Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellite image reveals the floristic variation of the Amazonas region

18.03.2008
Regional variation in the flora of impenetrable rainforest can be assessed by means of satellite images.

In her dissertation, Principal Research Scientist Sirpa Thessler from MTT (Agrifood Research Finland) combined field observations made in the lowland rainforests of the Amazonas region with satellite image analysis and was also able to predict the floristic variation of unexplored areas.

By knowing the differences in species composition between areas, conservation and land use can be planned and carried out effeciently. When the floristic variaton of the region is known, new conservation areas can be planned effectively to complement the existing ones.

INDICATOR SPECIES WERE OBSERVED IN THE FIELD

In her dissertation, Ms Thessler examined the field observations made by the University of Turku Amazon research group in the rainforests of Ecuador, Peru and Costa Rica and combined these with Landsat satellite images taken from the same areas.

The species richness in the rainforests is immense, for which reason observations in the field are practically always limited in certain indicator species. They provide information about the environmental variation of the region, such as the nutrient content and humidity of soil, thus also describe the general patterns of flora .

In Thessler’s study, the indicator species included grass- and shrub-like Melastomataceae species and ferns in the understorey as well as tree and palm species in the canopy layer.

PIXEL VALUES REVEAL VARIATION

Field observations on hundreds of plant species were statistically summarised in three dimensions, in order to be able to present the satellite image based predictions of compositional variation in a single map. In addition various vegetation types were classified from the satellite images.

“I found a statistical association between the field observations and the pixel values of the satellite images, which led me to conclude that the images are indicative of the floristic patterns,” Ms Thessler states.

The researcher was equipped with field observations from a combined area of 47 square kilometres: based on these, she was able to predict the flora of an area of 4,100 square kilometres. Thessler points out that by satellite images we do not achieve a level of accuracy equal to field observations, but in rainforests with practically impenetrable forest they constitute one possible method.

“Surveying the flora of rainforests by means of field observations is difficult, time consuming and expensive. Even a rough estimate made with the aid of satellite images is better than nothing,” Ms Thessler sums up.

NEIGHBOURS PROVIDE RELIABLE INFORMATION

Sirpa Thessler’s dissertation also revealed that the “k Nearest Neighbour” method used for forest inventories in Finland and several other European countries also provides reliable information when it comes to tropical rainforests.

The method involves the examination of a single pixel in a satellite image and searching the pixels, named neighbours, that are closest in their spectral values and from which field observations are available. The letter “k” refers to the number of neighbours. Based on the known neighbours, the floristic class, for example, or another indicator of the species composition can be predicted for the pixels over the study area.

“The method seems quite promising. It produced good accuracies in predicting the floristic variation of a rainforest,” Thessler relates.

Ulla Jauhiainen | alfa
Further information:
http://www.mtt.fi

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>