STEP 2: WHAT IS POLLINATION
Pollination is the process of plant reproduction. Pollination occurs when pollen grains from the male part of the plant (anther) are transferred to the female part of the plant (stigma).
Upon pollination, the flower will start producing seeds. Some flowers (like sunflowers and poppies) produce seeds within the flower. For others, the flowers become fruit (like apples and mangoes). Pollinators (like bees, butterflies, and bats) transfer pollen from one flower to another when they go searching for nectar to drink.
Cross-pollination is the transfer of pollen between two different flowers of the same species, with the help of a pollinator species. When a pollinator species like a bee searches for nectar, they climb inside the flower, brushing past the anther and covering their hairs with pollen. When they move on to the next flower, some pollen from the previous flower falls off onto the next flower’s stigma as they climb inside. This fertilizes the flower so it can produce seeds and fruit. Cross pollination is an evolutionary adaptation plants have developed to create genetic diversity and improve the plant’s ability to adapt to environmental change. Fossil records indicate beetles and flies were the original pollinators 150 million years ago.
Self-pollination is the transfer of pollen to the stigma of the same flower using the wind to move the male anther to the female stigma. This type of pollination is like creating a clone, because there is no introduction of new genetic material like there is in cross-pollination. Any flowering plant that has both male and female parts close together can self-pollinate. In this process of pollination, the seeds produced are less likely to germinate, and plants won’t produce as much fruit. Over time, this can lead to fewer resources, resulting in the disappearance of species that rely on the existence of certain plants being present.
Can you guess how many trips bees make to gather enough honey to fill a 12 oz. jar?
It takes 80,000 trips, or a journey equivalent to going around the world twice—80,150 km or 49,802 miles!
WHY ARE POLLINATORS SO IMPORTANT?
Habitat Recovery: The pollination process creates new plant growth, which helps ecosystems to recover from natural and human disturbances. Cross-pollination introduces new genetic material to a population so they can be more tolerant of environmental changes. It’s like having a well-equipped toolbox instead of just a knife.
Keystone Species: Pollinator species ensure the genetic diversity of plants and their reproductive success. Pollinators are a keystone species, because they are key in sustaining their ecosystem. If pollinators disappeared, the impact to our environment and the rest of the living community would be disastrous and would potentially lead to the entire ecosystem disappearing altogether.
BENEFITS OF POLLINATOR SPECIES
- Approximately 1,000 of the 1,330 food crops grown across the world are pollinated by animals (cross-pollination).
- Pollinators facilitate the continuous and sustainable growth of ecosystems by providing essential resources, like shelter and food.
- Pollinators support processes that reverse the effects of global warming by storing atmospheric carbon and moisture in the soil.
- Roots from new growth bind the soil, preventing erosion and water evaporation. Plant roots filter toxins from water that passes through the soil before it reaches the water table and the ocean.
THE WORLD’S LARGEST POLLINATOR?
The red ruffed lemur (Varecia rubra) is 20-22 inches (50–55 cm) in length, not including the tail. Although they prefer to eat fruits, they also love to snack on flowers, nectar, and pollen. By sticking their long noses deep into a flower, red ruffed lemurs can easily access the hidden nectar. While they feed, pollen sticks to the ruff of fur around their faces. As they travel from tree to tree, the pollen drops from their fur and pollinates other flowers. This makes them one of the largest pollinators in the world!
We suspect that their long and fuzzy 24-26 inch (60–65 cm) tails might also carry and deposit pollen. What do you think?
WHY POLLINATORS NEED OUR HELP
- Agriculture and housing developments are replacing their habitat, taking away important resources they need to live.
- The use of commercial pesticides on plants can make pollinators and other animals sick or even kill them, because they are made of harmful chemicals.
- Air pollution from human activities can confuse a pollinator’s sense of smell, making it harder to find flowers.
- Nighttime pollinators like bats and moths can be disoriented from unnatural city lights, making it harder to find flowers.
- Non-native and invasive species introduced by human activities take important resources from the native community. Without regulation, they can grow out of control, and lead to a less diverse and more fragile ecosystem.
FOR EDUCATORS-Lesson 2: GOALS, OBJECTIVES, RESOURCES, AND MORE