外来经济树种对红河干热河谷传粉网络的影响

Dry-hot valley is area with low plant-cover and fragile ecological environment, but plant yield of seeds and fruit could be great due to richness of sunshine and heat under circumstance of enough water supplies. Thus, agro-forestry scale has been quickly developed by cultivation of neem (Azadirachta indica) and moringa (Moringa oleifera) in valley areas of Honghe River, Yunnan Province. But flowering period of neem and moringa are overlapping with some local plants, which are, Litchi chinensis, Mangifera indica, Capparis wui, Passiflora altebiloba, and Phyllanthus emblica. Moreover, all of these domesticated and indigenous plants rely on Apis and Xylocopa as pollinators. Thus, pollination interference between foreign introduced plant and local indigenous plant need to be confirmed.. By research work of pollinating, breeding systems, and paternity analysis, the extent of local generalized pollinators supporting on introduced plants and the influence on pollination of indigenous plants could be showed, which is concerned with environmental protection. It could also provide the basic information of formation and maintenance of pollination network for further set of plant community, improving output of agroforestry system, and benefit the understanding of plant-pollinator interaction in terrestrial ecosystem, and give advice to conservation of pollination insects, and also to the strategy and management of domesticated plants blending in local pollination network.

干热河谷地区植被稀少，生态脆弱。然而光热资源丰富，在水分保证的情况下植物产出明显。因此近年来林农复合种植在云南红河流域干热河谷发展迅速，外来经济树种印楝和辣木的栽培面积也在逐年扩大。而印楝与辣木在花期上与原生植被元江山柑、月叶西番莲、余甘子，以及乡土果树荔枝和芒果存在重叠，传粉过程又需要共同依靠蜜蜂和木蜂等泛化传粉者。外来植物与当地传粉者建立起联系后对原有传粉网络和乡土植物授粉产生的影响有待确定。. 研究基于传粉生态学理论，以外来引种植物和乡土植物的花粉干扰为切入，揭示本地泛化传粉者如何支持外来植物传粉并参考对照显示对乡土植物授粉的影响程度。可以了解影响传粉成功和传粉者能量投资的因素，为保护原生植被生殖环境不受破坏，及外来树种与乡土果树进行林农复合配置提供依据。进一步深化对陆地生态系统的认识和植物-传粉者相互作用的理解，为外来植物融入本地传粉网络和传粉昆虫保护提供参考。

印楝和辣木作为全球广泛引种的多用途树种，在云南红河流域干热河谷地区引种已有十余年并形成了规模化的栽培，与当地主要经济林木荔枝和芒果，以及原生植物元江山柑、余甘子等存在花期部分重叠并共享泛化传粉昆虫。为了解本地泛化传粉者对外来树种传粉成功的支持包容程度和对乡土果树及原生植物的传粉影响，本研究通过分析传粉网络结构（连接数、传粉网络嵌套程度、传粉冗余度）、传粉者访花频率、吸引传粉者机制（花蜜糖含量和花气味化合物）以及花粉干扰程度，结果表明由于传粉者类型不同，传粉竞争和干扰现象主要发生在外来树种印楝、辣木和乡土果树荔枝、芒果四种植物之间。且主要传粉者仍偏好于访问乡土果树荔枝和芒果，四种植物混交和纯林的座果率差异不显著。外来树种印楝和辣木对乡土果树荔枝和芒果当前形成的传粉竞争仅存在于访花层面，传粉者的传粉效率能够同时满足外来树种和乡土果树的结实。印楝和辣木能够融入到红河干热河谷地区的传粉网络，目前的栽培规模尚不会对荔枝和芒果的繁育造成影响。