Population dynamics of grass-forb complexes on a semidesert range and some demographic aspects of James rushpea (<i>Hoffmanseggia jamesii</i> Torr. and Gray)

TitlePopulation dynamics of grass-forb complexes on a semidesert range and some demographic aspects of James rushpea (Hoffmanseggia jamesii Torr. and Gray)
Publication TypeThesis
Year of Publication1981
AuthorsSuliman MMohamed
Number of Pages169
Date Published1981
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypePh.D. Dissertationpp
Call Number00328
Keywordsdemography, Hoffmanseggia, demography,grass-forb complexes, dissertation, dissertations, grass-forb complex,population dynamics, Hoffmanseggia,demography, plant,James rushpea,Hoffmanseggia, population dynamics,grass-forb, theses, thesis
AbstractDynamics of forbs and important grass species from 1915 to 1974 were investigated utilizing records from long-term charted quadrats on the Jornada Experimental Range, USDA, SEA-AR, in southern New Mexico. A short-term demographic study focusing on longevity and age-structure of the perennial forb, James rushpea (Hoffmanseggia jamesii), was also conducted using a technique for counting growth increments. Interesting results were obtained by the study of some demographic aspects of James rushpea. A maximum number of 9 growth increments was found for this species. A highly significant correlation (P<.001) was found between the number of growth increments and the cormlike base circumference (cm.). Age-structure of this species was described by two patterns: A J-shaped pattern on protected and highly disturbed sites, and an inverse J-shaped pattern on lightly grazed sites.