Sentences with phrase «savanna fires»

Off the coast of Namibia, for several months a year, a layer of smoke from African savanna fires drifts over a persistent deck of low clouds.

Not exact matches

It also has a supply of smoke from the natural and human - caused fires that whip across the savannas of southern Africa.

Analyzing the distribution of trees across the basin, they found that fire - related savannas can dominate the flooded parts already when rainfall drops below 1500 mm / year, whereas in other parts rainfall as low as 1000 mm / year can be tolerated.

Brain suspected that they had been burned by humans because the degree of charring indicated temperatures of more than 1,100 degrees Fahrenheit, while natural grass fires on the savanna burn no hotter than 700 degrees.

Chimps that live on the savanna in Senegal may hold clues to how early humans reacted to fire.

Stein Mano and Meinrat Andreae of the Max Planck Institute for Chemistry in Mainz studied smoke samples from fires in Siberian forests, Californian chaparral and South African savanna, and from grass - burning experiments in their laboratory.

«But when native savannas are invaded by weeds such as gamba grass, fuel loads are dramatically increased and fires can burn up to five times hotter than a native wildfire,» Dr Adams said.

As the forest becomes shorter and its canopy more open, compromising its remarkable resistance to fire, it is clear that drought in tandem with fire could swiftly push the tall, dense rainforests of the region towards savanna scrub.

The study, which appears in the December 2009 issue of the journal The American Naturalist, says that positive feedback loops between fire and trees associated with savannas can make fires more likely in these ecosystems.

«We used a mathematical model to show that positive feedback loops between fire frequency and savanna trees, alone or together with grasses, can stabilize ecological communities in a savanna state, blocking conversion of savannas to forest,» said the study's leading author Brian Beckage, associate professor in the Department of Plant Biology at the University of Vermont.

Globally, most biomes showed significant increases in fire weather season metrics with the exceptions of temperate and montane grasslands, savannas and shrublands and boreal forests / taiga and tundra (Table 2).

The highest correlations between the net land carbon flux and continental biome mean fire weather season metrics were observed in the tropical and subtropical forests, grasslands and savannas and xeric shrublands of South America where regional fire weather season length metrics accounted for between 15.7 and 29.7 % of the variations in global net land carbon flux (Table 5).

South America's tropical and subtropical forests, grasslands and savannas have experienced tremendous fire weather season length changes, with a median increase of 33 days over the last 35 years (Fig. 3a and Table 6).

In the first continent - wide study of the effects of fire on bird and mammal diversity in the African savanna environment, researchers have found that increasing «pyrodiversity» boosts the variety of species of mammals by around 20 percent and of birds by 30 percent in savannas with high rainfall.

Hot fires in Australia's tropical savanna contribute one to three percent of our country's greenhouse gas emissions each year.

The short - term effects of an extensive and high - intensity fire on vertebrates in the tropical savannas of the central Kimberley, northern Australia.

This level offered some great timing challenges and was very charming; then soon after, you are running through the savanna during a huge storm, then journeying through the aftermath by dealing with fires that are everywhere.

By analogy, a forest may persist in the drying - induced transition to savanna if there are insufficient nucleation points (most likely fire ignition points, see The Role of Fire) to break open the forest and trigger the transformation.&rafire ignition points, see The Role of Fire) to break open the forest and trigger the transformation.&raFire) to break open the forest and trigger the transformation.»

It comes from, among other things, inefficient stoves, diesel trucks, campfires and fires in forests and savannas.

North American forest vegetation types could spread with up to 4 °C warming; but with greater warming, forest cover could be reduced by savanna expansion of up to 50 %, partly due to the impacts of fire (Bachelet et al., 2001).

Fire exclusion can transform savannas to forests (e.g., Bowman et al., 2001), with an upper (albeit technically unfeasible) global estimate of potential doubling of closed forest cover (Bond et al., 2005).

But we may focus on stationary and mobile plant, fires in forests and savannas and domestic cooking fires.

Once fires caused by these droughts and continued deforestation have reduced the Amazon's size by half, says Sampaio, desertification will slowly transform the terrain into a «tropical savanna».

It is more probable that forests will be replaced by ecosystems that have more resistance to multiple stresses caused by temperature increase, droughts and fires, such as tropical savannas.»

proposed that the initial focus will be in northern Australia where tropical savannas are subject to frequent and extensive fire.

[31] Tropical Savannas Cooperative Research Centre, Eureka win for Arnhem Land Fire Project, Savanna Links, Issue 34, 2007.