Studies on the Resources and Eco-physiological Characteristics of Antirhea chinensis in Guangdong
In order to understand the resources and eco-physiological characteristics of Antirhea chinensis,the tran-sect method was used to investigate the resources of A.chinensis in 67 nature reserves in Guangdong,and the net photosynthetic rate,transpiration rate,diurnal variation of environmental factors,chlorogreenness,carbon and nitro-gen content of plants and habitats,and stable carbon and nitrogen isotope composition of A.chinensis were deter-mined.The results showed that 280 individuals of A.chinensis were recorded in 123 habitats of 10 protected areas,among which Dangan Island and Erzhou Island in Zhuhai,Huangyangshan and Guogaidong in Doumen,and Shang-chuan Island in Taishan were the new distribution points of A.chinensis,with the largest number of 148 plants at 62 sites in Sanzhoutian of Shenzhen.The carbon and nitrogen contents of A.chinensis plants were significantly higher than those in habitat soil and rock.The ratios of δ13C and δ15N in leaves were-34.51‰ and-0.94‰,respective-ly,which were significantly lower or higher than the corresponding values of roots and stems.The chlorogreenness(SPADvalue)of normal green leaves was 41.0,which was significantly higher than that of yellow leaves(17.6).At the day of the determination,the average net photosynthetic rate was 5.55 μmol·m-2·s-1.The average transpi-ration rate was 0.59 mmol·m-2·s-1.The average water use efficiency was 9.13,indicating that A.chinensis main-tained normal physiological activities with lower net photosynthetic rate and transpiration rate but higher water use efficiency under the condition of relatively low air temperature and relative atmospheric humidity in winter.
Antirhea chinensisstable carbon and nitrogen isotopechlorogreenness(SPAD)photosynthetic ratetranspiration ratewater use efficiency