Demographic characteristics and economic development are the major determinants of urban shape and pattern of urbanization in Gombe which gave rise to rapid population growth. These determinants resulted to unplanned urban growth, unprecedented urbanization and land use change as a result contributing in the rapid reduction of vegetation cover and loss of arable land in the surrounding urban environment. The aim of this paper is on the impact of urbanization on vegetation cover. Both primary and secondary data was employed in this work. Socio-economic data and information on the status of tree species were gathered through questionnaire survey that involved 195 respondents using purposive sampling techniques in the study area. While the land use land cover analysis was carried out using ArcGis 10.5 and Edras Imagine 9.0. The finding was made to capture as accurate as possible six land use land cover classes as they changed through time. The result of the work shows a rapid decrease on the vegetation and a gradual increase in settlements between 1976 and 2016 due to the fact that Gombe metropolis became the capital of Gombe state in 1996. Also only few tree species were found within the study area, as most trees are cut down for various developmental purposes. The study recommends that urgent attention on conservation of vegetal resources within the metropolis should be encouraged.
Creation of an Exceptional Natural Phenomenon of Chains of Dunes and Lagoons through a Rare Balance of Five Key Elements in the National Park Lençóis Maranhenses in the Northeast of Brazil: Sand, Rain, Wind, River and Vegetation – An Artistic Approach (Published)
During our travels in the State of Maranhão in the northeast of Brazil, we explored the region of the National Park Lençóis Maranhenses in 2012 and 2013 before crossing the park during 5 days in September 2013 with the aim to produce nature art photography and organize subsequent itinerant exhibition throughout the country and abroad. We could confirm in loco the creation and constant modification of an exceptional natural phenomenon of chains of dunes and lagoons through a rare balance of five key elements in the park: sand, rain, wind, river and vegetation. Questions were raised and answers need to be found. Where is the sand coming from? What are the roles of the tides? How is the wind transforming the dunes? What are the natural lagoons or water ponds that exist in the middle of the dunes? What is the role of the vegetation? The dunes are in constant movement, what is their annual rate of dislocation? Is the balance of the five key elements to recreate the phenomenon threatened at present time or in the future, for instant due to ongoing, negative climate changes? A special approach was taken, as the production of nature photography of the dunes and lagoons in the park allowed us to know and observe the vast park area very closely. For the consecution of the aim of the research, we collected data based on bibliographic research, extents field studies in the area of the Lençóis Maranhenses National Park in 2012 and 2013, while conducting interviews with the habitants of the three communities living in the middle of the park and realizing artistic productions of nature photography and itinerant exhibitions to accompany the process of creation of dunes and lagoons in the park. We concluded that the balance of the five key elements to recreate the phenomenon depends on some fundamental factors such as, for instant, the same direction of the steady winds throughout the year, the elevation of the groundwater level due to rainfall during the month of January until July and the drying out of the water ponds during the month of July to December. We could distinguish the existence of free dunes inside the park and the fixed dunes on the Southern borders of the park and near to the village Atins. An important role plays the vegetation, that are fixing the dunes and delimitating the area of the park as further crowing of dunes is inhibited beyond theses areas due to the fixation of the dunes by vegetation. Furthermore, vegetation can deviate the direction of the winds, which might result in some cases in accumulation of a great amount of sand where vegetation was able to fix itself on the surface of a dune (the so called shadow dunes). In the first six months, due to rainfall, elevated groundwater level causing the creation of lagoons or water ponds, the free dunes in the park are almost not migrating, whereas during the months between July and December, with the drying out of the lagoons, sinking of the groundwater level and the continuing steady winds, the free dunes are migrating and moving in average 20m per year. The change of the landscape is confirmed by members of the three families living in the middle of the park, the Paulos, the Britos and the habitants of Baixa Grande during interviews. In the dry period of the year without rainfall, algae and vegetation can be found on the bottom of the lagoons and serve as food for domestic animals as pigs, horses and sheeps that are walking free inside the park. One scenario in the future is that the crossing of the park might be prohibit by the park administration alleging environmental prejudice to the balance of the park, as well as dust left behind while camping inside the park. Based on our experience, this kind of alternative tourism is not threatening the environment, as, for instant, we did not see any remains, and nothing was left behind by ourselves during the crossing and due to the fact that only few people are entering the park by food. As the results of our research show, the exceptional natural phenomenon of chains of dunes and lagoons through a rare balance of five key elements in the park: sand, rain, wind, river and vegetation continuous to be intact and is not threatened, even not due to climate changes that occurred in this area. In recent years, it could be observed that, due to a dryer year with less rain occurrence during the month of January to July, the lagoons dried out in the subsequence months very quickly. Some lagoons contain fish. Even drying out (in the case of the not perennial water ponds) in the second half of the year and located in the middle of the park with no other water source visible next to it, the fish reappears in the following rainy season at the beginning of the year. One explanation is the possible ability of the fish to adapt to the situation by digging themselves into the sand into ground water layers where they are able to survive. Future research needs to be carried out to accompany closely the recreation and constant modification of an exceptional natural phenomenon of chains of dunes and lagoons through a rare balance of the five key elements needed.
Accumulation and Contamination of Heavy Metals in Soil and Vegetation from Industrial Area of Ikirun, Osun State, Nigeria (Published)
Samples of soil and vegetation were analyzed for their heavy metal contents using standard methods. Samples were collected around a steel rolling mill along Ikirun, Osogbo road, Osun State. Results of vegetation revealed highest iron concentration (17305.00mg/kg), highest chromium concentration (1088.00mg/kg), highest nickel concentration (303.40mg/kg), and highest lead concentration (38.88mg/kg) at VG 7. Soil analysis showed highest iron concentration at SS3 (29895 mg/kg), highest cobalt concentration at SS6 (510 mg/kg), highest nickel concentration at SS6 (882 mg/kg), highest lead concentration at SS7 (2525 mg/kg) and highest chromium concentration at SS6 (2935 mg/kg). This suggests that the area was grossly contaminated mostly with iron, chromium, lead and nickel especially in soil. Plant concentration factor was in the range 0.03 вЂ“ 0.63 for iron, 0.10 вЂ“ 0.62 for cobalt, 0.01 -0.76 for nickel, 0.00002 вЂ“ 0.02 for lead and 0.09 вЂ“ 0.95 for chromium. Plant absorption of heavy metals from soil was in the order Cr>Ni>Fe>Co>Pb. Integrated pollution index of soil showed low to extreme high level of pollution. Statistical significant differences were observed between means of heavy metals in study area and control site. Strong positive correlations were observed between pairs of metal in vegetation and pairs of metal in soil. Inter-element correlations were however observed to be weak between the two media. Levels of metals in control sample were not as high as levels obtained at the steel rolling mill.