| 1. |
- Pärn, J., et al.
(författare)
-
Nitrogen-rich organic soils under warm well-drained conditions are global nitrous oxide emission hotspots
- 2018
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3 -), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3 - and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3 --N kg-1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3 - explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.
|
|
| 2. |
- Tedersoo, Leho, et al.
(författare)
-
Global patterns in endemicity and vulnerability of soil fungi.
- 2022
-
Ingår i: Global change biology. - : Wiley. - 1365-2486 .- 1354-1013. ; 28:22, s. 6696-6710
-
Tidskriftsartikel (refereegranskat)abstract
- Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms.
|
|
| 3. |
- Choudhury, Maidul I., et al.
(författare)
-
Application of Floating Beds Constructed with Woodchips for Nitrate Removal and Plant Growth in Wetlands
- 2024
-
Ingår i: Water, Air and Soil Pollution. - : Springer. - 0049-6979 .- 1573-2932. ; 235:8
-
Tidskriftsartikel (refereegranskat)abstract
- Constructed wetlands and constructed floating wetlands are widely used for nitrogen (N) removal from surface water to combat eutrophication in freshwaters. Two main N removal pathways in freshwaters are plant biomass N uptake and denitrification, i.e. transformation of nitrate (NO3-) to nitrous oxide (N2O) or nitrogen gas (N2) by different microbes possessing nirK, nirS, nosZI, and nosZII genes. In this study, we tested woodchips-based floating beds (WFBs) as a nature-based and environment-friendly method to remove nitrate-nitrogen (NO3-N) from water. Moreover, we tested whether WFBs could support the growth of three selected plant species and the abundance of microbes on plant roots and woodchips as a proxy for WFBs' denitrification potential. We conducted a greenhouse experiment for 90 days and measured NO3-N removal rates from water in WFBs mesocosms during five sampling occasions. Plant biomass production, biomass N uptake, and plant morphology related to N uptake and abundance of denitrifying organisms were measured at the end of the experiment. NO3-N removal rates were 29.17 +/- 11.07, 28.18 +/- 12.62, 25.28 +/- 9.90, and 22.16 +/- 7.79 mg L-1 d-1 m-2 (mean +/- standard deviation) in Glyceria maxima, Juncus effusus, Filipendula ulmaria, and unplanted WFBs treatments, respectively for whole experimental period. N content in above- and belowground biomass of studied species ranged between 0.98 - 1.15 and 1.09 - 1.28 (% dry weight), respectively. Plant relative biomass production was 215 +/- 61, 67 +/- 18, and 7 +/- 17 (% dry weight) for G. maxima, J. effusus and F. ulmaria, respectively. Denitrifiers were detected both on plant roots and woodchips, indicating WFBs' denitrification potential. Our study highlights that WFBs could be applied to enhance NO3-N removal from surface water through plant biomass uptake and denitrification processes. Future studies should consider the long-term in situ application of WFBs for NO3-N removal from water.
|
|
| 4. |
- Mikryukov, Vladimir, et al.
(författare)
-
Connecting the multiple dimensions of global soil fungal diversity
- 2023
-
Ingår i: Science advances. - 2375-2548. ; 9:48
-
Tidskriftsartikel (refereegranskat)abstract
- How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.
|
|
