| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Emsens, Willem-Jan, et al.
(author)
-
Competition for light as a bottleneck for endangered fen species : An introduction experiment
- 2018
-
In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 220, s. 76-83
-
Journal article (peer-reviewed)abstract
- Many endangered plant species remain absent in rewetted, previously drained fens. We performed a 3-year introduction experiment with endangered fen species (9 Carex- and 6 bryophyte species) in 4 hydrologically restored fens to investigate which factors hamper establishment and survival. Carex species were introduced as adults and seedlings, mosses as gametophytes. Introductions were done on (initially) bare soil, which allowed us to exclude excessive competition for light during the first year. First year survival of the transplants was high in all fens (mean survival = 96%), indicating that there were no direct abiotic constraints on establishment. However, survival analysis revealed that a decrease in relative light intensity (RLI) at the soil surface during consecutive years (indicating an increase in biotic competition for light) drove high mortality rates in most species. As a result, overall final survival was lowest in the two most productive (low light) fens (mean survival = 38%), while most transplants persisted in the two less productive (high light) fens (mean survival = 79%). Taller and faster-growing Carex species were able to outgrow light limitation near the soil surface, and thus had a higher overall survivability than smaller and slower-growing species. Light limitation also drove the loss of 5 out of 6 bryophyte species. We conclude that both dispersal limitation and asymmetric competition for light may explain the lack and loss of small and endangered plant species in rewetted fens. A minimum empirical threshold of c. 30% relative light intensity near the soil surface is required for successful introduction.
|
|
| 5. |
|
|
| 6. |
- Larsson, Maja, et al.
(author)
-
Vanadium bioavailability in soils amended with blast furnace slag
- 2015
-
In: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 296, s. 158-165
-
Journal article (peer-reviewed)abstract
- Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800mgVkg-1) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.
|
|
