Plant diversity, conservation significance, and community structure of two protected areas under different governance

Protected areas have become a vital component of the global biodiversity conservation strategy due to the increasing extinction and vulnerability of different species in the 21st century. The International Union for Conservation of Nature (IUCN) emphasises the need to harness all available resources and models, including collaborative and indigenous forest conservation practices, to ensure holistic global biodiversity conservation strategies. In Ghana, besides the shared governance of protected area management, there also exists the governance by indigenous community models in which traditional structures (clans and stools) use taboos, deities, totems, and myths as tools in managing protected areas. To study the effectiveness of the various governance systems in protected area management, we compared species diversity, vegetation structure, and biomass stock of an area under shared governance (wildlife sanctuary) to communal governance (sacred grove). Each protected area was purposively stratified and each stratum assigned condition score based on the degree to which the area has been disturbed. Six spatially separated plots (at least 200 m apart) with sizes 25 × 25 m were demarcated in each of the two protected areas. All trees with a diameter ≥ 10 cm at breast height were inventoried. For each tree, the diameter and height were measured and further used for biomass stock estimation. Each tree conservation significance was determined based on star ratings in-country and the IUCN red list of threatened species database. The study recorded a total of 201 trees consisting of 40 species and 23 families with a higher diversity in the wildlife sanctuary. Anogeissus leiocarpus mostly dominated the sacred grove, while the wildlife sanctuary was dominated by Trichilia prieureana, Ceiba pentandra, Cola gigantea, Pycnanthus angolensis, Cola caricifolia, and Pterygota macrocarpa. Most trees in the sacred grove were green star rated, with one scarlet, red and black tree. Only one tree was vulnerable, endangered with a decreasing population trend. The wildlife sanctuary is also characterised mainly by green star ratings, with few red, pink, and scarlets. Most of the species were least concerned on the IUCN list, with three been vulnerable and one endangered species. Mean diameter at breast height (dbh) and the average height was greater in wildlife sanctuary than the sacred grove. Basal area and above-ground biomass were 12.814 m2ha−1, 922 Mg ha−1, and 5.156 m2ha−1, 211 Mg ha−1 for the wildlife sanctuary and the sacred grove, respectively. Though the wildlife sanctuary supports a greater composition and diversity of plant species than the sacred grove, some synergies could be seen in both governance models. Therefore, both governance models should be employed to ensure sustainable management of the country's protected areas and diverse resources.