Yes! Preschool age children, and even toddlers and infants, benefit from having their teachers and care givers support their early experiences and explorations with natural phenomena. They have so much fun learning about the properties of liquid while splashing a small pan of water, or exploring how some objects float and others sink (try putting a pumpkin in a plastic tub of water and see where it sits in the water!).
The 'labs' are experiences that can be repeated and added to so children explore a topic such as how plants grow from seeds, and a phenomenon such as shadows as they use flashlights and observe changes to their shadows during different times of the day.
Since you have a membership you can access all of the 'Early Years' columns that have been published every month since 2005 in NSTA's journal, Science and Children, and see the lesson plans describing explorations and discussion about how young children have fun (and their teachers too!) learning core science concepts.