In the Northern Hemisphere, the growth rings of tree stumps are sparse in the south half and dense in the north half. The opposite is true in the southern hemisphere. Take the Northern Hemisphere as an example. The sunlight in the Northern Hemisphere mainly shines from the south to the north. The south can get more solar radiation and more heat, so the trees grow better in the south. The width of the ring indicates that the environment and climate are suitable, and the trees grow faster. In the Northern Hemisphere, independent big trees usually have luxuriant branches and leaves in the south and smooth bark, while the branches in the north are sparse and rough bark.
Other methods for identifying directions in the field:
1. The watch and the sun can determine the direction by adjusting the direction of the needle according to the position of the sun. The pithy formula is: half time is for the sun, and the twelve points are for the north. The time is local time, 24-hour system. This method is very useful when there is no compass in the wild.
2. Snow buildings and mounds, etc., mostly snow in the north area melts slowly, while pits and other depressions are on the contrary.
3. The moon appears in the western sky at dusk; The first quarter moon (about the seventh and eighth day of every month) appears in the south at dusk and sinks in the west at midnight.
The crescent moon rises in the southeast at dusk and sinks in the west before sunrise; The full moon (about the 15th and 16th of every month) rises in the east at dusk, in the south at midnight, and sinks in the west at sunrise.
