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Higher temperatures increase nutrient availability in the High Arctic, causing elevated competitive pressure and a decline in Papaver radicatum

Modin, Hanna LU (2016) In Student thesis series INES NGEK01 20161
Dept of Physical Geography and Ecosystem Science
Abstract
Linking changes in the vegetation cover with factors that can moderate the effects of climate change is central to our understanding of Arctic ecosystems and their susceptibility to change. The aim of this study has been to investigate the moderating effects of soil conditions. A High Arctic population of Papaver radicatum was studied in relation to the prevailing surface temperature, active layer depth, soil moisture and soil water variables such as pH and conductivity at the site.

Data was collected between 2004 and 2013 in the Zackenberg valley in NE Greenland. A negative trend over time was found in the number of P. radicatum flowers, as well as correlations between P. radicatum and conductivity, Ca2+ and dissolved total nitrogen... (More)
Linking changes in the vegetation cover with factors that can moderate the effects of climate change is central to our understanding of Arctic ecosystems and their susceptibility to change. The aim of this study has been to investigate the moderating effects of soil conditions. A High Arctic population of Papaver radicatum was studied in relation to the prevailing surface temperature, active layer depth, soil moisture and soil water variables such as pH and conductivity at the site.

Data was collected between 2004 and 2013 in the Zackenberg valley in NE Greenland. A negative trend over time was found in the number of P. radicatum flowers, as well as correlations between P. radicatum and conductivity, Ca2+ and dissolved total nitrogen (DTN). Surface temperatures increased, causing a deeper active layer and intensified weathering. The intensified weathering resulted in higher concentrations of ions in the soil water. No ion reached toxic levels, and the release of cations improved the nutrient status of the acidic soil. Together with warmer temperatures, this made the site more favourable for biological activity, elevating the competitive pressure. DTN decreased in correlation with dissolved organic carbon (DOC), since decomposition rates did not increase rapidly enough to meet the amplified demand on nitrogen and organic carbon. Due to P. radicatum’s high susceptibility to competition, the elevated competitive pressure is the most plausible reason for its decline.

Previous studies have found that P. radicatum responds to warmer temperatures with increased growth. The results of this study contradict those of the previous studies, which were performed with open top chambers or over an altitudinal gradient instead of over time. This stresses the importance of integrating the plants’ full ecological context and allowing for complex feedback mechanisms to develop when studying the responses of Arctic plants to climate change. (Less)
Abstract (Swedish)
Syftet med denna studie har varit att undersöka hur jordmånens egenskaper influerar arktisk växtlighet under en tid av globala temperaturförändringar. Vi behöver veta mer om hur olika faktorer kan påverka förhållandet mellan temperaturökningar och växtlighetens respons, då det ger oss en bättre förståelse för arktiska ekosystem och deras känslighet för förändringar. En högarktisk population av Papaver radicatum har studerats i relation till rådande yttemperatur, aktivt lager, jordfukt samt jordvattenvariabler såsom pH och konduktivitet.

Data samlades in mellan 2004 och 2013 i Zackenbergdalen, nordöstra Grönland. P. radicatum påvisade en negativ trend över tid samt korrelationer med konduktivitet, Ca2+ och totalt löst kväve (DTN).... (More)
Syftet med denna studie har varit att undersöka hur jordmånens egenskaper influerar arktisk växtlighet under en tid av globala temperaturförändringar. Vi behöver veta mer om hur olika faktorer kan påverka förhållandet mellan temperaturökningar och växtlighetens respons, då det ger oss en bättre förståelse för arktiska ekosystem och deras känslighet för förändringar. En högarktisk population av Papaver radicatum har studerats i relation till rådande yttemperatur, aktivt lager, jordfukt samt jordvattenvariabler såsom pH och konduktivitet.

Data samlades in mellan 2004 och 2013 i Zackenbergdalen, nordöstra Grönland. P. radicatum påvisade en negativ trend över tid samt korrelationer med konduktivitet, Ca2+ och totalt löst kväve (DTN). Yttemperaturerna steg, vilket ledde till ett djupare aktivt lager och ökad vittring. Med ökad vittring följde högre jonkoncentrationer i jordvattnet. Ingen jon nådde dock toxiska nivåer och ökningen av katjoner förbättrade näringstillgängligheten i jorden. Tillsammans med varmare yttemperaturer gjorde detta att platsen blev mer gynnsam för biologisk aktivitet, vilket sannolikt höjde konkurrenstrycket på platsen. DTN minskade i korrelation med löst organiskt kol (DOC), då nedbrytningstakten inte ökade tillräckligt fort för att täcka en förhöjd åtgång av kväve och organiskt kol. Då P. radicatum är mycket känslig för konkurrens är det ökade konkurrenstrycket den mest sannolika anledningen till dess nedgång.

Tidigare studier har funnit att P. radicatum reagerar på varmare temperaturer med ökad tillväxt. Resultaten i denna studie motsäger de tidigare studierna, som utfördes i kammarexperiment eller över en höjdgradient istället för över tid. Detta understryker vikten av att studera växterna i deras fulla ekologiska kontext samt att avsätta tid för att viktiga återkopplingsmekanismer ska hinna utvecklas. (Less)
Please use this url to cite or link to this publication:
author
Modin, Hanna LU
supervisor
organization
alternative title
Högre temperaturer förbättrar näringstillgängligheten i Högarktis, vilket ökar konkurrenstrycket och leder till en minskning av Papaver radicatum
course
NGEK01 20161
year
type
M2 - Bachelor Degree
subject
keywords
Papaver radicatum, High Arctic, soil conditions, Zackenberg, Greenland, climate change, global warming, Arctic vegetation, Arctic plant, Arctic Poppy, active layer depth, soil moisture, competitive pressure
publication/series
Student thesis series INES
report number
373
language
English
id
8875404
date added to LUP
2016-05-30 16:39:17
date last changed
2016-05-30 16:39:17
@misc{8875404,
  abstract     = {Linking changes in the vegetation cover with factors that can moderate the effects of climate change is central to our understanding of Arctic ecosystems and their susceptibility to change. The aim of this study has been to investigate the moderating effects of soil conditions. A High Arctic population of Papaver radicatum was studied in relation to the prevailing surface temperature, active layer depth, soil moisture and soil water variables such as pH and conductivity at the site.

Data was collected between 2004 and 2013 in the Zackenberg valley in NE Greenland. A negative trend over time was found in the number of P. radicatum flowers, as well as correlations between P. radicatum and conductivity, Ca2+ and dissolved total nitrogen (DTN). Surface temperatures increased, causing a deeper active layer and intensified weathering. The intensified weathering resulted in higher concentrations of ions in the soil water. No ion reached toxic levels, and the release of cations improved the nutrient status of the acidic soil. Together with warmer temperatures, this made the site more favourable for biological activity, elevating the competitive pressure. DTN decreased in correlation with dissolved organic carbon (DOC), since decomposition rates did not increase rapidly enough to meet the amplified demand on nitrogen and organic carbon. Due to P. radicatum’s high susceptibility to competition, the elevated competitive pressure is the most plausible reason for its decline.

Previous studies have found that P. radicatum responds to warmer temperatures with increased growth. The results of this study contradict those of the previous studies, which were performed with open top chambers or over an altitudinal gradient instead of over time. This stresses the importance of integrating the plants’ full ecological context and allowing for complex feedback mechanisms to develop when studying the responses of Arctic plants to climate change.},
  author       = {Modin, Hanna},
  keyword      = {Papaver radicatum,High Arctic,soil conditions,Zackenberg,Greenland,climate change,global warming,Arctic vegetation,Arctic plant,Arctic Poppy,active layer depth,soil moisture,competitive pressure},
  language     = {eng},
  note         = {Student Paper},
  series       = {Student thesis series INES},
  title        = {Higher temperatures increase nutrient availability in the High Arctic, causing elevated competitive pressure and a decline in Papaver radicatum},
  year         = {2016},
}