Insect biomass decline scaled to species diversity: General patterns derived from a hoverfly community.
Proc Natl Acad Sci U S A
; 118(2)2021 01 12.
Article
em En
| MEDLINE
| ID: mdl-33431568
ABSTRACT
Reports of declines in biomass of flying insects have alarmed the world in recent years. However, how biomass declines reflect biodiversity loss is still an open question. Here, we analyze the abundance (19,604 individuals) of 162 hoverfly species (Diptera Syrphidae), at six locations in German nature reserves in 1989 and 2014, and generalize the results with a model varying decline rates of common vs. rare species. We show isometric decline rates between total insect biomass and total hoverfly abundance and a scale-dependent decline in hoverfly species richness, ranging between -23% over the season to -82% at the daily level. We constructed a theoretical null model to explore how strong declines in total abundance translate to changing rank-abundance curves, species persistence, and diversity measures. Observed persistence rates were disproportionately lower than expected for species of intermediate abundance, while the rarest species showed decline and appearance rates consistent with random expectation. Our results suggest that large insect biomass declines are predictive of insect diversity declines. Under current threats, even the more common species are in peril, calling for a reevaluation of hazards and conservation strategies that traditionally target already rare and endangered species only.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Modelos Estatísticos
/
Biomassa
/
Biodiversidade
/
Dípteros
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
Europa
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2021
Tipo de documento:
Article