Temperature and the biomass of flying midges (Diptera: Chironomidae) in the high Arctic
We tested the hypothesis that habitat temperature is the driving variable determining both the short-term and seasonal patterns of abundance (biomass) of Eying adult non-biting midges (Chironomidae) in the high Arctic. Malaise traps were used to record the Eight activity patterns of adult chironomids during the 1992 and 1993 seasons at two contrasting sites, a polar semi-desert and a tundra heath adjacent to Ny Angstrom lesund, Spitsbergen, Svalbard. The relationship between flight activity, measured as chironomid biomass captured, and macro and microclimatic parameters was examined. Mean and minimum screen temperatures were the best single predictors of chironomid activity. Best subsets regression was used to establish predictive relationships between biomass captured and climatic parameters for each site. Again, macroclimatic temperature variables emerged as the best predictors, together with much smaller contributions from relative humidity and precipitation. The species composition of the chironomid community changed as the summer progressed and the 'average' individual became smaller. However, when cumulative biomass captured per trap was plotted against cumulative day degrees above zero, starting at snow melt, the relationship on both sites in 1992, an average year, was approximately linear or at most slightly curved. This suggested that biomass capture was mainly a function of temperature and time. By contrast, in 1993, the warmest year on record (1961-93), the initial response was again almost linear but later became asymptotic, suggesting that the supply of chironomids available for capture was depleted, despite suitably high temperatures. This contrast between years (100 day degrees) provided an opportune analogue for the likely effects of climate warming on chironomid activity. The implications for the food supply of tundra-breeding birds are discussed in the context of the known emergence patterns of Arctic chironomids
Details
Publication status:
Published
Author(s):
Authors: Hodkinson, I. D., Coulson, S. J., Webb, N. R., Block, W., Strathdee, A. T., Bale, J. S., Worland, M. R.
This website uses cookies to improve your experience. We'll assume you're okay with this, but you can opt-out if you wish.AcceptRead more
Privacy & Cookies Policy
Privacy Overview
This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.