Abstract: The standing biomass and energy of four communities in the strand ecological protective circle in Tianjin Economic and Technological Development Area(TADA), China, were 28.55 t穐m^-2 and 525.91?10⁹ J穐m^-2 in tree shrub herb community, 28.11 t穐m^-2 and 503.27?10⁹ J穐m^-2 in shrub community, 24.30 t穐m^-2 and 355.68?10⁹ J穐m^-2 in herb community. They were higher than those in primary community. The distribution of biomass and energy in the tree shrub herb community were tree >shrub >herb, and shrub> herb in shrub herb community. The rank order of total standing crop of N, P, K, Na, Ca, Mg and Cl were herb community 2481.87 kg穐m^-2 >shrub community 518.16 kg穐m^-2 >tree shrub herb community 499 49 kg穐m^-2 >shrub herb community 99.22kg穐m^-2 >the primary community 28.34 kg穐m^-2 .The pattern of elemental distributions were same as biomass and energy: tree > shrub > herb in tree shrub herb community, shrub>herb in shrub herb community. But the percent of herb in the shrub herb community increased.

Key words: Weed community, Tillage method, Herbicide, Cornfield, Diversity