The primary consideration is avoiding a monoculture. If you sit down and study which types of plants sequester the most carbon, and plant a forest comprised en

The primary consideration is avoiding a monoculture. If you sit down and study which types of plants sequester the most carbon, and plant a forest comprised entirely of that species, you run into a few problems: First, parasites tend to be much worse. Whichever parasite prefers that particular type of plant will have an enormous food supply and a subsequent population explosion, with dire consequences for the entire forest. As the plants die, they will release the carbon they've stored. Second, different plants prioritize pulling different resources out of the ground. There isn't a simple recipe of ax carbon dioxide, bx water, cx nitrogen, dx phosphorus etc = x kg carbon sequestered. Some species need more nitrogen, some need more phosphorus, some need more water etc. Different areas of the soil will have different concentrations of each resource the plants need. By having a diverse population, you will better utilize the soil's diverse resources. https://phys.org/news/2018-10-species-rich-forests-carbon-monocultures.html https://phys.org/news/2018-10-species-rich-forests-carbon-mo... DOI: 10.1126/science.aat6405 In the study, the monocultures they studied included monocultures of bamboo and eucalyptus, which are extremely productive monocultures. These plots were still less productive than diverse forests. You're correct about algae scrubbing carbon faster than forests, however algae to do not sequester appreciable amounts of carbon. It's released back into the environment nearly as quickly as it is removed. Trees, on the other hand, sequester lots of carbon in their trunks and root systems, so they are an important consideration with regards to anthropogenic climate change.