[O] merge trees?

[Matt Price]

Eveyr year at this time, I struggle with the structure of my course syllabi, and move bits an pieces around with wild abandon.  At the end of my struggles, my course outline will be filled with headings like this:
------------------------
** <2015-10-06 Tue> Spatial History
Thinking about the visual presentation of information, especially in map form
*** Readings
+ Franco Moretti, /Graphs, Maps, Trees/, ch. 1 ([[http://2012.hackinghistory.ca/wp-content/uploads/2012/09/placing-history.pdf][Graphs]]).
+ Knowles, A. K. “GIS and History.” [[http://2012.hackinghistory.ca/wp-content/uploads/2012/09/pariser-filter-bubble.pdf][/Placing History: How Maps, Spatial Data, and GIS Are Changing Historical Scholarship/]] (2008): 1–13.
+ Bondenhamer, David J. “History and GIS: Implications for the Discipline.” /Placing History: How Maps, Spatial Data, and GIS Are Changing Historical Scholarship/ (2008): 219-234.
+ Theibault, John. “[[http://writinghistory.trincoll.edu/evidence/theibault-2012-spring/][Visualizations and Historical Arguments]].” Writing History in the Digital Age, March 23, 2012.
*** Lab: Google Maps and _javascript_
--------------------------

Unfortunately, the Seminar topics, labs, and readings do not always match up very well. It occurs to me that it would be preferable to maintain separate trees of seminar topics and labs, and merge them, so eg:

* Topics

** Introduction

** Crowds and Publics

** Spatial History

* Labs

** Intro to HTML

** Styling with CSS

** The Google Maps _javascript_ API

The two subtrees can be manipulated independently, then merged to create something like:

* Schedule
** <2015-09-15>

*** Seminar: Introduction

*** Lab: Intro to HTML

(each subheading will also include content, e.g., a description of the class, some lab instructions, etc.).

Is there an easy way to do this already? Or is the best thing to do to write a piece of elisp that generates the appropriate structure using org-element, and put that code in a babel block? And if the latter, does anyone, um, want to write the code for me?

Many thanks for your help,

Matt