Effects of artificial light on flowering of foredune vegetation

Abstract

The impact of ecological light pollution involves alteration of periods of natural light, a fact that has proven effects on ecosystems. Few studies have focused on the impact of this pollution on wild plant species, and none on coastal dune plants. Many coastal dunes and their plants are adjacent to tourist areas, and these might be affected by light pollution. Such is the case of the Natural Reserve Dunas de Maspalomas (Gran Canaria), where some individuals of the plant species Traganum moquinii, located in the El Ingles beach foredune zone, are affected by light pollution. This study examines the effect of light pollution on the flowering process and, by extension, the reproductive cycle of these plants. Plants located closer to high artificial illumination sources receive similar to 2,120 h/yr of intense light more than plants located furthest from those artificial lighting sources. Parts of the plants of Traganum moquinii exposed directly to the artificial light show a significant decrease in the production of flowers, compared to the parts in plants in shade, and to the plants more distant from artificial lights. In consequence, plants exposed more directly to artificial light have a lower potential for seed reproduction. The spectrum of artificial light also affects the plants, and light between 600 and 700 nm primarily affects the reproductive cycle of the Traganum moquinii species. The implications for the ecological and geomorphological functioning of the dune system are discussed, because this species plays a decisive role in the formation of foredune zones and nebkhas in arid dune systems.