Scientists have found that different populations of a plant species, which is closely related to many crops of worldwide importance, use very different strategies to adapt to environmental changes, which gives experts new options to engineer crops to better survive climate change and tackle future food security.

A common assumption is that populations of the same species use the same processes to adapt to common stressors, but experts at the University of Nottingham have discovered that this is not always the case. Instead, they reveal a surprising degree of “evolutionary flexibility.”

In a new study, published in the Proceedings of the National Academy of Sciences, Professor Levi Yant from the School of Life Sciences discovered that neighboring “sister” populations of a previously unstudied Brassica species adapt to a coastal habitat in very different ways. In this case, very high salinity levels, which are an increasing threat due to climate change.

The species studied—Brassica fruticulosa—is a close relative of cabbage, broccoli, cauliflower, rapeseed and radish.

Studying these wild relatives of these important crops can reveal existing “natural solutions” that evolution has already found. Scientists can then use this information to “future-proof” important crops worldwide to adapt to environmental stressors—such as climate change.

To carry out the research, the team of researchers exhaustively surveyed all the Brassica species in the region of Northern Spain and identified this single one that had exceptional populations that were adapted to high salinity, while the rest of the populations of the same species were not. The plants in this region naturally evolved to very salty Mediterranean coasts in Spain.

They then grew all the Brassica fruticulosa populations in the lab and using genomics, physiology, and molecular biology, they determined the differing populations adapted to the same stressor, in this case, high salinity, in different ways.

The different adaptation strategies to high salinity, each with different genetic and mechanistic foundations, were very surprising.

Professor Yant said, “People generally expect that closely related populations of a given species would adapt to the same environmental stressor in the same way due to genetic or physiological constraints. However, this hasn’t been commonly tested due to practical limitations. Here, my collaborator, Dr. Silvia Busoms, decided to look at many populations, not only a few.

“In our new study, we show that, even at the level of neighboring populations, contrasting adaptive strategies control adaptive responses to high coastal salinity in Brassica fruticulosa. This indicates multiple options for engineering an agriculturally crucial adaptation: soil salinization.

“These results will be of interest to not only those studying fundamental mechanisms of adaptation, but also resilience improvement in Brassica species.”

With about 90% of New Zealand’s natural wetlands drained or severely damaged during the past decades, we need to understand the role of native plants in the restoration of these important habitats.

Our new research details the history of raupō (bulrush) from the time before people arrived in Aotearoa. It shows this resilient, opportunistic plant—and taonga species—can play an important role in restoring wetlands and freshwater quality.

An unexpected finding was that the decline of freshwater quality in many lakes did not really kick in until the mid-20th century with the intensification of agriculture. Until then, lake water quality indicators generally showed these ecosystems remained healthy. The prolific expansion of raupō after Aotearoa was first settled may have helped.

Thriving on material washed from disturbed catchments, raupō acted as an ecological buffer, intercepting nutrients and sediments, and reducing potentially harmful effects on freshwater ecosystems.

From the mid-20th century, as water quality began to deteriorate, raupō populations—and any buffering effects—were generally in decline as wetlands and lake shallows were drained for grazing land and better access to water supply.

Lessons from this plant’s past can be put to good use today as we strive to bring back the mauri (life force) of our freshwater systems.

Survival strategies for hard times

Before settlement, when dense forest covered most of the country, raupō was surviving on the fringes. As a wetland plant, it likes its roots submerged, but needs light to grow.

Its preferred niche is the shallow margins of lakes, ponds and streams or nutrient-rich swamps. Before people, these places were much less common. Forests typically grew right up to the water’s edge and extended across some swamps.

Under these conditions, raupō evolved strategies for survival: aerated roots to cope with water logging; tiny, abundant seeds that spread far and wide on the wind; rhizomes (underground stems) that extend from the mother plant and store carbohydrates to keep the plant alive in lean times.

Raupō can even build floating root mats, from sediment trapped by its rhizomes, that extend out across open water and even detach from the shoreline to become mobile raupō islands.

With these survival strategies, raupō could wait for better times which, in Aotearoa’s dynamic environment, duly arrived.

Episodic agents of disruption—storms, floods, earthquakes, landslides, volcanic ashfall—created opportunities. Local forest damage allowed light to penetrate to ground level, and slips and floods brought nutrient-rich sediment from soils.

Raupō would seize these opportunities to expand. But they were typically short-lived as the inevitable process of forest succession returned the environment to stability—and raupō back to a state of patient hibernation.

Hitting the jackpot

Then people arrived, with fire and hungry mouths to feed. This time, the disturbances persisted. Forest clearances endured, sediments rich in nutrients flooded wetlands and lakes, and raupō, supremely equipped for just this scenario, spread across swamps and lake shores as wildfires spread on land.

Our tūpuna (ancestors) observed this behavior, as well as what was happening around raupō. Insects and birds were feeding and nesting. Freshwater fish, crays, shellfish and eel spawned among its fertile beds.

This new-found abundance also offered a range of resource opportunities. Raupō’s flax-like leaves were woven into mats, rope and string. Leaves and stems were used like thatch to cloak the roofs and walls of whare.

Traditional poi were often made from raupō leaves. Some iwi, particularly in the south, used the stems to build lightweight boats for navigating rivers and lakes. Flower stalks, shoots and young leaves were eaten, and the rhizomes and roots, when cooked, provided edible carbohydrates. The most cherished raupō kai, however, were cakes baked using the copious raupō pollen.

Unsurprisingly, for many iwi raupō remains a taonga species today, treasured for this array of resources and for its ecological and even spiritual roles in maintaining the mauri of freshwater habitats, upon which so much depends.

For some iwi, raupō are seen as kaitiaki (guardians) watching over a lake or wetland, and signaling its health. In these ways, raupō also connects us with other Indigenous communities. Although raupō is native to this country, the same species is found in Australia and parts of East Asia, while relatives in the genus Typha (Greek for marsh) occur naturally on all continents, except Antarctica.

Similar practices occurred wherever raupō and its relatives are found. This connection between cultural and ecological roles is one of the fascinating findings from our research. We describe raupō as a “human-associated species,” not just because of its taonga status, but because its fate seems so closely linked to people.

More work needs to be done, but history tells us raupō has an important role in restoring the health of our freshwater ecosystems. Not only can it soak up nutrients and contaminants, but as both a native and taonga species, it can assist remediation solutions that are ecologically and culturally supportive and sustainable.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Just like people confronted with a sea of options at the grocery store, bees foraging in meadows encounter many different flowers at once. They must decide which ones to visit for food, but it isn’t always a straightforward choice.

Flowers offer two types of food: nectar and pollen, which can vary in important ways. Nectar, for instance, can fluctuate in concentration, volume, refill rate and accessibility. It also contains secondary metabolites, such as caffeine and nicotine, which can be either disagreeable or appealing, depending on how much is present. Similarly, pollen contains proteins and lipids, which affect nutritional quality.

When confronted with these choices, you’d think bees would always pick the flowers with the most accessible, highest-quality nectar and pollen. But they don’t. Instead, just like human grocery shoppers, their decisions about which flowers to visit depend on their recent experience with similar flowers and what other flowers are available.

I find these behaviors fascinating. My research looks at how animals make daily choices—especially when looking for food. It turns out that bees and other pollinators make the same kinds of irrational “shopping” decisions humans make.

Predictably irrational

Humans are sometimes illogical. For instance, someone who wins $5 on a scratch ticket immediately after winning $1 on one will be thrilled—whereas that same person winning $5 on a ticket might be disappointed if they’re coming off a $10 win. Even though the outcome is the same, perception changes depending on what came before.

Perceptions are also at play when people assess product labels. For instance, a person may expect an expensive bottle of wine with a fancy French label to be better than a cheap, generic-looking one. But if there’s a mismatch between how good something is and how good someone expects it to be, they may feel disproportionately disappointed or delighted.

Humans are also very sensitive to the context of their choice. For example, people are more likely to pay a higher price for a television when a smaller, more expensive one is also available.

These irrational behaviors are so predictable, companies have devised clever ways to exploit these tendencies when pricing and packaging goods, creating commercials, stocking shelves, and designing websites and apps. Even outside a consumer setting, these behaviors are so common that they influence how politicians design public policy and attempt to influence voting behavior.

Like minds

Research shows bumblebees and humans share many of these behaviors. A 2005 study found that bees evaluate the quality of nectar relative to their most recent feeding experience: Bees trained to visit a feeder with medium-quality nectar accepted it readily, whereas bees trained to visit a feeder with high-quality nectar often rejected medium-quality nectar.

My team and I wanted to explore whether floral traits such as scents, colors and patterns might serve as product labels for bees. In the lab, we trained groups of bees to associate certain artificial flower colors with high-quality “nectar”—actually a sugar solution we could manipulate.

For example, we trained one group to associate blue flowers with high-quality nectar. We then offered that group medium-quality nectar in either blue or yellow flowers.

We found that the bees were more willing to accept the medium-quality nectar from yellow flowers than they were from blue. Their expectations mattered.

In another recent experiment, we gave bumblebees a choice between two equally attractive flowers—one high in sugar concentration but slower to refill and one quick to refill but containing less sugar. We measured their preference between the two, which was similar.

We then expanded the choice by including a third flower that was even lower in sugar concentration or even slower to refill. We found that the presence of the new low-reward flower made the intermediate one appear relatively better.

These results are intriguing and suggest, for both bees and other animals, available choices may guide foraging decisions.

Potential uses

Understanding these behaviors in bumblebees and other pollinators may have important consequences for people. Honeybees and bumblebees are used commercially to support billions of dollars of crop production annually.

If bees visit certain flowers more in the presence of other flowers, farmers could use this tendency strategically. Just as stores stock shelves to present unattractive options alongside attractive ones, farmers could plant certain flower species in or near crop plants to increase visitation to the target crops.

This article is republished from The Conversation under a Creative Commons license. Read the original article.