Typically in a shopping center there are the in line tenants (those within a shopping center or mall parcel) who have leases and often times there are anchor stores who run a store on a parcel they own but within the area that makes up what the public views as the overall shopping complex.
The in line tenants typically have a lease with the owner of the shopping center. The developer or shopping center manager typically negotiates a "Reciprocal Easement Agreement" or REA with the anchor stores (those who own their own parcels but operate as part of the overall "center") which sets forth agreements so that the anchor tenants and in line tenants create a homogenous shopping center presence. Common area maintenance or "CAM" is often shared in by the anchor tenants along with or in some proportion to that of the in line tenants. There is generally a provision in the REA that deals with defining the nature and type of the common area charges (parking lot maintenance, landscaping, walk ways, etc.) as well as the proportion that the particular parcel owner shall pay. There is also typically a Default or Remedies provision that sets forth the manner and nature of the enforcement. At a minimum, the REA is like any other contract and a failure to perform is a breach of contract. I hope this is of help to you.