Research Questions
Changes after mountain pine beetle attack
The blue stain fungi, brought to lodgepole pines by mountain pine beetle, can attack xylem of trees which damage the transpiration system in the meantime. The detail of transpiration changing is showing in Fig 14. When lodgepole pine right attacked by mountain pine beetles, transpiration is still working, but needles are changing to less bright and darker green. This stage will continue for around one year, which is called "green attack". In the summer of second year after attacked, needles of lodgepole pines are changing color to red. At the point, transpiration shut down completely, but evaporation is still happening but it can only make pines loss more water. This stage is called "red attack" and could stay for 2 to 3 years. After "red attack" stage, needles turn to gray and most foliage will fall down in the next couple years. This stage is called "gray attack".
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Now, it is time to ask:
When transpiration in lodgepole pines changed during mountain pine beetle attack, then moisture in soil would change, then what would happen to nutrients in soil? When there is no stream to bring them into trees, would more nutrients be left in soil during mountain pine beetle attack or after mountain pine beetle outbreak? Is there any differences of nutrients between different mortality of lodgepole pines?
In this level, only total percentage of nitrogen, total percentage of carbon and total percentage of phosphorus had been tested.
Null Hypothesis
Soil nutrients (total percentage of nitrogen, carbon and phosphorus) stay in the SAME level between different mortality of lodgepole pine caused by mountain pine beetles' attacks.
Alternative Hypothesis
Soil nutrients (total percentage of nitrogen, carbon and phosphorus) show significant differences between different mortality of lodgepole pine stands caused by mountain pine beetles' attacks.