Bos Merijn M, Veddeler Dorthe, Bogdanski Anne K, Klein Alexandra-Maria, Tscharntke Teja, Steffan-Dewenter Ingolf, Tylianakis Jason M
Agroecology, University of Goettingen, Waldweg 26, Goettingen D-37073, Germany.
Ecol Appl. 2007 Sep;17(6):1841-9. doi: 10.1890/06-1763.1.
The recent trend to place monetary values on ecosystem services has led to studies on the economic importance of pollinators for agricultural crops. Several recent studies indicate regional, long-term pollinator declines, and economic consequences have been derived from declining pollination efficiencies. However, use of pollinator services as economic incentives for conservation must consider environmental factors such as drought, pests, and diseases, which can also limit yields. Moreover, "flower excess" is a well-known reproductive strategy of plants as insurance against unpredictable, external factors that limit reproduction. With three case studies on the importance of pollination levels for amounts of harvested fruits of three tropical crops (passion fruit in Brazil, coffee in Ecuador, and cacao in Indonesia) we illustrate how reproductive strategies and environmental stress can obscure initial benefits from improved pollination. By interpreting these results with findings from evolutionary sciences, agronomy, and studies on wild-plant populations, we argue that studies on economic benefits from pollinators should include the total of ecosystem processes that (1) lead to successful pollination and (2) mobilize nutrients and improve plant quality to the extent that crop yields indeed benefit from enhanced pollinator services. Conservation incentives that use quantifications of nature's services to human welfare will benefit from approaches at the ecosystem level that take into account the broad spectrum of biological processes that limit or deliver the service.
最近对生态系统服务进行货币估值的趋势引发了关于传粉者对农作物经济重要性的研究。最近的几项研究表明传粉者在区域内呈长期减少趋势,授粉效率下降已产生了经济后果。然而,将传粉者服务用作保护的经济激励措施时,必须考虑干旱、病虫害等环境因素,这些因素也会限制产量。此外,“花朵过剩”是植物一种众所周知的繁殖策略,可作为抵御限制繁殖的不可预测外部因素的保障。通过对三种热带作物(巴西的百香果、厄瓜多尔的咖啡和印度尼西亚的可可)授粉水平对收获果实数量的重要性进行三个案例研究,我们说明了繁殖策略和环境压力如何掩盖授粉改善带来的最初益处。通过结合进化科学、农学以及对野生植物种群研究的结果来解读这些结果,我们认为关于传粉者经济效益研究应纳入生态系统过程的整体,这些过程包括:(1)实现成功授粉;(2)调动养分并改善植物品质,从而使作物产量确实受益于传粉者服务的增强。利用对自然服务对人类福祉量化的保护激励措施,将受益于生态系统层面的方法,这种方法考虑到了限制或提供该服务的广泛生物过程。