The opening of buds on Douglas-fir trees each spring is the result of a complex interplay between cold and warm temperatures during the winter, scientists with the U.S. Forest Service's Pacific Northwest Research Station have found.
Their research—which is featured in the December issue of Science Findings, a monthly publication of the station—led to the development of a novel model to help managers predict budburst under different scenarios of future climate.
"We take it for granted that buds will open each spring, but, in spite of a lot of research on winter dormancy in plants, we don't really understand how the plants are sensing and remembering temperatures," said Connie Harrington, research forester and the study's lead. "The timing of budburst is crucial because, if it occurs prematurely, the new growth may be killed by subsequent frosts, and if it occurs too late, growth will be reduced by summer drought."
Although scientists have long recognized that some plants require a certain amount of exposure to cold temperatures in the winter and warm temperatures in the spring to initiate the opening of buds, the precise interaction between these chilling and forcing requirements has, until now, been largely unexplored. Harrington and her station colleagues Peter Gould and Brad St Clair addressed this knowledge gap, which has implications for forecasting the effects of climate change on plants, by conducting greenhouse experiments in Washington and Oregon using Douglas-fir, an ecologically and economically important species.For their experiments, the researchers exposed Douglas-fir seedlings from 59 areas in western Oregon, western Washington, and northern California to a range of winter conditions. After the seedlings finished their first year of growth, they were divided into groups and placed in different locations where their exposure to temperatures varied according to predetermined scenarios. In the spring, the scientists monitored the seedlings and documented the length of time it took for their buds to open.
The plants were responding, the researchers found, to both warm and cold temperatures they experienced during the winter and spring. And, they noted that the same temperatures can have different effects depending on how often they occur—a fact that may seem counterintuitive at first. While some winter warming may hasten spring budburst, substantial periods of mid-winter warming, such as is projected under several future climate scenarios, may actually delay, not promote, normal budburst.
Harrington and her colleagues used their findings and research results from other species to develop a novel model that depicts this gradual tradeoff between chilling and forcing temperatures and have verified its accuracy using historical records. They found that the model was fairly accurate in predicting past budburst in Douglas-fir plantations, which indicates it works well with real-world conditions.
Because the model is based on biological relationships between plants and temperature, the researchers expect it will be fairly straightforward to modify for use with other species and for other areas. Managers, for example, could use the model to predict changes in budburst for a wide range of climatic projections and then evaluate the information to determine if selecting a different species to plant or stock from a different seed zone would be a useful management strategy.
To read the December issue of Science Findings online, visit http://www.treesearch.fs.fed.us/pubs/36960.
The PNW Research Station is headquartered in Portland, Oregon. It has 11 laboratories and centers located in Alaska, Oregon, and Washington and about 425 employees.
Yasmeen Sands | EurekAlert!
Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli
26.04.2017 | University of the Basque Country
New data unearths pesticide peril in beehives
21.04.2017 | Cornell University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences