Shinto ceremonies need certain sorts of supplies. For example, rice is a central part of all offerings. A jinja that cannot get rice is going to have major problems performing standard matsuri. Fortunately, there is still no problem getting rice in Japan, and it is unlikely to become problematic in the near future.
Other supplies are in a much worse situation. For example, sakaki, the evergreen tree whose branches are placed on kamidana beside the ofuda, and used to make the tamagushi that are used in many matsuri, is suffering from some sort of disease in Japan, making it hard to get good leaves. It is possible to get Japanese-grown sakaki in my local supermarket, but it is twice as expensive as the sakaki imported from China.
There are also problems with the supply of reeds for thatching. They grow in wetlands by rivers, but most of those have been drained over the last fifty or sixty years, making them much harder to get. This was part of the reason why the main structures in the Daijōkyū for last year’s Daijōsai were roofed with boards, rather than being thatched, as is traditional: the Imperial Household Agency judged that it would be difficult and expensive to get hold of the necessary reeds.
The Shinto world is aware of this problem, and is taking steps to deal with it. Jingū needs a lot of reeds for its Grand Renewal, the Shikinen Sengū, and it has secured suitable areas of land, where it is growing the reeds, and storing them up to ensure that it has enough. Similarly, the Renewal uses a lot of hinoki, Japanese cypress, and straight trees several centuries old are needed for some particular parts. The future problem here was noticed a century ago, and Jingū started growing hinoki forests on its own land, managing them to grow suitable trees. After a century, they finally had some trees that were usable in the last Renewal, in 2013, and because the woodlands are managed they think that they might actually be able to supply everything in another hundred years. (Monitoring the trees and helping them to grow straight means that they do not take as long to reach the necessary dimensions, apparently.)
Another example was reported a few weeks ago in Jinja Shinpō. As I mentioned in the post on Red Torii, it is not uncommon for structures at jinja to be painted with lacquer (“urushi”, in Japanese). Urushi is a natural product, from a tree, and was, in the past, a major product of Japan. However, that is no longer true, and 97% of all lacquer used in Japan now is imported. Recently, the Cultural Agency declared that repairs to National Treasures and Important Cultural Properties must use domestic urushi rather than imported because, as a natural product, the imported lacquer is not quite the same, and this matters for cultural treasures.
A jinja in Sendai, Ōsaki Hachimangū, was pushed to action by this. The main structures there are Important Cultural Properties, and they are all lacquered. The current level of domestic supply is adequate if you are repairing a lacquer bowl, but not if you have to lacquer a whole complex of buildings. Thus, the jinja bought an area of land, and created an urushi plantation on it. It will, apparently, be at least twenty years before any urushi can be harvested there, but in the long term it will make the jinja much more sustainable.
I can easily imagine more such initiatives happening within Shinto, as large and wealthy jinja try to ensure the sustainability of their traditional activities.