Biodiversity and Biomass on Abandoned Lands in Loess Plateau in North Shaanxi of China.

This paper takes Hejiaou river region as the research object by time-space mutual substitution method to probe biodiversity and biomass of 29 sample abandoned lands. The results show that: (1) Biodiversity of vegetation changes along with the abandoned age of biomass. Simpson index, Shannon-Weiner index, Margalef richness index and Pielou evenness index reach the maximum when the abandoned age is 10 or 11 years. And biomass increases along with the growth of the abandoned age. (2) Biodiversity and biomass of different site types vary from one to another. For Simpson index, sunny slope>cloudy slope>semi-cloudy slope>semi-sunny slope. For Shannon-Weiner index and Pielou evenness index, sunny slope>cloudy slope>semi-sunny slope>semi-cloudy slope. For Margalef richness index, semi-sunny slope>semi-cloudy slope>cloudy slope>sunny slope. For biomass, cloudy slope>semi-cloudy slope>sunny slope>semi-sunny slope. The difference among Simpson index, Margalef richness index and Pielou evenness index is not apparent in terms of site type. But sunny slope and semi-cloudy slope of Shannon-Weiner index are distinguished from each other (p<0.05). And there is a great difference among biomass of four site types (p<0.05). (3) Simpson index, Shannon-Weiner index, Margalef richness index and Pielou evenness index have no linear correlation with biomass, indicating that biodiversity and biomass are not correlated. [ABSTRACT FROM AUTHOR]