What is a key characteristic of a lichen in ecological terms?

A key characteristic of lichen is its ability to perform photosynthesis, which is facilitated by the photosynthetic partner, usually a green alga or cyanobacterium, living in a symbiotic relationship with a fungal component. This unique association allows lichen to convert sunlight into energy, effectively making them capable of producing their own food while also providing nutrients to the fungal partner. This characteristic enables lichens to thrive in a variety of environments, often in areas where few other organisms can survive, such as rocky surfaces and harsh climates.

In ecological terms, lichens play a crucial role in primary succession by colonizing bare substrates, contributing to soil formation, and facilitating the establishment of more complex plant communities over time. Their ability to absorb nutrients and moisture directly from the air, rather than the soil, allows them to flourish in nutrient-poor environments, further highlighting their adaptability and ecological significance.