Theory:Doctor Who television discontinuity and plot holes/In the Forest of the Night


 * The Doctor's theory and supposition that the trees don't burn due them collectively acting to withhold Oxygen is dubious at best. Trees don't consume oxygen, they produce it. Simply arranging for the trees in a given area to not produce oxygen once a fire is lit would not extinguish the fire, as there is still oxygen already present. Failing to add more wouldn't extinguish it. Think fires in office buildings, apartment complexes and the like. No trees around to continually produce oxygen, yet fires still burn.
 * Just like most of the living things, trees consume carbon dioxide and produce oxygen. They just SEEM to produce oxygen because they produce oxygen by photosynthesis and quantity of produced oxygen is greater than consumed oxygen. If trees can somehow control their photosynthesis and respiration (as the Doctor suggested), they would rapidly consume oxygen and emit carbon dioxide, extinguishing fire. (Of course, this doesn't make sense in real life, but in whoniverse...who knows?)


 * Whether or not trees can withold their oxygen is irrelevant when you realise a solar flare is composed of plasma, not fire.


 * Once they realize what they are up against and the disaster that has befallen them, Clara says "If you can't save them all, save who you can. The Tardis. It's a lifeboat, isn't it? Not everybody has to die." They make their way back to the Tardis, and inexplicably Clara says that the Doctor has to leave without the kids, and without her and Danny. Who exactly was she anticipating that the TARDIS would be a lifeboat for?
 * The Doctor. Clara believed that the kids should be with their families at the end, and she and Danny would bring them home since Clara didn't want to leave Danny behind. She had hoped she could convince the Doctor to save himself.


 * Why are Clara and Danny suddenly teaching little kids instead of the teenagers from previous episodes? (And terrible teachers to boot, so busy chatting a flirting, they're not even paying attention to the kids, starting with losing Maebh in the first place.)
 * They weren't little kids - they were Year 8 students (12-13), which is secondary school age. Clara and Danny teach specific subjects, not ages of students; we just only saw one or two of their classes as and when necessary.


 * Why doesn't Maebh's mother call her phone? Why don't any of the parents call their kids? Why does Maebh's mom think she can find her by randomly biking around London?


 * The Doctor says the Tunguska blast "should have knocked the planet off its axis?" It was just a comet. Not even the Cretaceous–Paleogene extinction impact did that. Speaking of which, where were the planet-rescuing trees then?
 * The Doctor was just exaggerating tree's influences on Tunguska incident. Also, meteorite that caused K-T extinction was actually a freighter controlled by Cybermen. (TV: Earthshock) Even planet-rescuing trees can't foresee time-travelling robot's attempt to destroy the Earth.


 * The solar-flare seems to have magically skirted right past the Van Allen belt that would have taken the brunt of such an event.


 * The trees just disappear at the end and apparently everything is back to normal. What about the damage done by the roots? What about the animals loosed from the zoo, the toppled statues, and other incidental damage that would certainly be world-wide?


 * The notion that humanity would forget such an event in the 21st century is absurd -- this very episode shows wide-spread news coverage. There would be YouTube videos and Twitter comments, and more. None of that will just disappear.


 * Why is the Doctor referencing multiple modern messaging systems in the right century when this Doctor especially is known for having his thoughts all over the place and not even once mentions another messaging system?


 * Why is Ruby suddenly an expert about trees when five minutes earlier she didn't even know that the rings are indications for the age ?


 * In the flashback of Mr. Pink teaching, the problem can't be solved with the informations on the board and the methods of solving this problem (at least with the right amount of information) are teached in elementary school while these children are year 8 students.