Data from: The importance of shrubland and local agroecological practices for pumpkin production in sub-Saharan smallholdings

Land-use and local field management affect pollinators, pest damage, and
ultimately crop yields. Agroecology is implemented as a sustainable
alternative to conventional agricultural practices, but little is known
about its potential for pollination and pest management. Sub-Saharan
Africa is underrepresented in studies investigating the relative
importance of pests and pollinators for crop productivity and how this
might be influenced by surrounding landscapes or agroecological practices.
In Malawi, we selected 24 smallholder farms differing in landscape-scale
shrubland cover, implementation of manual pest removal as an indicator of
an agroecological pest management practice, and the number of
agroecological soil practices employed at the household level, such as
mulching, intercropping, and soil conservation tillage. We established
pumpkin plots and assessed the abundance and richness of flower visitors
and damage of flowers (florivory) caused by pest herbivores on flowers.
Using a full-factorial hand pollination and exclusion experiment on each
plot, we investigated the relative contribution of pollination and
florivory to pumpkin yield. Increasing shrubland cover decreased honeybee
abundance but increased the abundance and richness of non-honeybee
visitors. Manual removal of herbivores considered to be pests reduced
flower visitors, whereas more agroecological soil management practices
increased flower visitors. Neither shrubland cover nor agroecological
management affected florivory. Pollinator limitation, but not florivory,
constrained pumpkin fruit set, and increasing visitor richness decreased
the relative differences between hand- and animal-pollinated flowers. We
recommend improved protection of shrubland habitats and increasing
agroecological soil practices to promote pollinator richness on
smallholder farms.

土地利用与田间局部管理会影响传粉者、害虫危害及最终作物产量。农业生态学作为传统农业实践的可持续替代方案被推行，但人们对其在传粉与害虫管理方面的潜力知之甚少。撒哈拉以南非洲在探讨害虫与传粉者对作物生产力的相对重要性，以及这种重要性如何受周边景观或农业生态实践影响的研究中代表性不足。在马拉维，我们选取了24个小农户农场，这些农场在景观尺度灌丛覆盖度、作为农业生态害虫管理实践指标的人工除虫实施情况、以及家庭层面采用的农业生态土壤实践数量（如覆盖耕作、间作和水土保持耕作）上存在差异。我们建立了南瓜试验田，评估了访花者的丰度与丰富度，以及害虫取食造成的花损伤（花食性）。通过在每个试验田开展全因子人工授粉与排除实验，我们研究了传粉与花食性对南瓜产量的相对贡献。灌丛覆盖度增加会降低蜜蜂丰度，但会提高非蜜蜂访花者的丰度与丰富度。人工清除被视为害虫的植食性动物会减少访花者，而采用更多农业生态土壤实践则会增加访花者。灌丛覆盖度与农业生态管理均未影响花食性。传粉者限制（而非花食性）制约了南瓜坐果率，且访花者丰富度增加会缩小人工授粉与动物授粉花朵间的相对差异。我们建议加强灌丛栖息地保护，并增加农业生态土壤实践的采用，以提升小农户农场的传粉者丰富度。