"I am a very good driver and I have driven ATVs and I am pretty sure that if there is something else you would want me to drive I would be able to do that without any inconvenience."
This is a straight forward question which won't need much effort in answering. Either you can drive these vehicles or you can't. Feel free to mention what vehicles you feel comfortable in driving and also if there is something specific that you might want to mention here, please make sure you do so. For instance, in addition to the ATVs what other vehicles you can drive? This might help you in scoring some brownie points in front of the interviewer. But in case you can't drive please mention if you are learning or the reason why you can't.
"I am doing masters in forestry through open university and will be completing it next year. I believe that this will help me in growing in this career and also improve my knowledge about this field."
Do you have any plans of going for a masters degree in forestry? Or do you have one already or are you already enrolled in some masters course and about to complete it. The answer to this question will help the interviewer in determining whether you will be a good fit for the job and an asset for the company in future. Inform the interviewer about your plans and also how you believe this will help you in future.