Analysis of Climate Change in Rainforest Ecosystems of Southwestern Nigeria

Abstract

Increasing global climate change affects ecological systems worldwide and raises concerns on the vulnerability of products and services from the forest. This study investigated climate change in forests of southwest Nigeria, using six forest reserves in three of the six states in this region. Remotely sensed air temperature (°C) and rainfall (mm/yr) of these forests for 60 years were obtained from the Climate Research Unit Time Series (CRU-TS) of University of East Anglia, UK. The data were subjected to time series and regression analyses to determine the occurrences of abrupt changes in temperature and rainfall values over the forest reserves, while temporal and spatial trends were also investigated. Analysis of long-term trends in the time series suggested a sequence of alternately decreasing and increasing trends in mean annual precipitation and air temperature in these forests for the period of study. Also, analysis of the air temperature indicated that the average temperature had increased significantly over the 60-year period, rainfall increased insignificantly with high variability (CV=±13.3%). Results further indicated that there have been statistically significant increased air temperatures and rainfall in all the forest reserves especially in the second 30-year period (1983-2012) at about 5% and 43% respectively. This change in climate could reduce the natural ability of forests in providing ecosystem services. Hence, forest-dependent communities should adopt strategies to cope with the changing climate