pathogenic fungi insect defoliation soil chemical stress microorganism activity
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Oak tree decline is linked to the effects of pathogenic fungi, insect defoliation, soil chemical stress, and microorganism activity. Which factor is an abiotic condition that is affecting oak tree decline?
Possibilities:
- pathogenic fungi
- insect defoliation
- soil chemical stress
- microorganism activity

soil chemical stress