Biodiversity is the totality of species living on Planet Earth. The places where species live are called habitats. An ecosystem is a collection of habitats and their inherent species. The Biosphere is that part of our planet where ALL life occurs ::: that means it incorporates different ecosystems.
There are parts of our planet, such as the molten core, that might not contain life. Perhaps we have yet to discover new forms of life that are beyond our comprehension.
There are different ways of gathering habitats together, for example we could group the saltwater areas into a common ‘ocean’ or several ‘seas’. But what would we do with the shorelines that all this water washes against? Should it be part of the ocean (i.e. its borders), or just ‘coastline’. If it’s coastline then is it part of the land too (terrestrial ecosystem)? What about all of the rivers and streams that flow down to the sea? Are they oceanic, freshwater, or part of the land? Not easy!
People sometimes ask ‘are we part of biodiversity’? Yes indeed, we are alive, therefore ‘living species’. I know at times that some people think we are different from everything else, but we are not so different. We breathe air, we need food, water and sleep; somewhere to make a home and raise some young ::: same as most species. In fact as a species, humans are remarkably successful ~ we’ve colonised most of the planet. But unfortunately we have yet to learn how to live in balance with our environment. In the event of us becoming extinct it will be largely due to our own destructive efforts ~ converting the Living Planet into money!