Research shows plants in Africa 'green up' ahead of rainy season by Staff Writers Southampton UK (SPX) Jul 03, 2018
A study led by the University of Southampton has shown the greening up of vegetation prior to the rainy season in Africa is more widespread than previously understood. Geographers from Southampton, working with scientists at Lancaster University, used remote sensing data (satellite imagery), sourced over a 16 year period (2000-2016), to examine when plants in the continent began and finished their green period of growth. This was compared with meteorological data showing the onset and conclusion of the rains.1 The researchers found that over 80 per cent of the natural vegetation commenced greening up before the beginning of the rainy season. This was most prominent in woodlands in the southern part of Africa, which saw greening as early as three months before the start of the rains. Only an estimated four per cent showed greening up after the rain began, and these were confined to the Sudano-Sahelian region above the equator. The study examined crops, grasslands and woodland. It showed that crops typically began their growing season after the wet weather, while woodlands mainly greened up a week or more before the arrival of the rains. Grasslands fell into two groups, those which greened at the same time as rain and those which greened much earlier. Jadu Dash, Professor in remote sensing at the University of Southampton comments: "These findings add further evidence to the 'pre-rain green up' phenomenon observed locally across vegetation types in Africa. The results contradict the widely held view that rainfall drives the onset and end of the vegetation growing season across Africa. "Our study raises questions as to what environmental cues are initiating vegetation growth when rain isn't a factor. Climate change adds an extra dimension to this, making it even more important to understand how plants are responding to these cues." Several theories have been suggested for what drives plants to green up, other than rainfall. Among these are a form of climatic memory mechanism in plants, day length, temperature, air humidity and physical attributes of plants, such as their ability to tap reserves of nutrients or deep root systems which access underground water sources. Further research is needed to more fully understand these cues. The African continent contains the world's largest area of savanna and around 17 per cent of the world's tropical forests. Savannas alone account for 30 per cent of the primary production from global terrestrial vegetation, underlining the importance of African vegetation. The paper Large Scale Pre Rain Vegetation Green Up Across Africa is published in the journal Global Change Biology.
Threats, reforms and challenges: A momentous week for Ethiopia Addis Ababa (AFP) June 30, 2018 Ethiopia has capped an extraordinary week in which its new prime minister, Abiy Ahmed, pushed ahead with bold reforms undeterred by a grenade attack that sparked fears of backlash by hardliners. Just three days after a blast killed two people at a rally Abiy had addressed in the heart of the capital, the prime minister greeted a delegation from Eritrea, a neighbour with whom Ethiopia has been at war - both hot and cold - for decades. Abiy took office in April after years of anti-government unr ... read more
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