Collection of boilerplate for licensing that can be used for OSE-related content.
This page assumes that you know about Creative Commons (CC) licenses.
Any work (e.g., text, image, video) that you create is "automatically" protected by copyright. (No explicit copyright notice is required!) If you want others to re-use and build upon your work, you - as the copyright holder - have to give others an explicit license.
A clearly visible license
- makes it easy for others use and build upon OSE-related content.
- helps to promote OSE, by requiring attribution to OSE.
Copyright 2020 John Doe This work is licensed under A Suitable License Requiring Attribution. Attribute this work to "OSE, www.opensourceecology.org"
Since you created the work, put your name (instead of John Doe) as the copyright holder.
It is not required/necessary that OSE is the copyright holder because on the next line you state a suitable license that makes it easy for OSE and others to re-use it. [Is it possible/preferable to name OSE as the copyright holder with or w/o its permission?]
CC BY-SA Boilerplate
OSE favors a copyleft/reciprocal license such as CC's Share-Alike (SA). This Wiki does so.
So, this notice is typically what you should do:
Copyright 2020 John Doe Licensed under a Creative Commons Attribution-Share Alike (CC BY-SA) 4.0 International License (creativecommons.org/licenses/by-sa/4.0/). Attribute this work to "OSE, www.opensourceecology.org".
YouTube (YT) offers (only) two licenses:
- YouTube license 
- CC BY
The YT license essentially allows Google to host your video and other users to view the video on YT. (Users are not allowed to download or modify it.) So, giving a suitable license makes sense.
If you have several videos in a playlist, you can state the notice in the playlist description (but users may not see it):
All content on this playlist is copyrighted by the owner of this playlist. All content on this playlist is licensed under a Creative Commons Attribution-Share Alike (CC BY-SA) 4.0 International License (creativecommons.org/licenses/by-sa/4.0/). Attribute this work to "OSE, www.opensourceecology.org".