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Assembly processes under severe abiotic filtering: adaptation mechanisms of weed vegetation to the gradient of soil constraints.

Nikolic N, Böcker R, Kostic-Kravljanac L, Nikolic M - PLoS ONE (2014)

Bottom Line: We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale).The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves.The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio.

View Article: PubMed Central - PubMed

Affiliation: Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia.

ABSTRACT

Questions: Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response?

Location: Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate.

Methods: We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale).

Results: The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio.

Conclusion: Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations of species which are typically observed as a consequence of strong environmental filtering, as for instance on sites affected by industrial activities.

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The mass ratio of N:P in weed vegetation and cereal crops along the soil pollution gradient.Leaf N:P along the complex soil gradient indicated by the pollution load (a); leaf N:P along the decreasing plant available P concentrations in polluted soils (b); biomass N:P in weed vegetation as a function of soil N:P ratio (c). H - regulatory coefficient, slope of the linear trend line. Leaf N and P concentrations are weighted by the relative proportion of a species in total biomass per m2, sampled when crop was at milky ripeness phase (Z71–75).
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pone-0114290-g009: The mass ratio of N:P in weed vegetation and cereal crops along the soil pollution gradient.Leaf N:P along the complex soil gradient indicated by the pollution load (a); leaf N:P along the decreasing plant available P concentrations in polluted soils (b); biomass N:P in weed vegetation as a function of soil N:P ratio (c). H - regulatory coefficient, slope of the linear trend line. Leaf N and P concentrations are weighted by the relative proportion of a species in total biomass per m2, sampled when crop was at milky ripeness phase (Z71–75).

Mentions: Finally, the sustenance of weed growth (Figure 1), accompanied by the remarkable change in floristic composition of weed vegetation (Figures 2–5) was underpinned by the maintenance of the N:P ratio in the biomass of weeds along the soil pollution gradient, while this ratio had not been sustained in the crop biomass (Figure 9a). Moreover, the same pattern of change of the biomass N:P ratio between the weeds and the cereal crops was observed along the gradient of plant-available P in the polluted soils (Figure 9b). Figure 9c shows that the weed biomass N:P ratio was only very weakly influenced by the external supply of N and P (in the range of soil N:P values measured in this study). This was also indicated by a high value of the regulatory coefficient H of 10.8 (Figure 9c). The value of the regulatory coefficient H for cereal crops (wheat and barley) was much lower (1.56, not shown).


Assembly processes under severe abiotic filtering: adaptation mechanisms of weed vegetation to the gradient of soil constraints.

Nikolic N, Böcker R, Kostic-Kravljanac L, Nikolic M - PLoS ONE (2014)

The mass ratio of N:P in weed vegetation and cereal crops along the soil pollution gradient.Leaf N:P along the complex soil gradient indicated by the pollution load (a); leaf N:P along the decreasing plant available P concentrations in polluted soils (b); biomass N:P in weed vegetation as a function of soil N:P ratio (c). H - regulatory coefficient, slope of the linear trend line. Leaf N and P concentrations are weighted by the relative proportion of a species in total biomass per m2, sampled when crop was at milky ripeness phase (Z71–75).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256224&req=5

pone-0114290-g009: The mass ratio of N:P in weed vegetation and cereal crops along the soil pollution gradient.Leaf N:P along the complex soil gradient indicated by the pollution load (a); leaf N:P along the decreasing plant available P concentrations in polluted soils (b); biomass N:P in weed vegetation as a function of soil N:P ratio (c). H - regulatory coefficient, slope of the linear trend line. Leaf N and P concentrations are weighted by the relative proportion of a species in total biomass per m2, sampled when crop was at milky ripeness phase (Z71–75).
Mentions: Finally, the sustenance of weed growth (Figure 1), accompanied by the remarkable change in floristic composition of weed vegetation (Figures 2–5) was underpinned by the maintenance of the N:P ratio in the biomass of weeds along the soil pollution gradient, while this ratio had not been sustained in the crop biomass (Figure 9a). Moreover, the same pattern of change of the biomass N:P ratio between the weeds and the cereal crops was observed along the gradient of plant-available P in the polluted soils (Figure 9b). Figure 9c shows that the weed biomass N:P ratio was only very weakly influenced by the external supply of N and P (in the range of soil N:P values measured in this study). This was also indicated by a high value of the regulatory coefficient H of 10.8 (Figure 9c). The value of the regulatory coefficient H for cereal crops (wheat and barley) was much lower (1.56, not shown).

Bottom Line: We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale).The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves.The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio.

View Article: PubMed Central - PubMed

Affiliation: Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia.

ABSTRACT

Questions: Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response?

Location: Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate.

Methods: We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale).

Results: The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio.

Conclusion: Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations of species which are typically observed as a consequence of strong environmental filtering, as for instance on sites affected by industrial activities.

Show MeSH
Related in: MedlinePlus