Wildlife Photographer of the Year 2017 finalists – in pictures | Environment

These emblematic saguaro cacti in Arizona’s Sonoran Desert National Monument tower at more than 12 metres. The roots weave a maze just below the surface, radiating as far as the plant is tall, to absorb precious rainfall. The saturated limbs are vulnerable to hard frost – their flesh may freeze and crack, while the mighty arms twist down under their loads. Finalist 2017, Plants and Fungi