Utility of stream mesocosms for climate change research

Wang, Zining (2020). Utility of stream mesocosms for climate change research. University of Birmingham. Ph.D.

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Abstract

The utility of stream mesocosms was examined in a study of replicability of water physicochemstry and benthic macroinvertebrate assemblages in an array of artificial flumes near the River Itchen in southern U.K. High quality groundwater supply and similar exposure to the environment lead water physicochemistry to be highly replicate across all channels. The within- and between-flume replicate design reduced macroinvertebrate assemblages’ variability temporally, but the structure of macroinvertebrate assemblages in mesocosms shift seasonally. The highly temporal replicability of mesocosms allowed a long-term (i.e. 1- year) study of drought in these stream mesocosms.
Seven water depth treatments were applied in a series (n=21) of artificial flumes to construct a linear varying drought gradient so that each treatment was replicated three times. The drought experiment lasted a course from August, 2013 to August, 2014. Algal growth and the abundance of three grazer taxa were negatively correlated with both drought intensity and drought duration. Additionally, the drought intensity impact on algal growth shifted with drought duration. Conversely, drought intensity had a fixed negative impact on decomposition process. Shredder community structure was altered by drought impact reducing shredder abundance and shredding efficiency. However, the shredding efficiency in freshwater ecosystem was more related to shredding efficiency of specialist shredder rather than shredder abundance.
The mesocosms could mimic freshwater ecosystem physiochemistry environment and macroinvertebrate assemblage effectively and comprehensively, which provided an access to study the impact of natural disturbance on freshwater ecosystem. This study developed the understanding of the drought effect on the entire freshwater ecosystem.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):