Posts tagged CU
CU study: Spruce beetle infestation in N. Colo. tied to drought
Oct 10th
The new study is important because it shows that drought is a better predictor of spruce beetle outbreaks in northern Colorado than temperature alone, said lead study author Sarah Hart, a CU-Boulder doctoral student in geography. Drought conditions appear to decrease host tree defenses against spruce beetles, which attack the inner layers of bark, feeding and breeding in the phloem, a soft inner bark tissue, which impedes tree growth and eventually kills vast swaths of forest.
Spruce beetles, like their close relatives, mountain pine beetles, are attacking large areas of coniferous forests across the West. While the mountain pine beetle outbreak in the Southern Rocky Mountains is the best known and appears to be the worst in the historical record, the lesser known spruce beetle infestation has the potential to be equally or even more devastating in Colorado, said Hart, lead author on the new study.
“It was interesting that drought was a better predictor for spruce beetle outbreaks than temperature,” said Hart of the geography department. “The study suggests that spruce beetle outbreaks occur when warm and dry conditions cause stress in the host trees.”
A paper on the subject was published online in the journal Ecology. Co-authors include CU-Boulder geography Professor Thomas Veblen; former CU-Boulder graduate student Karen Eisenhart, now at Edinboro University of Pennsylvania; and former CU-Boulder students Daniel Jarvis and Dominik Kulakowski, now at Clark University in Worcester, Mass. The National Science Foundation and the National Geographic Society funded the study.
The new study also puts to rest false claims that fire suppression in the West is the trigger for spruce beetle outbreaks, said Veblen.
Spruce beetles range from Alaska to Arizona and live in forests of Engelmann spruce and subalpine fir trees in Colorado. The CU-Boulder study area included sites in the White River, Routt, Arapaho, Roosevelt and Grand Mesa national forests as well as in Rocky Mountain National Park.
The CU-Boulder team assembled a long-term record of spruce beetle outbreaks from the northern Front Range to the Grand Mesa in western Colorado using a combination of historical documents and tree ring data from 1650 to 2011. Broad-scale outbreaks were charted by the team from 1843-1860, 1882-1889, 1931-1957 and 2004 to 2010.
The researchers used a variety of statistical methods to tease out causes for variations in the dataset at 18 sites in Colorado. “The extent to which we could distinguish between the warming signals and the drought signals was surprising,” said Veblen. “These are two things that easily can get mixed together in most tree ring analyses.”
There are several lines of evidence that drought is the main driver of the spruce beetle outbreak. The new study showed when northwest Colorado was in a warm, wet climate period from 1976 to 1998, for example, both spruce beetle reproduction and tree defenses like “pitching” beetles out of tree interiors with resin were likely high. But during that period of warming, outbreak was minimal.
The strongest climate correlation to spruce beetle outbreaks was above average annual values for the Atlantic Multi-decadal Oscillation, or AMO, a long-term phenomenon that changes sea-surface temperatures in the North Atlantic. Believed to shift from cool to warm phases roughly every 60 years, positive AMO conditions are linked to warmer and drier conditions over much of North America, including the West.
Veblen said the AMO shifted from its cool to warm phase in the 1990s, meaning the climate phenomenon could be contributing to drought conditions in the West into the middle of this century. A 2006 tree-ring study involving Veblen, his former student, Thomas Kitzberger and researchers from several other institutions concluded that the warm phase of AMO also was correlated to increased wildfires in the West.
In addition to AMO, the researchers looked at two other ocean-atmosphere oscillations — the El Nino Southern Oscillation and the Pacific Decadal Oscillation — as well as past temperatures, precipitation and aridity to better understand the spruce beetle outbreaks. The team found that another effective predictor of drought conditions was summer “vapor pressure deficit,” a measurement of atmospheric dryness, said Veblen.
In the new study, the researchers were particularly interested in “radial growth” rates of tree rings from sub-canopy trees of various species in the study areas that thrived following outbreaks. One hallmark of spruce beetle outbreaks is that slow radial growth rates in such areas are followed by extremely rapid radial growth rates, an indication smaller trees flourish in the absence of the larger spruce trees because of decreased competition for water and increased opportunities for photosynthesis, said Hart.
The area of high-elevation forests affected by spruce beetles is growing in the West, Hart said. “In 2012, U.S. Forest Service surveys indicated that more area was under attack by spruce beetles than mountain pine beetles in the Southern Rocky Mountains, which includes southern Wyoming, Colorado and northern New Mexico,” she said. “The drought conditions that promote spruce beetle outbreak are expected to continue.”
One big concern about spruce beetle outbreaks is their effects on headwater streams that are important for water resources, said Veblen. “In the short term, trees killed by spruce beetles will lead to less water use by trees and more water discharge into streams. But in the long term, the absence of the trees killed by beetles may lead to less persistence of snow and earlier runoff.”
Veblen said it might seem counterintuitive to some that spruce-fir subalpine forests in Colorado are larger by area than lodgepole/ponderosa pine forests. “It is probably because spruce and subalpine forests are found in more remote areas not as visible to most people,” he said. “But potentially, the current spruce beetle outbreak could affect a larger area than the mountain pine beetle outbreak.”
The study had its beginnings in 1986, when Veblen and his students began compiling spruce and subalpine fir tree rings from various study sites in the Colorado mountains. Tree rings from individual trees — which carry information about weather, climate and even events like volcanic eruptions — can be matched up and read with rings from other trees, much like the pages of a book, from year to year and even from season to season.
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CU soccer rolls over the Ducks for 10th win
Oct 7th
BOULDER – Hayley Hughes lit a spark for the University of Colorado soccer team, pushing the Buffaloes past the Oregon Ducks 1-0 at Prentup Field on Sunday.
Hughes led the team with four shots, all on goal. In the 63rd minute, Hughes got the ball from 40 yards out, and didn’t waste any time blasting the ball toward the net and into the right corner for her first goal of the season.
“Hayley spent half of the season last year as a striker so we know she’s dangerous going forward,” CU head coach Danny Sanchez said. “It was just a great shot, their goal keeper Abby Steele is a great goal keeper. I feel she’s one of the top goal keepers in the league and to beat her today, we needed something special and that was a special shot from Hayley.”
With continued defensive pressure, the Buffs’ 1-0 lead would hold through regulation to give the Buffs their 10th win of the season. The win was the Buffs’ first over the Ducks in four meetings. The Buffs (10-2 overall, 1-1 Pac-12 Conference) have recorded back-to-back conference wins for the second time since joining the Pac-12, with the previous consecutive wins coming at USC and Arizona last season.
Oregon falls to 2-6-3, 0-2-1 Pac-12, with all of their defeats being determined by a single goal.
“All twelve teams (in the conference) are quality, and I think it’s maybe more of a situation where Oregon is desperate for result with where their season is going and that’s a dangerous team.” Sanchez said. “You can see the dangerous players that they have. I’m really pleased with how we came out, both halves. I felt the first twenty minutes of the game and the first twenty minutes of the second half were very good. And then at the end of the day … we defended great. They have dangerous players. So I’m just really pleased to get the result and to get a shut out.”
Though Oregon outshot Colorado 15-13 (including a nine to five differential in the second half), the Buffs were consistently more on target, hitting nine to Oregon’s four on goal.
The game was also a battle of two outstanding goal keepers, who combined for a total of 12 saves. Oregon’s Abby Steele leads the conference in saves and ranks in Oregon’s all-time top four in shutouts, wins and saves. Annie Brunner continues to have the best season of her career at Colorado. She currently ranks in the conference’s top five in shutouts and goals-against average.
With Sunday’s victory, Brunner becomes one of just four CU keepers to record at least 10 wins in a single season. For the second straight season, Brunner has shutout at least seven opponents (joining 2003 Big 12 Championship team member Jessica Keller as the only Buffs to have had back-to-back seasons with at least seven shutouts each year).
“I think at the end of the day it was just a good hard fought Pac-12 game,” Sanchez said. “I thought both goal keepers were very good. I thought Brunner was rock solid today dealing with those set pieces and a lot of corner kicks late when Oregon was pushing numbers. I thought it was a good hard fought game.”
The game began with Oregon keeping pressure in Buffs’ territory, but not being able to get any good looks at the net or retain possession for long.
Though Colorado and Oregon State had scored all three of their goals in the first 14 minutes on Friday, it wasn’t until the 14th minute on Sunday that a team was able to take a shot. A Bianca Jones free kick was sent over the wall, where Olivia Pappalardo was able to get her head on the ball, though she couldn’t get a shot. Darcy Jerman was ready for the rebound, but sent the ball just high. The Buffs continued on the attack, with Hughes, Jerman and Madison Krauser all making Steele work for saves in just over a one minute span.
Nineteen minutes into the first half, Oregon was finally able to get their first shot off, though Pugh was off her mark. The Buffs got back-to-back looks at the net in the following minutes, with Anne Stuller sending a free kick just over the post in the 22nd minute.
The Ducks responded with three consecutive shots of their own. Maryn Beutler and Lilly Archer were both blocked by the strong CU defense. Oregon continued to press the Buffs’ net, but Pugh once again shot wide.
The Buffs would only get one more opportunity before halftime. With under seven minutes remaining, they took a corner kick. Though no Buff got the first ball, Paxton was able to take it back and edge to the left side, but was blocked.
Oregon caused a stir in front of the net in the final three minutes of the first half. Ryann Davie got to the net, but shot the ball high. Following the Ducks’ corner kick, Riley Smith was right at the net, but got blocked, keeping the game scoreless at the break.
The opening of the second half was full of action. The Ducks and Buffs would trade off two shots apiece in the first nine minutes. For CU, Krauser was blocked in the 47th and Hughes sent a deep shot at Steele in the 51st. In the 48th and 54th minutes, Oregon’s Archer and Pugh both made Brunner work for saves.
In the 63rd minute, Hughes took an amazing shot from deep to put the Buffs up 1-0.
“The ball just kind of popped out, I was at the top of the box and it just happened to hit me,” Hughes said. “I chested it and it just fell perfectly to my feet and not I’m going to say I was aiming for the top corner, but you know, I kind of just got a good strike on it and it just bent kind of into that corner away from the keeper. I’m really pumped about it. It’s my first goal this season.”
The Buffs kept the pressure high following Hughes’ goal. CU and Oregon traded off shots in the following six minutes, with Alyssa Herwatt getting the ball from the right and taking a close range shot that Steele had to hop on for the save. The Buffs backline had a few close calls in the 71st minute. First, Beutler shot the ball to the far post, forcing Brunner to dive for the save. The ball was deflected off Brunner’s fingertips and Ashlee Schulz came in for the rebound at the left post, but hit the ball just wide.
“That’s a really athletic team,” Hughes said. “They’re good players. It’s great to get up 1-0, but then you know the attack is going to be after you. I think us four in the back, obviously just the whole team had to stay really compact and just work off each other and I think we had great coverage. I’m just really proud of everyone. We defended as a team.”
The Buffs continued to focus on defense, allowing just three more shots in the final 16 minutes.
“It‘s awesome,” Brunner said of the win. “I feel like we finally have the grit. We were in all these games last year, but we finally have the grit to get it through and win.”
The Buffs leave the Centennial State for the first time this season for a three game road trip. CU takes on Washington State at 2 p.m. MT on Friday, Oct. 11 and faces Washington at noon MT on Sunday, Oct. 13. The Buffs return to Berkeley, Calif. to take on California (where they earned their first victory in the Pac-12) at 1:30 p.m. MT on Friday, Oct. 18 before returning for their final two home games.
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Marlee Horn Graduate Assistant SID University of Colorado O: 303.492.7525 C: 719.821.0689 marlee.horn@colorado.edu CUBuffs.com
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Simpson notches career-high kills to whip Washington State for a 3-1 Pac-12 record
Oct 7th
BOULDER — Junior outside hitter Taylor Simpson recorded a career-high 23 kills as the University of Colorado volleyball team defeated Washington State 3-1 to win its third straight Pac-12 Conference match this season.
The Buffs won 25-17, 25-21, 25-27, 25-19 to improve to 11-3 overall, 3-1 in the Pac-12. WSU is now 14-3, 1-3 in the Pac-12. This is the first time since 2006 that the Buffs have won three conference matches in a row.
“It was definitely a hard-fought match,” Simpson said. “They definitely put their hands on any hit that I had, but we had some good sets and were doing really well passing-wise. I thought it was a good match.”
Simpson hit .333 in the match with seven errors on 48 attacks. She also added seven digs and four blocks assists. Nikki Lindow had an error-free hitting night with 10 kills on 19 swings for a match-high .526 hitting percentage. At the net she led the Buffs with five block assists.
CU hit .278 in the win with 61 kills. Nicole Edelman had 45 assists and added six kills on 13 errorless attacks to hit .462. She also had a double-double with 10 digs. Alexis Austin and Kerra Schroeder each recorded seven kills for CU and Kelsey English tacked on another six in the victory. Cierra Simpson led CU in the back row with 14 of CU’s 49 digs.
Colorado out-blocked the Cougars 8.0-4.0. Besides blocks from Lindow and Taylor Simpson, English and Schroeder each put up three block assists and Austin added the final one for CU.
“I am very proud of them (the team),” coach Liz Kritza said. “We talked in the locker room before the match about this being more important than the match that we played on Friday. This is the follow-up match, and it’s the one that lets us show that it’s not just a team that can pull an upset and then dip down. It’s part of establishing our identity within this league and across the country nationally in volleyball.”
The Buffs held WSU to a .200 hitting efficiency with 54 kills and 26 errors on 140 attacks. The Cougars were led by Kyra Holt’s 19 kills and Jaicee Harris added 10 kills.
“It’s a victory and we took it,” Kritza said “It wasn’t pretty all the time. I can look at every single player on the roster, and they’re celebrating the fact that it was a victory, but they also know that there’s another side to this. We want continual improvement. We have to get back in the gym; we’re going back on the road for two weeks. We have four tough road matches, and the expectations are getting higher and higher within our group. That’s a very good thing. I always love that they know that I hate losing and love winning, but I want to put ourselves in a position to sustain these victories. This can be a really special season for us.”
The Buffs took a 13-7 lead in the first set before WSU called its first timeout. After the break, the Cougars got within two points (14-12) to force the Buffs to call a timeout of their own. The quick intermission worked well for CU as the team recorded an 8-3 run to go back up 22-15. From there the Buffs were able to finish the set with three of the next five points. Taylor Simpson had a hot hand in the frame, hitting .818 with nine kills and no errors on 11 swings. The Buffs hit .517 as a team with 17 kills and only two errors on 29 swings.
WSU led for the first part of the second set, taking an 11-6 lead. The Buffs started to put a stop to the Cougar’s attack and got back within a point at 13-12. CU continued its comeback and evened the score at 15-15. The Buffs went ahead of WSU with a 4-2 run (19-18) and from that point on the Buffs would never trail as they finished 25-21.
CU forced the Cougars to use a timeout after taking a 9-4 advantage to start the third set. Out of the break, WSU recorded a 5-3 run (12-9) and this time the Buffs decided to spend a timeout. CU retained the lead and went up 19-15, but the Cougars got back within a point at 21-20, so the Buffs used their final timeout of the set. The two teams would battle it out to the end and needed extra points, and in the end it was WSU with the 27-25 win.
The fourth set was a close fought one. The Buffs had a 14-10 lead before WSU took three straight points to get within a point at 14-13. After a quick CU timeout, the Buffs used a 6-3 run to take a 20-16 advantage. The Cougars tried to slow CU down with another timeout, but the Buffs were determined to finish the match and won the set 25-19.
The Buffs will head to northern California next week for a pair of matches. CU will face California on Wednesday, Oct. 9 at 8:30 p.m. MT. The Buffs will take on No. 7 Stanford on Saturday, Oct. 12 at 8 p.m. MT. Both matches will be televised regionally on the Pac-12 Network.
COLORADO BUFFALOES
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