The author is explicitly calling for action by stating, "let us strike hard." This is a rallying cry for readers to actively participate in ensuring the preservation of the redwood species.
The choice of strong language contributes to the persuasive tone of the article, motivating readers to engage in some form of advocacy or support for the cause.
The author goes on to highlight the threat facing the redwood species, particularly the sempervirens or redwood. By mentioning that the government has sold every section of the entire redwood belt, the author is underscoring the imminent danger and the need for swift intervention. This choice emphasizes the scarcity of time and the gravity of the situation.