 For many years, research has been carried out into the relationship between temperature and chironomid distribution pattern due to the impact of temperature on chironomid emergence.
<clarity>  For many years, research has been carried out into the relationship between temperature and chironomid distribution pattern due to the impact of temperature on chironomid emergence.
 For many years, research has been carried out into the relationship between temperature and chironomid distribution due to the impact of temperature on chironomid emergence.