ECOLOGY AND CONSERVATION 259 



these symbiotic structures will be fully understood. It is urgently 

 important to the practice of forestry to know whether these mycor- 

 rhizas are of vital importance to forest trees or not. 



155. Landscape Gardening.— Ecology is as fundamental to land- 

 scape gardening as to forestry and crop -production. It is as essential 

 for the landscape gardener as for anyone else concerned with the 

 growing of plants to know the general ecological relations of each 

 species of plants with which he deals. Furthermore, it is essential 

 that he have a thorough training in the structure and development 

 of plant communities in order that he may make naturalistic plant- 

 ings intelligently. He should understand the significance of eco- 

 logical equivalents in order that he may vary the floristic composi- 

 tion of his plantings without sacrificing the optimum habitat condi- 

 tions for the plants. The symbiotic relations between ornamental 

 plants when planted in groups or in extensive communities is a field 

 about which we know surprisingly little. It is well known that plants 

 do influence one another, that some species get along well in the same 

 planting and others do not, but these facts have never been organized 

 or classified and the reasons for them are very obscure. This is, 

 therefore, another very fertile field for future investigation. This is 

 especially true of symbiotic relations below the surface of the soil, 

 that is, the interrelations of the root systems of ornamental plants. 



156. Ecology and Conservation.— Conservation may be defined 

 as the prevention of waste and it usually refers to preventage of 

 wastage of such natural resources as minerals, soil, water, and plants 

 and animals including man. The word conservation implies neither 

 use nor lack of use but it permits use so long as there is no wastage. 



Plant ecology is not concerned with the conservation of minerals 

 but it is intimately concerned with the conservation of soil, water, 

 and living things. The conservation of both soil and water is based 

 largely on the maintenance of a proper plant cover and it is neces- 

 sarv, therefore, for the conservationist in these fields to have an inti- 

 mate knowledge of the ecology of the plants concerned. The plant- 

 ing of shelter belts and other windbreaks for the prevention of soil 

 erosion by wind also depends for its success upon a knowledge of the 

 ecological requirements of the plants that are to be used. 



The conservation of wildlife has received an increasing amount of 

 attention during the past few years. Wildlife includes all native 

 species of both plants and animals. The conservation of wildlife, 

 therefore, includes the conservation of wild flowers as well as of 

 forests and grasslands and the conservation of non-game animals, 



