by Imagine a bee crawling into a bright yellow flower.
This simple interaction can be seen many times. It is also a vital indicator of the health of our environment – and one that I have spent hundreds of hours of fieldwork observing.
Interactions between plants and pollinators help plants reproduce, support pollinator species such as bees, butterflies and flies, and benefit both agricultural and natural ecosystems.
These one-to-one interactions occur within complex networks of plants and pollinators.
In my lab at the University of Colorado Boulder, we are interested in how these networks change over time and how they respond to stresses such as climate change. My team emphasizes long-term data collection in hopes of uncovering trends that would otherwise go unnoticed.
Working at Elk Meadow
Ten years ago, I started working in Elk Meadow, located at an elevation of 9,500 feet (or 2,900 meters) at the University of Colorado Mountain Research Station.
I wanted a local field site that would allow regular observation to study the dynamics of plant pollinator networks. This beautiful sub-alpine meadow, full of wildflowers and just 40 minutes from campus, fits the bill.
Since 2015, often accompanied by members of my lab, I have taken weekly walks to Elk Meadow. We visit from the first flower in May to the last in October. We watch pollinators visit flowers in plots scattered across the meadow, walking the edge to minimize trampling. Morning is the best time to visit as pollinator activity is high and thunderstorms often roll in at midday during the summer in the Rocky Mountains.
Viewing the network
Elk Meadow is rich in biodiversity. Over the years, we have observed 7,612 interactions among more than 1,038 unique pairs of species. 310 species of pollinators and 45 species of plants made these pairings.
Pollinators include not only a wide variety of bees, but also flies, butterflies, beetles and the odd hummingbird. Expert entomologists help us identify some of the insects.
Among the plants are species that are widespread, like the common dandelion, and some that are only found in the Rocky Mountains, like the Colorado columbine.
Common but vital
Collecting data in Elk Meadow is fun, but it’s also serious science. Our data are useful for understanding the dynamics of plant-pollinator interactions within and across seasons.
For example, we learned which interactions between plants and pollinators are stable and which change over time and space. We consistently observed interactions between generalist species and their multiple partners over time and in different plots across the meadow.
Generalist species can tolerate a range of environmental conditions, which means they are more often available to interact.
In other words, generalist species are more likely to be alive, active and foraging in the case of pollinators – or flowering in the case of plants – compared to species that can only survive if environmental conditions such as temperature, sunlight and rain all right support them.
Generalist species are vital in networks, but often do not receive the same conservation attention as rare species. Even these common species can decline due to environmental changes that destabilize entire ecosystems. Protecting these species is important to maintain biodiversity.
In it for the long term
As we collect more years of data, our study is increasingly useful for understanding how pollinator networks and populations are changing – especially as signs of climate change gradually emerge. Most ecological studies are designed or funded for only one or a few years, making our 10-year dataset one of the few for plant pollinator networks.
Only with long-term ecological data can we detect trends in responses to climate change, particularly because of the high variability of weather and populations from year to year.
The National Science Foundation supports a network of long-term ecological research stations across the US, including the Niwot Ridge Long-Term Ecological Research Program near Elk Meadow, which is dedicated to the study of high mountain species and ecosystems.
Colorado’s climate, like much of the world, is experiencing significant changes such as rising temperatures, earlier snowmelt and more rain in late winter and spring instead of snow. These changes result in earlier runoff from mountains, drier soils and more severe droughts. These shifts can have important consequences for plants and pollinators, including changes in where species are found, how many there are, and when they flower or show.
High altitude communities of plants and pollinators may be particularly vulnerable to climate change impacts as temperature increases are higher in these areas compared to lower elevations.
We have seen warmer and drier conditions at Elk Meadow. Reflected in this trend, we observed annual variation in temperature and drought conditions that will help us understand and predict how different species will fare in a warmer and drier future.
Climate change is causing pollinator declines and is expected to become more important in the coming years. Current threats include pesticide use, light pollution and the destruction of wild habitats for farming and development.
The state of Colorado recently commissioned a study to assess the health of Colorado’s native pollinators and make recommendations on how to protect them.
An appreciation of the current landscape of pollinators
Working at Elk Meadow provided opportunities for my students to conduct independent research and receive valuable training and mentorship.
My students and I encourage the beauty of the living things on the meadow and observe their cycles.
Elk Meadow is a place to clear my mind and research new ideas. It is also a place to observe and record how one tiny patch of our planet is changing in response to big changes happening around it.
This article is republished from The Conversation, a non-profit, independent news organization that brings you facts and analysis to help you make sense of our complex world.
It was written by: Julian Resasco, University of Colorado Boulder.
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Julian Resasco receives funding from the University of Colorado and the National Science Foundation.
