Final answer:
Ecological restoration is the field that develops methods to restore degraded areas to their natural state, and it is a part of conservation biology, which is multidisciplinary and focuses on restoring habitats and ecosystems.
Step-by-step explanation:
The new and expanding field that uses ecological principles to develop methods to restore degraded areas to their natural state is called Ecological Restoration. This field is a part of conservation biology, which employs a wide array of scientific and mathematical tools to assess and restore biodiversity. Conservation biology is a multidisciplinary science that has seen growth and transformation, incorporating methods from genetics, earth systems science, and climatology, among others.
Ecological restoration involves restoring habitats and ecosystems to a semblance of their previous ecological function. This can include rewilding, which is an effort to increase resilience and biodiversity by reconnecting habitats. The ultimate aim is to restore ecosystems to a state that resembles their condition prior to degradation, often through methods like reserve design, invasive species management, and monitoring biodiversity.