香港鸭嘴草+野古草+金茅群落的生物量和第一性生产力

Phytomass and Net Primary Productivity of the Grassland in Hong Kong.

香港鸭嘴草＋野古草＋金茅群落的生物量和第一性生产力管东生（中山大学环境科学系，广州５１０２７５）ＰｈｙｔｏｍａｓａｎｄＮｅｔＰｒｉｍａｒｙＰｒｏｄｕｃｔｉｖｉｔｙｏｆｔｈｅＧｒａｓｌａｎｄｉｎＨｏｎｇＫｏｎｇ．ＧｕａｎＤｏｎｇｓｈｅｎｇ（Ｄｅｐａｒ...

hytomass and net primary production (NPP) of the grassland consisting of Ischaemum spp.+ Arundinella setosa + Eulalia speciosa community have been estimated by harvest method.The results showed that:(1)Above ground phytomass including standing dead matter and litter,was 589 g·m -2 ,of which living phytomass,standing dead matter and litter comprised 63%,26% and 11% respectively. Under ground phytomass was 475 g·m -2 ;(2)Above-ground live phytomass showed a significant seasonal pattern.The grasses sprouted in early spring and their phytomass increased steadily until September,then the live phytomass began to decline;(3) The above-ground current phytomass was not obviously related to monthly rainfall but related to temperature,evaporation and bright sunshine in the study area with plentiful rainfall;(4)Estimated by aggregate peak phytomass(live+dead),470g·m -2 ·yr -1 was considered as the net above-ground primary production (NAPP) of the grasses. The NAPP of the grasses estimated by aggregated peak phytomass(live+dead) was 36% higher than peak phytomass (live only) and 27% higher than aggregated peak phytomass (live only).NPP of the grassland was 763g·m -2 .