More than 75 percent decline over 27 years in total flying insect biomass in protected areas

Summary

Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.

Related articles

• An evidence-based study mapping the decline in freshwater ponds in the Severn Vale catchment in the UK between 1900 and 2019

  This research paper investigates the decline in the number and density of freshwater ponds in the Severn Vale catchment, UK, over a period from 1900 to 2019. It emphasizes the impact of land use changes on pond loss and aims to provide a baseline for conservation efforts.

• Green Gears

  This document discusses various aspects of aquaculture and its significance in sustainable resource management, particularly focusing on fish farming practices and strategies for resource rehabilitation.

• From barriers to solutions: an ensemble ranking-based framework for circular economy adoption

  This research investigates barriers to Circular Economy (CE) adoption and proposes a robust framework to assess and overcome these barriers, utilizing multiple decision-making techniques to prioritize solutions.

• The Ripple Effect: One Person Can Make a Difference

  A motivational speech highlighting the inspiring actions of N. S. Rajappan, a 75-year-old man who, despite his physical limitations, actively cleans Vembanad Lake, thereby encouraging others to take environmental action.

• The Ripple Effect: Making a Difference through Small Actions

  A motivational speech highlighting the story of N. S. Rajappan, a 75-year-old man who, despite his physical limitations, made a significant impact on the environment by cleaning Vembanad Lake, inspiring others to take small actions for nature.