The transitional zone between two distinct communities is known as an ecotone. An ecotone is a boundary area where two different ecosystems or communities meet and interact. It is a transition zone characterized by a mixture of species and ecological processes from both adjacent communities. Ecotones can occur between any two ecosystems, such as between a forest and a grassland, a freshwater and a marine ecosystem, or even between different vegetation types within a single ecosystem.

Ecotones are dynamic and constantly changing due to the interactions between the two adjacent communities. They can vary in width, from a few meters to several kilometers, and their characteristics depend on factors such as climate, topography, and the specific communities involved.

Characteristics of Ecotones:
- Species Diversity: Ecotones often have higher species diversity compared to the adjacent communities since they support species from both ecosystems. This is because different species may have adapted to specific conditions in each community, and the ecotone provides a range of habitats.

- Edge Effects: Ecotones are subject to edge effects, which refer to the unique conditions and processes that occur at the boundaries of ecosystems. Edge effects can include changes in temperature, humidity, light availability, and the presence of specialized species that thrive in these transition areas.

- Ecological Processes: Ecotones are important for ecological processes such as nutrient cycling, energy flow, and the movement of organisms between ecosystems. They act as corridors, allowing species to disperse and migrate, and they facilitate the exchange of genetic material between populations.

- Succession: Ecotones can undergo ecological succession, where the composition and structure of the community change over time. As one community gradually replaces the other, the characteristics of the ecotone also change.

Importance of Ecotones:
- Biodiversity Conservation: Ecotones often support unique and specialized species that are adapted to the specific conditions found at the transition zone. Protecting ecotones is crucial for conserving biodiversity and ensuring the survival of these species.

- Ecological Resilience: Ecotones play a role in maintaining the resilience of ecosystems by providing buffer zones that can absorb disturbances and prevent the spread of disturbances from one community to another.

- Ecological Services: Ecotones provide various ecological services, such as water filtration, soil stabilization, and habitat connectivity. They contribute to the overall functioning and health of ecosystems.

In conclusion, ecotones are transitional zones between distinct communities where a mixture of species and ecological processes from both communities occur. They are dynamic and important for biodiversity conservation, ecological resilience, and the provision of ecological services.