The Fall

A picturesque alpine lake and valley of yellow pines boarders a remote mountain range in the fall. Every year when the days get shorter, less sunlight is available. When the temperature drops these pine trees undertake a process called abscission. Their leaves will change colour from a lush green to an orangey yellow colour before dropping off completely for the winter. Plants that undertake this annual process are referred to as 'deciduous trees' and do so to conserve energy and survive the harsh conditions throughout the winter. Plant leaves are green due to the pigment chlorophyll. During the warmer months deciduous trees produce a lot of chlorophyll so the plant can utilise the sunlight and make food. During autumn these plants stop wasting energy to make chlorophyll due to the reduction of sunlight and temperature. Other pigments called carotenoids are now the remaining pigments in the leaves which produces the vibrant yellow and orange colour before the leaves drop off completely.