It can be easy to get lost in the flood of amazing observations. To make sure that you see all the observations you care about, you can subscribe to places and taxa, and follow people, so that you are alerted to all new observations of these. These alerts will come via email (unless you've turned email notifications off in your Profile) and on your Dashboard.
The only trick to watch out for comes from us being part of the global iNaturalist Network. If you subscribe to ferns on the fern page, you'll get email notifications about all the fern observations in the whole world.
To restrict your notifications to just the ferns of New Zealand, or just the ferns of Wellington, or wherever, you can subscribe to a place (like New Zealand) and then edit that subscription to restrict it to ferns.
You can also follow people to make sure that you don't miss their observations. If you wanted to be alerted to all of the observations Leon Perrie makes, go to his profile page (you can get to any user's profile page by clicking their user name on any NatureWatch NZ page) and, in this case, click the "Follow leonperrie" link.