I'm working on a project attempting to identify suitable woodland habitat for red squirrel translocation wherein conservation efforts could be focused. Below is a small section of the map showing where individual tree species polygons have been dissolved, using a 100m buffer dissolve, to appear as larger "wooded area" polygons.
For the purpose of my project, I want to identify suitable forest areas over 200ha in size, with a suitable make up of tree species. To do this I need to determine homogenous blocks as seperate from those they are not in contact with, and then determine the size and make up of these blocks. There are ~150,000 polygons in the shapefile, so manually selecting each is not a possibility.
I think some form of spatial dissolve would be most suitable, Identifying one homogenous block as "Block 1" for example, and then using Select by Attributes to create a new shapefile with only polygons ("Blocks") with an area greater than 200ha. I am, however, unsure in how to do this. (I am very limited in my knowledge of GIS, and had the help of a phd student as well as some on here in getting this far). Thank you for any help you can give.
EDIT: USing ArcGIS/ArcMap for Desktop 9.3, with ArcInfo licence type.