Effects of harvesting on the biomass of plant species

Abstract

In South China's Guangdong Province, like other parts of the developing world, most vegetation undergo heavy harvesting for domestic fuel. A few villagers in Hong Kong still collect biomass from hillsides for cooking. Two experiments in Hong Kong and two observations in Guangdong were conducted in grasslands and shrublands to examine the effects of three experimental harvesting frequencies on the biomass of dominant species and to observe the impacts of long-term practical harvesting on the biomass of dominant species. Over 2 years of harvesting experiment, the range of the aboveground biomass of six individual dominant species changed from 26–154 g m −2 to 6–135 g m −2 on Hong Kong experimental site 1 and from 14–875 g m −2 to 3–207 g m −2 on Hong Kong experimental site 2. Biyearly harvesting did not significantly reduce the aboveground biomass of dominant species, but yearly and half-yearly harvesting did so. The aboveground biomass in the half-yearly harvested treatment was higher in August than in February. The uncut hillsides gave higher aboveground biomass than the often-cut hillsides in Guangdong. The six dominant species together at the Hong Kong and Guangdong sites contributed over 75% to the aboveground biomass of the vegetation. The plant species scarcely changed their percentage biomass contributions with seasons.