<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body>
<p><a href="https://news.illinois.edu/view/6367/1809224114">Spring
forest flowers likely a key to bumble bee survival, Illinois
study finds | Illinois</a></p>
<p>Mola, J. M., et al. (2021). "Long-term surveys support declines
in early season forest plants used by bumblebees." Journal of
Applied Ecology n/a(n/a).<br>
Populations of bumblebees and other pollinators have declined
over the past several decades due to numerous threats, including
habitat loss and degradation. However, we can rarely investigate
the role of resource loss due to a lack of detailed long-term
records of forage plants and habitats. We used 22-year repeated
surveys of more than 262 sites located in grassland, forest, and
wetland habitats across Illinois, USA to explore how the abundance
and richness of bumblebee food plants have changed over the period
of decline of the endangered rusty patched bumblebee Bombus
affinis. We documented a decline in abundance of bumblebee forage
plants in forest understories, which our phenology analysis
suggests provide the primary nectar and pollen sources for
foundress queens in spring, a critical life stage in bumblebee
demography. By contrast, the per-unit area abundance of food
plants in primarily midsummer-flowering grassland and wetland
habitats had not declined. However, the total area of grasslands
had declined across the region resulting in a net loss of
grassland resources. Synthesis and applications. Our results
suggest a decline in spring-flowering forest understorey plants is
a previously unappreciated bumblebee stressor, compounding factors
like agricultural intensification, novel pathogen exposure and
grassland habitat loss. These findings emphasize the need for
greater consideration of habitat complementarity in bumblebee
conservation. We conclude that the continued loss of early season
floral resources may add additional stress to critical life stages
of bumblebees and limit restoration efforts if not explicitly
considered in pollinator conservation.<br>
<br>
<br>
</p>
<pre class="moz-signature" cols="72">--
Dr. David W. Inouye
Professor Emeritus
Department of Biology
University of Maryland
Principal Investigator
Rocky Mountain Biological Laboratory</pre>
</body>
</html>