Vegetation Response to Recent Trends in Climate and Landuse Dynamics in a Typical Humid and Dry Tropical Region under Global Change

Abstract

e influence of global change on vegetation cover and processes has drawn increasing attention in the past few decades. In this study, we used remotely sensed rainfall and land surface temperature to investigate the spatiotemporal pattern and trend in vegetation condition using NDVI as proxy from 2001 to 2017 in a humid and dry tropical region. We also determined the partial correlation coefficient of temperature and rainfall with NDVI and the response of NDVI to changes in landcover categories due to human activities. We found that the mean annual maximum NDVI was 0.42, decreasing at a rate of 0.06 per decade. About 27.4% of the area was found to have experienced a significant negative trend in vegetation cover, while only 0.34% exhibited significant increasing vegetation vigour. Land surface temperature increased at a mean rate of 0.75°C/decade, with higher rates in agriculture, savanna, settlements, woodlands, and riparian vegetation than in forest and mangrove vegetations. Precipitation also reduced at a mean rate of 58.69 mm/decade, with higher rates in agriculture savanna and riparian vegetation than in sahelian grasslands, mangrove, forest, and woodlands. NDVI was negatively correlated with temperature in savanna, settlements, degraded forest, and sahelian grasslands providing confirmation of ongoing land degradation. It was concluded that vegetation vigour will continue to decline under rainfall and increasing temperature conditions especially in dryer regions. e use of land surface temperature in this study is particularly valuable in highlighting areas where changes in NDVI occurred as a result of synergistic action between climate and human-induced landcover changes. Our findings underscore the importance of landuse policies that account for spatial variation in synergistic relationships between the nexus of climate and land conversion processes that influence vegetation cover change in different landcover types in tropical regions.

Spatiotemporal Response of Vegetation to Rainfall and Air Temperature Fluctuations in the Sahel: Case Study in the Forest Reserve of Fina, Mali

“…Many authors [12][13][14] used NDVI to study the response of vegetation dynamics to climate variability. This relation is evaluated at every scale from local to global scales and the results showed a strong relationship between rainfall and vegetation index.…”

“…It is established that in the semi-arid region, the correlation between NDVI and precipitation is highest for a multi-month average and NDVI is controlled by soil moisture in the concurrent month [21]. In addition, temperature has a negative influence on vegetation growth [12]. Many studies have reported on the relationship between rainfall and NDVI, but few touched the lag correlation between them.…”

Predictive Modeling of Transport Infrastructure Space for Urban Growth Phenomena in Developing Countries’ Cities: A Case Study of Kano — Nigeria

“…The effects of the Sahel Savannah Africa's severe climatic conditions (drought, desert encroachment, etc.) and other anthropogenic activities -erosion, mining, bush burning, and pastoral farming have been stressed for the changing landscape and loss of flora and fauna in the region [50][51][52]. Similar patterns of spatial transition gains and losses occurred in 2013 to 2019.…”

Spatiotemporal Response of Vegetation to Rainfall and Temperature fluctuations in the Sahel. Case study in the Forest Reserve of Fina, Mali

“…Many authors [10,11,12] used NDVI to study the response of vegetation dynamics to climate variability. This relation is evaluated at every scale from local to global scales and the results showed strong relationship between rainfall and vegetation index.…”

“…It is established that in the semi-arid region, the correlation be-tween NDVI and precipitation is highest for a multi-month average and NDVI is con-trolled by soil moisture in the concurrent month [16]. Also, temperature has a negative influence on vegetation growth [10]. Many studies have reported on the relationship between rainfall and NDVI and few touched the lag correlation between them.…”