Most biodiverse tropical grassland / savannah (flora)

According to a study published in Philosophical Transactions of the Royal Society B on 8 August 2016, the tropical grassy biome (TGB) with the greatest variety of flora (based on vascular plants) is the Cerrado of Brazil, a wooded savannah that covers some 20% of the country. The ecoregion contains at least 6,500 species of vascular plant, which are also known as tracheophytes or “higher plants”; the study did not account for non-vascular plants such as mosses. The next most flora species-rich TGBs, based on the same data-set, are the dry evergreen forests of south-east Indochina and the Central Zambezian Miombo woodlands, which are home to 4,000 and 3,800 different vascular plants, respectively.

The Cerrado ecoregion covers an area of some 2 million square kilometres (772,200 square miles) in Brazil and includes areas of open grassland, wooded savannah and wetland habitat. It is the second-largest biome in South America after the Amazon rainforest.

The Cerrado is one of the most diverse tropical grasslands in terms of vertebrates too. As reported in this same study, within a 10 x 10-kilometre (6.2 x 6.2-mile) cell, a total of 555 bird, mammal and amphibian species were identified, though many more are found throughout the entire ecozone. Rare species that favour this savannah ecosystem include the Brazilian tapir (Tapirus terrestris, maned wolf (Chrysocyon brachyurus and Brazilian merganser (Mergus octosetaceus).

Vascular plants are distinguished by their use of xylem and phloem tissue to transport water and nutrients and represent more than 90% of all vegetation on Earth. Non-vascular plants (such as mosses, liverworts and most algae) employ alternative methods of internal transportation and, for the most part, require moist and/or shady conditions to survive.

The study was a collaboration between Charles Darwin University and the Commonwealth Scientific and Industrial Research Organisation, aka CSIRO (both Australia) and the University of Liverpool (UK), led by Dr Brett Murphy of Charles Darwin University, Northern Territory, Australia.