Rarity of endemic medicinal plants and role of herbaria for their conservation against environmental challenges

Abstract

Endemic plants are restricted to particular place, topography and climate. There are about 34 hotspot range from Tropical Andes with 15,000 endemic plants and covering 5.0% of total endemic flora Atlantic forest with 8000 endemic plants and covering 2.7% of total endemic World flora etc. The small population size and distribution range of endemic species, their unique biological features, especially the loss of dispersal ability, tough ecological specialization, and predicted low genetic diversity, render them extremely vulnerable to environmental changes. Because population size and population identity can influence growth and survival differently across environmental stress gradients. But endemic species grows naturally in a single geographical area, the size of which could be either narrow or relatively large and not all endemic species are rare, just as not all rare species must necessarily be endemic. Serious consequences for biodiversity/deforestation and forest degradation are the habitat loss mainly due to climatic changes for vegetation clearing, mostly for agricultural expansion and thus considered to be the most important driver of population decline and species extinctions worldwide. The impact of deforestation is more severe in hotspots containing high concentrations of globally endemic species. Other than climate change herbarium collections used for investigations include documentation of shifts in plant biodiversity with increasing urbanization, population extinction of environmentally sensitive plants, conservation priorities for taxa in endangered habitats, and human-induced reductions in individual plant size. The Pakistan Museum of Natural History (PMNH) being unique of its kind and paying major role for combating most of the issues for endemic plants.