Grass supports the dynamics of soil systems IT SEEMS to be the ‘‘in’’ thing currently to knock what used to be considered ‘‘motherhood’’ institutions and ac- tivities. For example, some environmentalists have sug- gested that the home lawn is an institution that has outliv- ed its usefulness. According to the Canadian Garden Council nothing. could be further from the truth. On the other hand, the planting of trees has been promoted by many as if it’s a new concept. Some environmentalists see tree- planting as a solution to all of our world environment problems ~— particularly global warming due to increased amounts of carbon diox- ide in the air. Planting trees mzy be new to these people, but it has been promoted by gardeners and the garden industry for decades — in fact, for at least a century. As it happens, neither grass nor trees are major sources of at- mospheric oxygen (to help counteract the growing amounts .of carbon dioxide), although what oxygen is produced in their leaves, as a by-product of photosyn- thesis, is certainly worth having. The greatest benefits of grass and trees come from their protec- tion and enrichment of the soil in, which they grow. All. carbon fixed in’ organic matter (biomass) and not submersed in water is, in time, subject to oxidation, and thus the "formation of carbon dioxide. This .may -be in an accelerated form, -such as burning, or in a slow :form, such as biodegradation of plant materials (rotting in a com- ‘post pile, for example). In this latter instance, microorganisms ‘are involved in the processes _ which ultimately will form humus , that enriches our soils. > With’ woody plants such as . trees, much carbon accumulates in wood that may maintain its struc- tural integrity for years before the .. plant dies and decomposes, or is _j harvested for wood used in con- ’