Land-use/Land-cover Changes and Deforestation in Effan Forest Reserve, Kwara State, Nigeria

Abstract

Remote sensing/GIS techniques are a versatile tool for x-raying serial forest structural changes in retrospect. It would be impossible to evaluate past occurrences and changes in forest extents in past decades at Effan Forest Reserve without non-conventional means. Therefore, we adopted remote sensing technology using Landsat images to evaluate land-use change and degradation rates in the area with a view to ascertaining causal factors for possible minimization of forest degradation in Effan Forest Reserve. Land-use/land-cover changes were analyzed using USGS-Landsat TM and ETM images of 1987, 2002, 2014 and 2019. Field-data were collected using handheld GPS receiver and spatial statistical analyses were conducted using the ground control points (GCPs). For inventory data, a systematic sampling technique was adopted using ten 1.05 km-transects at 500 m intervals. A total of 50 sample plots of 50 × 50 m were used. All tree species with Dbh ≥10 cm were enumerated. Nineteen tree species in ten families were encountered with Vitellaria paradoxa as the most-frequently occurring species in the area. IUCN-listed endangered Pterocarpus erinaceus, hitherto abundant in the area, was rarely encountered during the survey, while Vitellaria paradoxa is gradually shrinking, going the relative abundance in the area. The result further showed that primary and secondary forests decreased considerably by 258.03 ha (46.72%) and 9.18 ha (3.63%), respectively, with a total forest loss of 50.3% in 32 years (8.4 hayr-1, 1.6% per annum). While forest plantation size doubled by 369.72 ha within the period. This is worrisome as the remaining fragmented forests appeared to be on the decline, except the riparian vegetation, due to inaccessibility to the riparian by loggers. It thus appeared that forest protection approaches were ineffective. Increased protection efforts could save this forest reserve, and the concerned authority should consider a focused-enrichment planting involving indigenous species for ecosystem-repair.

An AHP GIS-based Methodology for the Stability Assessment of the Djebel El Ouahch Collapsees on the Numidian Flysh Formation in Northeast Algeria's Constantine Region

“…This result is consistent with those of Hamunyela, et al [4] and Kilungu, et al [5], who reported a decrease in primary (montane) forest in the Kilimanjaro WHS, Tanzania. Also, the result is similar to those of Adeyemi & Owolabi [51]; Sievers, et al [13]; Zeb [52], and Htun, et al [48] who showed decreasing primary/mangrove/dense/closed forests in Effan Forest Reserve in Nigeria, Sundarbans natural WHS in India, the District Chitral in Pakistan, and Popa Mountain Park in Central Myanmar, respectively. Also, the result is similar to those of Morin, et al [29] and Ullah, et al [53] who reported reductions in forest land cover in the Dilijan National Park of Armenia and Teknaf Wildlife Sanctuary of Bangladesh, respectively.…”