title: A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.
abstract: Major reforestation programs have been initiated on hillsides prone to erosion and landslides in China, but no framework exists to guide managers in the choice of plant species. We developed such a framework based on the suitability of given plant traits for fixing soil on steep slopes in western Yunnan, China. We examined the utility of 55 native and exotic species with regard to the services they provided. We then chose nine species differing in life form. Plant root system architecture, root mechanical and physiological traits were then measured at two adjacent field sites. One site was highly unstable, with severe soil slippage and erosion. The second site had been replanted 8 years previously and appeared to be physically stable. How root traits differed between sites, season, depth in soil and distance from the plant stem were determined. Root system morphology was analysed by considering architectural traits (root angle, depth, diameter and volume) both up- and downslope. Significant differences between all factors were found, depending on species. We estimated the most useful architectural and mechanical traits for physically fixing soil in place. We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity. Scores were assigned to each species based on traits. No one species possessed a suite of highly desirable traits, therefore mixtures of species should be used on vulnerable slopes. We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.
authors.affiliation: AgroParis Tech, UMR AMAP, Montpellier, France.
authors.forename: Murielle
authors.initials: M
authors.lastname: Ghestem
authors.affiliation: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, China.
authors.forename: Kunfang
authors.initials: K
authors.lastname: Cao
authors.affiliation: Kunming Institute of Botany, Kunming, Yunnan, China.
authors.forename: Wenzhang
authors.initials: W
authors.lastname: Ma
authors.affiliation: CNRS, UMR AMAP, Montpellier, France.
authors.forename: Nick
authors.initials: N
authors.lastname: Rowe
authors.affiliation: CNRS, UMR CEFE, Montpellier, France.
authors.forename: Raphaëlle
authors.initials: R
authors.lastname: Leclerc
authors.affiliation: AgroParisTech, Centre de Nancy, Nancy, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Gadenne
authors.affiliation: INRA, UMR AMAP, Montpellier, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Stokes
mesh_terms: D002681:China; D017753:Ecosystem; D065928:Forests; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000033:anatomy & histology / Q000502:physiology; D010944:Plants / Q000033:anatomy & histology*; D012987:Soil / Q000737:chemistry*; D013045:Species Specificity
chemical_list: D012987:Soil
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