Academic Freedom of the Faculty Member as Citizen

Thomas I. Emerson, David Haber
1963 Law & Contemporary Problems  
The composition and amount of the soil seed bank will change by Management factor ecosystems, Understanding these changes can help explain vegetation change is affect resuscitation. For this purpose, this study examines the changes resulting from corrective action of planet nonnative Atriplex canescens plant. Sampling in the three masses planting of Atriplex two, ten and twenty years in terms of environmental factors, and the homogeneity of similarities in places under the shrubs, between the
more » ... rubs, between the shrubs were taken. In addition, a control area adjacent to each site where the plant had not been done to compare the sampling was done. In total 54 soil samples from the soil surface depth with approach Random -systematic before the start of the growing season Samples were taken and then soil samples were transferred to the greenhouse for seed germination. Data were collected species of grown and rank-abundance plot diagram For of the sites studied, traced and also Frequency distribution models in cluded geometric, log-series, Broken-stick and Log-normal On the data›s Were fitted and Was selected The best model distribution. Also, Jaccard similarity index and divider clustering for different sites were calculated and plotted. The results of rank-abundance plot diagram Studied Places shows the curve from control plots all sites have steeper from plot curve under and between shrubs has so species diversity of seed bank control Site is lower. Broken-stick model and Log-Normal conform to the treatment site 20, which represents a stable community with high diversity and evenness. The results also showed Jaccard similarity index the -10year-old site under shrub and between shrubs are maximum Likelihood (0.75) Soil seed banks and also in -20years-old sites this similarity reaches its maximum. The overall results indicate that restoration of rangeland by planting Atriplex cause increase the species diversity of soil seed bank in study area the of course the amount this changes depends on duration of its implementation.
doi:10.2307/1190644 fatcat:otnqgy44zbfobhqbhk2wi3amhu