Straw Albedo Mitigates Extreme Heat

Fields that are not tilled after crop harvesting reflect a greater amount of solar radiation than tilled fields.  This phenomenon can reduce temperatures in heat waves by as much as 2 °C, as researchers have demonstrated in a recent study.

Straw Albedo Mitigates Extreme Heat

Scientists Look to Bacteria to Protect Crop Yields in the Face of Climate Change

Plants are often thought of as the masters of photosynthesis, the process by which sunlight, carbon dioxide and water are converted into usable energy, but when it comes to efficiency, they are beaten out by a rather surprising rival: bacteria.

Plants use resources, such as minerals and water, to promote their growth, but they also are restrained by the enzymes they need to complete photosynthesis, particularly an enzyme commonly known as RuBisCo.

Both plants and bacteria rely on RuBisCo to fix, or transform, carbon dioxide in the initial stages of photosynthesis.  Unfortunately, RuBisCo can also react with oxygen, creating an unusable molecule that the plant must spend further energy to recycle.  The result wastes far more nutrients than the plants need, costing both resources and money, and places a theoretical limit on crop yields.

Recently, research teams from Cornell University and Rothamsted Research in the United Kingdom began looking for ways around this barrier.  They selected genes from bacteria that have evolved a way to bypass this dilemma and inserted them into plant cells, hoping that the bacterial addition would bestow the same advantages onto plants and provide food crops a way to boost yields under the pressures imposed by climate change.

"If proved effective, this technology would decrease the amount of key nutrients like nitrogen and, most notably, water needed by the plant, while increasing the yield," said Lin Myat, a postdoctoral fellow of molecular biology and genetics at Cornell and lead on the study.  Both nutrients are valuable additions to any crop plant, especially under the pressure of increasing droughts.

In some key food crops, such as wheat or rice, the unwanted RuBisCo reaction happens roughly one-quarter of the time.  While some crop plants like corn have devised ways to reduce the likeliness of this wasteful reaction, they require additional energy to do so. With a growing population to feed and limited resources, finding new ways to avoid the RuBisCo problem without expending extra energy in crop plants has become an increasingly studied topic.

Scientists Look to Bacteria to Protect Crop Yields in the Face of Climate Change

How Nature Affects the Carbon Cycle

In 2011 more than half of the terrestrial world’s carbon uptake was in the southern hemisphere – which is unexpected because most of the planet’s land surface is in the northern hemisphere – and 60% of this was in Australia.

That is, after a procession of unusually rainy years, and catastrophic flooding, the vegetation burst forth and the normally empty arid center of Australia bloomed. Vegetation cover expanded by 6%.

Human activity now puts 10 billion tonnes of carbon into the atmosphere annually, and vegetation in 2011 mopped up 4.1 billion tonnes of that, mostly in Australia.

There remains a great deal of uncertainty about the carbon cycle and how the soils and the trees manage the extra carbon.  Nobody knows what will happen to this extra carbon now in the hot dry landscapes of Australia:  will it be tucked away in the soil?  Will it be returned to the atmosphere by subsequent bushfires? 

As scientists are fond of saying, more research is necessary.

How Nature Affects the Carbon Cycle