Tree lichens are a type of symbiotic organism that consists of a fungus and an alga or cyanobacterium living together. The fungus provides structure and protection, while the alga or cyanobacterium photosynthesizes and provides nutrients. Tree lichens can be found growing on the bark or branches of trees and are important for ecosystem health as they contribute to nutrient cycling and provide habitat for various organisms. **

Mycorrhiza is a symbiotic association between a fungus and the roots of a plant. The fungus helps the plant absorb nutrients from the soil, especially phosphorus, in exchange for receiving sugars produced by the plant through photosynthesis. Lichens, on the other hand, are a symbiotic relationship between a fungus and either algae or cyanobacteria. The fungus provides structure and protection, while the algae or cyanobacteria provide food through photosynthesis. Both mycorrhiza and lichens play important roles in nutrient cycling and ecosystem health. **

Lichens are not harmful to trees. In fact, they are a symbiotic relationship between fungi and algae or cyanobacteria that can actually benefit trees by providing nutrients and aiding in the breakdown of organic matter. While lichens can sometimes be found on stressed or dying trees, they are not the cause of the tree's decline but rather take advantage of the tree's weakened state. Overall, lichens are not harmful to trees and are a natural part of the ecosystem. **

No, cacti do not have lichens. Lichens are a symbiotic organism composed of a fungus and algae or cyanobacteria, while cacti are a type of succulent plant. Lichens are often found growing on rocks, trees, or other surfaces, but not on cacti. **

The concept of harmony is most closely related to the interaction of different notes and chords in music. Harmony refers to the simultaneous sounding of different pitches to create a pleasing sound. While rhythm and melody are also important elements in music, harmony specifically deals with the vertical aspect of music, focusing on how notes and chords interact with each other. Therefore, harmony belongs more to the realm of harmony itself. **

Rhythm refers to the pattern of sounds and silences in music, creating a sense of movement and pulse. Melody is the sequence of musical notes that are perceived as a single entity, often the most recognizable and memorable part of a song. Harmony involves the combination of different musical notes played or sung simultaneously, creating a pleasing sound. While rhythm provides the framework for the timing of music, melody is the main tune, and harmony adds depth and richness to the overall sound. **

Lichens in symbiosis have several benefits. They can survive in harsh environments where neither fungi nor algae could survive alone. Lichens can also act as bioindicators of air quality, as they are sensitive to pollution and changes in their environment. Additionally, lichens play a role in soil formation and nutrient cycling, contributing to ecosystem health and stability. **

An improvising melody instrument is a musical instrument that is capable of playing improvised melodies, such as the saxophone, trumpet, or guitar. These instruments are able to create spontaneous and unique melodies during a musical performance. An accompanying rhythm group consists of instruments that provide the rhythmic foundation for the music, such as drums, bass, and keyboard. Together, the improvising melody instrument and the accompanying rhythm group work together to create a dynamic and cohesive musical experience, with the melody instrument taking the lead and the rhythm group providing the underlying groove and support. **