Conservation of species can take place in their original environment (in-situ) or outside of it (ex-situ).
Examples of ex-situ conservation are zoos and seed banks. Zoos host animals outside of their original environment, under highly controlled conditions. Animals are no longer subject to predation, don’t have to provide for themselves, and have access to advanced healthcare.
Seed banks preserve the starting unit of many plants. Because seeds have evolved to disperse far and wide, either by wind or carried by insects, even excreted by mammals (hello fruit), they are some of the most resistant biological things in the world. They can stay dormant for very long periods of time, and be used to start a plant culture at a later point. Hence, they are a useful ex-situ plant conservation practice.
The main issue with ex-situ conservation is that it neglects the environment. Animals may be sheltered away from the natural environment they evolved in, but unfortunately this means they will no longer be able to survive and live in what would be their original environment.
Similarly, the environment is ever-changing, so unless the animals are there to experience it and adapt accordingly, their abilities would soon fail to match the pressures of a natural…