Natural Resources, School of


Date of this Version



Stevens, A.P. (2011) Discovering Native Bees. Green Teacher Magazine. 93: 36-37.




NATURAL SYSTEMS PROVIDE humans with a variety of services essential to our survival. Ecosystem services such as climate regulation, water purification, oxygen production, waste treatment and detoxification, flood prevention, and pollination are provided at no cost, yet their true value is immeasurable. In our economydriven world, these systems are often taken for granted, and as a consequence many are in peril. Understanding their role is a critical first step towards ensuring that they endure. Pollination, the process of moving pollen grains from one flower to another to stimulate fruit and seed production, is among the easiest of these services to understand. Pollination is important for successful reproduction of all flowering plant species, both wild and cultivated. It allows intact ecosystems to continue functioning efficiently, and it provides food and other products for human consumption. Despite its importance, pollinators have been declining in number over the past two decades. Although some plants, including most major cereal crops (corn, rice, wheat, barley, and oats) rely on wind dispersal for pollination, 70 to 90 percent of flowering plants rely on animal pollinators. These plants include fruits and vegetables consumed by humans and other animals. Without pollinators to facilitate pollen transfer, these plants will cease to produce fruit altogether. The best way to ensure that such ecosystem services remain intact and functional is to understand their value in economic terms. If we understand the costs associated with losing the services, we will be more likely to take steps to avoid paying those costs. Determining the economic value of ecosystem services presents a challenge, but the best estimates use traditional economic models to establish a ballpark value. Researchers have estimated the global value of all ecosystem services at US$33 trillion per year. The value of pollination alone is estimated between US$20 and 40 billion for the United States, and up to US$200 billion globally. An economic perspective provides a useful framework for adults. An alternative approach-one that better illustrates the issue for children-is to examine the nutritional impact of a world that lacks animal pollinators. Approximately one-third of the food we eat comes from animal-pollinated plant crops. Pollinators affect not only the fruit and vegetable content of our diets (see the table below), but also availability of meat and dairy products (e.g., cattle are often fed alfalfa and clover, which are pollinated by bees).