Unidad para el Conocimiento, Uso y Valoración de la Biodiversidad, Centro de Estudios Conservacionistas-CECON-, Facultad de Ciencias Químicas y Farmacia, Universidad de San Carlos de Guatemala, Avenida La Reforma 0-63 zona 10, 01010, Ciudad de Guatemala, Guatemala.
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, 70-275, 04510, Ciudad de México, México.
Oecologia. 2020 Nov;194(3):333-344. doi: 10.1007/s00442-020-04715-8. Epub 2020 Jul 25.
Land-use alteration and climate seasonality have profound effects on bee species diversity by influencing the availability of nesting and floral resources. Here, using twelve sites embedded in an agriculture-forest mosaic in the tropical highlands of Guatemala, we investigated the relative effects of climate seasonality and landscape heterogeneity on bee and floral-resource community structure and on their mutualistic network architecture. We found that climate seasonality affected bee diversity, which was higher in the wet season and associated positively with the availability of floral resources across both seasons. Bee community composition also differed between seasons and it was mainly driven by floral-resource richness and the proportion of agricultural, semi-natural and forest cover. In addition to the effects on bee diversity, climate seasonality also affected flower-bee visitation networks. We documented higher relative (null model corrected) nestedness in the dry season compared to the wet season. Niche partitioning as a result of competition for scarce resources in the dry season could be the process driving the differences in the network structure between seasons. Furthermore, relative nestedness was consistently smaller than zero, and relative modularity and specialization were consistently larger than zero in both seasons, suggesting the existence of isolated groups of interacting partners in all our flower-bee visitation networks. Our results highlight the effect of climatic seasonality and the importance of preserving local floral resources and natural heterogeneous habitats for the conservation of bee communities and their pollination services in tropical highlands.
土地利用变化和气候季节性通过影响筑巢和花卉资源的可利用性，对蜜蜂物种多样性产生深远影响。在这里，我们使用 12 个位于危地马拉热带高地农业-森林镶嵌体中的地点，调查了气候季节性和景观异质性对蜜蜂和花卉资源群落结构及其互利网络结构的相对影响。我们发现气候季节性影响蜜蜂多样性，在雨季更高，与两个季节的花卉资源可用性呈正相关。蜜蜂群落组成也因季节而异，主要由花卉资源丰富度以及农业、半自然和森林覆盖的比例驱动。除了对蜜蜂多样性的影响外，气候季节性还影响了花-蜂访问网络。我们记录到在旱季比雨季具有更高的相对嵌套性（经零模型校正）。在旱季，由于稀缺资源的竞争导致生态位分化，可能是导致季节间网络结构差异的过程。此外，在两个季节中，相对嵌套性始终小于零，而相对模块性和专业化性始终大于零，这表明在我们所有的花-蜂访问网络中都存在相互作用的孤立伙伴群体。我们的研究结果强调了气候季节性的影响以及保护当地花卉资源和自然异质生境对热带高地蜜蜂群落及其传粉服务的重要性。
