• Journal of Forest and Environmental Science
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• v.39 no.1
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• pp.1-12
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• 2023

To understand the health conditions and growth patterns of forest estate for environmental resilience and climate change mitigation, assessment of structure and species diversity is paramount. This study aimed at assessing the structure, alpha, and beta diversities of tree species in three ecological zones in Taraba, Nigeria for management purposes. In recent time, no research has been reported on the structure and beta diversity of the study areas. A systematic sampling design was used for data collection. Five sample plots of 50×50 m were laid in each of the six natural forest areas. The result showed a mean DBH (42.5 cm) and a tree height (15.0 m) from the forests. The forests have a structure of an inverse "J-shape," which is typical of natural forests in the tropics. The southern Guinea savanna zone had the highest mean Shannon-Weiner diversity index (2.8). The least beta diversity index (0.02) was between Baissa and Jen Gininya forest areas. Baissa and Bakin Dutse Protected Forest Areas (PFAs) contained 76.5% of the tree species. There is a high chance of all tree species to be found in these 2 forest areas. Proximity to a location influences how similar two tree species are, according to the least beta diversity index (0.02) recorded. The Federal Government's method of management for the forest, known as Gashaka Gumti National Park, may be responsible for the high beta diversity index in the Montane ecozone. Therefore, it should be strongly encouraged to practice strict oversight of natural areas, as their contributions to reducing climate change in Taraba State, Nigeria, cannot be overstated.

• Journal of the Korean Geographical Society
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• v.43 no.5
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• pp.743-760
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• 2008

This paper attempts to examine how Maryland's Priority Funding Area (PFA) designation and incentive program has influenced the location of infrastructure investment. Is Maryland's PFA program reducing sprawl? In order to answer this question, data on the water and sewer infrastructure investments between 1997 and 2003 are collected from each county in the state. Empirical works are composed of two parts. The first part of the empirical analysis examines the pattern of water and sewer investment that has gone in and outside the PFAs between 1997 and 2003 at the county level. The second part of the empirical study shows at a county level the conditions that influence decisions to go in and outside the PFA. Regression models with various specifications are used for the analysis. The findings reveal that state fund has worked as designed. The coefficients of state fund in all estimations are significant and have expected signs implying that a county with more state fund tends to invest more in PFA as less outside.