Literature review dataset

Ensuring the sustainability of crop production, whilst simultaneously taking actions to mitigate the environmental impacts of agriculture, is a current global priority. Given around 75% of global food crop yields benefit from pollination services provided by diverse wild and managed insect taxa, management strategies that support diverse communities of pollinator taxa are valuable to ensure ongoing pollination service provisioning and agricultural production. In addition to pollination, realised crop yields are also influenced by other biotic and abiotic factors which vary across different spatial and temporal scales. This thesis addresses three important aspects of crop pollination, namely the need to merge disparate research fields, the degree to which pollinator taxa service multiple crops and regions and how pollination interacts with crop tree physiological factors such as tree vigour. First, I reviewed the literature to evaluate the knowledge gaps concerning pollinator effectiveness and the utility of using remote sensing in crop pollination research. I conducted surveys and pollen deposition trials to identify pollinators in avocado, mango and macadamia crops in three geographically distinct growing regions in Australia across three years. Using single visit deposition rates, bipartite networks and spatial analyses I also investigated pollinator service provisioning and the land use types that influence pollinator communities in these crop and regions. Using hand pollination trials over two years I investigated the impact of supplemental cross pollination on the yield of avocado trees. My first review identified important research directions to account for pollination processes occurring at a community level including: plant-pollinator interactions, heterospecific pollen transfer and variation in pollination outcomes. My second review identified the areas in which remote sensing technologies can facilitate our understanding of interactions between pollinators, pollination services, environmental and plant physiological factors which affect final harvest measures. Using multi-crop, multi-year and multi-region crop-pollinator networks I demonstrated that shared wild pollinator taxa visit multiple crops across several regions. In particular, honey bees (A. mellifera) and two families of wild visitors, Syrphidae and Calliphoridae, are present across all regions and crops. Further, regional comparisons for both avocado and mango crops identified additional shared families that were locally abundant such as Coccinellidae and native Apidae. I found that the effect of additional cross pollination on trees of different vigour varied between individual orchard blocks and across years. General patterns relating to the impact of interaction between tree vigour and pollination on yield were discernible in this study, with lower and medium vigour trees responding more positively to supplemental pollination than high vigour trees. High variability in results and differences in effect response across orchard blocks highlight the need to investigate further factors at a tree and block scale, in future analyses. My research indicates that there is significant potential to identify shared pollinators that provide services across multiple crops. Pollination management strategies that are regionally specific and that include bee and non-bee taxa and co-flowering crop species are needed to ensure ongoing effective and resilient pollination services are delivered to crop systems. The merging of different research fields, such as remote sensing, pollinator ecology and precision agriculture offers exciting new approaches to facilitate our understanding of these complex crop-pollinator interactions.

保障作物生产可持续性，同时采取行动减缓农业的环境影响，是当前全球首要议题。鉴于全球约75%的粮食作物产量依赖于多样野生及人工饲养昆虫类群（wild and managed insect taxa）提供的传粉服务（pollination services），支持多样传粉昆虫类群群落的管理策略，对保障持续的传粉服务供给与农业生产具有重要价值。除传粉作用外，实际作物产量还受到其他生物与非生物因子的影响，这些因子随不同空间与时间尺度发生变化。本研究围绕作物传粉研究的三个重要方向展开：一是整合不同研究领域的必要性，二是传粉昆虫类群可为多种作物及多个区域提供传粉服务的程度，三是传粉作用与作物树势等林木生理因子的相互作用机制。
首先，本研究通过文献综述，评估了传粉昆虫有效性相关的研究空白，以及遥感（remote sensing）技术在作物传粉研究中的应用价值。本研究在三年时间内，于澳大利亚三个地理分隔的种植区域开展了野外调查与花粉沉积试验，以鉴定鳄梨、芒果与澳洲坚果作物中的传粉昆虫类群。本研究还通过单次访花沉积速率、二元网络（bipartite networks）与空间分析方法，探究了上述作物与区域内的传粉服务供给情况，以及影响传粉昆虫群落的土地利用类型。本研究开展了为期两年的人工授粉试验，探究了补充异花授粉对鳄梨树产量的影响。
第一项综述研究明确了需关注群落尺度传粉过程的重要研究方向，包括植物-传粉者互作（plant-pollinator interactions）、异种花粉传递（heterospecific pollen transfer）以及传粉结果的变异。第二项综述研究明确了遥感技术可助力我们理解传粉昆虫、传粉服务、环境因子与植物生理因子之间相互作用的方向，这些因子最终会影响作物收获量。本研究通过构建多作物、多年份、多区域的作物-传粉者网络，证实了共享的野生传粉昆虫类群可访问多个区域的多种作物。其中，西方蜜蜂（Apis mellifera）以及两个野生访花昆虫类群——食蚜蝇科（Syrphidae）和丽蝇科（Calliphoridae）——在所有区域与作物中均有分布。此外，针对鳄梨与芒果作物的区域对比分析还识别出其他本地丰度较高的共享类群，包括瓢虫科（Coccinellidae）与本土蜜蜂科（Apidae）类群。
本研究发现，补充异花授粉对不同树势林木的影响存在果园地块间与年份间的差异。本研究可识别出树势与传粉作用的交互效应对产量影响的总体规律：树势较低与中等的林木相较于高树势林木，对补充授粉的响应更为积极。研究结果存在较高变异性，且不同果园地块的效应响应存在差异，这表明未来分析需进一步探究林木与地块尺度的相关因子。
本研究表明，识别可跨多种作物提供传粉服务的共享传粉昆虫类群具有巨大潜力。为保障作物系统能够获得持续、高效且具有韧性的传粉服务，需制定区域特异性的传粉管理策略，涵盖蜂类与非蜂类传粉类群以及同期开花的作物物种。整合遥感、传粉昆虫生态学与精准农业（precision agriculture）等不同研究领域，可为我们理解这些复杂的作物-传粉者互作关系提供极具前景的新方法。