Exotic garden plants partly substitute for native plants as resources for pollinators when native plants become seasonal
- PDF / 3,006,052 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 66 Downloads / 249 Views
PLANT-MICROBE-ANIMAL INTERACTIONS – ORIGINAL RESEARCH
Exotic garden plants partly substitute for native plants as resources for pollinators when native plants become seasonally scarce Michael Staab1,2 · Maria Helena Pereira‑Peixoto1,3 · Alexandra‑Maria Klein1 Received: 25 August 2020 / Accepted: 10 October 2020 © The Author(s) 2020
Abstract Urban green spaces such as gardens often consist of native and exotic plant species, which provide pollen and nectar for flower-visiting insects. Although some exotic plants are readily visited by pollinators, it is unknown if and at which time of the season exotic garden plants may supplement or substitute for flower resources provided by native plants. To investigate if seasonal changes in flower availability from native vs. exotic plants affect flower visits, diversity and particularly plant–pollinator interaction networks, we studied flower-visiting insects over a whole growing season in 20 urban residential gardens in Germany. Over the course of the season, visits to native plants decreased, the proportion of flower visits to exotics increased, and flower-visitor species richness decreased. Yet, the decline in flower-visitor richness over the season was slowed in gardens with a relatively higher proportion of flowering exotic plants. This compensation was more positively linked to the proportion of exotic plant species than to the proportion of exotic flower cover. Plant–pollinator interaction networks were moderately specialized. Interactions were more complex in high summer, but interaction diversity, linkage density, and specialisation were not influenced by the proportion of exotic species. Thus, later in the season when few native plants flowered, exotic garden plants partly substituted for native flower resources without apparent influence on plant–pollinator network structure. Late-flowering garden plants support pollinator diversity in cities. If appropriately managed, and risk of naturalisation is minimized, late-flowering exotic plants may provide floral resources to support native pollinators when native plants are scarce. Keywords Bees · Flower visitors · Non-native species · Seasonal shift · Networks
Introduction Communicated by Carlos L. Ballare. Michael Staab and Maria Helena Pereira-Peixoto contributed equally to this manuscript. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00442-020-04785-8) contains supplementary material, which is available to authorized users. * Maria Helena Pereira‑Peixoto maria.pereira‑[email protected]‑freiburg.de 1
Department of Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Straße 4, 79106 Freiburg, Germany
2
Freiburg Institute of Advanced Studies (FRIAS), University of Freiburg, Albertstraße 19, 79104 Freiburg, Germany
3
CAPES Foundation, Ministry of Education of Brazil, Brasília, DF 70040‑020, Brazil
Flying insects, including many wild pollinator species, have been dramatically declining in Europe (Hallmann et al. 2017;
Data Loading...
