The effects of crop type, landscape composition and agroecological practices on biodiversity and ecosystem services in tropical smallholder farms
The effects of crop type, landscape composition and agroecological practices on biodiversity and ecosystem services in tropical smallholder farms
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作物类型、景观组成和农业生态实践对热带小农农场生物多样性和生态系统服务的影响
DOI：
10.1111/1365-2664.14380
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发表时间：
2023
影响因子：
5.7
通讯作者：
Steffan‐Dewenter, Ingolf
中科院分区：
文献类型：
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作者：
Vogel, Cassandra;Poveda, Katja;Iverson, Aaron;Boetzl, Fabian A.;Mkandawire, Tapiwa;Chunga, Timothy L.;Küstner, Georg;Keller, Alexander;Bezner Kerr, Rachel;Steffan‐Dewenter, Ingolf
在热带地区，小农农业是世界上一些最具生物多样性景观的特征。农业生态学作为可持续农业的途径已在撒哈拉以南非洲提出并实施，但小农农业实践对生物多样性和生态系统服务的影响尚未得到充分研究。同样，不同的景观要素，如灌木或草地覆盖，对生物多样性和生态系统服务的贡献仍然未知。我们选择了24个村庄，这些村庄位于马拉维不同的灌木和草地覆盖的景观中。在每个村庄，我们评估了不同作物类型（豆类单作、玉米-豆类间作和玉米单作）的小农田间8个分类群的生物多样性和与作物类型、灌木和草地覆盖、农业生态害虫数量和土壤管理措施相关的生态系统服务。增加灌木覆盖改变了甲虫和土壤细菌群落。随着灌丛盖度的增加，玉米和豆田的甲壳瓢虫丰度增加，而间作田和豆田的甲壳瓢虫丰度降低。锦鲤丰度、丰富度和黄蜂丰度随土壤管理措施的增加而增加。单栽培的豆荚中，瓢虫、蜘蛛和寄生蜂的丰度较高，但这受到周围灌木覆盖的调节。在灌木较少的景观中，豆类的天敌丰度特别高，可能导致单作比间作对豆类的危害更小，而玉米单作的危害更高。在玉米中，草地覆盖和病虫害管理措施与损害呈正相关。大豆高危害田中，碳水化合物丰富度较高；玉米高危害田中，碳水化合物丰富度较高。寄生蜂丰度与大豆危害呈负相关。合成与应用。我们的研究结果表明，维持小农农场的生物多样性和生态系统服务不能用“一刀切”的方法来实现，而是应该适应景观背景和小农的优先事项。灌丛地对维持土壤细菌多样性具有重要意义，但对天敌有利的豆科植物种植可作为低灌丛地病虫害治理的补充。增加农业生态土壤管理方法的数量可以改善病虫害防治，而农业生态病虫害管理方法的有效性需要重新评估。
In the tropics, smallholder farming characterizes some of the world's most biodiverse landscapes. Agroecology as a pathway to sustainable agriculture has been proposed and implemented in sub‐Saharan Africa, but the effects of agricultural practices in smallholder agriculture on biodiversity and ecosystem services are understudied. Similarly, the contribution of different landscape elements, such as shrubland or grassland cover, on biodiversity and ecosystem services to fields remains unknown.We selected 24 villages situated in landscapes with varying shrubland and grassland cover in Malawi. In each village, we assessed biodiversity of eight taxa and ecosystem services in relation to crop type, shrubland and grassland cover and the number of agroecological pest and soil management practices on smallholder's fields of different crop types (bean monoculture, maize‐bean intercrop and maize monoculture).Increasing shrubland cover altered carabid and soil bacteria communities. Carabid abundance increased in maize but decreased in intercrop and bean fields with increasing shrubland cover. Carabid abundance and richness and wasp abundance increased with soil management practices. Carabid, spider and parasitoid abundances were higher in bean monocultures, but this was modulated by surrounding shrubland cover. Natural enemy abundances in beans were especially high in landscapes with little shrubland, possibly leading to lower bean damage in monocultures compared to intercropped fields, whereas maize monocultures had higher damage. In maize, grassland cover and pest management practices were positively related to damage. Carabid abundance was higher fields with high bean damage, and increased carabid richness in fields with high maize damage. Parasitoid abundance was negatively associated with bean damage.Synthesis and application. Our results suggest that maintaining biodiversity and ecosystem services on smallholder farms is not achievable with a ‘one size fits all’ approach but should instead be adapted to the landscape context and the priorities of smallholders. Shrubland is important to maintain carabid and soil bacterial diversity, but legume cultivation beneficial to natural enemies could complement pest management in landscapes with a low shrubland cover. An increased number of agroecological soil management practices can lead to improved pest control while the effectiveness of agroecological pest management practices needs to be re‐evaluated.