Wednesday, 20 February 2019

Mega experiment shows species interact more towards tropics and lowlands

One of the largest field experiments ever conducted is providing the best evidence yet in support of a key Darwinian theory—that interactions between species are stronger toward the tropics and at lower elevations.

An international research team used a simple experiment that mimics how plants and animals interact with each other—leaving seeds out for 24 hours to see how many are consumed by animals. Seven thousand seed beds were deployed across a huge geographic area, with 70 sites cutting across 18 mountains from Alaska to the Equator.

“Theory predicts that interactions among species—like predation and competition—will be strongest in the warm, productive, biodiverse ecosystems of the tropics and at low elevations,” says lead author Anna Hargreaves, who launched the project while at UBC’s Biodiversity Research Centre. She is now a professor at McGill University.

“For example, the spectacular diversity of tropical trees is thought to result partly from stronger interactions between plants and the animals that prey on their seeds, which shapes how and where plants grow and adapt.”

But until recently, evidence for this key ecological theory was inconclusive and came from small-scale studies that used different methods.

The new study found seed consumption, or predation, increased by 2.6 per cent for every 10 degrees of latitude toward the Equator and by 0.4 per cent for every 100-metre decline in elevation. In total, seed predation increased 17 per cent between Alaska and Equator and by 17 per cent from 4,000 metres above sea level to sea level.

The researchers used consistent methods from the Arctic to Equator and replicated the 24-hour experiment several times during each latitude’s natural seed-producing period.

“These interactions form the basis of how ecosystems function and the direct benefits of those ecosystems to human society,” says Santiago David, a PhD student at UBC who ran one of the study sites in Colombia. “Understanding global patterns in key interactions between species, such as seed predation, is essential when we think about managing or restoring the ecosystems, especially in the face of climate change.”

Ants preying on seeds in Baja, Mexico. Credit: Sula Vanderplank/Botanical Research Institute of Texas

A banana slug eating seeds, southern B.C., Canada. Credit: Anna Hargreaves, University of British Columbia, McGill University

High latitude low elevation site in the Yukon. Credit: Anna Hargreaves, University of British Columbia, McGill University

Predation driven by insects, other invertebrates

By protecting some seeds from mammals, the researchers showed that the study’s large-scale patterns are being driven by the smallest seed predators: insects and other invertebrates.

The only other standardized experiment of comparable scale used clay model caterpillars and found that attack rates on the model caterpillars increased toward low latitudes—an interaction also driven largely by invertebrates.

“Taken together, these experiments suggest that invertebrates play an outsized role in the community dynamics and evolution of tropical and lowland ecosystems,” says Hargreaves. “And yet we know relatively little about invertebrates, for example, how climate change is affecting their populations.”

The researchers are now combining fake caterpillars with the seeds to determine if the patterns they found with one form of predation hold true with another.

The study, “Seed predation increases from the Arctic to the Equator and from high to low elevations,” involved researchers from 13 institutions across the Americas, was published today in Science Advances.

Photos and video of insects and animals eating seeds at study depots, and wide shots of regions involved in study are available here.

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New Executive Director at Leighton Art Centre

Stephanie Doll is the new executive director at the Leighton Art Centre south of Calgary.

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Green Ash and Conks

Furniture maker Brian Gladwell transforms chunks of salvaged wood for his latest show in Regina.

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B.C. budget has little to hate, but few new policies to love

A CBC story on the B.C. budget quoted UBC policy professor Paul Kershaw.

“It’s not historic, it’s not a fundamentally dramatic change, but there are systemic changes as part of a slow overhauling of our tax system,” said Kershaw.

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NDP candidates push for stronger climate action as Singh supports LNG Canada

UBC academics were quoted in a Canadian Press story on NDP leader Jagmeet Singh’s stance on climate change and support for LNG Canada.

Simon Donner, a geography professor and climate-change expert, said LNG Canada would operate for decades and make it harder for the country to meet longer-term targets.

Political science professor Richard Johnston said Singh likely wants to align himself with B.C.’s NDP government.

Stories appeared on CTV, National Post, Regina Leader Post and other outlets.

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Convenience and control: Online sexually transmitted infection testing offers many benefits

Online sexually transmitted infection (STI) testing removes some of the barriers that prevent people from getting tested while still providing key information about health and wellness, according users.

Researchers with the BC Centre for Disease Control (BCCDC) and University of British Columbia (UBC) published three studies evaluating the user experience of a free and confidential online testing called GetCheckedOnline, during the first few years of its operation.

GetCheckedOnline, provided by the BCCDC, tests for STIs and blood-borne infections such as HIV and hepatitis C. It is the first online sexual health service in B.C. and is available to people living in Metro Vancouver and, in partnership with Island Health and Interior Health Authorities, some parts of Vancouver Island and the Interior. More than 12,000 tests have been completed since it launched in 2014, and 43 per cent of people have used it for testing more than once.

“Users of GetCheckedOnline indicated that talking about their sexual activity with health care providers and fearing judgement and discrimination were some of the barriers that had kept them from getting tested previously,” said Travis Salway, a postdoctoral fellow with the BCCDC who was involved in the research. “These barriers were more commonly reported by GetCheckedOnline users than by those who had gone to clinics for testing, indicating the online service is filling an unmet need for some people.”

Rod Knight, an assistant professor in the UBC department of medicine, conducted interviews with gay, bisexual and other men who have sex with men to learn more about their experience with the service. This group often faces stigma in healthcare settings which can deter them from getting the HIV and other STI tests they need. They reported very positive experiences because they weren’t required to see a clinician and discuss their sexual activity in order to get tested. The interviewees also said the online service gave them more autonomy throughout the testing process.

“They found the online service more flexible, more convenient and they liked the enhanced privacy,” he said. “They felt more comfortable doing their own swabs and more control over how the testing occurs.”

While online health care is expected to be more convenient for users, there are concerns that it won’t deliver the same opportunities to educate patients about their health, well-being and preventative measures. One of the studies compared clients’ knowledge of HIV, testing and prevention among clinic visitors and GetCheckedOnline users. The researchers found that GetCheckedOnline users had equal knowledge of HIV as people who had gone to clinics for testing, even three months after testing.

“We want the online users to get all the information they would get in the clinic,” said Salway. “We found that the online service delivers key information about HIV testing similar to how it would be delivered in the clinic.”

Knight pointed out that while the online service is an important addition to sexual health services, it can’t replace the clinics.

“The individuals I spoke to were also quite satisfied with clinic-based testing and wanted to be able to visit a clinic when needed,” he said. “For example, if they tested positive for an STI then they would go to an STI clinic or see their doctor. With online services, we need good processes in place to connect clients with doctors when need be.”

Some users also noted face-to-face visits provide opportunities to discuss other health matters and can lead to referrals for further care. Previous research from the BCCDC shows there is a growing interest in integrating mental and sexual health services.

“Some guys expressed concerns about missed opportunities to discuss substance use and mental health issues like anxiety about HIV,” said Knight.

“I think we can say that the evidence is in: internet-based testing services like GetCheckedOnline are effective,” said Mark Gilbert, medical lead for GetCheckedOnline at the BCCDC who was also involved in the research. “We are continuing our work to expand the service sustainably in B.C.”

The studies were recently published in Sexually Transmitted Infections:

To use GetCheckedOnline, visit, and follow these steps:

  • Create an account. You will need a promotional code to set up your account. You will be asked to provide some personal information, including name, date of birth, gender, city and phone number. This is so the lab can process your samples and we can contact you about your results
  • Give samples at a lab. Create a lab form in GetCheckedOnline and take it to a participating LifeLabs location on your mobile device. You will not be asked to show ID or your BC Care Card. At the lab, you will be asked to give a blood and/or urine sample, and you may be given a swab kit to take home.
  • Get your test results. You will receive an email from GetCheckedOnline letting you know when your test results are ready. If any of your results are positive or inconclusive, a nurse will contact you to talk about treatment or retesting.

Your GetCheckedOnline account will be linked to your electronic chart at the Provincial STI Clinic at BCCDC using a unique number.

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