|Title||Methods of studying shrubby plants in relation to grazing|
|Publication Type||Journal Article|
|Year of Publication||1930|
|Keywords||JRN, shrubby plants|
It is common knowledge that continued overgrazing, such as is prevalent on the semidesert ranges of the Southwest, reduces the stand of desirable forage plants and leads to serious range depletion, especially during periods of drought. Such depletion allows erosion of the valuable topsoil layer and permits rainfall to run off in torrential floods with consequent damage to agricultural lands and urban property in the valleys. Native vegetation, therefore, plays an important role, not only in range conservationand improvement, but also in the protection of watersheds. This report is concerned with the vegetation and especially with the plant succession found on various types of clay soils occupying nearly 32,000 acres, or approximately one-sixth, of LL the entire Jornada Experimental Range and covering large areas in the southern portions of Arizona and New Mexico and the western part of Texas. Different areas of the soils studied present everystage of vegetative development from complete denudation to the climax of dense tobosa grass (Hilari c nautici). The denuded and seriously depleted areas present the most critical problems on range units, and their restoration is of the greatest importance. They are practically worthless for grazing and furnish no watershed protection. They also complicate management of the whole unit and are factors in the silt accumulation of flood waters. They support Drymaria holosteoidesandAstragalus spp., poisonous plants which cause serious losses of livestock. Sampson (6) 3 has shown that the grazing value of the vegetative cover is determined essentially by the stage of succession. Plant succession was studied on the range to determine how natural revegetation occurs and the grazing values produced by each stage of development.