This discussion may help you out.
Ignore this bit below - i'm talking garbage!
One thing that I see, and maybe that's the way you are supposed to upload to your board, is that your setup is programming the 2560 using AvrDude. Again, I don't know this particular board, or how it's setup in the Arduino IDE, but I would have thought that the pre-loaded bootloader in the 2560 (assuming there is one) would be used just like on the basic UNO boards.
It looks like AvrDude is programming the 2560 but then the verification of the uploaded code fails, and after that the USB serial port disconnects.
It may also be worth looking around to see if there are any Youtube videos on getting started with this board just in case you've got a setting wrong.