The Green Shield-moss Buxbaumia viridis (Bryopsida, Buxbaumiaceae) is an endangered, legally protected bryophyte considered as an ancient forest species both in Poland and elsewhere in Europe. This paper presents new localities for NE Poland, specifically in the Białowieża Forest. As an epixylous species, it is threatened by logging and intensive forest management. It is of utmost importance to protect this species' habitat, particularly at the present time when increased logging is proposed.

The research subject is the differentiation of plant communities and the preservation status of wet meadows of the Calthion palustris alliance at sites included in subsidy packages 4 and 5 of the agri-environmental scheme. The habitat was studied on 697 agri-environmental plots located in different areas of Poland. The obtained results show high differentiation of the plant communities, which could be considered as representative of the Calthion palustris alliance meadows in Poland. Disturbances in the habitat conditions were observed on most of the plots and they included: disappearance of characteristic species of the Calthion palustris alliance, encroachment of native, expansive species as well as desiccation of the habitat and the associated eutrophication, caused mostly by unidirectional land drainage systems. The study also attempted to determine the conservation prospects of the habitat considering measures implemented under the agri-environmental scheme.