Hero Image

Marin IJ Articles

It’s all about timing

  • Nanette Londeree
  • “When the flower blossoms, the bee will come,” posits author Srikumar Rao. But what if they don’t? What if the timing between flowers blooming and the bee’s arrival to pollinate are off? While it might seem like a minor seasonal mishap, it could have significant impacts if those flowers are important food crops. The finely tuned dance between plants and their pollinators is essential for much of our food production, and it may be at risk due to warming temperatures.  

    You’ve heard about the importance of pollinators - birds, bees, butterflies, bats, and other small mammals that travel from plant to plant carrying pollen on their bodies to transfer genetic material. They are responsible for bringing us one out of every three bites of food, sustaining our ecosystems, and producing natural resources by helping plants reproduce. Timing is everything for pollinators to be successful - the plants they visit must be ready with pollen when they get there.  

    The study of the timing of seasonal biological activities is called phenology. First introduced in 1853 by Belgian botanist Charles Morren, it is the science that measures the timing of life cycle events in plants, animals, and microbes, and detects how the environment influences the timing of those events. Many birds time their nesting so that eggs hatch when insects are available to feed nestlings, and insects often synchronize their emergence with leaf out in host plants. Alterations in temperature and precipitation can directly impact the abundance and distribution of plants and animals. 

    Climate change is impacting phenological events like flowering and animal migration. Around the world, many spring events are happening earlier, and fall events later than they have in the past. Some species seem to be adjusting to more frequent unseasonal temperatures, drought, and extreme storms that come with climate change, but not all species are responding at the same speed or in the same ways. Plants may bloom before butterflies emerge to pollinate them, or caterpillars may emerge before migratory birds arrive to feed them to their young. How plants and animals respond to changes in their environment can help us predict whether their populations will grow or shrink – making phenology a “leading indicator” of climate change impacts.

    So, what does this mean to us gardeners?

    As our local climate changes, it may impact what we grow, when we plant and harvest, and pest activity.  We’re likely to see a longer growing season, reduced chilling days, shorter dormancy periods for deciduous plants and extended periods that require irrigation. Insect pests may be present for more of the year and with larger populations. And pollinators like hummingbirds and bees, might arrive either too early or too late to feed on the flowers they rely on, which in turn can affect our garden’s food production.  

    Now is a good time to start carefully observing seasonal events – the appearance of the first buds on a favorite plant, the first flowers on your fruit trees, the appearance of an indicator species of bird or insect, along with any unusual weather events. This phenological information, in your very own microclimate, can help guide you in making informed choices about what to grow and when to plant in the coming seasons.  

    Even better - write down what you observe. While it might seem mundane, according to Aldo Leopold, considered by many to be the father of wildlife ecology, “Keeping records enhances the pleasure of the search and the chance of finding order and meaning in these events.” By noting our observations, we become more aware. Want to go one step further and share what’s going on in your own back yard?  Become a volunteer observer for the USA National Phenology Network, a national science and monitoring initiative focused on phenology. Through their program Nature’s Notebook, https://www.usanpn.org/ researchers, resource managers, educators and others use your data for scientific discovery and decision-making. Your data are a big deal!