A/HRC/34/49 19. The benefits of biodiversity are particularly evident in relation to the right to food. Genetic diversity within species increases the yield of commercial crops, 29 and species richness in freshwater fisheries is associated with greater productivity. 30 (Tree species diversity and richness also increase production of timber, which supports the fulfilment of the right to housing.31) Biodiversity is especially crucial to the stability and resilience of food sources. Increasing diversity of fish species is associated with greater stability of fisheries, 32 and “resiliency in agroecosystems to environmental change depends on the innate attributes of crop varieties, which makes preserving crop biodiversity [e.g., through seed banks] a vital part of food security”.33 Access to a diverse variety of local plants helps to protect vulnerable rural communities, in particular, which may rely on them when harvests fail or sudden expenses occur. 34 Climate change will test the resiliency of agriculture and fisheries more and more, and “the increased use of agricultural biodiversity will play an essential part in the adaptation and mitigation actions needed to cope with climate change and ensuring continued sustainable supplies of healthy food, providing adaptive capacity, diverse options to cope with future change and enhanced resilience in food production systems”.35 20. Food security also depends on the biodiversity of the surrounding environment. “Successfully raising any single crop requires more than its seeds; a multitude of species are necessary, from microbes, insects, worms, and small vertebrates in the soil to a host of species above ground that control pests, fertilize soils, and pollinate flowers. Marked population declines have been observed in organisms vital to agriculture in recent years, and these losses bear directly on food security.” 36 For example, biodiversity directly contributes to the effective pollination and seed dispersal of useful plants and increases resistance to agricultural pests and exotic plants.37 In this respect, the unusually high losses in recent years of colonies of Apis mellifera (western honeybees), an important pollinator, have been of particular concern, since pollination is necessary for more than three quarters of the 107 leading global food crops, including many fruits and vegetables that are important sources of micronutrients and vitamins. 38 21. Biodiversity also helps to support the right of access to clean and safe water. Increased forest areas significantly improve water flow regulation by reducing runoff and providing greater water storage. 39 Diverse animal, plant and algae species help to draw excess nitrogen and phosphorus from aquatic ecosystems. 40 Bivalve molluscs, which filtrate large amounts of water in both marine and freshwater environments, can play a particularly important role in water purification. For example, a freshwater mussel species in South 29 30 31 32 33 34 35 36 37 38 39 40 8 See Cardinale and others, “Biodiversity loss and its impact on humanity”, p. 62. P.A. Harrison and others, “Linkages between biodiversity attributes and ecosystem services: a systematic review”, Ecosystem Services, vol. 9 (September 2014), pp. 191 and 195. Cardinale and others, “Biodiversity loss and its impact on humanity”, p. 62. See also Harrison and others, “Linkages between biodiversity attributes and ecosystem services”. Cardinale and others, “Biodiversity loss and its impact on humanity”, p. 62. Bernstein, “Biological diversity and public health”, p. 158. Ecosystems and Human Well-being: Biodiversity Synthesis, p. 30; Connecting Global Priorities, pp. 111-112. Connecting Global Priorities, p. 6. Bernstein, “Biological diversity and public health”, p. 158. Ecosystems and Human Well-being: Biodiversity Synthesis, pp. 25 and 29. Intergovernmental Science-Policy Platform on Biodiversity, “Summary for policymakers of the assessment report on pollinators, pollination and food production” (2016), pp. 8 and 16; Connecting Global Priorities, p. 81. Harrison and others, “Linkages between biodiversity attributes and ecosystem services”, p. 195. Connecting Global Priorities, p. 48.