RESPOND: To answer or react to something. For example, When someone calls your name you RESPOND by looking to see who called you. Or you RESPOND verbally by saying "I am here!". When someone writes you a letter you RESPOND by sending a letter back to them.
An ecosystem can respond to change either disastrously or greatly. If an ecosystem is treated responsibly, the ecosystem will respond greatly, but if it's irresponsibly treated the ecosystem will surely be destroyed and respond insignificantly.
Respond means to answer. It can be a response to a demand, an answer to a question, but it is always an answer or counter demand. "I have the right to respond to the question the way I see fit." "The witness did not respond to the question immediately, so the lawyer asked again."
No, respond means in the present, now or in the future; responded means in the past, previously: I have that information and can respond to the inquiry. I will respond to your inquiry as soon as I can. I responded to the inquiry last week.