Plant ecology a single growth-limiting resource, perhaps for light in agricultural systems with sufficient water and nutrients, or in dense stands of marsh vegetation, but in many natural ecosystems plants may be colimited by several resources, e.g. light, phosphorus and nitrogen at the same time. Therefore, there are many details that remain to be uncovered, particularly the kinds of competition that arise in natural plant communities, the specific resource(s), the relative importance of different resources, and the role of other factors like stress or disturbance in regulating the importance of competition. Mutualism is defined as an interaction "between two species or individuals
Artificial cartilage field. Artificial cartilage is a new research topic and much is still unknown. There is a lot of unknown factors involving ASCPs and more studies need to be conducted to make a more supported conclusion about the regenerative functions of ASCPs. Additionally, growth factors have been thoroughly evaluated, however specific combinations still need to be studied further in order to more effectively generate a tissue that can mimic the properties of natural cartilage. Artificial cartilage Artificial cartilage is a synthetic material made of hydrogels or polymers that aims to mimic the functional properties of natural cartilage in the human body.