Sentence:  Not all stand types have an <WSD>alderwood</WSD> equivalent. For example, "Quercus petraea" and "Fagus" rarely grow with alder, so the <WSD>alderwood</WSD> equivalents of stand types 6A and 6C are the same as those of 6B and 6D, and there are no <WSD>alderwood</WSD> equivalents of been woodland. 
Meaning of the word marked with <WSD> tags:  A wood largely populated with alder trees.