hi, i can suggest you some links

http://www.ccsenet.org/journal/index.php/jgg/article/viewFile/8994/8603

http://www.yadvindermalhi.org/uploads/1/8/7/6/18767612/francis_msc_dissertation_copy.pdf

https://www.clarku.edu/departments/geography/pdfs/Rogan_GIS_46n01_054-076-Vaclavik.pdf

https://scholar.google.com/scholar?q=Analysis+land+use+land+cover+change+of+a+forest+ecosystem&hl=en&as_sdt=0&as_vis=1&oi=scholart&sa=X&ei=q_PqVPCIBsW6UczKgugI&ved=0CBkQgQMwAA

What about eCognition Software?

I have already used it for this similar purpose.

@cherine - never heard of it

@Yudhish - thank you

The IDRISI Software is good choise for image classification and land use and land cover change. It have  tools for REDD+.

http://www.clarklabs.org/products/index.cfm

http://www.clarklabs.org/products/land-change-modeler.cfm

Thank you all for the software.

However, how do I establish  boundary, bearing in mind the ecosystem boundary is different from the forest boundary?

The ecosystem boundary is arbitrary. You can only characterize the core of the ecosystem but defining the sharp boundary is difficult. Instead, you can use the buffer zone say 5 - 10 km. around the reserve forest for studying the changes.

I like ecognition better than other software. It worth trying 

ecognition is better in land and OCM for coastal water

Can you please provide a little more information?  Specifically, what is the reason for your study?  Are you interested in the ecosystem, or the forest area in the Reserve?  Also, how far back do you want to begin exploring how land cover has changed?  Thirty years?  Ten years?  Remote sensing data is an excellent way of exploring land cover change.  You can create boundaries on the images if you are only interested in data for the forest reserve (that is, a specific site within the ecosystem).  Different remote sensors vary by how far back you can retrieve the data.

@susy: The study is on natural resource use by communities (dryland forest). The communities access the resources inside and outside the reserves. Thew reverses have no defined delineation (boundaries). As such, an ecosystem approach would be better, since the areas outside the reserves are now degraded. However, I am not sure how to establish the ecosystem boundary. I intend to go as far back as 50 years.

You may have to mark actual boundaries points physically with GPS  before remote sensing. RCMD (remot censing and Mapping ...)in Kasarani will be most helpful if you could visit their office to help you mark all boundaries