"The Management Plan describes the natural beauty, special qualities and key characteristics of a Protected Landscape. This will articulate the features of the landscape which warrant its nationally designated and protected status" - first glance this looks ace!
https://www.gov.uk/government/publications/the-protected-landscapes-duty/guidance-for-relevant-authorities-on-seeking-to-further-the-purposes-of-protected-landscapes#when-to-apply-the-duty