Climate change could increase plant reproduction costs, study finds
A new study from the University of Georgia sheds light on how plants respond to stressful environmental conditions presented by climate change. In an article published in Proceedings of the Royal Society B, the researchers showed that plants grown under drier conditions simulating the effects of climate change had higher reproductive costs than those grown under current conditions. The results offer clues as to how plant populations might respond to climate change and could provide guidance for the development of conservation strategies.
The term “reproduction costs” refers to the idea that living organisms that invest their energy in current reproduction have less availability to invest in future needs, such as survival, growth, and reproduction. In low-stress environments, where resources are plentiful, these costs can be negligible or difficult to detect. However, under resource-constrained and more stressful conditions, these costs are often intensified, with pronounced negative effects on future survival and reproduction.
Postdoctoral fellows Elena Hamann and Susana Wadgymar, now assistant professor of biology at Davidson College, and associate professor Jill Anderson of the Odum School of Ecology and the Department of Genetics, studied how the drier conditions accompanying climate change are altering breeding costs of Boechera stricta. , a flowering montane plant of the mustard family.
“The idea was to study whether climate change, which usually imposes more stressful conditions, can alter these reproductive costs and how this can affect the evolution of populations along the altitude,” said Hamann, author main article.
The study took place over six years in the Rockies. The researchers set up experimental gardens at five different elevations within the plant’s natural range. High elevation sites are cooler, with later snowmelt, shorter growing seasons, and increased soil moisture compared to lower elevation sites.
To simulate climate change, the researchers experimentally manipulated the snow in the gardens. Each year, they applied an early snow removal treatment to half of the plots to mimic reduced snowpack in winter, snowmelt in early spring, and decreased water availability during the growing season. In the witness gardens, they left the snowpack intact. They monitored the survival, flowering success, and fecundity – or number of seeds produced – of the plants.
At the lower elevation sites, which are naturally warmer and drier, they found pronounced reproductive costs under early control and snow removal treatments: plants that reproduced well in the first year had shorter life span and were less likely to recur in the future. In addition, early snow removal at mid-altitude caused the same effect, compared to control conditions. According to Hamann, these results indicate that reproduction costs are likely to increase as climate change progresses.
Surprisingly, at higher elevations the trend was reversed: plants in snow plots had lower reproductive costs than in control plots. The researchers hypothesized that instead of increasing water stress, as snow removal at low elevations does, early snow removal extended the otherwise short growing season at higher elevations, making conditions more favorable for them. plants.
Hamann said that taken together, the results support their hypothesis that climate change impacts the costs of plant reproduction.
“It basically shows that climate change affects and modifies these reproductive costs and that breeding is likely to act accordingly,” she said.
Hamann believes that in this case, selection – the process by which organisms with certain characteristics are more likely to survive and reproduce – may favor individuals Boechera stricta with shorter lifespans under conditions of climate change, although that more research is needed to draw a conclusion.
“In the future, it would be interesting to compare the past and present lifespans of Boechera stricta to see if climate change has already acted on these traits,” she said.
Hamann and Anderson are now testing how snow removal alters models of natural selection and experimentally heating temperatures in some of their gardens to study this effect more specifically. Hamann suggested that future research might focus on disentangling the effects of water availability versus temperature to better understand the impacts of climate change.
Anderson and Hamann hope this study will allow researchers to identify plant populations particularly vulnerable to climate change and plan appropriate management practices to conserve biodiversity in a rapidly changing climate.
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Elena Hamann et al, Reproductive costs under experimental climate change across altitudes in the perennial forb Boechera stricta, Proceedings of the Royal Society B: Biological Sciences (2021). DOI: 10.1098 / rspb.200.3134
Quote: Climate change could increase plant reproduction costs, according to study (2021, July 14) retrieved July 14, 2021 from https://phys.org/news/2021-07-climate-reproduction.html
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