Biomass,energy and nutrient distribution in communities of the strand ecological protective circle, TADA, China

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·hm -2 and 525 91×10 9 J·hm -2 in tree shrub herb community, 28.11 t·hm -2 and 503 27×10 9 J·hm -2 in shrub community, 24 30 t·hm -2 and 355 68×10 9 J·hm -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·hm -2 shrub community 518 16 kg·hm -2 tree shrub herb community 499 49 kg·hm -2 shrub herb community 99 22?kg·hm -2 the primary community 28 34 kg·hm -2 .The pattern of elemental distributions were same as biomass and energy: tree shrub herb in tree shrub herb community, shrubherb in shrub herb community. But the percent of herb in the shrub herb community increased.