Photosynthesis from space

28/09/2015

Satellite observations of the global photosynthetic activity of our planet offer a new way to study the performance of agricultural crops.

Data collected by the Global Ozone Monitoring Experiment-2 instrument (GOME-2), aboard the European meteorological satellite Metop-A, have shown that the Midwest region of the United States has greater photosynthetic activity than any other place on Earth. , during the growing season of plants in the Northern Hemisphere. According to a team of researchers led by Luis Guanter of the Institute of Space Sciences in Berlin, these results show that satellite observations can be used to improve estimates of agricultural productivity and the climatic impact on crop yields.

As is well known, the photosynthetic activity of some regions of the planet has changed over time, due to human action and the effects of climate change. For this reason, in recent decades have been carried out, on a global scale, different studies on phenomena that previously only addressed from a local perspective as, precisely, photosynthesis.

Through a completely new approach, Guanter and his collaborators have measured photosynthetic activity throughout the planet. To do this, they have used satellite technology to record the electromagnetic radiation absorbed and re-emitted by the leaves of plants as a result of photosynthesis. This phenomenon, called fluorescence, occurs in plants when sunlight excites the photosynthetic pigments of chlorophyll.

Thanks to the observations made by GOME-2, the researchers have drawn, for the first time, a large-scale map of terrestrial photosynthesis. The analysis of the fluorescence of the Corn Belt, a region of the Midwest of the United States where, since 1850, this cereal represents the dominant crop, show that the photosynthetic activity in this area of the planet is between a 50 and 75 percent higher than predicted by the theoretical models on the carbon cycle.

The comparison with measurements made on land on carbon flow and crop yield statistics has confirmed what Guanter and his collaborators have observed. These results, according to the journal Proceedings of the National Academy of Sciences (PNAS), can help improve the theoretical models that provide an estimate of agricultural productivity and the climatic impact on crop yields. However, the next goal of these researchers is to further refine the method of analysis used, in order to observe in more detail this green heart of our planet.

Source: Investigacionyciencia.es