Returning farmland to forests is important for the protection of ecological values. Eucommia ulmoides is considered to be a suitable species for reforestation in the hilly red soil region of southern China. The objective of this study was to investigate the relationship between the water supply and demand of an E. ulmoides plantation to provide insights into the feasibility of large-scale planting for ecological restoration and forest management activities in the hilly red soil region of southern China. With the measured precipitation, surface runoff and interflow and actual evapotranspiration (ETc) estimated by the modified P-M model, soil water storage (SWS) was estimated based on the water balance equation. Monthly variations of SWS were then compared with in situ measured SWS. The results showed that the estimated mean monthly water losses (the sum of the surface runoff, interflow and ETc) were 139.8 mm in a wet year and 120.0 mm in a dry year, while the measured mean monthly water input values (net precipitation) were 131.2 mm in a wet year and 70.8 mm in a dry year. Net soil water storage (Delta SWS) was negative in each month of the growing season in a dry year, but the soil water deficit was replenished during the following season. The model performance showed that the modified P-M model can be adapted to estimate the soil water storage in other forest catchments where no adequate in situ data are available. As a result of estimating the water balance and observing soil water storage in two different hydrological years, E. ulmoides is recommended as a suitable forest rehabilitation species in the study area, and a suitable plant region has been defined by the GIS technique based on the water balance model.
Eucommia tree (Eucommia ulmoides L.) plantations: The E. ulmoides plantation was established in 1989 at a planting rate of 2422 trees per hectare. The mean tree height and mean diameter at breast height were 9.7 m and 7.5 cm, respec- tively, in 2009. There was a (10 ± 2) % coverage of shrubs and a (25 ± 6) % coverage of some grass species, including Camellia oleifera, Dicranopteris pedata, Arte- misia annua, Flos lonicerae and Lonicera japonica.
|Climate change impacts||Effect of Nbs on CCI||Effect measures|
|Reduced water availability||Positive||Soil water storage value compared to bench marks of maximal field water-holding capacity (SWSf), 60 % of the maximal field water-holding capacity (60 % of SWSf) and wilting point soil water storage (SWSw)|
The experiments were conducted at the Ecological Benefit Monitoring Station of the Yangtze River Protection Forest, which is located in the Nu ̈’er’zhai catchment in Cili county (29°260 N, 111°130 E), Hunan Province, China