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A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.

Ghestem M, Cao K, Ma W, Rowe N, Leclerc R, Gadenne C, Stokes A - PLoS ONE (2014)

Bottom Line: Significant differences between all factors were found, depending on species.We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity.We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.

View Article: PubMed Central - PubMed

Affiliation: AgroParis Tech, UMR AMAP, Montpellier, France.

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.

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Root density of all species and proportion of coarse and fine roots.(a) Root area ratio (RAR) of all species. Negative values of RAR represent downslope orientation; (b) Coarse and fine roots area ratio (RAR).
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pone-0095876-g006: Root density of all species and proportion of coarse and fine roots.(a) Root area ratio (RAR) of all species. Negative values of RAR represent downslope orientation; (b) Coarse and fine roots area ratio (RAR).

Mentions: RAR was species-dependant (H8,100 = 50.25; P<0.001; Figure 6a), with A. americana having significantly higher RAR than all other species. When A. americana was removed from the analysis, the species effect was still significant (H7,86 = 38.78; P<0.001): F. tikoua, J. curcas, B. championii, P. stricta and R. chinensis all possessed significantly higher RAR than A. codonocephala, A. hispidus and C. anomala (Figure 6a). B. championii, P. stricta and R. chinensis all produced roots at depth of >50 cm.


A framework for identifying plant species to be used as 'ecological engineers' for fixing soil on unstable slopes.

Ghestem M, Cao K, Ma W, Rowe N, Leclerc R, Gadenne C, Stokes A - PLoS ONE (2014)

Root density of all species and proportion of coarse and fine roots.(a) Root area ratio (RAR) of all species. Negative values of RAR represent downslope orientation; (b) Coarse and fine roots area ratio (RAR).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126646&req=5

pone-0095876-g006: Root density of all species and proportion of coarse and fine roots.(a) Root area ratio (RAR) of all species. Negative values of RAR represent downslope orientation; (b) Coarse and fine roots area ratio (RAR).
Mentions: RAR was species-dependant (H8,100 = 50.25; P<0.001; Figure 6a), with A. americana having significantly higher RAR than all other species. When A. americana was removed from the analysis, the species effect was still significant (H7,86 = 38.78; P<0.001): F. tikoua, J. curcas, B. championii, P. stricta and R. chinensis all possessed significantly higher RAR than A. codonocephala, A. hispidus and C. anomala (Figure 6a). B. championii, P. stricta and R. chinensis all produced roots at depth of >50 cm.

Bottom Line: Significant differences between all factors were found, depending on species.We then combined these results with those concerning root physiological traits, which were used as a proxy for root metabolic activity.We also propose a conceptual model describing how to position plants on an unstable site, based on root system traits.

View Article: PubMed Central - PubMed

Affiliation: AgroParis Tech, UMR AMAP, Montpellier, France.

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.

Show MeSH
Related in: MedlinePlus