The topics ordered from broadest to narrowest are: Terrestrial ecosystems, Deserts, Subtropical desert, Vegetation found in the Mojave Desert, The Joshua tree and the creosote bush.
- The broadest topic is 'Terrestrial ecosystems' which include various biomes.
- The next topic is 'Deserts' which is narrower than terrestrial ecosystems.
- Within deserts, we have 'Subtropical desert' which further narrows down the topic.
- The narrowest topic is 'Vegetation found in the Mojave Desert'.
- Specific plants like the Joshua tree and the creosote bush are examples of the vegetation found in the Mojave Desert, and they are the narrowest topic within the Mojave Desert.
The probable question may be:
What is the hierarchical organization of topics from broadest to narrowest, starting with 'Terrestrial ecosystems' and ending with specific vegetation such as the Joshua tree and the creosote bush in the Mojave Desert?