Measured Sap Flow and Estimated Evapotranspiration of Tropical Eucalyptus urophylla Plantations in South China

During the period of September 12, 1999 to September 24, 2000, we measured sap flow ofeucalyptus (Euca/yptus urophylla S.T. Blake) plantations using heat pulse technique, and the relevantenvironmental vaiables, such as soil evaporation and canopy interception, etc, at Hetou and Jijia sites,Leizhou Peninsula, Guangdong Province. Based on the measurements of sap flow and estimates ofevapotranspiration, the following can be concluded: (1) the maximum of diurnal xylem sap flux density (SFD)at Hetou, where covered with coarse-textured soils formed on Quaternary sediments, was almost twice ofthat at Jijia, where located on clay-rich soils derived from basalt; (2) SFD was highly correlated to watervapor pressure deficit (VPD) of ambient air near the canopy layer, (3) the correlation between SFD and airtemperature also depends on soil properties and soil water potential; (4) the relative differences betweenmeasured and modeled evapotranspiration were small, being 5.26% at Hetou and 6.14% at Jijia; (5) theplantation transpiration accounted for 62.2% and 51.3% of the evapotranspiration at Hetou and Jijia,respectively; and (6) the averaged SFD per unit leaf area (ASPULA) was a good index to estimate theamount of water consumption of tree species.

Sap flow response of Eucaylyptus （Eucalyptus urophyila） to environmental stress in South China

Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R^2=0.76, P=0.01 at Hetou and R^2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X^3+15147X^2-1250.7X+2278.4 (R^2=0.68; P=0.01) at Hetou and Y=-101.67X^3-1.65X^2-376.4X+1914.8(R^2=0.40, P=0.05) at Jijia, where Ywas daily SFD, Xwas daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2kPa, within which daily SFD varied from 540±70L/(m^2·d) to 4739±115L/(m^2·d) at Hetou site, from 397±26L/(m^2·d) to 3414±191L/(m^2·d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity (<30%) and slightly lower under high relative humidity (>80%) compared with those at the Jijia site; (3) The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18±2.7 and 2±1MJ/(m^2·d), 669 and 0J/(cm^2·h) during the observation period.

Some Useful Wild Macrofungi from Liuxihe National Forest Park,Guangzhou,China

Abstract: Forty species of Basidiomycota from 21 genera in 15 families, collected from Liuxihe National Forest Park, Guangzhou, China, have values for use by local people. More than half of the species collected are edible, and some (Lactarius deliciosus, Boletus spp.) are gathered for commercial consumption in South China. Ten species have medicinal properties, and include Dictyophora, Ganoderma, Pisolithus and Scleroderma. Over 60% species (26 taxa) are ectomycorrhizal involving 12 edible fungi. The most abundant families were the Amanitaceae, Boletaceae and Sclerodermataceae, which form important ectomycorrhizal associations with coniferous and mixed broad-leafed trees in the Park. Prospective uses of these macrofungi are discussed.

Gender Issues in Household-based Bamboo Industries:A Case Study of Two Villages in Xinping County,Yunnan Province of China

A qualitative gender assessment of household-based bamboo industries was conducted in Zhuyuan and Lagadi villages in Laochang Township, Xinping County in Southwest China's Yunnan Province. Results showed that both women and men were actively involved in the production and marketing of bamboo products in the two villages. There were gender differences in bamboo-based rural industries that were closely associated with the ethnic habits, traditional norms of the rural society, the differences of educational levels that women and men achieved, and the gender blind-spots in the enforcement of laws and policies. It is evident that women were “equal” partners in the production of bamboo products, but “unequal” when the rights of access to and control over resources and personal independence are concerned. Suggestions are made to achieve a gender-balanced production system of bamboo products in rural areas of bamboo producing counties in Yunnan Province, China.

Biomass and Energy of Casuarina equisetiofolia Plantations in Southeast Coast of China

The biomass and energy production of Casuarina equisetifolia plantations aged 14 were studied in Huian County, Fujian Province, Southeast of China. The standing crop biomass was 152.60 t/ha, in which the biomass of bole was 67.02 t/ha, accounting for 43.94 % of the total, while that of root was 36.83 t/ha and 24.14 %, respectively. Net primary productivity was 10.17t/(ha.a).The range of gross caloric of components was 19.29～20.23 kJ/g, with the average 19.70 kJ/g. The standing crop energy was 2 987×10^6 kJ/ha. Net energy production was 196.8×10^6 kJ/ha, while solar energy conversion efficiency was 0.90%.