Our discussion about trees quickly turned to debate as the question of breathing and the role of leaves came up. Ideas were thrown out, wondered about, and conclusions were made. The concept that trees need leaves for their health seemed important, but the group was uncertain about the role leaves play. The idea of breathing was brought up, but quickly discounted. I think the children all realize that trees are not like humans and animals for which breathing is required. But some seemed to know something about the importance of air and it's necessity in keeping living things alive. While it was decided that trees don't breath, "blowing" was a useful term. They see the leaves blow, they feel the air made by the blowing, and somehow it made sense to them that this air is necessary for the trees too--but not so much in the winter when the trees sleep.
--You shouldn't pick off their leaves because the trees can't breath then.
--They don't breath.
--They do breath when the wind makes them blow.
--No no, people breath their air.
--But you shouldn't pick their leaves or they might die.
--But their leaves can fall off when it's ready and then it won't die.
--Yeah, when the weather changes to different weather and the leaves change to different colors, then you can pick them off.
--That's fall. Then the leaves fall off. Get it? Fall--leaves fall off? Get it?
--Yeah, but the tree stays, like the branches don't fall.
--Trees are strong, except for the leaves because they fall off.
--Yeah, because the leaves are the growing part.
--No, it all grows and gets bigger, but the leaves are the blowing part, so they aren't strong. But you can't pick them because the tree needs them.
--Yeah the tree needs them for breathing, I mean not for breathing but for blowing. But then it doesn't need those leaves anymore and so they fall off and they don't need blowing in the winter because it's very cold and then they hatch new ones again when it's time.
--Yeah, they need the leaves to blow but not in the winter, so they fall off before the winter comes..
--Yeah, that's what happens.
--Yeah, they sleep in the winter like bears and turtles.
--Oh, that's called hibernate. Bears hibernate.
--I think trees do that too.
A few days later, the concept of the sun came up. Louisa seems to know a little something about photosynthesis, but is unable to communicate the concept in a way the other children can understand. The following conversation followed:
--The leaves soak up the sun and give it to the tree.
--Yeah, in the summer the leaves take up all the sun and squeeze it into the other parts.
What about in the winter when the leaves are gone? Do the trees need sun then?
--Well, they have the left over sun stored up in their trunks. They don't need leaves in the winter because there's not really much sun and anyway, they hibernate.
There is some understanding that leaves are important for trees survival--they will die if the leaves are picked off. Air and sunlight are important for the tree and somehow, the leaves play a role in this. Children know about bears hibernating in winter and not needing the usuals (food, water), and so it must be that trees hibernate as well and don't need sun and air given to them by the leaves. In formulating their theories, they are using prior knowledge and applying it logically to an unknown. Critical collaborative thinking at it's finest! Our theories and hypothesis about leaves will continue and refine as we take this tree adventure together.