Scientists have found that previous studies on how humans affect the natural food chain have underestimated their impact.
It's no secret that humans affect nature in a big way. Many studies conducted on the topic in the past have found that certain human activities are posing a threat to nature, the existence of many species and the existence of man himself. A new study shows that human's impact on the natural food chain has been underestimated.
"Understanding the significance of the impact that humans have on ecosystems is a critical component in formulating long-term and effective conservation strategies," principal investigator Marco Musiani said. "Our results led us to believe that ecologists have underestimated the impact of humans on natural food chains. The data we collected shows that humans are deliberately or inadvertently engineering ecosystems regardless of whether they would be naturally pre-disposed to top-down or bottom-up effects. Even in protected areas, the influence of humans might be greater than we previously thought."
Scientists have long debated on whether an ecosystem and the food chain related to it is affected more by the productivity of plant species, known as bottom-side effect or by their predators known as top-down effects.
The study was conducted to see how humans affect food chains since most ecosystems are dominated by the human species. The study was conducted with the help of many high-tech animal tagging devices and motion sensor-activated cameras.
The research location stretched from the US-Canada border in the south, through to the provincial borders with British Columbia in the west and Calgary in the northeast
"We painstakingly monitored wolves, elk, cattle and plant species, as well as humans for five years. We evaluated how these species interacted across the landscape and ultimately found that humans dominated the ecosystem," Muhly said.
Muhly says that through the research, they found that the bottom-up effect, which is more forage- driven, was more influential than top-down effect.
"Our results contrast with research conducted in protected areas that suggested food chains are primarily regulated by predators," Muhly. "Rather, we found that humans influenced other species in the food chain in a number of direct and indirect ways, thus overshadowing top-down and bottom-up effects."
