catscratch
Well-Known Member
We started our tree project last week in my biology classes.
We did a study of plant response to environmental stimulus. Leaf color, plant height, vigor, etc. were correlated with stimuli that could have caused the responses. Then we discussed root types, specifically tap root vs fibrous roots and possible advantages to each in relation to climate and soil type. After that we went into Dr. Whitcomb's 4 inch rule and root pruning's affects on root type. We then addressed the hormonal control over root growth and how hormones are major contributors in most living systems.
Once that was done we shifted to the ecology of the forests dominated by the American Chestnut. Species dependent on American Chestnut were listed and discussed as well as human uses for them. How disease affected the Chestnut and everything using them was discussed in depth as well (the students were very interested in this and were fascinated with how many things were affected by the die-out of this tree).
After discussing the history of the American Chestnut we shifted to modern methods of bringing them back. We found 4 different organizations working on American Chestnuts to show that there is a strong effort to bring them back. Then we discussed 4 methods of being used to bring them back: inter-crossing surviving chestnuts, backcrossing, transgentics, and hypovirulence. This was a great introduction to genetics and some methods used to manipulate nature. Knowledge of these practices sparked debate about medicine, livestock, and some other stuff. Great discussion!
Finally, the students had a week to build or bring a pot to grow a tree in. They had to justify how their design would affect root growth and base it on the 4 in rule. No wrong answers here, just an idea or defense.
All seeds were planted in the same growing median and with the same volume of 500mL (some had less than 500mL, none were allowed more). Two seeds were available to chose from; Sawtooth or Chinese Chestnut. I have a flat of rootmaker 18's planted of each.
Plant growth will be measured on a weekly basis and each student will be involved in data collection as well as building their own spreadsheet and graphs.
Finally, root growth will be observed when we transplant to larger pots.
Students will take their trees home at the end of the project.
Special thanks to Wayne who provided the Chinese Chestnuts!
We did a study of plant response to environmental stimulus. Leaf color, plant height, vigor, etc. were correlated with stimuli that could have caused the responses. Then we discussed root types, specifically tap root vs fibrous roots and possible advantages to each in relation to climate and soil type. After that we went into Dr. Whitcomb's 4 inch rule and root pruning's affects on root type. We then addressed the hormonal control over root growth and how hormones are major contributors in most living systems.
Once that was done we shifted to the ecology of the forests dominated by the American Chestnut. Species dependent on American Chestnut were listed and discussed as well as human uses for them. How disease affected the Chestnut and everything using them was discussed in depth as well (the students were very interested in this and were fascinated with how many things were affected by the die-out of this tree).
After discussing the history of the American Chestnut we shifted to modern methods of bringing them back. We found 4 different organizations working on American Chestnuts to show that there is a strong effort to bring them back. Then we discussed 4 methods of being used to bring them back: inter-crossing surviving chestnuts, backcrossing, transgentics, and hypovirulence. This was a great introduction to genetics and some methods used to manipulate nature. Knowledge of these practices sparked debate about medicine, livestock, and some other stuff. Great discussion!
Finally, the students had a week to build or bring a pot to grow a tree in. They had to justify how their design would affect root growth and base it on the 4 in rule. No wrong answers here, just an idea or defense.
All seeds were planted in the same growing median and with the same volume of 500mL (some had less than 500mL, none were allowed more). Two seeds were available to chose from; Sawtooth or Chinese Chestnut. I have a flat of rootmaker 18's planted of each.
Plant growth will be measured on a weekly basis and each student will be involved in data collection as well as building their own spreadsheet and graphs.
Finally, root growth will be observed when we transplant to larger pots.
Students will take their trees home at the end of the project.
Special thanks to Wayne who provided the Chinese Chestnuts!
