I understand that trees and grape vines are covered under the laws of Orla. Is any woody plant such as a bush or a briar included? For example, blueberries and raspberries.

The botanic definition of a tree does not always correspond with the Halachic one, many plants we call a bush are Halachacly a tree in regards to of the Brachah on its fruit or Orlah as well as other ramifications. The Halachic definition of a tree is disputable and there is more than one opinion on this question. The common view is whatever plant that reproduces fruit form the same branch every year would be considered a tree regardless to its trunks' width or height, which is why Halachacly raspberries and blueberries are frees and the so called banana tree for instance is not. [see Piskei Tshuvot 203:3]