Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Scientists Discover How Climate Change Causes the Simultaneous Boom or Bust of Multiple Populations

18.02.2005


For the first time, scientists have shown precisely how weather conditions cause multiple populations of a species within a large geographical area to have simultaneous increases or decreases in their abundance, a process known as "spatial synchrony." A paper published this week in the journal Nature reveals that occasional severe weather conditions directly cause the rapid increase or decrease in abundance and mobility of an intestinal parasite that infects populations of an important game bird hunted on country estates in Northern England, causing them all to either decline or thrive simultaneously in breeding success. The research is the first to pinpoint the specific role of climate in causing such incidents of spatial synchrony in animals.


credit: Peter J. Hudson, Penn State



"Our study shows that climate events can synchronize the growth trajectory of populations over large areas, having effects on ecological processes that could be large and far reaching, including an increased risk of extinctions in vulnerable populations, says Peter J. Hudson, the Willaman Chair in Biology at Penn State University and the director of The Center for Infectious Disease Dynamics at Penn State. Other members of the research team include Isabella M. Cattadori, a postdoctoral research associate at Penn State, and Daniel T. Haydon, a lecturer at the University of Glasgow in the United Kingdom.

... mehr zu:
»Bust »Hudson


The researchers coupled their detailed field studies and ecological knowledge with statistical analyses of data that Hudson had obtained from the owners of 100 individual estates in Northern England, where populations of Red Grouse have been maintained as game birds for more than 100 years. The team used a statistical technique recently developed by Haydon -- a powerful new form of time-series analysis -- to analyze data on the numbers of Red Grouse that hunters annually harvested since as far back as 1840. The records provide a gauge of the abundance of each of the 100 independently managed populations for each year.

Using this technique, Husdon’s team was able to identify the specific years in which the grouse populations were all pushed into the same phase of increase or decrease in abundance. "Our analysis shows that these populations normally fluctuate in size independently, but in some years they all crash together or they all increase together," says Cattadori. "We suggest we have identified the mechanism that causes these populations to be driven into these collective forcing episodes." The researchers also report that synchrony in these grouse populations does not happen gradually over many years; rather, they all suddenly increase or crash together in just two or three years.

Haydon’s statistical technique allowed the researchers to gauge from the condition of each population whether its size would be expected to increase, decrease, or stay the same the next year under normal conditions, then to compare those predictions with actual population trajectories over the 100-year period. "What happens is that in some years, when these populations should be moving in different directions, they instead suddenly all move in the same direction," Hudson explains.

Hudson’s earlier research had demonstrated that infection by the gastrointestinal nematode, Trichostrongylus tenuis, reduces the reproductive success of the Red Grouse by causing the hen to lay fewer eggs and by reducing the likelihood that those eggs will hatch. His earlier research also had shown that climate conditions can influence both the transmission of the parasite and the survival of the grouse chicks. Warm and wet conditions allow the nematode population to increase and to climb onto the stalks of heather. Wet and relatively cold Mays followed by warm and relatively dry Julys result in an outbreak of nematodes and so, when the grouse eat the infested heather, they rapidly become diseased.

"In this study we now show that large-scale weather conditions directly affect transmission of the parasite and that these effects -- rather than the direct effects on chick survival -- are the major factor driving grouse populations into synchrony," Hudson reports. "We previously had discovered the temporal mechanism -- that the parasites affect the size of individual populations of the Red Grouse. Now, in this paper, we have discovered the spatial mechanism of synchrony between grouse populations -- that specific climate events either accelerate or decelerate parasite transmission, which is what causes the host populations to become synchronized during either the increasing or decreasing part of their abundance cycles."

Hudson’s research warns of the rapid ecological consequences of extreme and short-term fluctuations in weather conditions. "One of the characteristics of global climate change is that we are getting increased variation in temperature extremes -- sometimes we get colder winters followed by warmer summers and then suddenly we get a warm winter, for example," he says. The research indicates that brief episodes of extreme weather conditions may produce important ecological effects, and that these effects could be big, quick, and dynamic. "This result is important not just for Red Grouse but for our understanding of how large-scale global climate events and environmental factors can affect many local ecological processes and local populations of many species in which spatial synchrony is known to occur, including insects, rodents, birds, fish, and mammals," Hudson comments.

"One of the major environmental challenges of our age is to identify and understand the important mechanisms by which climate change influences such complex biological processes as fluctuations in the size of populations," says Hudson. "With the increasing variation in extreme weather conditions we now are experiencing, this challenge has become increasingly important and pressing."

This research was supported by the European Union Marie Curie Individual Fellowship (IMC) and by the Game Conservancy Trust in England.

Barbara K. Kennedy | EurekAlert!
Weitere Informationen:
http://www.psu.edu

Weitere Berichte zu: Bust Hudson

Weitere Nachrichten aus der Kategorie Ökologie Umwelt- Naturschutz:

nachricht Online-Karten: Schweinswale und Seevögel in Nord- und Ostsee
15.12.2017 | Bundesamt für Naturschutz

nachricht Wie Brände die Tundra langfristig verändern
12.12.2017 | Gesellschaft für Ökologie e.V.

Alle Nachrichten aus der Kategorie: Ökologie Umwelt- Naturschutz >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Immunsystem - Blutplättchen können mehr als bislang bekannt

LMU-Mediziner zeigen eine wichtige Funktion von Blutplättchen auf: Sie bewegen sich aktiv und interagieren mit Erregern.

Die aktive Rolle von Blutplättchen bei der Immunabwehr wurde bislang unterschätzt: Sie übernehmen mehr Funktionen als bekannt war. Das zeigt eine Studie von...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Nanostrukturen steuern Wärmetransport: Bayreuther Forscher entdecken Verfahren zur Wärmeregulierung

Der Forschergruppe von Prof. Dr. Markus Retsch an der Universität Bayreuth ist es erstmals gelungen, die von der Temperatur abhängige Wärmeleitfähigkeit mit Hilfe von polymeren Materialien präzise zu steuern. In der Zeitschrift Science Advances werden diese fortschrittlichen, zunächst für Laboruntersuchungen hergestellten Funktionsmaterialien beschrieben. Die hiermit gewonnenen Erkenntnisse sind von großer Relevanz für die Entwicklung neuer Konzepte zur Wärmedämmung.

Von Schmetterlingsflügeln zu neuen Funktionsmaterialien

Im Focus: Lange Speicherung photonischer Quantenbits für globale Teleportation

Wissenschaftler am Max-Planck-Institut für Quantenoptik erreichen mit neuer Speichertechnik für photonische Quantenbits Kohärenzzeiten, welche die weltweite...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Call for Contributions: Tagung „Lehren und Lernen mit digitalen Medien“

15.12.2017 | Veranstaltungen

Die Stadt der Zukunft nachhaltig(er) gestalten: inter 3 stellt Projekte auf Konferenz vor

15.12.2017 | Veranstaltungen

Mit allen Sinnen! - Sensoren im Automobil

14.12.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Weltrekord: Jülicher Forscher simulieren Quantencomputer mit 46 Qubits

15.12.2017 | Informationstechnologie

Wackelpudding mit Gedächtnis – Verlaufsvorhersage für handelsübliche Lacke

15.12.2017 | Verfahrenstechnologie

Forscher vereinfachen Installation und Programmierung von Robotersystemen

15.12.2017 | Energie und Elektrotechnik