A 200-year-old acacia, which has stood in the southern Kalahari, is a sanctuary for big and small.

The beloved Sausage Tree stands in the Selinda Reserve in the northeastern corner of Botswana, where it's dry and the rain is months away.

In the Afromontane forests of the Soutpansberg, a giant Outeniqua yellowwood hosts, feeds and shelters an array of plants and animals.

The Namaqua rock fig tree stands on the slope of a rocky hill in Namaqualand, South Africa and has withstood ever-rising temperatures and less and less rainfall each year.

The baobab tree has been around for 800 years, is more revered by insects, birds and animals than any other and is rooted on the savannah of the Malilangwe Game Reserve.

In a stretch of protected Amazon rainforest in Peru stands a 160-foot Brazil nut tree. Here, in one of the most bio-diverse regions on Earth, this 500-year-old titan thrives, thanks to alliances with some unexpected allies. Spend a year in the Tambopata National Reserve and meet the cast of characters that aid—and benefit from—the Brazil nut, from the forgetful agouti that plants its seeds throughout the jungle to the local harvesters that collect the nuts to the carpenter bees, the only creature strong enough to open and pollinate its flowers.