What's the best way to improve bee habitats?

This article first appeared atEnsia.

Each morning last summer, Michael Roswell walked through restored meadows and abandoned New Jersey farm fields, where leggy grasses and weeds grew unchecked and thick patches of bee balm, black-eyed Susans, mountain mints, goldenrod and purple-loosestrife added shots of magenta, yellow and white.

每次蜜蜂降落，罗斯威尔会挥动扫网，捕捉昆虫，所以他可以通过物种识别它。博士生在罗格斯大学，他试图回答一个看似简单的问题：什么样的花做蜜蜂是怎样的？

The answer may be complicated. A最近的分析由研究人员在美国地质调查局检测从超过260个开花植物群体的遗传物质在北达科他州蜜蜂的花粉。和蜜蜂只是一个物种：总而言之，U.S. Department of Agriculture estimates (PDF)there aremore than 4,000 bee speciesin the United States alone.

但要找到一个答案可能是难题中的重要部分，当谈到打击本土蜜蜂种群和蜜蜂群体的损失持续下降。蜜蜂生存从开花植物花蜜和花粉。大型景观变化 - 丰富的野花草原作物单一种植或开放土地，以郊区发展的转换损耗，例如 - 是授粉的威胁，may play a major role in declines通过使它更难蜜蜂和其他授粉找到一顿饭。

Researchers know that better habitat attracts more pollinators. Yet simply planting more flowers may not solve the problem of pollinator declines.Many ecologists agreethat restoring plant diversity to depleted landscapes is key to bolstering bee populations. The presence of plants that flower at different times during the spring, summer and fall helps to ensure that pollinators have food throughout the growing season and that everyone can find something they like to eat.

What’s less clear is how to do that in ways that really count.

As more non-profit, state and federal entities step up efforts to protect and restore pollinator habitat, scientists such as Roswell are working to figure out how to optimize habitat restoration projects for pollinators.

The right mix

“对于大多数蜂种的，我们根本不知道什么样的栖息地是要帮助他们的人口增长，”罗斯韦尔说。“一些的花卉资源，可能比其他人更重要。”

Last summer he collected about 20,000 bees. For each, he recorded the species, sex and what kind of flower it was collected from. He wants to get a better sense of how bees use habitat. That includes which flowers different bee species — and even males and females of the same species — prefer.

For most of these bee species, we simply don’t know what kind of habitat is going to help their populations grow. Some floral resources may be more important than others.”

Scientists at Florida State University; University of California, Davis; University of California, Berkeley; and the University of Minnesota have developedmathematical models以帮助工艺厂授粉的相互作用，如一个罗斯威尔的大数据集正在研究。

The goal, said Leithen M’Gonigle, a professor of biology at Florida State, is to gather information that can be used to create wildflower seed mixes for habitat restoration that include both plant species that pollinators like and plants that bloom at different times from spring to fall in order to support pollinators through life stages. Based on their findings, Neal Williams, an entomologist at UC Davis, will begin to test how bee populations respond to different seed mixes in field trials in the spring.

Making more bees

If knowing what flowers to plant is one side of the equation, knowing how bee populations respond to habitat restorations is the other, said Williams.

在一个特定的情节计数蜜蜂可以显示有多少个人蜜蜂和蜜蜂物种参观花有，但它不会告诉生态学家他们真正想知道：这些种植是否帮助扭转人口下降。现有种群可能只是重新分配自己更接近更好的栖息地。

As more non-profit, state and federal entities step up efforts to protect and restore pollinator habitat, scientists such as Roswell are working to figure out how to optimize habitat restoration projects for pollinators.

"From a conservation perspective, we want to make more bees, not just redistribute them," said Elizabeth Crone, a professor of population ecology and dynamics at Tufts University in Massachusetts.

Crone and Williams teamed up to see how bumblebee colonies grew and reproduced across a gradient of northern California habitats in one of the first studies to quantify how bee populations respond to floral resources. They found that colonies in habitats with lots of flowers throughout the growing season有大r and produced more queens (PDF)- 繁殖产量的措施 - 比耗尽栖息地的殖民地。

Yet even across depleted habitats, some colonies performed better than others. The findings, they said, show the importance of understanding how a colony reproduces in relation to its floral resources rather than just focusing on how many flowers it has access to.

How fast a colony starts to grow in the spring may be just as important as total number of flowers, noted Crone. She believes that maximizing conservation efforts requires understanding other factors that influence reproductive success, such as how easy it is for bees to find places to nest in the spring and what kind of resources queens need to survive the winter. In other words, floral diversity is important — but it’s not the entire answer for how to improve habitat to boost bee conservation.

“更好地了解这些基本的生命周期的因素可以帮助我们搞清楚我们还有什么应该做的养护除了种植花草，”她说。