Abstract
Tropical dry forests experience the highest deforestation rates on Earth, with major implications for the biodiversity of these ecosystems, as well as for its human occupants. Global remote sensing based forest cover data (2000−2012) point to the rapid loss of tropical dry forest in South America and Africa, also, if not foremost, inside formally protected areas. Here, we significantly extend the baseline of tropical dry forest loss inside a protected area in Ghana using a generalizable change detection technique. The forest cover change detection is based on the normalized difference vegetation index (NDVI) derived from historical Landsat data (1984–2015). Field measurements were carried out in dry semi-deciduous forest and in the adjacent savanna and woodland. Estimates of the canopy area index and above ground woody biomass were related to NDVI derived from Landsat 8 data. The change detection indicated significant NDVI decrease in a large area initially covered by tropical dry forest, associated with deforestation. The peak in deforestation was found to have occurred between 1990 and 2002, hereafter, the conservation status of the area was improved. A combination of remote sensing data corroborated by secondary data sources provides evidence for the almost complete clearance of a tropical dry forest inside a strictly protected area, attributable to logging and land clearing for arable farming. The NDVI change detection also revealed NDVI increase in the adjacent woodlands from 2002 to 2015, demonstrating woody encroachment. Historical fire data from the MODIS burned area product indicate that the deforested area experienced a high frequency of anthropogenic burning since 2004, which may have caused further degradation and largely prevents forest regeneration. The results show the ongoing destruction of tropical ecosystems even within ostensibly protected areas and ask for the revision of protection and management strategies of such areas.
Highlights
Deforestation and forest degradation (DD) represent a global problem (e.g. Hansen et al, 2013)
Plot averaged normalized difference vegetation index (NDVI) was related to both field estimated canopy area index (CAI) (R2 = 0.66, p < 0.0001, n = 37) and aboveground woody biomass (AGB) (R2 = 0.62, p < 0.0001, n = 37, Fig. 5)
Accumulated precipitation from January 2000 to January 2016 was retrieved from the tropical rainfall measuring mission (TRMM) (GIOVANNI, 2015)
Summary
Deforestation and forest degradation (DD) represent a global problem (e.g. Hansen et al, 2013). Deforestation and forest degradation (DD) represent a global problem Agricultural expansion and increasing levels of illegal logging and fire disturbance have dramatically increased DD since the end of the 19th century (Hansen and Treue, 2008; Hawthorne and Abu-Juam, 1995; Hosonuma et al, 2012; Wardell et al, 2003). Since 1990, the forest area in Ghana has decreased on average by 2% every year (FRA, 2010). The loss of natural forest in Ghana has significant socio-economic and ecological implications as these forests provide important ecosystem services and represent hotspots of biodiversity (Brooks et al, 2002; Norris et al, 2010)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
