Claudio Contreras / Aerial view of Red mangrove (Rhizophora mangle) coastal lagoon, Sian Ka'an Biosphere Reserve, Caribbean Sea, Mexico, January

Dr. Axel Gebauer / Oxeye daisy (Leucanthemum vulgare) abstract, Upper Lusatia Heath and Pond Landscape, Upper Lusatia UNESCO Biosphere Reserve, Germany

Dr. Axel Gebauer / Bacteria - iron and manganese oxidizers and their complementary reducers, in the mud of an empty fish pond, Upper Lusatia Heath and Pond Landscape, Upper Lusatia UNESCO Biosphere Reserve, Germany

Claudio Contreras / Tricoloured heron (Egretta tricolor), Guerrero Negro, Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico, May

Ashley Cooper / Old Cave houses in Guadix, Andalucia, Spain. Up to 10,000 people still live in cool underground houses dug out of the rock, this area known as the Barrio Santiago is a mix of modern cave houses and an...

Richard Robinson / Coral Reef topography at North Minerva Reef / Teleki Tokelau a disputed territory in the South Pacific between Tonga and Fiji.

Graham Eaton / Butter Tubs potholes at side of Thwaite to Hawes road, Yorkshire Dales, UK, November 2016.

Inaki Relanzon / Waterfall at Santa Fe Stream, Montseny Natural Park, a UNESCO National Park and Biosphere Reserve, Barcelona, Catalonia, Spain, June 2016.

Inaki Relanzon / Eagle fern (Pteridium aquilinum) frond unfurling, Montseny Natural Park, a UNESCO National Park and Biosphere Reserve, Barcelona, Catalonia, Spain, June 2016.

Claudio Contreras / American crocodile (Crocodylus acutus) portrait over seagrass bed in shallow ater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May.

Claudio Contreras / Green iguana (Iguana iguana) running, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / Common spiny-tailed iguana (Ctenosaura similis) in front of Green iguana (Iguana iguana), Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico