I could not find any information about the Conocarpus tree. Consequently, I did not find literature about this tree as a cause of thunderstorm asthma. Pollen (from grasses, Parietaria species and olive trees) and mold (Alternaria alternata) have been associated with thunderstorm-related asthma epidemics.
Regarding your second question, since pollens are known to travel great distances, cutting down trees doesn’t seem to be a reasonable solution. Educating people with asthma and pollen/mold allergy about this risk and advising them to stay indoors, keep windows closed, use their controller medications and possibly even wear protective, small-particle respiratory masks if they must be outdoors during thunderstorms that occur during the pollen season are suggestions to consider.
I hope this information is helpful.
Jacqueline A. Pongracic, MD, FAAAAI