SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Gough Laura) "

Sökning: WFRF:(Gough Laura)

  • Resultat 1-3 av 3
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Komatsu, Kimberly J., et al. (författare)
  • Global change effects on plant communities are magnified by time and the number of global change factors imposed
  • 2019
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:36, s. 17867-17873
  • Tidskriftsartikel (refereegranskat)abstract
    • Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects of biodiversity on ecosystem services. There is consensus that human activities are driving species extinctions at the global scale, but debate remains over whether GCDs are systematically altering local communities worldwide. Across 105 experiments that included over 400 experimental manipulations, we found evidence for a lagged response of herbaceous plant communities to GCDs caused by shifts in the identities and relative abundances of species, often without a corresponding difference in species richness. These results provide evidence that community responses are pervasive across a wide variety of GCDs on long-term temporal scales and that these responses increase in strength when multiple GCDs are simultaneously imposed.Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.
  •  
2.
  • Abbott, Benjamin W., et al. (författare)
  • Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
  • 2016
  • Ingår i: Environmental Research Letters. - : IOP Publishing: Open Access Journals / IOP Publishing. - 1748-9326 .- 1748-9326. ; 11:3
  • Tidskriftsartikel (refereegranskat)abstract
    • As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
  •  
3.
  • Barthelemy, Hélène, 1986- (författare)
  • Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems
  • 2016
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Reindeer appear to have strong positive effects on plant productivity and nutrient cycling in strongly nutrient-limited ecosystems. While the direct effects of grazing on vegetation composition have been intensively studied, much less is known about the indirect effect of grazing on plant-soil interactions. This thesis investigated the indirect effects of ungulate grazing on arctic plant communities via soil nutrient availability and plant nutrient uptake.At high density, the deposition of dung alone increased plant productivity both in nutrient rich and nutrient poor tundra habitats without causing major changes in soil possesses. Plant community responses to dung addition was slow, with a delay of at least some years. By contrast, a 15N-urea tracer study revealed that nutrients from reindeer urine could be rapidly incorporated into arctic plant tissues. Soil and microbial N pools only sequestered small proportions of the tracer. This thesis therefore suggests a strong effect of dung and urine on plant productivity by directly providing nutrient-rich resources, rather than by stimulating soil microbial activities, N mineralization and ultimately increasing soil nutrient availability. Further, defoliation alone did not induce compensatory growth, but resulted in plants with higher nutrient contents. This grazing-induced increase in plant quality could drive the high N cycling in arctic secondary grasslands by providing litter of a better quality to the belowground system and thus increase organic matter decomposition and enhance soil nutrient availability. Finally, a 15N natural abundance study revealed that intense reindeer grazing influences how plants are taking up their nutrients and thus decreased plant N partitioning among coexisting plant species.Taken together these results demonstrate the central role of dung and urine and grazing-induced changes in plant quality for plant productivity. Soil nutrient concentrations alone do not reveal nutrient availability for plants since reindeer have a strong influence on how plants are taking up their nutrients. This thesis highlights that both direct and indirect effects of reindeer grazing are strong determinants of tundra ecosystem functioning. Therefore, their complex influence on the aboveground and belowground linkages should be integrated in future work on tundra ecosystem N dynamic.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-3 av 3
Typ av publikation
tidskriftsartikel (2)
doktorsavhandling (1)
Typ av innehåll
refereegranskat (2)
övrigt vetenskapligt (1)
Författare/redaktör
Cornelissen, J. Hans ... (2)
Gough, Laura (2)
Abbott, Benjamin W. (1)
Jones, Jeremy B. (1)
Schuur, Edward A. G. (1)
Chapin, F. Stuart, I ... (1)
visa fler...
Bowden, William B. (1)
Bret-Harte, M. Syndo ... (1)
Epstein, Howard E. (1)
Flannigan, Michael D ... (1)
Harms, Tamara K. (1)
Hollingsworth, Teres ... (1)
Mack, Michelle C. (1)
McGuire, A. David (1)
Natali, Susan M. (1)
Rocha, Adrian V. (1)
Tank, Suzanne E. (1)
Turetsky, Merritt R. (1)
Vonk, Jorien E. (1)
Wickland, Kimberly P ... (1)
Aiken, George R. (1)
Alexander, Heather D ... (1)
Amon, Rainer M. W. (1)
Benscoter, Brian W. (1)
Bergeron, Yves (1)
Bishop, Kevin (1)
Blarquez, Olivier (1)
Bond-Lamberty, Ben (1)
Breen, Amy L. (1)
Buffam, Ishi (1)
Cai, Yihua (1)
Carcaillet, Christop ... (1)
Carey, Sean K. (1)
Chen, Jing M. (1)
Chen, Han Y. H. (1)
Christensen, Torben ... (1)
Cooper, Lee W. (1)
de Groot, William J. (1)
DeLuca, Thomas H. (1)
Dorrepaal, Ellen (1)
Fetcher, Ned (1)
Finlay, Jacques C. (1)
Forbes, Bruce C. (1)
French, Nancy H. F. (1)
Gauthier, Sylvie (1)
Girardin, Martin P. (1)
Goetz, Scott J. (1)
Goldammer, Johann G. (1)
Grogan, Paul (1)
Guo, Laodong (1)
visa färre...
Lärosäte
Umeå universitet (2)
Stockholms universitet (1)
Jönköping University (1)
Språk
Engelska (3)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (2)
Teknik (1)
Lantbruksvetenskap (1)

År

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy