Analysis of the soil water balance for large-scale reforestation with Eucommia ulmoides in the hilly red soil region of southern China

Huang, Z. G. X. et al., 2016. Regional Environmental Change

Original research (primary data)
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Abstract

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.

Case studies

Basic information

  • Case ID: INT-217-1
  • Intervention type: Created habitats
  • Intervention description:

    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.

  • Landscape/sea scape ecosystem management: No
  • 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)
  • Approach implemented in the field: Yes
  • Specific location:

    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

  • Country: China
  • Habitat/Biome type: Created forest |
  • Issue specific term: Not applicable

Evidence

  • Notes on intervention effectivness: Effectiveness determined by comparing the amount of soil water content to a benchmark needed to sustain the plantation – therefore if at or above the benchmark then effective “Apparently, the observed monthly soil water storage was higher than 60 % of SWSf and SWSw during the whole growing stage. That is, the soil water storage in a dry year could meet the water con- sumption by the E. ulmoides plantation as well as in a wet year.”
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: No
  • Impacts for the ecosystem: Not reported
  • Ecosystem measures:
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: No
  • Experimental evalution done: Not applicable
  • Non-experimental evalution done: Empirical case study
  • Study is systematic: