Grazers and pollinators shape plant evolution

Oct 21, 2013

It has long been known that the characteristics of many plants with wide ranges can vary geographically, depending on differences in climate. But changes in grazing pressure and pollination can also affect the genetic composition of natural plant populations, according to a new study.

Researchers at Uppsala University and Stockholm University are presenting the new study this week in the journal Proceedings of the National Academy of Sciences, PNAS.

It is known that a prominent floral display increases attractiveness to , but also increases the risk of damage from grazing animals and seed-eating insects. To investigate how pollinators and grazing animals affect the characteristics of natural plant populations, these researchers studied bird's eye primrose populations in alvar grasslands on the Baltic island of Öland. Two distinct morphs of primrose occur there: a short morph that produces its flowers close to the ground and a tall morph that displays its flowers well above the ground. The tall morph is better at attracting pollinators, but, on the other hand, it is more frequently damaged by and seed predators.

In the scientists have shown that grazing pressure and pollination intensity determine whether the short or the tall primrose morph reproduces more successfully. The difference in plant height has a genetic basis, and over time differences in reproductive success affect the of plant populations. For a period of eight years, the researchers documented changes in the proportion of short plants in natural populations and field experiments. The results show that altered grazing pressure leads to rapid changes in the genetic composition of the primrose populations, specifically in the proportion of short plants.

The Agricultural Landscape of Southern Öland has been a World Heritage Site since 2000. The grazing pressure on the alvar grasslands of Öland has increased dramatically in the last fifteen years as a result of measures taken to keep the landscape open.

"The study shows that grazing pressure impacts not only which plants dominate but also the genetic composition of the plant populations. These findings help us understand how differences in environmental conditions influence the evolution of genetic differentiation among ," says Professor Jon Ågren at the Evolutionary Biology Centre.

Explore further: Biodiversity in Ontario's Great Lakes region may be greater than we thought

More information: Mutualists and antagonists drive among-population variation in selection and evolution of floral display in a perennial herb, www.pnas.org/cgi/doi/10.1073/pnas.1301421110

Related Stories

Caribou the missing piece of arctic warming puzzle

May 01, 2013

In the first study of its type in Canada, new research has shown caribou have a role to play in climate warming in the arctic. Despite declining herd numbers, caribou grazing is controlling plant growth in ...

Multi-paddock grazing is superior to continuous grazing

Jun 15, 2011

A long-term study verifies multi-paddock grazing improves vegetation, soil health and animal production relative to continuous grazing in large-scale ranches, according to Texas AgriLife Research scientists.

Recommended for you

Plants with dormant seeds give rise to more species

5 hours ago

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

8 hours ago

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Plants with dormant seeds give rise to more species

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...