Cities are not considered natural ecosystems as they are built and maintained by humans.

Biodiversity refers to the variety of life forms, including plants, animals, and microorganisms, as well as the genetic variation within each species.

Tropical rainforests are characterized by their tall trees, dense understory, and incredibly high levels of biodiversity.

Climate, which encompasses temperature, precipitation, and sunlight, is the primary factor that determines the distribution of ecosystems on Earth.

Deserts are characterized by low precipitation, extreme temperatures, and sparse vegetation, but they typically have low humidity.

Adaptation refers to the process by which organisms acquire traits that improve their survival and reproduction in a particular environment.

While honeybees are important pollinators, they are not typically considered keystone species, which have a disproportionately large impact on their ecosystem relative to their abundance.

Resilience refers to the ability of an ecosystem to recover from disturbances and maintain its structure and function.

All of the options listed are threats to biodiversity.

Conservation refers to the management of natural resources to ensure their long-term availability and sustainability.

Introducing invasive species is not a conservation strategy, as it can harm native ecosystems and biodiversity.

Ecology is the scientific study of the interactions between organisms and their environment, including the structure and function of ecosystems.

Manufacturing is not an ecosystem service, as it is a human activity that does not directly benefit ecosystems.

Restoration refers to the process of repairing damaged ecosystems and restoring them to a more natural state.

Deserts are not typically considered biodiversity hotspots, as they are characterized by low species richness compared to other ecosystems.