is composed by the natural land (forests, savannahs, swamp formations), semi-natural land (plantations), anthropized land (agriculture lands, built-up area), and water land. These ecosystems have changed according to different trends 1990–2000, 2000–2020 and 1990–2020. The agricultural land showed an increasing trend of 143%, following by the built up area (37%). From 1990 to 2020, a decreasing of 45% has been observed in the savannah land, plantation land (41%), forest land (30%) and swampy land (17%). Also, the Ramsar site ecological context is at medium level despite the increasing of the landscape Ecological Risk Index: 0.1899, 0.2128, and 0.2165 in 1990, 2000, and 2020, respectively. Between 1990 and 2000, the creation process occurred in the built-up area and agriculture land, attrition within forest and plantation classes, dissection in swampy land, aggregation for savannah and shrinkage in water area. From 2000 to 2020, the agriculture land and swampy land continued to experience the same spatial transformation processes respectively. Dissection has observed within the forest land, attrition in water area, and aggregation for built-up area. The perforation process has observed within plantation, and fragmentation in Savannah. Finally, the development of agricultural activities and built-up areas are leading to change in the spatial structure of the Ramsar site landscape. To better conserve the biodiversity of these area, it will be necessary to characterize the still natural ecosystems. This will make it possible to propose a comprehensive management plan that integrates the agricultural and urbanization policy of the government, and the sustainable development goals.Item Attributes and ecological potentials of dumpsite flora in the peri-urban area of Ibadan, Nigeria(2023) Olubode, O.S.; Ibrahim, B.A.Dumpsites are spaces used disposal of urban and peri-urban wastes. Their public health concern has not made them to be adequately explored for positive potentials in Nigeria. This study investigated the the floristic structure and comparative potential of a dumpsite with arable farms for conservation and phytoremediation. The study was conducted at a 10-hectare peri-urban Lapite dumpsite (N 07o34.121ʹ, E 003o54.857ʹ) in Ibadan, Oyo State, Nigeria; and three arable farmlands (Control) located 200 m-300 m away from Dumpsite. Stratified sampling was conducted using 414 quadrats (each 1m2) in five strata of dumpsite, and a systematic sampling of flora of farms with 263 quaddrats in 21 transects laid 5 m apart. Data were collected on species composition, abundance,density and frequency of occurence. They were subjected to analysis of Relative importance value (RIV), density, and multivariate analysis. Species with phytoremediation potentials were identified. Ninety one species of herbaceous flora in 33 families and 99 species in 38 families were enumerated on the dumpsite and farmlands respectively. Solanum nigrum L., Tridax procumbens Linn., Amaranthus spinosus Linn., Laportea aestuans (Linn.) chew., Acalypha fimbriata Schum. & Thonn., and Lufa cylindrica Mill were the most dominant species on the dumpsite with RIVs of 8.40, 8.17, 7.54, 7.21, 6.38 and 5.79 respectively. Talinum fruticosum (L.) Juss., Tridax procumbens L., Euphorbia heterophylla Linn., Spermacoce ocymoides Burm f., and Tithonia diversifolia (Hemsl.) A. Gray were most dominant on farmlands with RIVs of 13.74, 7.05, 6.60, 6.07, and 5.57 respectively. Dumpsite flora had higher diversity (H`=3.501) than control plots (H`=3.294). The dominance value (0.0486) was low compared to the control farms (0.07131). The lora of the two sites were grouped by habitatt preference.Higher species diversity and pervasive presence of invasive Tridax procumbens linn., Laportea aestuans (Linn.) chew., and Lufa cylindrica Mill. On dumpsite indicated potentials for phytoremediation, and candidacy as functional groups and bio-indicators of ecosystem health.