Significance of direct and indirect pollination ecosystem services to the apple industry in the Western Cape of South Africa

[摘要] ENGLISH ABSTRACT: Insect pollinators play an important role in producing crops in global agriculture. Pollinatordependentcrops contribute to maintaining a healthy variety in the human diet and often have ahigh market value, beneficial for local or regional economies. Insect crop pollinators can eitherbe from natural areas adjacent to orchards, or they can be brought into orchards by beekeepersthat manage them. Pollination by wild pollinators is an ecosystem service, while managedpollinators (mostly honeybees) is a humanly managed service, considered not to be related to theecosystem. Ecosystem services and their economic value have often been used as an incentivefor conservation, although it is sometimes difficult to characterise and quantify them. Wild andmanaged pollinators have been reported to be threatened in several regions around the world, andthere is concern about the effect a pollination deficit may have on crop production. Differentcrops and cultivars have different levels of dependence on insect pollination due to acombination of biological, physical and management factors. In this study, the pollinationdependence of the Granny Smith apple cultivar and the respective contributions of wild andmanaged pollinators are investigated in the Western Cape province of South Africa. GrannySmith apples show a significant increase in production with insect pollination (wild andmanaged). Managed honeybees are more abundant in orchards than wild honeybees, and alsoprovide a better pollination service. This difference between the pollination service of wild andmanaged honeybees are specifically noted in the quality, where managed honeybees pollinationresult in significantly more seeds per fruit and consequently produce a better shaped apple. Thestudy goes further by quantifying the ecosystem services to the managed honeybee industrythrough a questionnaire completed by beekeepers. It was found that 49% of the managed hives inthe Western Cape rely to some extent on natural vegetation as a forage source. Furthermore 18%of honey produced is also from natural vegetation and the wild honeybee population replenishmanaged honeybee stocks if they become depleted. Although managed honeybees are notusually considered an ecosystem service, it is clear that they are still linked to the ecosystem viathese pathways. It is thus obvious that all pollination sources are linked to the environment, notjust wild pollinators. A further economic valuation of the ecosystem service studied, and to theargument for conservation of pollinators and the resources they depend on.

[发布机构] Stellenbosch University