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Title: Temperature, not net primary productivity, drives continental-scale variation in insect flight activity
The amount of energy available in a system constrains large-scale patterns of abundance. Here, we test the role of temperature and net primary productivity as drivers of flying insect abundance using a novel continental-scale data source: weather surveillance radar. We use the United States NEXRAD weather radar network to generate a near-daily dataset of insect flight activity across a gradient of temperature and productivity. Insect flight activity was positively correlated with mean annual temperature, explaining 38% of variation across sites. By contrast, net primary productivity did not explain additional variation. Grassland, forest and arid-xeric shrubland biomes differed in their insect flight activity, with the greatest abundance in subtropical and temperate grasslands. The relationship between insect flight abundance and temperature varied across biome types. In arid-xeric shrublands and in forest biomes the temperature–abundance relationship was indirectly (through net primary productivity) or directly (in the form of precipitation) mediated by water availability. These results suggest that temperature constraints on metabolism, development, or flight activity shape macroecological patterns in ectotherm abundance. Assessing the drivers of continental-scale patterns in insect abundance and their variation across biomes is particularly important to predict insect community response to warming conditions. This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.  more » « less
Award ID(s):
2017582 1840230
PAR ID:
10560267
Author(s) / Creator(s):
;
Publisher / Repository:
The Royal Society Publishing
Date Published:
Journal Name:
Philosophical Transactions of the Royal Society B: Biological Sciences
Volume:
379
Issue:
1904
ISSN:
0962-8436
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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