How has the ecosystem changed within the past 100 years?

How do ecosystems change over time? ... Different drivers of ecosystem change take more or less time to react to changes. For example, some species might become extinct quickly when they lose their habitat, but for others, like trees, it can take centuries.

explination

q1: artillery

q2: simon bolivar

q3:   their workers and farmers demanded a return to spanish rule.

q4: drafted new constitutions

q5: oligarchies have replaced monarchies