This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications mini...This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.展开更多
The objective of this paper is to test three main hypotheses in grassland succession by using 17-year observational data： （i） species diversity increases during early pioneering stages; （ii） the similarity rate o...The objective of this paper is to test three main hypotheses in grassland succession by using 17-year observational data： （i） species diversity increases during early pioneering stages; （ii） the similarity rate of experimental plant communities increases along with the succession process （dissimilarity rate among plots decrease with succession age）;and （i i） plant communities in different ifeld plots converge towards a quite similar composition during the initial years of succession. Results draw from quantitative statistics which including： the general development of plant communities, Shannon’s H and E, Bray-Curtis dissimilarity and community turnover, indicate that after first 5 years of succession, species diversity rapidly becomes alike among all the plots. The average species number in al plots increased constantly from 8 to 25. Meanwhile, the total species number for al plots increased constantly from 23 to 55, accompanied by a steady decrease in Standard Deviation （S.D.） from 4.6 to 0.3. Additional y, dissimilarity of al stands in species composition decreased, indicating a clear trend towards a rapid convergence in species richness and composition. The most important effect of cessation of weeding is that the artiifcial diversity gradient from 1 to 16 species gets diminished by immigration in species poor plots.展开更多
文摘This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.
基金Chinese Scholarship Council(CSC)(201206390030)the China Bureau of Foreign Experts,the Ministry of Education of China(111 Program,Grant 2008-B08044)"985 Programme"of Minzu University of China(Grant Number MUC98504-14,MUC98507-08)
文摘The objective of this paper is to test three main hypotheses in grassland succession by using 17-year observational data： （i） species diversity increases during early pioneering stages; （ii） the similarity rate of experimental plant communities increases along with the succession process （dissimilarity rate among plots decrease with succession age）;and （i i） plant communities in different ifeld plots converge towards a quite similar composition during the initial years of succession. Results draw from quantitative statistics which including： the general development of plant communities, Shannon’s H and E, Bray-Curtis dissimilarity and community turnover, indicate that after first 5 years of succession, species diversity rapidly becomes alike among all the plots. The average species number in al plots increased constantly from 8 to 25. Meanwhile, the total species number for al plots increased constantly from 23 to 55, accompanied by a steady decrease in Standard Deviation （S.D.） from 4.6 to 0.3. Additional y, dissimilarity of al stands in species composition decreased, indicating a clear trend towards a rapid convergence in species richness and composition. The most important effect of cessation of weeding is that the artiifcial diversity gradient from 1 to 16 species gets diminished by immigration in species poor plots.
