On Tu Bishevat we celebrate our connection to the land of Israel. Not many people know that another Jewish holiday lies exactly half a year away from Tu Bishevat. This is Tu Beav, which celebrates our connection to the remainder of the Jewish people. (There's the obvious connection you have with "a certain member" of the Jewish people. But there's also a more specific meaning - Tu Beav is traditionally the date when the entire tribe of Binyamin was once again allowed to marry with the rest of the Jewish people.)
There is a message in the timing of these holidays, exactly six months apart from each other. When you get to the extreme of love for the land of Israel, it is time to turn around and increase your love for the people of Israel, and vice versa. Both are valuable, but ultimately they must accompanied by each other.