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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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Related in: MedlinePlus

Aboveground biomass of cereal crops (milky ripeness, Z71–75) and accompanying weeds along the soil pollution gradient.Visual zones of crop growth are defined as in Table 1.
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pone-0114290-g001: Aboveground biomass of cereal crops (milky ripeness, Z71–75) and accompanying weeds along the soil pollution gradient.Visual zones of crop growth are defined as in Table 1.

Mentions: The fluvial deposition of mining waste over arable fields caused a decrease in the total plant biomass (crop + weeds) along the transects matching the spatial gradient perpendicular to the water channel (Figure 1). While the increasing pollution load (indicated by the increasing soil Stot concentrations) caused a severe growth reduction of cereal crop, the weed biomass remained at higher levels than on the relatively unaffected (Stot<2 g kg−1) soils along the gradient (Figure 1). The floristic composition of weed assemblages (recorded over the 2-months survey period) significantly varied among all the a priori delineated zones of crop growth disorders (Table S1). The weed assemblages on the most-severely degraded soils (Zone 4) were clearly set apart and had the highest floristic homogeneity (Table 2); the analysis of species association further showed that, along the whole transect, the φ coefficient higher than +0.5 was only found in the most severely degraded soils, namely among the following species: Rumex acetosella, Agrostis capillaris, and Persicaria lapathifolia (see Cluster C1, Figure 2). The differentiation of weed vegetation along the soil gradient was chiefly achieved by a remarkable shift in dominance relations (species abundances), and not by a prominent presence/absence turnover. Of the total of 84 weed species recorded in the survey, 63% were present on both relatively undamaged calcareous soils of the Zone 1 and on the most severely altered acidic soils where substantial reduction of crop growth occurs in Zone 4 (Table S2).


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)

Aboveground biomass of cereal crops (milky ripeness, Z71–75) and accompanying weeds along the soil pollution gradient.Visual zones of crop growth are defined as in Table 1.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0114290-g001: Aboveground biomass of cereal crops (milky ripeness, Z71–75) and accompanying weeds along the soil pollution gradient.Visual zones of crop growth are defined as in Table 1.
Mentions: The fluvial deposition of mining waste over arable fields caused a decrease in the total plant biomass (crop + weeds) along the transects matching the spatial gradient perpendicular to the water channel (Figure 1). While the increasing pollution load (indicated by the increasing soil Stot concentrations) caused a severe growth reduction of cereal crop, the weed biomass remained at higher levels than on the relatively unaffected (Stot<2 g kg−1) soils along the gradient (Figure 1). The floristic composition of weed assemblages (recorded over the 2-months survey period) significantly varied among all the a priori delineated zones of crop growth disorders (Table S1). The weed assemblages on the most-severely degraded soils (Zone 4) were clearly set apart and had the highest floristic homogeneity (Table 2); the analysis of species association further showed that, along the whole transect, the φ coefficient higher than +0.5 was only found in the most severely degraded soils, namely among the following species: Rumex acetosella, Agrostis capillaris, and Persicaria lapathifolia (see Cluster C1, Figure 2). The differentiation of weed vegetation along the soil gradient was chiefly achieved by a remarkable shift in dominance relations (species abundances), and not by a prominent presence/absence turnover. Of the total of 84 weed species recorded in the survey, 63% were present on both relatively undamaged calcareous soils of the Zone 1 and on the most severely altered acidic soils where substantial reduction of crop growth occurs in Zone 4 (Table S2).

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