Tag Archives: vegetation

Biblische Ökosysteme widerstehen mehr als sieben Dürrejahren

Tübinger Forscherin weist hohe Widerstandskraft der Vegetation im Nahen Osten gegenüber Klimaveränderungen nach

Die Ökosysteme des Nahen Ostens beherbergen eine weltweit einzigartige Artenvielfalt, darunter auch die Vorläufer der wichtigsten Nutzpflanzen. Doch die Klimaszenarien gerade für diese Trockengebiete sind alarmierend: In einer Region, in der bereits jetzt pro Kopf besonders wenig Wasser verfügbar ist, werden in Zukunft noch weniger Niederschläge erwartet. Dies könnte die Funktion dieser Ökosysteme sowie das Überleben wichtiger Arten bedrohen. Ein Forscherteam unter der Leitung von Professorin Katja Tielbörger vom Institut für Evolution und Ökologie der Universität Tübingen hat in Israel Langzeitexperimente durchgeführt, um diese Prognosen zu testen. Über neun Jahre hinweg wurden die artenreichen Pflanzengemeinschaften künstlicher Trockenheit ausgesetzt, wie sie für die Klimaszenarien relevant sind. Auch die Auswirkung von höheren Niederschlägen als üblich untersuchten die Wissenschaftler. Sie wählten vier Ökosysteme entlang eines Trockenheitsgradienten aus, die von extremer Wüste mit 90 Millimetern Jahresniederschlag bis hin zu feucht-mediterranen Bedingungen bei 800 Millimetern Regen im Jahr reichten. (more…)

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Radar-Fernerkundung: Forschung für Landwirtschaft und Klima

Das Erntejahr 2014 nähert sich dem Ende und in ganz Deutschland zeichnen sich für Weizen, Mais & Co. insgesamt gute Erträge ab. Standortabhängig zeigen sich jedoch extreme Unterschiede. Für optimalen Anbau ist es daher wichtig, den Zustand des Bodens und der Pflanze stets zu kennen. Radaraufnahmen sind besonders gut geeignet, flächendeckende Beobachtungen durchzuführen – per Flugzeug oder per Satellit. (more…)

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Grünes Licht für das „Blaue Band“

Bundesweite Lösung für lebendige Flüsse wird umgesetzt

Lange schon hatte es der NABU gefordert: ein Bundesprogramm „Blaues Band“ für lebendige Flüsse. Nun ist eine wichtige Hürde genommen. Etwas versteckt, im Unterkapitel zum Hochwasserschutz, findet sich im Koalitionsvertrag der neuen Bundesregierung folgende Aussage: „Es wird ein Bundesprogramm ‚Blaues Band‘ aufgelegt, um die Renaturierung von Fließgewässern und Auen zu fördern.“ Das Programm kommt also, und das ist gut so. (more…)

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Satellites See Double Jeopardy for SoCal Fire Season

PASADENA, Calif. – New insights into two factors that are creating a potentially volatile Southern California wildfire season come from an ongoing project using NASA and Indian satellite data by scientists at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.; and Chapman University, Orange, Calif.

The scientists tracked the relationship between rainfall and the growth and drying-out of vegetation in recent months, during an abnormally dry year. They found the timing of rains triggered regional vegetation growth in January and early February, which then dried out faster than normal during a period of low rainfall, strong winds and high temperatures in March and April. The combination likely elevates wildfire risks by increasing available fuel. (more…)

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Study Finds Severe Climate Jeopardizing Amazon Forest

PASADENA, Calif. – An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.

An international research team led by Sassan Saatchi of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA’s Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA’s QuikScat spacecraft. (more…)

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The Ecology of Voter Signs

Students in Mitchell Pavao-Zuckerman’s UA ecology class took to the streets of Tucson last week to lend their eyes and minds to real science.

You might have looked out your kitchen window last week to see a group of college students standing on the sidewalk clutching notepads and contemplating your front yard. If so, don’t worry – they were likely just counting the shrubbery.

The students in Mitchell Pavao-Zuckerman’s ecology class at the University of Arizona conducted surveys of six neighborhoods. From Nov. 5-9, they canvassed Tucson’s urban landscape as part of a five-year study of how socio-economic factors influence urban ecology within the city. (more…)

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NASA Maps How Nutrients Affect Plant Productivity

PASADENA, Calif. – A new analysis led by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has estimated how much the growth of plants worldwide is limited by the amount of nutrients available in their soil. The maps produced from the research will be particularly useful in evaluating how much carbon dioxide Earth’s ecosystems may be able to soak up as greenhouse gas levels increase.

A research team led by JPL research scientist Josh Fisher used 19 years of data from NASA, National Oceanic and Atmospheric Administration and international satellites to assess the maximum possible growth of vegetation all over the world based upon available water and light conditions. The scientists then cross-compared that potential maximum with observed vegetation productivity as measured by satellites. This is the first time such an analysis has been conducted. (more…)

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Blanket Bogs Need Protection from Climate Change

Blanket bogs, which provide vital habitats for a unique range of plants, birds, small mammals, reptiles and amphibians, are at risk of declining as a result of climate change.

Research by the Universities of Exeter and Bristol in the UK and Macquarie University in Australia, published in the journal Nature Climate Change, shows for the first time how rising temperatures will threaten these sensitive ecosystems.

The study highlights the urgency of developing a plan to protect these important habitats.

Found in wet, coastal areas of high latitude regions, blanket bogs cover around 700,000 hectares of land in the UK, much of it designated as a Site of Special Scientific Interest (SSSI). Blanket bogs are found in the north and west of the UK, extending from Devon in the south to Shetland in the north, and it has been estimated that 10 to15 per cent of the world’s blanket bog occurs in Britain. As well as being crucial in supporting wildlife, blanket bogs also capture and store large amounts of carbon, helping to mitigate against climate change, and reduce the risk of flooding, by slowing down water flow. With some blanket peat being over 9,000 years old, they also hold historically-significant archaeological material. (more…)

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